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kc3-lang/angle/src/tests/gl_tests/WebGLCompatibilityTest.cpp

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  • Author : Kai Ninomiya
    Date : 2020-10-08 17:57:47
    Hash : e0780931
    Message : Suppress gl_test failures on Mac ARM64 (Apple DTK) BuiltinVariableFragDepthClampingFloatRBOTest.Below1/ES3_OpenGL CopyTexImageTest.DeleteAfterCopyingToTextures/ES2_OpenGL GLSLTest.MaxVaryingVec2Arrays/ES2_Metal GLSLTest.MaxVaryingVec3ArrayAndOneFloatArray/ES2_Metal GLSLTest.MoreNestedCompoundStructsWithSamplersAsFunctionArg/ES2_OpenGL GLSLTest.NestedCompoundStructsWithSamplersAsFunctionArg/ES2_OpenGL GLSLTest.NestedStructsWithSamplersAsFunctionArg/ES2_OpenGL GLSLTest.NestedStructsWithSamplersAsFunctionArg/ES3_OpenGL MipmapTestES3.BaseLevelTextureBug/ES3_OpenGL MipmapTestES3.GenerateMipmapBaseLevel/ES3_OpenGL MipmapTestES3.GenerateMipmapCubeBaseLevel/ES3_OpenGL MipmapTestES3.GenerateMipmapMaxLevel/ES3_OpenGL MipmapTestES3.GenerateMipmapPreservesOutOfRangeMips/ES3_OpenGL OcclusionQueriesTest.MultiQueries/ES2_Metal Texture2DBaseMaxTestES3.GenerateMipmapAfterRedefineAndRebase/ES3_OpenGL Texture2DFloatTestES2.TextureFloatLinearLegacyTest/ES2_Metal Texture2DFloatTestES2.TextureFloatLinearLegacyTest/ES2_OpenGL Texture2DFloatTestES2.TextureFloatLinearTest/ES2_Metal Texture2DFloatTestES2.TextureFloatLinearTest/ES2_OpenGL Texture2DFloatTestES3.TextureFloatLinearLegacyTest/ES3_OpenGL Texture2DFloatTestES3.TextureFloatLinearTest/ES3_OpenGL TimerQueriesTest.TimeElapsed/ES3_OpenGL TimerQueriesTest.TimeElapsedMulticontextTest/ES3_OpenGL WebGLCompatibilityTest.TextureCopyingFeedbackLoops/ES2_OpenGL WebGLCompatibilityTest.TextureCopyingFeedbackLoops/ES3_OpenGL Bug: chromium:1132295 Change-Id: If64dc67275063c8046dbc941d92de273fbc226e5 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2461674 Commit-Queue: Kai Ninomiya <kainino@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>

  • src/tests/gl_tests/WebGLCompatibilityTest.cpp
  • //
    // Copyright 2015 The ANGLE Project Authors. All rights reserved.
    // Use of this source code is governed by a BSD-style license that can be
    // found in the LICENSE file.
    //
    
    // WebGLCompatibilityTest.cpp : Tests of the GL_ANGLE_webgl_compatibility extension.
    
    #include "test_utils/ANGLETest.h"
    
    #include "common/mathutil.h"
    #include "test_utils/gl_raii.h"
    
    namespace
    {
    
    bool ConstantColorAndAlphaBlendFunctions(GLenum first, GLenum second)
    {
        return (first == GL_CONSTANT_COLOR || first == GL_ONE_MINUS_CONSTANT_COLOR) &&
               (second == GL_CONSTANT_ALPHA || second == GL_ONE_MINUS_CONSTANT_ALPHA);
    }
    
    void CheckBlendFunctions(GLenum src, GLenum dst)
    {
        if (ConstantColorAndAlphaBlendFunctions(src, dst) ||
            ConstantColorAndAlphaBlendFunctions(dst, src))
        {
            EXPECT_GL_ERROR(GL_INVALID_OPERATION);
        }
        else
        {
            ASSERT_GL_NO_ERROR();
        }
    }
    
    // Extensions that affect the ability to use floating point textures
    constexpr const char *FloatingPointTextureExtensions[] = {
        "",
        "GL_EXT_texture_storage",
        "GL_OES_texture_half_float",
        "GL_OES_texture_half_float_linear",
        "GL_EXT_color_buffer_half_float",
        "GL_OES_texture_float",
        "GL_OES_texture_float_linear",
        "GL_EXT_color_buffer_float",
        "GL_EXT_float_blend",
        "GL_CHROMIUM_color_buffer_float_rgba",
        "GL_CHROMIUM_color_buffer_float_rgb",
    };
    
    }  // namespace
    
    namespace angle
    {
    
    class WebGLCompatibilityTest : public ANGLETest
    {
      protected:
        WebGLCompatibilityTest()
        {
            setWindowWidth(128);
            setWindowHeight(128);
            setConfigRedBits(8);
            setConfigGreenBits(8);
            setConfigBlueBits(8);
            setConfigAlphaBits(8);
            setWebGLCompatibilityEnabled(true);
        }
    
        template <typename T>
        void TestFloatTextureFormat(GLenum internalFormat,
                                    GLenum format,
                                    GLenum type,
                                    bool texturingEnabled,
                                    bool linearSamplingEnabled,
                                    bool renderingEnabled,
                                    const T textureData[4],
                                    const float floatData[4])
        {
            ASSERT_GL_NO_ERROR();
    
            constexpr char kVS[] =
                R"(attribute vec4 position;
    varying vec2 texcoord;
    void main()
    {
        gl_Position = vec4(position.xy, 0.0, 1.0);
        texcoord = (position.xy * 0.5) + 0.5;
    })";
    
            constexpr char kFS[] =
                R"(precision mediump float;
    uniform sampler2D tex;
    uniform vec4 subtractor;
    varying vec2 texcoord;
    void main()
    {
        vec4 color = texture2D(tex, texcoord);
        if (abs(color.r - subtractor.r) +
            abs(color.g - subtractor.g) +
            abs(color.b - subtractor.b) +
            abs(color.a - subtractor.a) < 8.0)
        {
            gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0);
        }
        else
        {
            gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
        }
    })";
    
            ANGLE_GL_PROGRAM(samplingProgram, kVS, kFS);
            glUseProgram(samplingProgram.get());
    
            // Need RGBA8 renderbuffers for enough precision on the readback
            if (IsGLExtensionRequestable("GL_OES_rgb8_rgba8"))
            {
                glRequestExtensionANGLE("GL_OES_rgb8_rgba8");
            }
            ANGLE_SKIP_TEST_IF(!IsGLExtensionEnabled("GL_OES_rgb8_rgba8") &&
                               getClientMajorVersion() < 3);
            ASSERT_GL_NO_ERROR();
    
            GLRenderbuffer rbo;
            glBindRenderbuffer(GL_RENDERBUFFER, rbo.get());
            glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8, 1, 1);
    
            GLFramebuffer fbo;
            glBindFramebuffer(GL_FRAMEBUFFER, fbo.get());
            glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, rbo.get());
    
            GLTexture texture;
            glBindTexture(GL_TEXTURE_2D, texture.get());
    
            if (internalFormat == format)
            {
                glTexImage2D(GL_TEXTURE_2D, 0, internalFormat, 1, 1, 0, format, type, textureData);
            }
            else
            {
                if (getClientMajorVersion() >= 3)
                {
                    glTexStorage2D(GL_TEXTURE_2D, 1, internalFormat, 1, 1);
                }
                else
                {
                    ASSERT_TRUE(IsGLExtensionEnabled("GL_EXT_texture_storage"));
                    glTexStorage2DEXT(GL_TEXTURE_2D, 1, internalFormat, 1, 1);
                }
                glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 1, 1, format, type, textureData);
            }
    
            if (!texturingEnabled)
            {
                // Depending on the entry point and client version, different errors may be generated
                ASSERT_GLENUM_NE(GL_NO_ERROR, glGetError());
    
                // Two errors may be generated in the glTexStorage + glTexSubImage case, clear the
                // second error
                glGetError();
    
                return;
            }
            ASSERT_GL_NO_ERROR();
    
            glUniform1i(glGetUniformLocation(samplingProgram.get(), "tex"), 0);
            glUniform4fv(glGetUniformLocation(samplingProgram.get(), "subtractor"), 1, floatData);
    
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
            drawQuad(samplingProgram.get(), "position", 0.5f, 1.0f, true);
            EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
    
            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
            drawQuad(samplingProgram.get(), "position", 0.5f, 1.0f, true);
    
            if (linearSamplingEnabled)
            {
                EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
            }
            else
            {
                EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::red);
            }
    
            glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture.get(),
                                   0);
            glBindTexture(GL_TEXTURE_2D, 0);
            if (!renderingEnabled)
            {
                EXPECT_GLENUM_EQ(GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT,
                                 glCheckFramebufferStatus(GL_FRAMEBUFFER));
                return;
            }
    
            GLenum framebufferStatus = glCheckFramebufferStatus(GL_FRAMEBUFFER);
            if (framebufferStatus == GL_FRAMEBUFFER_UNSUPPORTED)
            {
                std::cout << "Framebuffer returned GL_FRAMEBUFFER_UNSUPPORTED, this is legal."
                          << std::endl;
                return;
            }
            ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, framebufferStatus);
    
            ANGLE_GL_PROGRAM(renderingProgram, essl1_shaders::vs::Simple(),
                             essl1_shaders::fs::UniformColor());
            glUseProgram(renderingProgram.get());
    
            glUniform4fv(glGetUniformLocation(renderingProgram.get(), essl1_shaders::ColorUniform()), 1,
                         floatData);
    
            drawQuad(renderingProgram.get(), essl1_shaders::PositionAttrib(), 0.5f, 1.0f, true);
    
            EXPECT_PIXEL_COLOR32F_NEAR(
                0, 0, GLColor32F(floatData[0], floatData[1], floatData[2], floatData[3]), 1.0f);
        }
    
        void TestExtFloatBlend(GLenum internalFormat, GLenum type, bool shouldBlend)
        {
            constexpr char kVS[] =
                R"(void main()
    {
        gl_PointSize = 1.0;
        gl_Position = vec4(0, 0, 0, 1);
    })";
    
            constexpr char kFS[] =
                R"(void main()
    {
        gl_FragColor = vec4(0.5, 0, 0, 0);
    })";
    
            ANGLE_GL_PROGRAM(program, kVS, kFS);
            glUseProgram(program);
    
            GLTexture texture;
            glBindTexture(GL_TEXTURE_2D, texture);
            glTexImage2D(GL_TEXTURE_2D, 0, internalFormat, 1, 1, 0, GL_RGBA, type, nullptr);
            EXPECT_GL_NO_ERROR();
    
            GLFramebuffer fbo;
            glBindFramebuffer(GL_FRAMEBUFFER, fbo);
            glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);
            ASSERT_EGLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
    
            glClearColor(1, 0, 1, 1);
            glClear(GL_COLOR_BUFFER_BIT);
            EXPECT_PIXEL_COLOR32F_NEAR(0, 0, GLColor32F(1, 0, 1, 1), 0.001f);
    
            glDisable(GL_BLEND);
            glDrawArrays(GL_POINTS, 0, 1);
            EXPECT_GL_NO_ERROR();
    
            glEnable(GL_BLEND);
            glBlendFunc(GL_CONSTANT_COLOR, GL_ZERO);
            glBlendColor(10, 1, 1, 1);
            glViewport(0, 0, 1, 1);
            glDrawArrays(GL_POINTS, 0, 1);
            if (!shouldBlend)
            {
                EXPECT_GL_ERROR(GL_INVALID_OPERATION);
                return;
            }
            EXPECT_GL_NO_ERROR();
    
            if (!IsOpenGLES())
            {
                // GLES test machines will need a workaround.
                EXPECT_PIXEL_COLOR32F_NEAR(0, 0, GLColor32F(5, 0, 0, 0), 0.001f);
            }
    
            // Check sure that non-float attachments clamp BLEND_COLOR.
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
            glDrawArrays(GL_POINTS, 0, 1);
    
            EXPECT_PIXEL_COLOR_NEAR(0, 0, GLColor(0x80, 0, 0, 0), 1);
        }
    
        void TestDifferentStencilMaskAndRef(GLenum errIfMismatch);
    
        // Called from RenderingFeedbackLoopWithDrawBuffersEXT.
        void drawBuffersEXTFeedbackLoop(GLuint program,
                                        const std::array<GLenum, 2> &drawBuffers,
                                        GLenum expectedError);
    
        // Called from RenderingFeedbackLoopWithDrawBuffers.
        void drawBuffersFeedbackLoop(GLuint program,
                                     const std::array<GLenum, 2> &drawBuffers,
                                     GLenum expectedError);
    
        // Called from Enable[Compressed]TextureFormatExtensions
        void validateTexImageExtensionFormat(GLenum format, const std::string &extName);
        void validateCompressedTexImageExtensionFormat(GLenum format,
                                                       GLsizei width,
                                                       GLsizei height,
                                                       GLsizei blockSize,
                                                       const std::string &extName,
                                                       bool subImageAllowed);
    };
    
    class WebGL2CompatibilityTest : public WebGLCompatibilityTest
    {};
    
    // Context creation would fail if EGL_ANGLE_create_context_webgl_compatibility was not available so
    // the GL extension should always be present
    TEST_P(WebGLCompatibilityTest, ExtensionStringExposed)
    {
        EXPECT_TRUE(IsGLExtensionEnabled("GL_ANGLE_webgl_compatibility"));
    }
    
    // Verify that all extension entry points are available
    TEST_P(WebGLCompatibilityTest, EntryPoints)
    {
        if (IsGLExtensionEnabled("GL_ANGLE_request_extension"))
        {
            EXPECT_NE(nullptr, eglGetProcAddress("glRequestExtensionANGLE"));
        }
    }
    
    // WebGL 1 allows GL_DEPTH_STENCIL_ATTACHMENT as a valid binding point.  Make sure it is usable,
    // even in ES2 contexts.
    TEST_P(WebGLCompatibilityTest, DepthStencilBindingPoint)
    {
        GLRenderbuffer renderbuffer;
        glBindRenderbuffer(GL_RENDERBUFFER, renderbuffer.get());
        glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, 32, 32);
    
        GLFramebuffer framebuffer;
        glBindFramebuffer(GL_FRAMEBUFFER, framebuffer.get());
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER,
                                  renderbuffer.get());
    
        EXPECT_GL_NO_ERROR();
    }
    
    // Test that attempting to enable an extension that doesn't exist generates GL_INVALID_OPERATION
    TEST_P(WebGLCompatibilityTest, EnableExtensionValidation)
    {
        glRequestExtensionANGLE("invalid_extension_string");
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // Test enabling the GL_OES_element_index_uint extension
    TEST_P(WebGLCompatibilityTest, EnableExtensionUintIndices)
    {
        if (getClientMajorVersion() != 2)
        {
            // This test only works on ES2 where uint indices are not available by default
            return;
        }
    
        EXPECT_FALSE(IsGLExtensionEnabled("GL_OES_element_index_uint"));
    
        GLBuffer indexBuffer;
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer.get());
    
        GLuint data[] = {0, 1, 2, 1, 3, 2};
        glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(data), data, GL_STATIC_DRAW);
    
        ANGLE_GL_PROGRAM(program, "void main() { gl_Position = vec4(0, 0, 0, 1); }",
                         "void main() { gl_FragColor = vec4(0, 1, 0, 1); }");
        glUseProgram(program.get());
    
        glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, nullptr);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        if (IsGLExtensionRequestable("GL_OES_element_index_uint"))
        {
            glRequestExtensionANGLE("GL_OES_element_index_uint");
            EXPECT_GL_NO_ERROR();
            EXPECT_TRUE(IsGLExtensionEnabled("GL_OES_element_index_uint"));
    
            glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, nullptr);
            EXPECT_GL_NO_ERROR();
        }
    }
    
    // Test enabling the GL_OES_standard_derivatives extension
    TEST_P(WebGLCompatibilityTest, EnableExtensionStandardDerivitives)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_OES_standard_derivatives"));
    
        constexpr char kFS[] =
            R"(#extension GL_OES_standard_derivatives : require
    void main() { gl_FragColor = vec4(dFdx(vec2(1.0, 1.0)).x, 1, 0, 1); })";
        ASSERT_EQ(0u, CompileShader(GL_FRAGMENT_SHADER, kFS));
    
        if (IsGLExtensionRequestable("GL_OES_standard_derivatives"))
        {
            glRequestExtensionANGLE("GL_OES_standard_derivatives");
            EXPECT_GL_NO_ERROR();
            EXPECT_TRUE(IsGLExtensionEnabled("GL_OES_standard_derivatives"));
    
            GLuint shader = CompileShader(GL_FRAGMENT_SHADER, kFS);
            ASSERT_NE(0u, shader);
            glDeleteShader(shader);
        }
    }
    
    // Test enabling the GL_EXT_shader_texture_lod extension
    TEST_P(WebGLCompatibilityTest, EnableExtensionTextureLOD)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_EXT_shader_texture_lod"));
    
        constexpr char kFS[] =
            R"(#extension GL_EXT_shader_texture_lod : require
    uniform sampler2D u_texture;
    void main() {
        gl_FragColor = texture2DGradEXT(u_texture, vec2(0.0, 0.0), vec2(0.0, 0.0), vec2(0.0,
    0.0));
    })";
        ASSERT_EQ(0u, CompileShader(GL_FRAGMENT_SHADER, kFS));
    
        if (IsGLExtensionRequestable("GL_EXT_shader_texture_lod"))
        {
            glRequestExtensionANGLE("GL_EXT_shader_texture_lod");
            EXPECT_GL_NO_ERROR();
            EXPECT_TRUE(IsGLExtensionEnabled("GL_EXT_shader_texture_lod"));
    
            GLuint shader = CompileShader(GL_FRAGMENT_SHADER, kFS);
            ASSERT_NE(0u, shader);
            glDeleteShader(shader);
        }
    }
    
    // Test enabling the GL_EXT_frag_depth extension
    TEST_P(WebGLCompatibilityTest, EnableExtensionFragDepth)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_EXT_frag_depth"));
    
        constexpr char kFS[] =
            R"(#extension GL_EXT_frag_depth : require
    void main() {
        gl_FragColor = vec4(0.0, 0.0, 0.0, 1.0);
        gl_FragDepthEXT = 1.0;
    })";
        ASSERT_EQ(0u, CompileShader(GL_FRAGMENT_SHADER, kFS));
    
        if (IsGLExtensionRequestable("GL_EXT_frag_depth"))
        {
            glRequestExtensionANGLE("GL_EXT_frag_depth");
            EXPECT_GL_NO_ERROR();
            EXPECT_TRUE(IsGLExtensionEnabled("GL_EXT_frag_depth"));
    
            GLuint shader = CompileShader(GL_FRAGMENT_SHADER, kFS);
            ASSERT_NE(0u, shader);
            glDeleteShader(shader);
        }
    }
    
    // Test enabling the GL_EXT_texture_filter_anisotropic extension
    TEST_P(WebGLCompatibilityTest, EnableExtensionTextureFilterAnisotropic)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_EXT_texture_filter_anisotropic"));
    
        GLfloat maxAnisotropy = 0.0f;
        glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &maxAnisotropy);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        GLTexture texture;
        glBindTexture(GL_TEXTURE_2D, texture.get());
        ASSERT_GL_NO_ERROR();
    
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, 1.0f);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        GLfloat currentAnisotropy = 0.0f;
        glGetTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, &currentAnisotropy);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        if (IsGLExtensionRequestable("GL_EXT_texture_filter_anisotropic"))
        {
            glRequestExtensionANGLE("GL_EXT_texture_filter_anisotropic");
            EXPECT_GL_NO_ERROR();
            EXPECT_TRUE(IsGLExtensionEnabled("GL_EXT_texture_filter_anisotropic"));
    
            glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &maxAnisotropy);
            ASSERT_GL_NO_ERROR();
            EXPECT_GE(maxAnisotropy, 2.0f);
    
            glGetTexParameterfv(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, &currentAnisotropy);
            ASSERT_GL_NO_ERROR();
            EXPECT_EQ(1.0f, currentAnisotropy);
    
            glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, 2.0f);
            ASSERT_GL_NO_ERROR();
        }
    }
    
    // Test enabling the EGL image extensions
    TEST_P(WebGLCompatibilityTest, EnableExtensionEGLImage)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_OES_EGL_image"));
        EXPECT_FALSE(IsGLExtensionEnabled("GL_OES_EGL_image_external"));
        EXPECT_FALSE(IsGLExtensionEnabled("GL_OES_EGL_image_external_essl3"));
        EXPECT_FALSE(IsGLExtensionEnabled("NV_EGL_stream_consumer_external"));
    
        constexpr char kFSES2[] =
            R"(#extension GL_OES_EGL_image_external : require
    precision highp float;
    uniform samplerExternalOES sampler;
    void main()
    {
        gl_FragColor = texture2D(sampler, vec2(0, 0));
    })";
        EXPECT_EQ(0u, CompileShader(GL_FRAGMENT_SHADER, kFSES2));
    
        constexpr char kFSES3[] =
            R"(#version 300 es
    #extension GL_OES_EGL_image_external_essl3 : require
    precision highp float;
    uniform samplerExternalOES sampler;
    out vec4 my_FragColor;
    void main()
    {
        my_FragColor = texture(sampler, vec2(0, 0));
    })";
        if (getClientMajorVersion() >= 3)
        {
            EXPECT_EQ(0u, CompileShader(GL_FRAGMENT_SHADER, kFSES3));
        }
    
        glBindTexture(GL_TEXTURE_EXTERNAL_OES, 0);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        GLint result;
        glGetIntegerv(GL_TEXTURE_BINDING_EXTERNAL_OES, &result);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        if (IsGLExtensionRequestable("GL_OES_EGL_image_external"))
        {
            glRequestExtensionANGLE("GL_OES_EGL_image_external");
            EXPECT_GL_NO_ERROR();
            EXPECT_TRUE(IsGLExtensionEnabled("GL_OES_EGL_image_external"));
    
            EXPECT_NE(0u, CompileShader(GL_FRAGMENT_SHADER, kFSES2));
    
            glBindTexture(GL_TEXTURE_EXTERNAL_OES, 0);
            EXPECT_GL_NO_ERROR();
    
            glGetIntegerv(GL_TEXTURE_BINDING_EXTERNAL_OES, &result);
            EXPECT_GL_NO_ERROR();
    
            if (getClientMajorVersion() >= 3 &&
                IsGLExtensionRequestable("GL_OES_EGL_image_external_essl3"))
            {
                glRequestExtensionANGLE("GL_OES_EGL_image_external_essl3");
                EXPECT_GL_NO_ERROR();
                EXPECT_TRUE(IsGLExtensionEnabled("GL_OES_EGL_image_external_essl3"));
    
                EXPECT_NE(0u, CompileShader(GL_FRAGMENT_SHADER, kFSES3));
            }
            else
            {
                EXPECT_EQ(0u, CompileShader(GL_FRAGMENT_SHADER, kFSES3));
            }
        }
    }
    
    // Verify that shaders are of a compatible spec when the extension is enabled.
    TEST_P(WebGLCompatibilityTest, ExtensionCompilerSpec)
    {
        EXPECT_TRUE(IsGLExtensionEnabled("GL_ANGLE_webgl_compatibility"));
    
        // Use of reserved _webgl prefix should fail when the shader specification is for WebGL.
        constexpr char kVS[] =
            R"(struct Foo {
        int _webgl_bar;
    };
    void main()
    {
        Foo foo = Foo(1);
    })";
    
        // Default fragement shader.
        constexpr char kFS[] =
            R"(void main()
    {
        gl_FragColor = vec4(1.0,0.0,0.0,1.0);
    })";
    
        GLuint program = CompileProgram(kVS, kFS);
        EXPECT_EQ(0u, program);
        glDeleteProgram(program);
    }
    
    // Test enabling the GL_NV_pixel_buffer_object extension
    TEST_P(WebGLCompatibilityTest, EnablePixelBufferObjectExtensions)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_NV_pixel_buffer_object"));
        EXPECT_FALSE(IsGLExtensionEnabled("GL_OES_mapbuffer"));
        EXPECT_FALSE(IsGLExtensionEnabled("GL_EXT_map_buffer_range"));
    
        // These extensions become core in in ES3/WebGL2.
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() >= 3);
    
        GLBuffer buffer;
        glBindBuffer(GL_PIXEL_PACK_BUFFER, buffer);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        if (IsGLExtensionRequestable("GL_NV_pixel_buffer_object"))
        {
            glRequestExtensionANGLE("GL_NV_pixel_buffer_object");
            EXPECT_GL_NO_ERROR();
    
            // Create a framebuffer to read from
            GLRenderbuffer renderbuffer;
            glBindRenderbuffer(GL_RENDERBUFFER, renderbuffer);
            glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA4, 1, 1);
    
            GLFramebuffer fbo;
            glBindFramebuffer(GL_FRAMEBUFFER, fbo);
            glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER,
                                      renderbuffer);
            EXPECT_GL_NO_ERROR();
    
            glBindBuffer(GL_PIXEL_PACK_BUFFER, buffer);
            EXPECT_GL_NO_ERROR();
    
            glBufferData(GL_PIXEL_PACK_BUFFER, 4, nullptr, GL_STATIC_DRAW);
            glReadPixels(0, 0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
            EXPECT_GL_NO_ERROR();
        }
    }
    
    // Test enabling the GL_EXT_texture_storage extension
    TEST_P(WebGLCompatibilityTest, EnableTextureStorage)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_EXT_texture_storage"));
    
        GLTexture texture;
        glBindTexture(GL_TEXTURE_2D, texture);
    
        GLint result;
        glGetTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_IMMUTABLE_FORMAT, &result);
        if (getClientMajorVersion() >= 3)
        {
            EXPECT_GL_NO_ERROR();
        }
        else
        {
            EXPECT_GL_ERROR(GL_INVALID_ENUM);
        }
    
        if (IsGLExtensionRequestable("GL_EXT_texture_storage"))
        {
            glRequestExtensionANGLE("GL_EXT_texture_storage");
            EXPECT_GL_NO_ERROR();
            EXPECT_TRUE(IsGLExtensionEnabled("GL_EXT_texture_storage"));
    
            glGetTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_IMMUTABLE_FORMAT, &result);
            EXPECT_GL_NO_ERROR();
    
            const GLenum alwaysAcceptableFormats[] = {
                GL_ALPHA8_EXT,
                GL_LUMINANCE8_EXT,
                GL_LUMINANCE8_ALPHA8_EXT,
            };
            for (const auto &acceptableFormat : alwaysAcceptableFormats)
            {
                GLTexture localTexture;
                glBindTexture(GL_TEXTURE_2D, localTexture);
                glTexStorage2DEXT(GL_TEXTURE_2D, 1, acceptableFormat, 1, 1);
                EXPECT_GL_NO_ERROR();
            }
        }
    }
    
    // Test enabling the GL_OES_mapbuffer and GL_EXT_map_buffer_range extensions
    TEST_P(WebGLCompatibilityTest, EnableMapBufferExtensions)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_OES_mapbuffer"));
        EXPECT_FALSE(IsGLExtensionEnabled("GL_EXT_map_buffer_range"));
    
        // These extensions become core in in ES3/WebGL2.
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() >= 3);
    
        GLBuffer buffer;
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, buffer);
        glBufferData(GL_ELEMENT_ARRAY_BUFFER, 4, nullptr, GL_STATIC_DRAW);
    
        glMapBufferOES(GL_ELEMENT_ARRAY_BUFFER, GL_WRITE_ONLY_OES);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glMapBufferRangeEXT(GL_ELEMENT_ARRAY_BUFFER, 0, 4, GL_MAP_WRITE_BIT);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        GLint access = 0;
        glGetBufferParameteriv(GL_ELEMENT_ARRAY_BUFFER, GL_BUFFER_ACCESS_OES, &access);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        if (IsGLExtensionRequestable("GL_OES_mapbuffer"))
        {
            glRequestExtensionANGLE("GL_OES_mapbuffer");
            EXPECT_GL_NO_ERROR();
    
            glMapBufferOES(GL_ELEMENT_ARRAY_BUFFER, GL_WRITE_ONLY_OES);
            glUnmapBufferOES(GL_ELEMENT_ARRAY_BUFFER);
            glGetBufferParameteriv(GL_ELEMENT_ARRAY_BUFFER, GL_BUFFER_ACCESS_OES, &access);
            EXPECT_GL_NO_ERROR();
        }
    
        if (IsGLExtensionRequestable("GL_EXT_map_buffer_range"))
        {
            glRequestExtensionANGLE("GL_EXT_map_buffer_range");
            EXPECT_GL_NO_ERROR();
    
            glMapBufferRangeEXT(GL_ELEMENT_ARRAY_BUFFER, 0, 4, GL_MAP_WRITE_BIT);
            glUnmapBufferOES(GL_ELEMENT_ARRAY_BUFFER);
            glGetBufferParameteriv(GL_ELEMENT_ARRAY_BUFFER, GL_BUFFER_ACCESS_OES, &access);
            EXPECT_GL_NO_ERROR();
        }
    }
    
    // Test enabling the GL_OES_fbo_render_mipmap extension
    TEST_P(WebGLCompatibilityTest, EnableRenderMipmapExtension)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_OES_fbo_render_mipmap"));
    
        // This extensions become core in in ES3/WebGL2.
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() >= 3);
    
        GLTexture texture;
        glBindTexture(GL_TEXTURE_2D, texture);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 2, 2, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        glTexImage2D(GL_TEXTURE_2D, 1, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
    
        GLFramebuffer fbo;
        glBindFramebuffer(GL_FRAMEBUFFER, fbo);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);
        EXPECT_GL_NO_ERROR();
    
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 1);
        EXPECT_GL_ERROR(GL_INVALID_VALUE);
    
        if (IsGLExtensionRequestable("GL_OES_fbo_render_mipmap"))
        {
            glRequestExtensionANGLE("GL_OES_fbo_render_mipmap");
            EXPECT_GL_NO_ERROR();
    
            glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 1);
            EXPECT_GL_NO_ERROR();
        }
    }
    
    // Test enabling the GL_EXT_blend_minmax extension
    TEST_P(WebGLCompatibilityTest, EnableBlendMinMaxExtension)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_EXT_blend_minmax"));
    
        // This extensions become core in in ES3/WebGL2.
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() >= 3);
    
        glBlendEquation(GL_MIN);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        glBlendEquation(GL_MAX);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        if (IsGLExtensionRequestable("GL_EXT_blend_minmax"))
        {
            glRequestExtensionANGLE("GL_EXT_blend_minmax");
            EXPECT_GL_NO_ERROR();
    
            glBlendEquation(GL_MIN);
            glBlendEquation(GL_MAX);
            EXPECT_GL_NO_ERROR();
        }
    }
    
    // Test enabling the query extensions
    TEST_P(WebGLCompatibilityTest, EnableQueryExtensions)
    {
        // Seems to be causing a device lost. http://anglebug.com/2423
        ANGLE_SKIP_TEST_IF(IsAMD() && IsWindows() && IsOpenGL());
    
        EXPECT_FALSE(IsGLExtensionEnabled("GL_EXT_occlusion_query_boolean"));
        EXPECT_FALSE(IsGLExtensionEnabled("GL_EXT_disjoint_timer_query"));
        EXPECT_FALSE(IsGLExtensionEnabled("GL_CHROMIUM_sync_query"));
    
        // This extensions become core in in ES3/WebGL2.
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() >= 3);
    
        GLQueryEXT badQuery;
    
        glBeginQueryEXT(GL_ANY_SAMPLES_PASSED_EXT, badQuery);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glBeginQueryEXT(GL_ANY_SAMPLES_PASSED_CONSERVATIVE, badQuery);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glBeginQueryEXT(GL_TIME_ELAPSED_EXT, badQuery);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glQueryCounterEXT(GL_TIMESTAMP_EXT, badQuery);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glBeginQueryEXT(GL_COMMANDS_COMPLETED_CHROMIUM, badQuery);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        if (IsGLExtensionRequestable("GL_EXT_occlusion_query_boolean"))
        {
            glRequestExtensionANGLE("GL_EXT_occlusion_query_boolean");
            EXPECT_GL_NO_ERROR();
    
            GLQueryEXT query;
            glBeginQueryEXT(GL_ANY_SAMPLES_PASSED_EXT, query);
            glEndQueryEXT(GL_ANY_SAMPLES_PASSED_EXT);
            EXPECT_GL_NO_ERROR();
        }
    
        if (IsGLExtensionRequestable("GL_EXT_disjoint_timer_query"))
        {
            glRequestExtensionANGLE("GL_EXT_disjoint_timer_query");
            EXPECT_GL_NO_ERROR();
    
            GLQueryEXT query1;
            glBeginQueryEXT(GL_TIME_ELAPSED_EXT, query1);
            glEndQueryEXT(GL_TIME_ELAPSED_EXT);
            EXPECT_GL_NO_ERROR();
    
            GLQueryEXT query2;
            glQueryCounterEXT(query2, GL_TIMESTAMP_EXT);
            EXPECT_GL_NO_ERROR();
        }
    
        if (IsGLExtensionRequestable("GL_CHROMIUM_sync_query"))
        {
            glRequestExtensionANGLE("GL_CHROMIUM_sync_query");
            EXPECT_GL_NO_ERROR();
    
            GLQueryEXT query;
            glBeginQueryEXT(GL_COMMANDS_COMPLETED_CHROMIUM, query);
            glEndQueryEXT(GL_COMMANDS_COMPLETED_CHROMIUM);
            EXPECT_GL_NO_ERROR();
        }
    }
    
    // Test enabling the GL_ANGLE_framebuffer_multisample extension
    TEST_P(WebGLCompatibilityTest, EnableFramebufferMultisampleExtension)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_ANGLE_framebuffer_multisample"));
    
        // This extensions become core in in ES3/WebGL2.
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() >= 3);
    
        GLint maxSamples = 0;
        glGetIntegerv(GL_MAX_SAMPLES, &maxSamples);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        GLRenderbuffer renderbuffer;
        glBindRenderbuffer(GL_RENDERBUFFER, renderbuffer);
        glRenderbufferStorageMultisampleANGLE(GL_RENDERBUFFER, 1, GL_RGBA4, 1, 1);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        if (IsGLExtensionRequestable("GL_ANGLE_framebuffer_multisample"))
        {
            glRequestExtensionANGLE("GL_ANGLE_framebuffer_multisample");
            EXPECT_GL_NO_ERROR();
    
            glGetIntegerv(GL_MAX_SAMPLES, &maxSamples);
            EXPECT_GL_NO_ERROR();
    
            glRenderbufferStorageMultisampleANGLE(GL_RENDERBUFFER, maxSamples, GL_RGBA4, 1, 1);
            EXPECT_GL_NO_ERROR();
        }
    }
    
    // Test enabling the GL_ANGLE_instanced_arrays extension
    TEST_P(WebGLCompatibilityTest, EnableInstancedArraysExtensionANGLE)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_ANGLE_instanced_arrays"));
    
        // This extensions become core in in ES3/WebGL2.
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() >= 3);
    
        GLint divisor = 0;
        glGetVertexAttribiv(0, GL_VERTEX_ATTRIB_ARRAY_DIVISOR, &divisor);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        glVertexAttribDivisorANGLE(0, 1);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        if (IsGLExtensionRequestable("GL_ANGLE_instanced_arrays"))
        {
            glRequestExtensionANGLE("GL_ANGLE_instanced_arrays");
            EXPECT_GL_NO_ERROR();
    
            glGetVertexAttribiv(0, GL_VERTEX_ATTRIB_ARRAY_DIVISOR, &divisor);
            glVertexAttribDivisorANGLE(0, 1);
            EXPECT_GL_NO_ERROR();
        }
    }
    
    // Test enabling the GL_EXT_instanced_arrays extension
    TEST_P(WebGLCompatibilityTest, EnableInstancedArraysExtensionEXT)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_EXT_instanced_arrays"));
    
        // This extensions become core in in ES3/WebGL2.
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() >= 3);
    
        GLint divisor = 0;
        glGetVertexAttribiv(0, GL_VERTEX_ATTRIB_ARRAY_DIVISOR, &divisor);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        glVertexAttribDivisorEXT(0, 1);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        if (IsGLExtensionRequestable("GL_EXT_instanced_arrays"))
        {
            glRequestExtensionANGLE("GL_EXT_instanced_arrays");
            EXPECT_GL_NO_ERROR();
    
            glGetVertexAttribiv(0, GL_VERTEX_ATTRIB_ARRAY_DIVISOR, &divisor);
            glVertexAttribDivisorEXT(0, 1);
            EXPECT_GL_NO_ERROR();
        }
    }
    
    // Test enabling the GL_ANGLE_pack_reverse_row_order extension
    TEST_P(WebGLCompatibilityTest, EnablePackReverseRowOrderExtension)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_ANGLE_pack_reverse_row_order"));
    
        GLint result = 0;
        glGetIntegerv(GL_PACK_REVERSE_ROW_ORDER_ANGLE, &result);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        glPixelStorei(GL_PACK_REVERSE_ROW_ORDER_ANGLE, GL_TRUE);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        if (IsGLExtensionRequestable("GL_ANGLE_pack_reverse_row_order"))
        {
            glRequestExtensionANGLE("GL_ANGLE_pack_reverse_row_order");
            EXPECT_GL_NO_ERROR();
    
            glGetIntegerv(GL_PACK_REVERSE_ROW_ORDER_ANGLE, &result);
            glPixelStorei(GL_PACK_REVERSE_ROW_ORDER_ANGLE, GL_TRUE);
            EXPECT_GL_NO_ERROR();
        }
    }
    
    // Test enabling the GL_EXT_unpack_subimage extension
    TEST_P(WebGLCompatibilityTest, EnablePackUnpackSubImageExtension)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_EXT_unpack_subimage"));
    
        // This extensions become core in in ES3/WebGL2.
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() >= 3);
    
        constexpr GLenum parameters[] = {
            GL_UNPACK_ROW_LENGTH_EXT,
            GL_UNPACK_SKIP_ROWS_EXT,
            GL_UNPACK_SKIP_PIXELS_EXT,
        };
    
        for (GLenum param : parameters)
        {
            GLint resultI = 0;
            glGetIntegerv(param, &resultI);
            EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
            GLfloat resultF = 0.0f;
            glGetFloatv(param, &resultF);
            EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
            glPixelStorei(param, 0);
            EXPECT_GL_ERROR(GL_INVALID_ENUM);
        }
    
        if (IsGLExtensionRequestable("GL_EXT_unpack_subimage"))
        {
            glRequestExtensionANGLE("GL_EXT_unpack_subimage");
            EXPECT_GL_NO_ERROR();
    
            for (GLenum param : parameters)
            {
                GLint resultI = 0;
                glGetIntegerv(param, &resultI);
    
                GLfloat resultF = 0.0f;
                glGetFloatv(param, &resultF);
    
                glPixelStorei(param, 0);
    
                EXPECT_GL_NO_ERROR();
            }
        }
    }
    
    TEST_P(WebGLCompatibilityTest, EnableTextureRectangle)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_ANGLE_texture_rectangle"));
    
        GLTexture texture;
        glBindTexture(GL_TEXTURE_RECTANGLE_ANGLE, texture);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        GLint minFilter = 0;
        glGetTexParameteriv(GL_TEXTURE_RECTANGLE_ANGLE, GL_TEXTURE_MIN_FILTER, &minFilter);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        if (IsGLExtensionRequestable("GL_ANGLE_texture_rectangle"))
        {
            glRequestExtensionANGLE("GL_ANGLE_texture_rectangle");
            EXPECT_GL_NO_ERROR();
    
            EXPECT_TRUE(IsGLExtensionEnabled("GL_ANGLE_texture_rectangle"));
    
            glBindTexture(GL_TEXTURE_RECTANGLE_ANGLE, texture);
            EXPECT_GL_NO_ERROR();
    
            glTexImage2D(GL_TEXTURE_RECTANGLE_ANGLE, 0, GL_RGBA, 16, 16, 0, GL_RGBA, GL_UNSIGNED_BYTE,
                         nullptr);
            EXPECT_GL_NO_ERROR();
    
            glDisableExtensionANGLE("GL_ANGLE_texture_rectangle");
            EXPECT_GL_NO_ERROR();
    
            EXPECT_FALSE(IsGLExtensionEnabled("GL_ANGLE_texture_rectangle"));
    
            glBindTexture(GL_TEXTURE_RECTANGLE_ANGLE, texture);
            EXPECT_GL_ERROR(GL_INVALID_ENUM);
        }
    }
    
    // Test enabling the GL_NV_pack_subimage extension
    TEST_P(WebGLCompatibilityTest, EnablePackPackSubImageExtension)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_NV_pack_subimage"));
    
        // This extensions become core in in ES3/WebGL2.
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() >= 3);
    
        constexpr GLenum parameters[] = {
            GL_PACK_ROW_LENGTH,
            GL_PACK_SKIP_ROWS,
            GL_PACK_SKIP_PIXELS,
        };
    
        for (GLenum param : parameters)
        {
            GLint resultI = 0;
            glGetIntegerv(param, &resultI);
            EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
            GLfloat resultF = 0.0f;
            glGetFloatv(param, &resultF);
            EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
            glPixelStorei(param, 0);
            EXPECT_GL_ERROR(GL_INVALID_ENUM);
        }
    
        if (IsGLExtensionRequestable("GL_NV_pack_subimage"))
        {
            glRequestExtensionANGLE("GL_NV_pack_subimage");
            EXPECT_GL_NO_ERROR();
    
            for (GLenum param : parameters)
            {
                GLint resultI = 0;
                glGetIntegerv(param, &resultI);
    
                GLfloat resultF = 0.0f;
                glGetFloatv(param, &resultF);
    
                glPixelStorei(param, 0);
    
                EXPECT_GL_NO_ERROR();
            }
        }
    }
    
    TEST_P(WebGLCompatibilityTest, EnableRGB8RGBA8Extension)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_OES_rgb8_rgba8"));
    
        // This extensions become core in in ES3/WebGL2.
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() >= 3);
    
        GLRenderbuffer renderbuffer;
        glBindRenderbuffer(GL_RENDERBUFFER, renderbuffer);
        EXPECT_GL_NO_ERROR();
    
        glRenderbufferStorage(GL_RENDERBUFFER, GL_RGB8_OES, 1, 1);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8_OES, 1, 1);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        if (IsGLExtensionRequestable("GL_OES_rgb8_rgba8"))
        {
            glRequestExtensionANGLE("GL_OES_rgb8_rgba8");
            EXPECT_GL_NO_ERROR();
    
            EXPECT_TRUE(IsGLExtensionEnabled("GL_OES_rgb8_rgba8"));
    
            glRenderbufferStorage(GL_RENDERBUFFER, GL_RGB8_OES, 1, 1);
            EXPECT_GL_NO_ERROR();
    
            glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8_OES, 1, 1);
            EXPECT_GL_NO_ERROR();
        }
    }
    
    // Test enabling the GL_ANGLE_framebuffer_blit extension
    TEST_P(WebGLCompatibilityTest, EnableFramebufferBlitExtension)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_ANGLE_framebuffer_blit"));
    
        // This extensions become core in in ES3/WebGL2.
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() >= 3);
    
        GLFramebuffer fbo;
    
        glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, fbo);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        GLint result;
        glGetIntegerv(GL_READ_FRAMEBUFFER_BINDING_ANGLE, &result);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        glBlitFramebufferANGLE(0, 0, 1, 1, 0, 0, 1, 1, GL_COLOR_BUFFER_BIT, GL_NEAREST);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        if (IsGLExtensionRequestable("GL_ANGLE_framebuffer_blit"))
        {
            glRequestExtensionANGLE("GL_ANGLE_framebuffer_blit");
            EXPECT_GL_NO_ERROR();
    
            glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, fbo);
            glGetIntegerv(GL_READ_FRAMEBUFFER_BINDING_ANGLE, &result);
            EXPECT_GL_NO_ERROR();
        }
    }
    
    // Test enabling the GL_OES_get_program_binary extension
    TEST_P(WebGLCompatibilityTest, EnableProgramBinaryExtension)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_OES_get_program_binary"));
    
        // This extensions become core in in ES3/WebGL2.
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() >= 3);
    
        GLint result = 0;
        glGetIntegerv(GL_NUM_PROGRAM_BINARY_FORMATS, &result);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        glGetIntegerv(GL_PROGRAM_BINARY_FORMATS, &result);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        constexpr char kVS[] =
            R"(void main()
    {
        gl_Position = vec4(0.0, 0.0, 0.0, 1.0);
    })";
        constexpr char kFS[] =
            R"(precision highp float;
    void main()
    {
        gl_FragColor = vec4(1.0);
    })";
        ANGLE_GL_PROGRAM(program, kVS, kFS);
    
        glGetProgramiv(program, GL_PROGRAM_BINARY_LENGTH, &result);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        uint8_t tempArray[512];
        GLenum tempFormat  = 0;
        GLsizei tempLength = 0;
        glGetProgramBinaryOES(program, static_cast<GLsizei>(ArraySize(tempArray)), &tempLength,
                              &tempFormat, tempArray);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        if (IsGLExtensionRequestable("GL_OES_get_program_binary"))
        {
            glRequestExtensionANGLE("GL_OES_get_program_binary");
            EXPECT_GL_NO_ERROR();
    
            glGetIntegerv(GL_NUM_PROGRAM_BINARY_FORMATS, &result);
            glGetIntegerv(GL_PROGRAM_BINARY_FORMATS, &result);
            EXPECT_GL_NO_ERROR();
    
            GLint binaryLength = 0;
            glGetProgramiv(program, GL_PROGRAM_BINARY_LENGTH, &binaryLength);
            EXPECT_GL_NO_ERROR();
    
            GLenum binaryFormat;
            GLsizei writeLength = 0;
            std::vector<uint8_t> binary(binaryLength);
            glGetProgramBinaryOES(program, binaryLength, &writeLength, &binaryFormat, binary.data());
            EXPECT_GL_NO_ERROR();
    
            glProgramBinaryOES(program, binaryFormat, binary.data(), binaryLength);
            EXPECT_GL_NO_ERROR();
        }
    }
    
    // Test enabling the GL_OES_vertex_array_object extension
    TEST_P(WebGLCompatibilityTest, EnableVertexArrayExtension)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_OES_vertex_array_object"));
    
        // This extensions become core in in ES3/WebGL2.
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() >= 3);
    
        GLint result = 0;
        glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &result);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        // Expect that GL_OES_vertex_array_object is always available.  It is implemented in the GL
        // frontend.
        EXPECT_TRUE(IsGLExtensionRequestable("GL_OES_vertex_array_object"));
    
        glRequestExtensionANGLE("GL_OES_vertex_array_object");
        EXPECT_GL_NO_ERROR();
    
        EXPECT_TRUE(IsGLExtensionEnabled("GL_OES_vertex_array_object"));
    
        glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &result);
        EXPECT_GL_NO_ERROR();
    
        GLuint vao = 0;
        glGenVertexArraysOES(0, &vao);
        EXPECT_GL_NO_ERROR();
    
        glBindVertexArrayOES(vao);
        EXPECT_GL_NO_ERROR();
    
        glDeleteVertexArraysOES(1, &vao);
        EXPECT_GL_NO_ERROR();
    }
    
    // Verify that the context generates the correct error when the framebuffer attachments are
    // different sizes
    TEST_P(WebGLCompatibilityTest, FramebufferAttachmentSizeMismatch)
    {
        GLFramebuffer fbo;
        glBindFramebuffer(GL_FRAMEBUFFER, fbo);
    
        GLTexture textures[2];
        glBindTexture(GL_TEXTURE_2D, textures[0]);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 2, 2, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[0], 0);
    
        ASSERT_GL_NO_ERROR();
        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
    
        GLRenderbuffer renderbuffer;
        glBindRenderbuffer(GL_RENDERBUFFER, renderbuffer);
        glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, 3, 3);
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, renderbuffer);
    
        ASSERT_GL_NO_ERROR();
        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS,
                         glCheckFramebufferStatus(GL_FRAMEBUFFER));
    
        if (IsGLExtensionRequestable("GL_EXT_draw_buffers"))
        {
            glRequestExtensionANGLE("GL_EXT_draw_buffers");
            EXPECT_GL_NO_ERROR();
            EXPECT_TRUE(IsGLExtensionEnabled("GL_EXT_draw_buffers"));
    
            glBindTexture(GL_TEXTURE_2D, textures[1]);
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 2, 2, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
            glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, textures[1], 0);
            ASSERT_GL_NO_ERROR();
    
            ASSERT_GL_NO_ERROR();
            ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS,
                             glCheckFramebufferStatus(GL_FRAMEBUFFER));
    
            glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, 0);
    
            ASSERT_GL_NO_ERROR();
            ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
    
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 3, 3, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
    
            ASSERT_GL_NO_ERROR();
            ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS,
                             glCheckFramebufferStatus(GL_FRAMEBUFFER));
        }
    }
    
    // Test that client-side array buffers are forbidden in WebGL mode
    TEST_P(WebGLCompatibilityTest, ForbidsClientSideArrayBuffer)
    {
        constexpr char kVS[] =
            R"(attribute vec3 a_pos;
    void main()
    {
        gl_Position = vec4(a_pos, 1.0);
    })";
    
        constexpr char kFS[] =
            R"(precision highp float;
    void main()
    {
        gl_FragColor = vec4(1.0);
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, kFS);
    
        GLint posLocation = glGetAttribLocation(program.get(), "a_pos");
        ASSERT_NE(-1, posLocation);
        glUseProgram(program.get());
    
        const auto &vertices = GetQuadVertices();
        glVertexAttribPointer(posLocation, 3, GL_FLOAT, GL_FALSE, 4, vertices.data());
        glEnableVertexAttribArray(posLocation);
    
        ASSERT_GL_NO_ERROR();
        glDrawArrays(GL_TRIANGLES, 0, 6);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // Test that client-side element array buffers are forbidden in WebGL mode
    TEST_P(WebGLCompatibilityTest, ForbidsClientSideElementBuffer)
    {
        constexpr char kVS[] =
            R"(attribute vec3 a_pos;
    void main()
    {
        gl_Position = vec4(a_pos, 1.0);
    })";
    
        constexpr char kFS[] =
            R"(precision highp float;
    void main()
    {
        gl_FragColor = vec4(1.0);
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, kFS);
    
        GLint posLocation = glGetAttribLocation(program.get(), "a_pos");
        ASSERT_NE(-1, posLocation);
        glUseProgram(program.get());
    
        const auto &vertices = GetQuadVertices();
    
        GLBuffer vertexBuffer;
        glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer.get());
        glBufferData(GL_ARRAY_BUFFER, sizeof(vertices[0]) * vertices.size(), vertices.data(),
                     GL_STATIC_DRAW);
    
        glVertexAttribPointer(posLocation, 3, GL_FLOAT, GL_FALSE, 0, 0);
        glEnableVertexAttribArray(posLocation);
    
        ASSERT_GL_NO_ERROR();
    
        // Use the pointer with value of 1 for indices instead of an actual pointer because WebGL also
        // enforces that the top bit of indices must be 0 (i.e. offset >= 0) and would generate
        // GL_INVALID_VALUE in that case. Using a null pointer gets caught by another check.
        glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_BYTE, reinterpret_cast<const void *>(intptr_t(1)));
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // Test that client-side array buffers are forbidden even if the program doesn't use the attribute
    TEST_P(WebGLCompatibilityTest, ForbidsClientSideArrayBufferEvenNotUsedOnes)
    {
        constexpr char kVS[] =
            R"(void main()
    {
        gl_Position = vec4(1.0);
    })";
    
        constexpr char kFS[] =
            R"(precision highp float;
    void main()
    {
        gl_FragColor = vec4(1.0);
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, kFS);
    
        glUseProgram(program.get());
    
        const auto &vertices = GetQuadVertices();
        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 4, vertices.data());
        glEnableVertexAttribArray(0);
    
        ASSERT_GL_NO_ERROR();
        glDrawArrays(GL_TRIANGLES, 0, 6);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // Test that passing a null pixel data pointer to TexSubImage calls generates an INVALID_VALUE error
    TEST_P(WebGLCompatibilityTest, NullPixelDataForSubImage)
    {
        // glTexSubImage2D
        {
            GLTexture texture;
            glBindTexture(GL_TEXTURE_2D, texture);
    
            // TexImage with null data - OK
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
            EXPECT_GL_NO_ERROR();
    
            // TexSubImage with zero size and null data - OK
            glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
            EXPECT_GL_NO_ERROR();
    
            // TexSubImage with non-zero size and null data - Invalid value
            glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
            EXPECT_GL_ERROR(GL_INVALID_VALUE);
        }
    
        // glTexSubImage3D
        if (getClientMajorVersion() >= 3)
        {
            GLTexture texture;
            glBindTexture(GL_TEXTURE_3D, texture);
    
            // TexImage with null data - OK
            glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA, 1, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
            EXPECT_GL_NO_ERROR();
    
            // TexSubImage with zero size and null data - OK
            glTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 0, 0, 0, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
            EXPECT_GL_NO_ERROR();
    
            // TexSubImage with non-zero size and null data - Invalid value
            glTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 0, 1, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
            EXPECT_GL_ERROR(GL_INVALID_VALUE);
        }
    }
    
    // Tests the WebGL requirement of having the same stencil mask, writemask and ref for front and back
    // (when stencil testing is enabled)
    void WebGLCompatibilityTest::TestDifferentStencilMaskAndRef(GLenum errIfMismatch)
    {
        // Run the test in an FBO to make sure we have some stencil bits.
        GLRenderbuffer renderbuffer;
        glBindRenderbuffer(GL_RENDERBUFFER, renderbuffer.get());
        glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, 32, 32);
    
        GLFramebuffer framebuffer;
        glBindFramebuffer(GL_FRAMEBUFFER, framebuffer.get());
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER,
                                  renderbuffer.get());
    
        ANGLE_GL_PROGRAM(program, "void main() { gl_Position = vec4(0, 0, 0, 1); }",
                         "void main() { gl_FragColor = vec4(0, 1, 0, 1); }");
        glUseProgram(program.get());
        ASSERT_GL_NO_ERROR();
    
        // Having ref and mask the same for front and back is valid.
        glStencilMask(255);
        glStencilFunc(GL_ALWAYS, 0, 255);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        ASSERT_GL_NO_ERROR();
    
        // Having a different front - back write mask generates an error.
        glStencilMaskSeparate(GL_FRONT, 1);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        EXPECT_GL_ERROR(errIfMismatch);
    
        // Setting both write masks separately to the same value is valid.
        glStencilMaskSeparate(GL_BACK, 1);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        ASSERT_GL_NO_ERROR();
    
        // Having a different stencil front - back mask generates an error
        glStencilFuncSeparate(GL_FRONT, GL_ALWAYS, 0, 1);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        EXPECT_GL_ERROR(errIfMismatch);
    
        // Setting both masks separately to the same value is valid.
        glStencilFuncSeparate(GL_BACK, GL_ALWAYS, 0, 1);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        ASSERT_GL_NO_ERROR();
    
        // Having a different stencil front - back reference generates an error
        glStencilFuncSeparate(GL_FRONT, GL_ALWAYS, 255, 1);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        EXPECT_GL_ERROR(errIfMismatch);
    
        // Setting both references separately to the same value is valid.
        glStencilFuncSeparate(GL_BACK, GL_ALWAYS, 255, 1);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        ASSERT_GL_NO_ERROR();
    
        // Using different stencil funcs, everything being equal is valid.
        glStencilFuncSeparate(GL_BACK, GL_NEVER, 255, 1);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        ASSERT_GL_NO_ERROR();
    }
    
    TEST_P(WebGLCompatibilityTest, StencilTestEnabledDisallowsDifferentStencilMaskAndRef)
    {
        glEnable(GL_STENCIL_TEST);
        TestDifferentStencilMaskAndRef(GL_INVALID_OPERATION);
    }
    
    TEST_P(WebGLCompatibilityTest, StencilTestDisabledAllowsDifferentStencilMaskAndRef)
    {
        glDisable(GL_STENCIL_TEST);
        TestDifferentStencilMaskAndRef(GL_NO_ERROR);
    }
    
    // Test that GL_FIXED is forbidden
    TEST_P(WebGLCompatibilityTest, ForbidsGLFixed)
    {
        GLBuffer buffer;
        glBindBuffer(GL_ARRAY_BUFFER, buffer.get());
        glBufferData(GL_ARRAY_BUFFER, 16, nullptr, GL_STATIC_DRAW);
    
        glVertexAttribPointer(0, 1, GL_FLOAT, GL_FALSE, 0, nullptr);
        ASSERT_GL_NO_ERROR();
    
        glVertexAttribPointer(0, 1, GL_FIXED, GL_FALSE, 0, nullptr);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    }
    
    // Test the WebGL limit of 255 for the attribute stride
    TEST_P(WebGLCompatibilityTest, MaxStride)
    {
        GLBuffer buffer;
        glBindBuffer(GL_ARRAY_BUFFER, buffer.get());
        glBufferData(GL_ARRAY_BUFFER, 1024, nullptr, GL_STATIC_DRAW);
    
        glVertexAttribPointer(0, 1, GL_UNSIGNED_BYTE, GL_FALSE, 255, nullptr);
        ASSERT_GL_NO_ERROR();
    
        glVertexAttribPointer(0, 1, GL_UNSIGNED_BYTE, GL_FALSE, 256, nullptr);
        EXPECT_GL_ERROR(GL_INVALID_VALUE);
    }
    
    // Test the checks for OOB reads in the vertex buffers, non-instanced version
    TEST_P(WebGLCompatibilityTest, DrawArraysBufferOutOfBoundsNonInstanced)
    {
        constexpr char kVS[] =
            R"(attribute float a_pos;
    void main()
    {
        gl_Position = vec4(a_pos, a_pos, a_pos, 1.0);
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, essl1_shaders::fs::Red());
        GLint posLocation = glGetAttribLocation(program.get(), "a_pos");
        ASSERT_NE(-1, posLocation);
        glUseProgram(program.get());
    
        GLBuffer buffer;
        glBindBuffer(GL_ARRAY_BUFFER, buffer.get());
        glBufferData(GL_ARRAY_BUFFER, 16, nullptr, GL_STATIC_DRAW);
    
        glEnableVertexAttribArray(posLocation);
    
        const uint8_t *zeroOffset = nullptr;
    
        // Test touching the last element is valid.
        glVertexAttribPointer(posLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 0, zeroOffset + 12);
        glDrawArrays(GL_POINTS, 0, 4);
        ASSERT_GL_NO_ERROR();
    
        // Test touching the last element + 1 is invalid.
        glVertexAttribPointer(posLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 0, zeroOffset + 13);
        glDrawArrays(GL_POINTS, 0, 4);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Test touching the last element is valid, using a stride.
        glVertexAttribPointer(posLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 2, zeroOffset + 9);
        glDrawArrays(GL_POINTS, 0, 4);
        ASSERT_GL_NO_ERROR();
    
        // Test touching the last element + 1 is invalid, using a stride.
        glVertexAttribPointer(posLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 2, zeroOffset + 10);
        glDrawArrays(GL_POINTS, 0, 4);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Test any offset is valid if no vertices are drawn.
        glVertexAttribPointer(posLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 0, zeroOffset + 32);
        glDrawArrays(GL_POINTS, 0, 0);
        ASSERT_GL_NO_ERROR();
    
        // Test a case of overflow that could give a max vertex that's negative
        constexpr GLint kIntMax = std::numeric_limits<GLint>::max();
        glVertexAttribPointer(posLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 0, zeroOffset + 0);
        glDrawArrays(GL_POINTS, kIntMax, kIntMax);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // Test that index values outside of the 32-bit integer range do not read out of bounds
    TEST_P(WebGLCompatibilityTest, LargeIndexRange)
    {
        ANGLE_SKIP_TEST_IF(!EnsureGLExtensionEnabled("GL_OES_element_index_uint"));
    
        constexpr char kVS[] =
            R"(attribute vec4 a_Position;
    void main()
    {
        gl_Position = a_Position;
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, essl1_shaders::fs::Red());
        glUseProgram(program.get());
    
        glEnableVertexAttribArray(glGetAttribLocation(program, "a_Position"));
    
        constexpr float kVertexData[] = {
            1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
        };
    
        GLBuffer vertexBuffer;
        glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
        glBufferData(GL_ARRAY_BUFFER, sizeof(kVertexData), kVertexData, GL_STREAM_DRAW);
    
        constexpr GLuint kMaxIntAsGLuint = static_cast<GLuint>(std::numeric_limits<GLint>::max());
        constexpr GLuint kIndexData[]    = {
            kMaxIntAsGLuint,
            kMaxIntAsGLuint + 1,
            kMaxIntAsGLuint + 2,
            kMaxIntAsGLuint + 3,
        };
    
        GLBuffer indexBuffer;
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vertexBuffer);
        glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(kIndexData), kIndexData, GL_DYNAMIC_DRAW);
    
        EXPECT_GL_NO_ERROR();
    
        // First index is representable as 32-bit int but second is not
        glDrawElements(GL_LINES, 2, GL_UNSIGNED_INT, 0);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Neither index is representable as 32-bit int
        glDrawElements(GL_LINES, 2, GL_UNSIGNED_INT, reinterpret_cast<void *>(sizeof(GLuint) * 2));
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // Test for drawing with a null index buffer
    TEST_P(WebGLCompatibilityTest, NullIndexBuffer)
    {
        constexpr char kVS[] =
            R"(attribute float a_pos;
    void main()
    {
        gl_Position = vec4(a_pos, a_pos, a_pos, 1.0);
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, essl1_shaders::fs::Red());
        glUseProgram(program.get());
    
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
        glEnableVertexAttribArray(0);
    
        glDrawElements(GL_TRIANGLES, 0, GL_UNSIGNED_BYTE, 0);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // Test the checks for OOB reads in the vertex buffers, instanced version
    TEST_P(WebGL2CompatibilityTest, DrawArraysBufferOutOfBoundsInstanced)
    {
        constexpr char kVS[] =
            R"(attribute float a_pos;
    attribute float a_w;
    void main()
    {
        gl_Position = vec4(a_pos, a_pos, a_pos, a_w);
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, essl1_shaders::fs::Red());
        GLint posLocation = glGetAttribLocation(program.get(), "a_pos");
        GLint wLocation   = glGetAttribLocation(program.get(), "a_w");
        ASSERT_NE(-1, posLocation);
        ASSERT_NE(-1, wLocation);
        glUseProgram(program.get());
    
        GLBuffer buffer;
        glBindBuffer(GL_ARRAY_BUFFER, buffer.get());
        glBufferData(GL_ARRAY_BUFFER, 16, nullptr, GL_STATIC_DRAW);
    
        glEnableVertexAttribArray(posLocation);
        glVertexAttribPointer(posLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 0, 0);
        glVertexAttribDivisor(posLocation, 0);
    
        glEnableVertexAttribArray(wLocation);
        glVertexAttribDivisor(wLocation, 1);
    
        const uint8_t *zeroOffset = nullptr;
    
        // Test touching the last element is valid.
        glVertexAttribPointer(wLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 0, zeroOffset + 12);
        glDrawArraysInstanced(GL_POINTS, 0, 1, 4);
        ASSERT_GL_NO_ERROR();
    
        // Test touching the last element + 1 is invalid.
        glVertexAttribPointer(wLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 0, zeroOffset + 13);
        glDrawArraysInstanced(GL_POINTS, 0, 1, 4);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Test touching the last element is valid, using a stride.
        glVertexAttribPointer(wLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 2, zeroOffset + 9);
        glDrawArraysInstanced(GL_POINTS, 0, 1, 4);
        ASSERT_GL_NO_ERROR();
    
        // Test touching the last element + 1 is invalid, using a stride.
        glVertexAttribPointer(wLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 2, zeroOffset + 10);
        glDrawArraysInstanced(GL_POINTS, 0, 1, 4);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Test any offset is valid if no vertices are drawn.
        glVertexAttribPointer(wLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 0, zeroOffset + 32);
        glDrawArraysInstanced(GL_POINTS, 0, 0, 1);
        ASSERT_GL_NO_ERROR();
    
        // Test any offset is valid if no primitives are drawn.
        glVertexAttribPointer(wLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 0, zeroOffset + 32);
        glDrawArraysInstanced(GL_POINTS, 0, 1, 0);
        ASSERT_GL_NO_ERROR();
    }
    
    // Test the checks for OOB reads in the vertex buffers, ANGLE_instanced_arrays version
    TEST_P(WebGLCompatibilityTest, DrawArraysBufferOutOfBoundsInstancedANGLE)
    {
        ANGLE_SKIP_TEST_IF(!IsGLExtensionRequestable("GL_ANGLE_instanced_arrays"));
        glRequestExtensionANGLE("GL_ANGLE_instanced_arrays");
        EXPECT_GL_NO_ERROR();
    
        constexpr char kVS[] =
            R"(attribute float a_pos;
    attribute float a_w;
    void main()
    {
        gl_Position = vec4(a_pos, a_pos, a_pos, a_w);
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, essl1_shaders::fs::Red());
        GLint posLocation = glGetAttribLocation(program.get(), "a_pos");
        GLint wLocation   = glGetAttribLocation(program.get(), "a_w");
        ASSERT_NE(-1, posLocation);
        ASSERT_NE(-1, wLocation);
        glUseProgram(program.get());
    
        GLBuffer buffer;
        glBindBuffer(GL_ARRAY_BUFFER, buffer.get());
        glBufferData(GL_ARRAY_BUFFER, 16, nullptr, GL_STATIC_DRAW);
    
        glEnableVertexAttribArray(posLocation);
        glVertexAttribPointer(posLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 0, 0);
        glVertexAttribDivisorANGLE(posLocation, 0);
    
        glEnableVertexAttribArray(wLocation);
        glVertexAttribDivisorANGLE(wLocation, 1);
    
        const uint8_t *zeroOffset = nullptr;
    
        // Test touching the last element is valid.
        glVertexAttribPointer(wLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 0, zeroOffset + 12);
        glDrawArraysInstancedANGLE(GL_POINTS, 0, 1, 4);
        ASSERT_GL_NO_ERROR() << "touching the last element.";
    
        // Test touching the last element + 1 is invalid.
        glVertexAttribPointer(wLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 0, zeroOffset + 13);
        glDrawArraysInstancedANGLE(GL_POINTS, 0, 1, 4);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION) << "touching the last element + 1.";
    
        // Test touching the last element is valid, using a stride.
        glVertexAttribPointer(wLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 2, zeroOffset + 9);
        glDrawArraysInstancedANGLE(GL_POINTS, 0, 1, 4);
        ASSERT_GL_NO_ERROR() << "touching the last element using a stride.";
    
        // Test touching the last element + 1 is invalid, using a stride.
        glVertexAttribPointer(wLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 2, zeroOffset + 10);
        glDrawArraysInstancedANGLE(GL_POINTS, 0, 1, 4);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION) << "touching the last element + 1 using a stride.";
    
        // Test any offset is valid if no vertices are drawn.
        glVertexAttribPointer(wLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 0, zeroOffset + 32);
        glDrawArraysInstancedANGLE(GL_POINTS, 0, 0, 1);
        ASSERT_GL_NO_ERROR() << "any offset with no vertices.";
    
        // Test any offset is valid if no primitives are drawn.
        glVertexAttribPointer(wLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 0, zeroOffset + 32);
        glDrawArraysInstancedANGLE(GL_POINTS, 0, 1, 0);
        ASSERT_GL_NO_ERROR() << "any offset with primitives.";
    }
    
    // Test the checks for OOB reads in the index buffer
    TEST_P(WebGLCompatibilityTest, DrawElementsBufferOutOfBoundsInIndexBuffer)
    {
        constexpr char kVS[] =
            R"(attribute float a_pos;
    void main()
    {
        gl_Position = vec4(a_pos, a_pos, a_pos, 1.0);
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, essl1_shaders::fs::Red());
        GLint posLocation = glGetAttribLocation(program.get(), "a_pos");
        ASSERT_NE(-1, posLocation);
        glUseProgram(program.get());
    
        GLBuffer vertexBuffer;
        glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer.get());
        glBufferData(GL_ARRAY_BUFFER, 16, nullptr, GL_STATIC_DRAW);
    
        glEnableVertexAttribArray(posLocation);
        glVertexAttribPointer(posLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 0, nullptr);
    
        const uint8_t *zeroOffset   = nullptr;
        const uint8_t zeroIndices[] = {0, 0, 0, 0, 0, 0, 0, 0};
    
        GLBuffer indexBuffer;
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer.get());
        glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(zeroIndices), zeroIndices, GL_STATIC_DRAW);
        ASSERT_GL_NO_ERROR();
    
        // Test touching the last index is valid
        glDrawElements(GL_POINTS, 4, GL_UNSIGNED_BYTE, zeroOffset + 4);
        ASSERT_GL_NO_ERROR();
    
        // Test touching the last + 1 element is invalid
        glDrawElements(GL_POINTS, 4, GL_UNSIGNED_BYTE, zeroOffset + 5);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Test any offset if valid if count is zero
        glDrawElements(GL_POINTS, 0, GL_UNSIGNED_BYTE, zeroOffset + 42);
        ASSERT_GL_NO_ERROR();
    
        // Test touching the first index is valid
        glDrawElements(GL_POINTS, 4, GL_UNSIGNED_BYTE, zeroOffset + 4);
        ASSERT_GL_NO_ERROR();
    
        // Test touching the first - 1 index is invalid
        // The error ha been specified to be INVALID_VALUE instead of INVALID_OPERATION because it was
        // the historic behavior of WebGL implementations
        glDrawElements(GL_POINTS, 4, GL_UNSIGNED_BYTE, zeroOffset - 1);
        EXPECT_GL_ERROR(GL_INVALID_VALUE);
    }
    
    // Test the checks for OOB in vertex buffers caused by indices, non-instanced version
    TEST_P(WebGLCompatibilityTest, DrawElementsBufferOutOfBoundsInVertexBuffer)
    {
        constexpr char kVS[] =
            R"(attribute float a_pos;
    void main()
    {
        gl_Position = vec4(a_pos, a_pos, a_pos, 1.0);
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, essl1_shaders::fs::Red());
        GLint posLocation = glGetAttribLocation(program.get(), "a_pos");
        ASSERT_NE(-1, posLocation);
        glUseProgram(program.get());
    
        GLBuffer vertexBuffer;
        glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer.get());
        glBufferData(GL_ARRAY_BUFFER, 8, nullptr, GL_STATIC_DRAW);
    
        glEnableVertexAttribArray(posLocation);
        glVertexAttribPointer(posLocation, 1, GL_UNSIGNED_BYTE, GL_FALSE, 0, nullptr);
    
        const uint8_t *zeroOffset   = nullptr;
        const uint8_t testIndices[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 255};
    
        GLBuffer indexBuffer;
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer.get());
        glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(testIndices), testIndices, GL_STATIC_DRAW);
        ASSERT_GL_NO_ERROR();
    
        // Test touching the end of the vertex buffer is valid
        glDrawElements(GL_POINTS, 1, GL_UNSIGNED_BYTE, zeroOffset + 7);
        ASSERT_GL_NO_ERROR();
    
        // Test touching just after the end of the vertex buffer is invalid
        glDrawElements(GL_POINTS, 1, GL_UNSIGNED_BYTE, zeroOffset + 8);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Test touching the whole vertex buffer is valid
        glDrawElements(GL_POINTS, 8, GL_UNSIGNED_BYTE, zeroOffset + 0);
        ASSERT_GL_NO_ERROR();
    
        // Test an index that would be negative
        glDrawElements(GL_POINTS, 1, GL_UNSIGNED_BYTE, zeroOffset + 9);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // Test depth range with 'near' more or less than 'far.'
    TEST_P(WebGLCompatibilityTest, DepthRange)
    {
        glDepthRangef(0, 1);
        ASSERT_GL_NO_ERROR();
    
        glDepthRangef(.5, .5);
        ASSERT_GL_NO_ERROR();
    
        glDepthRangef(1, 0);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // Test all blend function combinations.
    // In WebGL it is invalid to combine constant color with constant alpha.
    TEST_P(WebGLCompatibilityTest, BlendWithConstantColor)
    {
        constexpr GLenum srcFunc[] = {
            GL_ZERO,
            GL_ONE,
            GL_SRC_COLOR,
            GL_ONE_MINUS_SRC_COLOR,
            GL_DST_COLOR,
            GL_ONE_MINUS_DST_COLOR,
            GL_SRC_ALPHA,
            GL_ONE_MINUS_SRC_ALPHA,
            GL_DST_ALPHA,
            GL_ONE_MINUS_DST_ALPHA,
            GL_CONSTANT_COLOR,
            GL_ONE_MINUS_CONSTANT_COLOR,
            GL_CONSTANT_ALPHA,
            GL_ONE_MINUS_CONSTANT_ALPHA,
            GL_SRC_ALPHA_SATURATE,
        };
    
        constexpr GLenum dstFunc[] = {
            GL_ZERO,           GL_ONE,
            GL_SRC_COLOR,      GL_ONE_MINUS_SRC_COLOR,
            GL_DST_COLOR,      GL_ONE_MINUS_DST_COLOR,
            GL_SRC_ALPHA,      GL_ONE_MINUS_SRC_ALPHA,
            GL_DST_ALPHA,      GL_ONE_MINUS_DST_ALPHA,
            GL_CONSTANT_COLOR, GL_ONE_MINUS_CONSTANT_COLOR,
            GL_CONSTANT_ALPHA, GL_ONE_MINUS_CONSTANT_ALPHA,
        };
    
        for (GLenum src : srcFunc)
        {
            for (GLenum dst : dstFunc)
            {
                glBlendFunc(src, dst);
                CheckBlendFunctions(src, dst);
                glBlendFuncSeparate(src, dst, GL_ONE, GL_ONE);
                CheckBlendFunctions(src, dst);
            }
        }
    
        // Ensure the same semantics for indexed blendFunc
        if (IsGLExtensionRequestable("GL_OES_draw_buffers_indexed"))
        {
            glRequestExtensionANGLE("GL_OES_draw_buffers_indexed");
            EXPECT_GL_NO_ERROR();
            EXPECT_TRUE(IsGLExtensionEnabled("GL_OES_draw_buffers_indexed"));
    
            for (GLenum src : srcFunc)
            {
                for (GLenum dst : dstFunc)
                {
                    glBlendFunciOES(0, src, dst);
                    CheckBlendFunctions(src, dst);
                    glBlendFuncSeparateiOES(0, src, dst, GL_ONE, GL_ONE);
                    CheckBlendFunctions(src, dst);
                }
            }
        }
    }
    
    // Test draw state validation and invalidation wrt indexed blendFunc.
    TEST_P(WebGLCompatibilityTest, IndexedBlendWithConstantColorInvalidation)
    {
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() < 3);
        ANGLE_SKIP_TEST_IF(!IsGLExtensionRequestable("GL_OES_draw_buffers_indexed"));
    
        glRequestExtensionANGLE("GL_OES_draw_buffers_indexed");
        EXPECT_GL_NO_ERROR();
        EXPECT_TRUE(IsGLExtensionEnabled("GL_OES_draw_buffers_indexed"));
    
        constexpr char kVS[] =
            R"(#version 300 es
    void main()
    {
        gl_PointSize = 1.0;
        gl_Position = vec4(0, 0, 0, 1);
    })";
    
        constexpr char kFS[] =
            R"(#version 300 es
    precision lowp float;
    layout(location = 0) out vec4 o_color0;
    layout(location = 1) out vec4 o_color1;
    void main()
    {
        o_color0 = vec4(1, 0, 0, 1);
        o_color1 = vec4(0, 1, 0, 1);
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, kFS);
        glUseProgram(program);
    
        glDisable(GL_BLEND);
        glEnableiOES(GL_BLEND, 0);
        glEnableiOES(GL_BLEND, 1);
    
        GLTexture texture1;
        glBindTexture(GL_TEXTURE_2D, texture1);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        EXPECT_GL_NO_ERROR();
    
        GLTexture texture2;
        glBindTexture(GL_TEXTURE_2D, texture2);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        EXPECT_GL_NO_ERROR();
    
        GLFramebuffer fbo;
        glBindFramebuffer(GL_FRAMEBUFFER, fbo);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture1, 0);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, texture2, 0);
        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
    
        GLenum drawbuffers[] = {GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1};
        glDrawBuffers(2, drawbuffers);
    
        glDrawArrays(GL_POINTS, 0, 1);
        EXPECT_GL_NO_ERROR();
    
        // Force-invalidate draw call
        glBlendFuncSeparateiOES(0, GL_CONSTANT_COLOR, GL_CONSTANT_COLOR, GL_CONSTANT_ALPHA,
                                GL_CONSTANT_ALPHA);
        EXPECT_GL_NO_ERROR();
    
        glBlendFuncSeparateiOES(1, GL_CONSTANT_ALPHA, GL_CONSTANT_ALPHA, GL_CONSTANT_COLOR,
                                GL_CONSTANT_COLOR);
        EXPECT_GL_NO_ERROR();
    
        glDrawArrays(GL_POINTS, 0, 1);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // Test getIndexedParameter wrt GL_OES_draw_buffers_indexed.
    TEST_P(WebGLCompatibilityTest, DrawBuffersIndexedGetIndexedParameter)
    {
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() < 3);
        ANGLE_SKIP_TEST_IF(!IsGLExtensionRequestable("GL_OES_draw_buffers_indexed"));
    
        GLint value;
        GLboolean data[4];
    
        glGetIntegeri_v(GL_BLEND_EQUATION_RGB, 0, &value);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
        glGetIntegeri_v(GL_BLEND_EQUATION_ALPHA, 0, &value);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
        glGetIntegeri_v(GL_BLEND_SRC_RGB, 0, &value);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
        glGetIntegeri_v(GL_BLEND_SRC_ALPHA, 0, &value);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
        glGetIntegeri_v(GL_BLEND_DST_RGB, 0, &value);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
        glGetIntegeri_v(GL_BLEND_DST_ALPHA, 0, &value);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
        glGetBooleani_v(GL_COLOR_WRITEMASK, 0, data);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glRequestExtensionANGLE("GL_OES_draw_buffers_indexed");
        EXPECT_GL_NO_ERROR();
        EXPECT_TRUE(IsGLExtensionEnabled("GL_OES_draw_buffers_indexed"));
    
        glDisable(GL_BLEND);
        glEnableiOES(GL_BLEND, 0);
        glBlendEquationSeparateiOES(0, GL_FUNC_ADD, GL_FUNC_SUBTRACT);
        glBlendFuncSeparateiOES(0, GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ZERO, GL_ZERO);
        glColorMaskiOES(0, true, false, true, false);
        EXPECT_GL_NO_ERROR();
    
        EXPECT_EQ(true, glIsEnablediOES(GL_BLEND, 0));
        EXPECT_GL_NO_ERROR();
        glGetIntegeri_v(GL_BLEND_EQUATION_RGB, 0, &value);
        EXPECT_GL_NO_ERROR();
        EXPECT_EQ(GL_FUNC_ADD, value);
        glGetIntegeri_v(GL_BLEND_EQUATION_ALPHA, 0, &value);
        EXPECT_GL_NO_ERROR();
        EXPECT_EQ(GL_FUNC_SUBTRACT, value);
        glGetIntegeri_v(GL_BLEND_SRC_RGB, 0, &value);
        EXPECT_GL_NO_ERROR();
        EXPECT_EQ(GL_SRC_ALPHA, value);
        glGetIntegeri_v(GL_BLEND_SRC_ALPHA, 0, &value);
        EXPECT_GL_NO_ERROR();
        EXPECT_EQ(GL_ZERO, value);
        glGetIntegeri_v(GL_BLEND_DST_RGB, 0, &value);
        EXPECT_GL_NO_ERROR();
        EXPECT_EQ(GL_ONE_MINUS_SRC_ALPHA, value);
        glGetIntegeri_v(GL_BLEND_DST_ALPHA, 0, &value);
        EXPECT_GL_NO_ERROR();
        EXPECT_EQ(GL_ZERO, value);
        glGetBooleani_v(GL_COLOR_WRITEMASK, 0, data);
        EXPECT_GL_NO_ERROR();
        EXPECT_EQ(true, data[0]);
        EXPECT_EQ(false, data[1]);
        EXPECT_EQ(true, data[2]);
        EXPECT_EQ(false, data[3]);
    }
    
    // Test that binding/querying uniforms and attributes with invalid names generates errors
    TEST_P(WebGLCompatibilityTest, InvalidAttributeAndUniformNames)
    {
        const std::string validAttribName =
            "abcdefghijklmnopqrstuvwxyz_ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
        const std::string validUniformName =
            "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_1234567890";
        std::vector<char> invalidSet = {'"', '$', '`', '@', '\''};
        if (getClientMajorVersion() < 3)
        {
            invalidSet.push_back('\\');
        }
    
        std::string vert = "attribute float ";
        vert += validAttribName;
        vert +=
            R"(;
    void main()
    {
        gl_Position = vec4(1.0);
    })";
    
        std::string frag =
            R"(precision highp float;
    uniform vec4 )";
        frag += validUniformName;
        // Insert illegal characters into comments
        frag +=
            R"(;
        // $ \" @ /*
    void main()
    {/*
        ` @ $
        */gl_FragColor = vec4(1.0);
    })";
    
        ANGLE_GL_PROGRAM(program, vert.c_str(), frag.c_str());
        EXPECT_GL_NO_ERROR();
    
        for (char invalidChar : invalidSet)
        {
            std::string invalidName = validAttribName + invalidChar;
            glGetAttribLocation(program, invalidName.c_str());
            EXPECT_GL_ERROR(GL_INVALID_VALUE)
                << "glGetAttribLocation unexpectedly succeeded for name \"" << invalidName << "\".";
    
            glBindAttribLocation(program, 0, invalidName.c_str());
            EXPECT_GL_ERROR(GL_INVALID_VALUE)
                << "glBindAttribLocation unexpectedly succeeded for name \"" << invalidName << "\".";
        }
    
        for (char invalidChar : invalidSet)
        {
            std::string invalidName = validUniformName + invalidChar;
            glGetUniformLocation(program, invalidName.c_str());
            EXPECT_GL_ERROR(GL_INVALID_VALUE)
                << "glGetUniformLocation unexpectedly succeeded for name \"" << invalidName << "\".";
        }
    
        for (char invalidChar : invalidSet)
        {
            std::string invalidAttribName = validAttribName + invalidChar;
            const char *invalidVert[]     = {
                "attribute float ",
                invalidAttribName.c_str(),
                R"(;,
    void main(),
    {,
        gl_Position = vec4(1.0);,
    })",
            };
    
            GLuint shader = glCreateShader(GL_VERTEX_SHADER);
            glShaderSource(shader, static_cast<GLsizei>(ArraySize(invalidVert)), invalidVert, nullptr);
            EXPECT_GL_ERROR(GL_INVALID_VALUE);
            glDeleteShader(shader);
        }
    }
    
    // Test that line continuation is handled correctly when valdiating shader source
    TEST_P(WebGLCompatibilityTest, ShaderSourceLineContinuation)
    {
        // Verify that a line continuation character (i.e. backslash) cannot be used
        // within a preprocessor directive in a ES2 context.
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() >= 3);
    
        const char *validVert =
            R"(#define foo this is a test
    precision mediump float;
    void main()
    {
        gl_Position = vec4(1.0);
    })";
    
        const char *invalidVert =
            R"(#define foo this \
        is a test
    precision mediump float;
    void main()
    {
        gl_Position = vec4(1.0);
    })";
    
        GLuint shader = glCreateShader(GL_VERTEX_SHADER);
        glShaderSource(shader, 1, &validVert, nullptr);
        EXPECT_GL_NO_ERROR();
    
        glShaderSource(shader, 1, &invalidVert, nullptr);
        EXPECT_GL_ERROR(GL_INVALID_VALUE);
        glDeleteShader(shader);
    }
    
    // Test that line continuation is handled correctly when valdiating shader source
    TEST_P(WebGL2CompatibilityTest, ShaderSourceLineContinuation)
    {
        const char *validVert =
            R"(#version 300 es
    precision mediump float;
    
    void main ()
    {
        float f\
    oo = 1.0;
        gl_Position = vec4(foo);
    })";
    
        const char *invalidVert =
            R"(#version 300 es
    precision mediump float;
    
    void main ()
    {
        float f\$
    oo = 1.0;
        gl_Position = vec4(foo);
    })";
    
        GLuint shader = glCreateShader(GL_VERTEX_SHADER);
        glShaderSource(shader, 1, &validVert, nullptr);
        EXPECT_GL_NO_ERROR();
        glShaderSource(shader, 1, &invalidVert, nullptr);
        EXPECT_GL_ERROR(GL_INVALID_VALUE);
        glDeleteShader(shader);
    }
    
    // Tests bindAttribLocations for reserved prefixes and length limits
    TEST_P(WebGLCompatibilityTest, BindAttribLocationLimitation)
    {
        constexpr int maxLocStringLength = 256;
        const std::string tooLongString(maxLocStringLength + 1, '_');
    
        glBindAttribLocation(0, 0, "_webgl_var");
    
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glBindAttribLocation(0, 0, static_cast<const GLchar *>(tooLongString.c_str()));
    
        EXPECT_GL_ERROR(GL_INVALID_VALUE);
    }
    
    // Test that having no attributes with a zero divisor is valid in WebGL2
    TEST_P(WebGL2CompatibilityTest, InstancedDrawZeroDivisor)
    {
        constexpr char kVS[] =
            R"(attribute float a_pos;
    void main()
    {
        gl_Position = vec4(a_pos, a_pos, a_pos, 1.0);
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, essl1_shaders::fs::Red());
    
        GLint posLocation = glGetAttribLocation(program.get(), "a_pos");
        ASSERT_NE(-1, posLocation);
    
        glUseProgram(program.get());
    
        GLBuffer buffer;
        glBindBuffer(GL_ARRAY_BUFFER, buffer.get());
        glBufferData(GL_ARRAY_BUFFER, 16, nullptr, GL_STATIC_DRAW);
    
        glEnableVertexAttribArray(posLocation);
        glVertexAttribDivisor(posLocation, 1);
    
        glVertexAttribPointer(0, 1, GL_UNSIGNED_BYTE, GL_FALSE, 0, nullptr);
        glDrawArraysInstanced(GL_POINTS, 0, 1, 4);
        ASSERT_GL_NO_ERROR();
    }
    
    // Tests that NPOT is not enabled by default in WebGL 1 and that it can be enabled
    TEST_P(WebGLCompatibilityTest, NPOT)
    {
        EXPECT_FALSE(IsGLExtensionEnabled("GL_OES_texture_npot"));
    
        // Create a texture and set an NPOT mip 0, should always be acceptable.
        GLTexture texture;
        glBindTexture(GL_TEXTURE_2D, texture.get());
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 10, 10, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        ASSERT_GL_NO_ERROR();
    
        // Try setting an NPOT mip 1 and verify the error if WebGL 1
        glTexImage2D(GL_TEXTURE_2D, 1, GL_RGBA, 5, 5, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        if (getClientMajorVersion() < 3)
        {
            ASSERT_GL_ERROR(GL_INVALID_VALUE);
        }
        else
        {
            ASSERT_GL_NO_ERROR();
        }
    
        if (IsGLExtensionRequestable("GL_OES_texture_npot"))
        {
            glRequestExtensionANGLE("GL_OES_texture_npot");
            ASSERT_GL_NO_ERROR();
    
            // Try again to set NPOT mip 1
            glTexImage2D(GL_TEXTURE_2D, 1, GL_RGBA, 5, 5, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
            ASSERT_GL_NO_ERROR();
        }
    }
    
    template <typename T>
    void FillTexture2D(GLuint texture,
                       GLsizei width,
                       GLsizei height,
                       const T &onePixelData,
                       GLint level,
                       GLint internalFormat,
                       GLenum format,
                       GLenum type)
    {
        std::vector<T> allPixelsData(width * height, onePixelData);
    
        glBindTexture(GL_TEXTURE_2D, texture);
        glTexImage2D(GL_TEXTURE_2D, level, internalFormat, width, height, 0, format, type,
                     allPixelsData.data());
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    }
    
    // Test that unset gl_Position defaults to (0,0,0,0).
    TEST_P(WebGLCompatibilityTest, DefaultPosition)
    {
        // Draw a quad where each vertex is red if gl_Position is (0,0,0,0) before it is set,
        // and green otherwise.  The center of each quadrant will be red if and only if all
        // four corners are red.
        constexpr char kVS[] =
            R"(attribute vec3 pos;
    varying vec4 color;
    void main() {
        if (gl_Position == vec4(0,0,0,0)) {
            color = vec4(1,0,0,1);
        } else {
            color = vec4(0,1,0,1);
        }
        gl_Position = vec4(pos,1);
    })";
    
        constexpr char kFS[] =
            R"(precision mediump float;
    varying vec4 color;
    void main() {
        gl_FragColor = color;
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, kFS);
        drawQuad(program.get(), "pos", 0.0f, 1.0f, true);
        EXPECT_PIXEL_COLOR_EQ(getWindowWidth() * 1 / 4, getWindowHeight() * 1 / 4, GLColor::red);
        EXPECT_PIXEL_COLOR_EQ(getWindowWidth() * 1 / 4, getWindowHeight() * 3 / 4, GLColor::red);
        EXPECT_PIXEL_COLOR_EQ(getWindowWidth() * 3 / 4, getWindowHeight() * 1 / 4, GLColor::red);
        EXPECT_PIXEL_COLOR_EQ(getWindowWidth() * 3 / 4, getWindowHeight() * 3 / 4, GLColor::red);
    }
    
    // Tests that a rendering feedback loop triggers a GL error under WebGL.
    // Based on WebGL test conformance/renderbuffers/feedback-loop.html.
    TEST_P(WebGLCompatibilityTest, RenderingFeedbackLoop)
    {
        constexpr char kVS[] =
            R"(attribute vec4 a_position;
    varying vec2 v_texCoord;
    void main() {
        gl_Position = a_position;
        v_texCoord = (a_position.xy * 0.5) + 0.5;
    })";
    
        constexpr char kFS[] =
            R"(precision mediump float;
    varying vec2 v_texCoord;
    uniform sampler2D u_texture;
    void main() {
        // Shader swizzles color channels so we can tell if the draw succeeded.
        gl_FragColor = texture2D(u_texture, v_texCoord).gbra;
    })";
    
        GLTexture texture;
        FillTexture2D(texture.get(), 1, 1, GLColor::red, 0, GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE);
    
        ASSERT_GL_NO_ERROR();
    
        GLFramebuffer framebuffer;
        glBindFramebuffer(GL_FRAMEBUFFER, framebuffer.get());
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture.get(), 0);
    
        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
    
        ANGLE_GL_PROGRAM(program, kVS, kFS);
    
        GLint uniformLoc = glGetUniformLocation(program.get(), "u_texture");
        ASSERT_NE(-1, uniformLoc);
    
        glUseProgram(program.get());
        glUniform1i(uniformLoc, 0);
        glDisable(GL_BLEND);
        glDisable(GL_DEPTH_TEST);
        ASSERT_GL_NO_ERROR();
    
        // Drawing with a texture that is also bound to the current framebuffer should fail
        glBindTexture(GL_TEXTURE_2D, texture.get());
        drawQuad(program.get(), "a_position", 0.5f, 1.0f, true);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Ensure that the texture contents did not change after the previous render
        glBindFramebuffer(GL_FRAMEBUFFER, 0);
        drawQuad(program.get(), "a_position", 0.5f, 1.0f, true);
        ASSERT_GL_NO_ERROR();
        EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::blue);
    
        // Drawing when texture is bound to an inactive uniform should succeed
        GLTexture texture2;
        FillTexture2D(texture2.get(), 1, 1, GLColor::green, 0, GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE);
    
        glBindFramebuffer(GL_FRAMEBUFFER, framebuffer.get());
        glActiveTexture(GL_TEXTURE1);
        glBindTexture(GL_TEXTURE_2D, texture.get());
        drawQuad(program.get(), "a_position", 0.5f, 1.0f, true);
        ASSERT_GL_NO_ERROR();
        EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::red);
    }
    
    // Multi-context uses of textures should not cause rendering feedback loops.
    TEST_P(WebGLCompatibilityTest, MultiContextNoRenderingFeedbackLoops)
    {
        constexpr char kUnusedTextureVS[] =
            R"(attribute vec4 a_position;
    varying vec2 v_texCoord;
    void main() {
        gl_Position = a_position;
        v_texCoord = (a_position.xy * 0.5) + 0.5;
    })";
    
        constexpr char kUnusedTextureFS[] =
            R"(precision mediump float;
    varying vec2 v_texCoord;
    uniform sampler2D u_texture;
    void main() {
        gl_FragColor = texture2D(u_texture, v_texCoord).rgba;
    })";
    
        ANGLE_GL_PROGRAM(unusedProgram, kUnusedTextureVS, kUnusedTextureFS);
    
        glUseProgram(unusedProgram.get());
        GLint uniformLoc = glGetUniformLocation(unusedProgram.get(), "u_texture");
        ASSERT_NE(-1, uniformLoc);
        glUniform1i(uniformLoc, 0);
    
        GLTexture texture;
        FillTexture2D(texture.get(), 1, 1, GLColor::red, 0, GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE);
        glBindTexture(GL_TEXTURE_2D, texture.get());
        // Note that _texture_ is still bound to GL_TEXTURE_2D in this context at this point.
    
        EGLWindow *window          = getEGLWindow();
        EGLDisplay display         = window->getDisplay();
        EGLConfig config           = window->getConfig();
        EGLSurface surface         = window->getSurface();
        EGLint contextAttributes[] = {
            EGL_CONTEXT_MAJOR_VERSION_KHR,
            GetParam().majorVersion,
            EGL_CONTEXT_MINOR_VERSION_KHR,
            GetParam().minorVersion,
            EGL_CONTEXT_WEBGL_COMPATIBILITY_ANGLE,
            EGL_TRUE,
            EGL_NONE,
        };
        auto context1 = eglGetCurrentContext();
        // Create context2, sharing resources with context1.
        auto context2 = eglCreateContext(display, config, context1, contextAttributes);
        ASSERT_NE(context2, EGL_NO_CONTEXT);
        eglMakeCurrent(display, surface, surface, context2);
    
        constexpr char kVS[] =
            R"(attribute vec4 a_position;
    void main() {
        gl_Position = a_position;
    })";
    
        constexpr char kFS[] =
            R"(precision mediump float;
    void main() {
        gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0);
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, kFS);
        glUseProgram(program.get());
    
        ASSERT_GL_NO_ERROR();
    
        // Render to the texture in context2.
        GLFramebuffer framebuffer;
        glBindFramebuffer(GL_FRAMEBUFFER, framebuffer.get());
        // Texture is still a valid name in context2.
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture.get(), 0);
        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
        // There is no rendering feedback loop at this point.
    
        glDisable(GL_BLEND);
        glDisable(GL_DEPTH_TEST);
        ASSERT_GL_NO_ERROR();
    
        drawQuad(program.get(), "a_position", 0.5f, 1.0f, true);
        ASSERT_GL_NO_ERROR();
        EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
    
        eglMakeCurrent(display, surface, surface, context1);
        eglDestroyContext(display, context2);
    }
    
    // Test for the max draw buffers and color attachments.
    TEST_P(WebGLCompatibilityTest, MaxDrawBuffersAttachmentPoints)
    {
        // This test only applies to ES2.
        if (getClientMajorVersion() != 2)
        {
            return;
        }
    
        GLFramebuffer fbo[2];
        glBindFramebuffer(GL_FRAMEBUFFER, fbo[0].get());
    
        // Test that is valid when we bind with a single attachment point.
        GLTexture texture;
        glBindTexture(GL_TEXTURE_2D, texture.get());
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture.get(), 0);
        ASSERT_GL_NO_ERROR();
    
        // Test that enabling the draw buffers extension will allow us to bind with a non-zero
        // attachment point.
        if (IsGLExtensionRequestable("GL_EXT_draw_buffers"))
        {
            glRequestExtensionANGLE("GL_EXT_draw_buffers");
            EXPECT_GL_NO_ERROR();
            EXPECT_TRUE(IsGLExtensionEnabled("GL_EXT_draw_buffers"));
    
            glBindFramebuffer(GL_FRAMEBUFFER, fbo[1].get());
    
            GLTexture texture2;
            glBindTexture(GL_TEXTURE_2D, texture2.get());
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
            glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, texture2.get(),
                                   0);
            ASSERT_GL_NO_ERROR();
        }
    }
    
    // Test that the offset in the index buffer is forced to be a multiple of the element size
    TEST_P(WebGLCompatibilityTest, DrawElementsOffsetRestriction)
    {
        constexpr char kVS[] =
            R"(attribute vec3 a_pos;
    void main()
    {
        gl_Position = vec4(a_pos, 1.0);
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, essl1_shaders::fs::Red());
    
        GLint posLocation = glGetAttribLocation(program.get(), "a_pos");
        ASSERT_NE(-1, posLocation);
        glUseProgram(program.get());
    
        const auto &vertices = GetQuadVertices();
    
        GLBuffer vertexBuffer;
        glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer.get());
        glBufferData(GL_ARRAY_BUFFER, sizeof(vertices[0]) * vertices.size(), vertices.data(),
                     GL_STATIC_DRAW);
    
        glVertexAttribPointer(posLocation, 3, GL_FLOAT, GL_FALSE, 0, 0);
        glEnableVertexAttribArray(posLocation);
    
        GLBuffer indexBuffer;
        const GLubyte indices[] = {0, 0, 0, 0, 0, 0, 0, 0};
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer.get());
        glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
    
        ASSERT_GL_NO_ERROR();
    
        const char *zeroIndices = nullptr;
    
        glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_BYTE, zeroIndices);
        ASSERT_GL_NO_ERROR();
    
        glDrawElements(GL_TRIANGLES, 4, GL_UNSIGNED_SHORT, zeroIndices);
        ASSERT_GL_NO_ERROR();
    
        glDrawElements(GL_TRIANGLES, 4, GL_UNSIGNED_SHORT, zeroIndices + 1);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // Test that the offset and stride in the vertex buffer is forced to be a multiple of the element
    // size
    TEST_P(WebGLCompatibilityTest, VertexAttribPointerOffsetRestriction)
    {
        const char *zeroOffset = nullptr;
    
        // Base case, vector of two floats
        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, zeroOffset);
        ASSERT_GL_NO_ERROR();
    
        // Test setting a non-multiple offset
        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, zeroOffset + 1);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, zeroOffset + 2);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, zeroOffset + 3);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Test setting a non-multiple stride
        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 1, zeroOffset);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2, zeroOffset);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 3, zeroOffset);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    void WebGLCompatibilityTest::drawBuffersEXTFeedbackLoop(GLuint program,
                                                            const std::array<GLenum, 2> &drawBuffers,
                                                            GLenum expectedError)
    {
        glDrawBuffersEXT(2, drawBuffers.data());
    
        // Make sure framebuffer is complete before feedback loop detection
        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
    
        drawQuad(program, "aPosition", 0.5f, 1.0f, true);
    
        // "Rendering to a texture where it samples from should geneates INVALID_OPERATION. Otherwise,
        // it should be NO_ERROR"
        EXPECT_GL_ERROR(expectedError);
    }
    
    // This tests that rendering feedback loops works as expected with GL_EXT_draw_buffers.
    // Based on WebGL test conformance/extensions/webgl-draw-buffers-feedback-loop.html
    TEST_P(WebGLCompatibilityTest, RenderingFeedbackLoopWithDrawBuffersEXT)
    {
        constexpr char kVS[] =
            R"(attribute vec4 aPosition;
    varying vec2 texCoord;
    void main() {
        gl_Position = aPosition;
        texCoord = (aPosition.xy * 0.5) + 0.5;
    })";
    
        constexpr char kFS[] =
            R"(#extension GL_EXT_draw_buffers : require
    precision mediump float;
    uniform sampler2D tex;
    varying vec2 texCoord;
    void main() {
        gl_FragData[0] = texture2D(tex, texCoord);
        gl_FragData[1] = texture2D(tex, texCoord);
    })";
    
        GLsizei width  = 8;
        GLsizei height = 8;
    
        // This shader cannot be run in ES3, because WebGL 2 does not expose the draw buffers
        // extension and gl_FragData semantics are changed to enforce indexing by zero always.
        // TODO(jmadill): This extension should be disabled in WebGL 2 contexts.
        if (/*!IsGLExtensionEnabled("GL_EXT_draw_buffers")*/ getClientMajorVersion() != 2)
        {
            // No WEBGL_draw_buffers support -- this is legal.
            return;
        }
    
        GLint maxDrawBuffers = 0;
        glGetIntegerv(GL_MAX_DRAW_BUFFERS, &maxDrawBuffers);
    
        // Test skipped because MAX_DRAW_BUFFERS is too small.
        ANGLE_SKIP_TEST_IF(maxDrawBuffers < 2);
    
        ANGLE_GL_PROGRAM(program, kVS, kFS);
        glUseProgram(program.get());
        glViewport(0, 0, width, height);
    
        GLTexture tex0;
        GLTexture tex1;
        GLFramebuffer fbo;
        FillTexture2D(tex0.get(), width, height, GLColor::red, 0, GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE);
        FillTexture2D(tex1.get(), width, height, GLColor::green, 0, GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE);
        ASSERT_GL_NO_ERROR();
    
        glBindTexture(GL_TEXTURE_2D, tex1.get());
        GLint texLoc = glGetUniformLocation(program.get(), "tex");
        ASSERT_NE(-1, texLoc);
        glUniform1i(texLoc, 0);
        ASSERT_GL_NO_ERROR();
    
        // The sampling texture is bound to COLOR_ATTACHMENT1 during resource allocation
        glBindFramebuffer(GL_FRAMEBUFFER, fbo.get());
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, tex0.get(), 0);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, tex1.get(), 0);
    
        drawBuffersEXTFeedbackLoop(program.get(), {{GL_NONE, GL_COLOR_ATTACHMENT1}},
                                   GL_INVALID_OPERATION);
        drawBuffersEXTFeedbackLoop(program.get(), {{GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1}},
                                   GL_INVALID_OPERATION);
        // A feedback loop is formed regardless of drawBuffers settings.
        drawBuffersEXTFeedbackLoop(program.get(), {{GL_COLOR_ATTACHMENT0, GL_NONE}},
                                   GL_INVALID_OPERATION);
    }
    
    // Test tests that texture copying feedback loops are properly rejected in WebGL.
    // Based on the WebGL test conformance/textures/misc/texture-copying-feedback-loops.html
    TEST_P(WebGLCompatibilityTest, TextureCopyingFeedbackLoops)
    {
        // TODO(crbug.com/1132295): Failing on Apple DTK.
        ANGLE_SKIP_TEST_IF(IsOSX() && IsARM64() && IsDesktopOpenGL());
    
        GLTexture texture;
        glBindTexture(GL_TEXTURE_2D, texture.get());
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 2, 2, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    
        GLTexture texture2;
        glBindTexture(GL_TEXTURE_2D, texture2.get());
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 2, 2, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    
        GLFramebuffer framebuffer;
        glBindFramebuffer(GL_FRAMEBUFFER, framebuffer.get());
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture.get(), 0);
    
        // framebuffer should be FRAMEBUFFER_COMPLETE.
        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
        ASSERT_GL_NO_ERROR();
    
        // testing copyTexImage2D
    
        // copyTexImage2D to same texture but different level
        glBindTexture(GL_TEXTURE_2D, texture.get());
        glCopyTexImage2D(GL_TEXTURE_2D, 1, GL_RGBA, 0, 0, 2, 2, 0);
        EXPECT_GL_NO_ERROR();
    
        // copyTexImage2D to same texture same level, invalid feedback loop
        glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 0, 0, 2, 2, 0);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // copyTexImage2D to different texture
        glBindTexture(GL_TEXTURE_2D, texture2.get());
        glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 0, 0, 2, 2, 0);
        EXPECT_GL_NO_ERROR();
    
        // testing copyTexSubImage2D
    
        // copyTexSubImage2D to same texture but different level
        glBindTexture(GL_TEXTURE_2D, texture.get());
        glCopyTexSubImage2D(GL_TEXTURE_2D, 1, 0, 0, 0, 0, 1, 1);
        EXPECT_GL_NO_ERROR();
    
        // copyTexSubImage2D to same texture same level, invalid feedback loop
        glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, 1, 1);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // copyTexSubImage2D to different texture
        glBindTexture(GL_TEXTURE_2D, texture2.get());
        glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, 1, 1);
        EXPECT_GL_NO_ERROR();
    }
    
    // Test that copying from mip 1 of a texture to mip 0 works.  When the framebuffer is attached to
    // mip 1 of a mip-complete texture, an image with both mips are created.  When copying from the
    // framebuffer to mip 0, it is being redefined.
    TEST_P(WebGL2CompatibilityTest, CopyMip1ToMip0)
    {
        // http://anglebug.com/4804
        ANGLE_SKIP_TEST_IF(IsD3D11());
    
        // http://anglebug.com/4805
        ANGLE_SKIP_TEST_IF(IsOpenGL() && IsIntel() && (IsWindows() || IsOSX()));
    
        GLFramebuffer framebuffer;
        glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
    
        GLTexture texture;
        glBindTexture(GL_TEXTURE_2D, texture);
    
        const GLColor mip0[4] = {
            GLColor::red,
            GLColor::red,
            GLColor::red,
            GLColor::red,
        };
        const GLColor mip1[1] = {
            GLColor::green,
        };
    
        // Create a complete mip chain in mips 0 to 2
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 2, 2, 0, GL_RGBA, GL_UNSIGNED_BYTE, mip0);
        glTexImage2D(GL_TEXTURE_2D, 1, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, mip1);
    
        // Framebuffer can bind to mip 1, as the texture is mip-complete.
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 1);
        EXPECT_GL_FRAMEBUFFER_COMPLETE(GL_FRAMEBUFFER);
    
        // Copy to mip 0.  This shouldn't crash.
        glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 0, 0, 1, 1, 0);
        EXPECT_GL_NO_ERROR();
    
        // The framebuffer is now incomplete.
        EXPECT_GLENUM_EQ(GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT,
                         glCheckFramebufferStatus(GL_FRAMEBUFFER));
    
        // http://anglebug.com/4802
        ANGLE_SKIP_TEST_IF(IsOpenGL() && IsNVIDIA());
    
        // http://anglebug.com/4803
        ANGLE_SKIP_TEST_IF(IsOpenGL() && IsAMD() && IsOSX());
    
        // Bind framebuffer to mip 0 and make sure the copy was done.
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 0);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);
        EXPECT_GL_FRAMEBUFFER_COMPLETE(GL_FRAMEBUFFER);
    
        EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
    }
    
    // Test that copying from mip 0 of a texture to mip 1 works.  When the framebuffer is attached to
    // mip 0 of a mip-complete texture, an image with both mips are created.  When copying from the
    // framebuffer to mip 1, it is being redefined.
    TEST_P(WebGL2CompatibilityTest, CopyMip0ToMip1)
    {
        // http://anglebug.com/4805
        ANGLE_SKIP_TEST_IF(IsOpenGL() && IsIntel() && IsWindows());
    
        ANGLE_SKIP_TEST_IF(IsOpenGL() && IsAMD() && IsWindows());
    
        GLFramebuffer framebuffer;
        glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
    
        GLTexture texture;
        glBindTexture(GL_TEXTURE_2D, texture);
    
        const GLColor mip0[4] = {
            GLColor::red,
            GLColor::red,
            GLColor::red,
            GLColor::red,
        };
        const GLColor mip1[1] = {
            GLColor::green,
        };
    
        // Create a complete mip chain in mips 0 to 2
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 2, 2, 0, GL_RGBA, GL_UNSIGNED_BYTE, mip0);
        glTexImage2D(GL_TEXTURE_2D, 1, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, mip1);
    
        // Framebuffer can bind to mip 0, as the texture is mip-complete.
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);
        EXPECT_GL_FRAMEBUFFER_COMPLETE(GL_FRAMEBUFFER);
    
        // Copy to mip 1.  This shouldn't crash.
        glCopyTexImage2D(GL_TEXTURE_2D, 1, GL_RGBA, 0, 0, 2, 2, 0);
        EXPECT_GL_NO_ERROR();
    
        // The framebuffer is still complete.
        EXPECT_GL_FRAMEBUFFER_COMPLETE(GL_FRAMEBUFFER);
        // Make sure mip 0 is untouched.
        EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::red);
        EXPECT_PIXEL_COLOR_EQ(1, 1, GLColor::red);
    
        // When reading back the framebuffer, the attached texture is not rebased, so the framebuffer
        // still sees the 1x1 mip.  The copy is flushed to this mip, which is incorrect.
        // http://anglebug.com/4792.
        ANGLE_SKIP_TEST_IF(IsVulkan());
    
        // Bind framebuffer to mip 1 and make sure the copy was done.
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 1);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 1);
        EXPECT_GL_FRAMEBUFFER_COMPLETE(GL_FRAMEBUFFER);
    
        EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::red);
        EXPECT_PIXEL_COLOR_EQ(1, 1, GLColor::red);
    }
    
    void WebGLCompatibilityTest::drawBuffersFeedbackLoop(GLuint program,
                                                         const std::array<GLenum, 2> &drawBuffers,
                                                         GLenum expectedError)
    {
        glDrawBuffers(2, drawBuffers.data());
    
        // Make sure framebuffer is complete before feedback loop detection
        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
    
        drawQuad(program, "aPosition", 0.5f, 1.0f, true);
    
        // "Rendering to a texture where it samples from should geneates INVALID_OPERATION. Otherwise,
        // it should be NO_ERROR"
        EXPECT_GL_ERROR(expectedError);
    }
    
    // Tests invariance matching rules between built in varyings.
    // Based on WebGL test conformance/glsl/misc/shaders-with-invariance.html.
    TEST_P(WebGLCompatibilityTest, BuiltInInvariant)
    {
        constexpr char kVS[] =
            R"(varying vec4 v_varying;
    void main()
    {
        gl_PointSize = 1.0;
        gl_Position = v_varying;
    })";
        constexpr char kFSInvariantGlFragCoord[] =
            R"(invariant gl_FragCoord;
    void main()
    {
        gl_FragColor = gl_FragCoord;
    })";
        constexpr char kFSInvariantGlPointCoord[] =
            R"(invariant gl_PointCoord;
    void main()
    {
        gl_FragColor = vec4(gl_PointCoord, 0.0, 0.0);
    })";
    
        GLuint program = CompileProgram(kVS, kFSInvariantGlFragCoord);
        EXPECT_EQ(0u, program);
    
        program = CompileProgram(kVS, kFSInvariantGlPointCoord);
        EXPECT_EQ(0u, program);
    }
    
    // Tests global namespace conflicts between uniforms and attributes.
    // Based on WebGL test conformance/glsl/misc/shaders-with-name-conflicts.html.
    TEST_P(WebGLCompatibilityTest, GlobalNamesConflict)
    {
        constexpr char kVS[] =
            R"(attribute vec4 foo;
    void main()
    {
        gl_Position = foo;
    })";
        constexpr char kFS[] =
            R"(precision mediump float;
    uniform vec4 foo;
    void main()
    {
        gl_FragColor = foo;
    })";
    
        GLuint program = CompileProgram(kVS, kFS);
        EXPECT_EQ(0u, program);
    }
    
    // Test dimension and image size validation of compressed textures
    TEST_P(WebGLCompatibilityTest, CompressedTextureS3TC)
    {
        if (IsGLExtensionRequestable("GL_EXT_texture_compression_dxt1"))
        {
            glRequestExtensionANGLE("GL_EXT_texture_compression_dxt1");
        }
    
        ANGLE_SKIP_TEST_IF(!IsGLExtensionEnabled("GL_EXT_texture_compression_dxt1"));
    
        constexpr uint8_t CompressedImageDXT1[] = {0x00, 0xf8, 0x00, 0xf8, 0xaa, 0xaa, 0xaa, 0xaa};
    
        GLTexture texture;
        glBindTexture(GL_TEXTURE_2D, texture);
    
        // Regular case, verify that it works
        glCompressedTexImage2D(GL_TEXTURE_2D, 0, GL_COMPRESSED_RGB_S3TC_DXT1_EXT, 4, 4, 0,
                               sizeof(CompressedImageDXT1), CompressedImageDXT1);
        ASSERT_GL_NO_ERROR();
    
        // Test various dimensions that are not valid
        glCompressedTexImage2D(GL_TEXTURE_2D, 0, GL_COMPRESSED_RGB_S3TC_DXT1_EXT, 3, 4, 0,
                               sizeof(CompressedImageDXT1), CompressedImageDXT1);
        ASSERT_GL_ERROR(GL_INVALID_OPERATION);
    
        glCompressedTexImage2D(GL_TEXTURE_2D, 0, GL_COMPRESSED_RGB_S3TC_DXT1_EXT, 4, 3, 0,
                               sizeof(CompressedImageDXT1), CompressedImageDXT1);
        ASSERT_GL_ERROR(GL_INVALID_OPERATION);
    
        glCompressedTexImage2D(GL_TEXTURE_2D, 0, GL_COMPRESSED_RGB_S3TC_DXT1_EXT, 2, 2, 0,
                               sizeof(CompressedImageDXT1), CompressedImageDXT1);
        ASSERT_GL_ERROR(GL_INVALID_OPERATION);
    
        glCompressedTexImage2D(GL_TEXTURE_2D, 0, GL_COMPRESSED_RGB_S3TC_DXT1_EXT, 1, 1, 0,
                               sizeof(CompressedImageDXT1), CompressedImageDXT1);
        ASSERT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Test various image sizes that are not valid
        glCompressedTexImage2D(GL_TEXTURE_2D, 0, GL_COMPRESSED_RGB_S3TC_DXT1_EXT, 4, 4, 0,
                               sizeof(CompressedImageDXT1) - 1, CompressedImageDXT1);
        ASSERT_GL_ERROR(GL_INVALID_VALUE);
    
        glCompressedTexImage2D(GL_TEXTURE_2D, 0, GL_COMPRESSED_RGB_S3TC_DXT1_EXT, 4, 4, 0,
                               sizeof(CompressedImageDXT1) + 1, CompressedImageDXT1);
        ASSERT_GL_ERROR(GL_INVALID_VALUE);
    
        glCompressedTexImage2D(GL_TEXTURE_2D, 0, GL_COMPRESSED_RGB_S3TC_DXT1_EXT, 4, 4, 0, 0,
                               CompressedImageDXT1);
        ASSERT_GL_ERROR(GL_INVALID_VALUE);
    
        glCompressedTexImage2D(GL_TEXTURE_2D, 0, GL_COMPRESSED_RGB_S3TC_DXT1_EXT, 0, 0, 0,
                               sizeof(CompressedImageDXT1), CompressedImageDXT1);
        ASSERT_GL_ERROR(GL_INVALID_VALUE);
    
        // Fill a full mip chain and verify that it works
        glCompressedTexImage2D(GL_TEXTURE_2D, 0, GL_COMPRESSED_RGB_S3TC_DXT1_EXT, 4, 4, 0,
                               sizeof(CompressedImageDXT1), CompressedImageDXT1);
        glCompressedTexImage2D(GL_TEXTURE_2D, 1, GL_COMPRESSED_RGB_S3TC_DXT1_EXT, 2, 2, 0,
                               sizeof(CompressedImageDXT1), CompressedImageDXT1);
        glCompressedTexImage2D(GL_TEXTURE_2D, 2, GL_COMPRESSED_RGB_S3TC_DXT1_EXT, 1, 1, 0,
                               sizeof(CompressedImageDXT1), CompressedImageDXT1);
        ASSERT_GL_NO_ERROR();
    
        glCompressedTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 4, 4, GL_COMPRESSED_RGB_S3TC_DXT1_EXT,
                                  sizeof(CompressedImageDXT1), CompressedImageDXT1);
        ASSERT_GL_NO_ERROR();
    
        // Test that non-block size sub-uploads are not valid for the 0 mip
        glCompressedTexSubImage2D(GL_TEXTURE_2D, 0, 2, 2, 2, 2, GL_COMPRESSED_RGB_S3TC_DXT1_EXT,
                                  sizeof(CompressedImageDXT1), CompressedImageDXT1);
        ASSERT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Test that non-block size sub-uploads are valid for if they fill the whole mip
        glCompressedTexSubImage2D(GL_TEXTURE_2D, 1, 0, 0, 2, 2, GL_COMPRESSED_RGB_S3TC_DXT1_EXT,
                                  sizeof(CompressedImageDXT1), CompressedImageDXT1);
        glCompressedTexSubImage2D(GL_TEXTURE_2D, 2, 0, 0, 1, 1, GL_COMPRESSED_RGB_S3TC_DXT1_EXT,
                                  sizeof(CompressedImageDXT1), CompressedImageDXT1);
        ASSERT_GL_NO_ERROR();
    
        // Test that if the format miss-matches the texture, an error is generated
        glCompressedTexSubImage2D(GL_TEXTURE_2D, 0, 2, 2, 2, 2, GL_COMPRESSED_RGBA_S3TC_DXT1_EXT,
                                  sizeof(CompressedImageDXT1), CompressedImageDXT1);
        ASSERT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    TEST_P(WebGLCompatibilityTest, L32FTextures)
    {
        constexpr float textureData[]   = {15.1f, 0.0f, 0.0f, 0.0f};
        constexpr float readPixelData[] = {textureData[0], textureData[0], textureData[0], 1.0f};
    
        for (auto extension : FloatingPointTextureExtensions)
        {
            if (strlen(extension) > 0 && IsGLExtensionRequestable(extension))
            {
                glRequestExtensionANGLE(extension);
                ASSERT_GL_NO_ERROR();
            }
    
            // Unsized L 32F
            {
                bool texture = IsGLExtensionEnabled("GL_OES_texture_float");
                bool filter  = IsGLExtensionEnabled("GL_OES_texture_float_linear");
                bool render  = false;
                TestFloatTextureFormat(GL_LUMINANCE, GL_LUMINANCE, GL_FLOAT, texture, filter, render,
                                       textureData, readPixelData);
            }
    
            if (getClientMajorVersion() >= 3 || IsGLExtensionEnabled("GL_EXT_texture_storage"))
            {
                // Sized L 32F
                bool texture = IsGLExtensionEnabled("GL_OES_texture_float") &&
                               IsGLExtensionEnabled("GL_EXT_texture_storage");
                bool filter = IsGLExtensionEnabled("GL_OES_texture_float_linear");
                bool render = false;
                TestFloatTextureFormat(GL_LUMINANCE32F_EXT, GL_LUMINANCE, GL_FLOAT, texture, filter,
                                       render, textureData, readPixelData);
            }
        }
    }
    
    TEST_P(WebGLCompatibilityTest, A32FTextures)
    {
        constexpr float textureData[]   = {33.33f, 0.0f, 0.0f, 0.0f};
        constexpr float readPixelData[] = {0.0f, 0.0f, 0.0f, textureData[0]};
    
        for (auto extension : FloatingPointTextureExtensions)
        {
            if (strlen(extension) > 0 && IsGLExtensionRequestable(extension))
            {
                glRequestExtensionANGLE(extension);
                ASSERT_GL_NO_ERROR();
            }
    
            // Unsized A 32F
            {
                bool texture = IsGLExtensionEnabled("GL_OES_texture_float");
                bool filter  = IsGLExtensionEnabled("GL_OES_texture_float_linear");
                bool render  = false;
                TestFloatTextureFormat(GL_ALPHA, GL_ALPHA, GL_FLOAT, texture, filter, render,
                                       textureData, readPixelData);
            }
    
            if (getClientMajorVersion() >= 3 || IsGLExtensionEnabled("GL_EXT_texture_storage"))
            {
                // Sized A 32F
                bool texture = IsGLExtensionEnabled("GL_OES_texture_float") &&
                               IsGLExtensionEnabled("GL_EXT_texture_storage");
                bool filter = IsGLExtensionEnabled("GL_OES_texture_float_linear");
                bool render = false;
                TestFloatTextureFormat(GL_ALPHA32F_EXT, GL_ALPHA, GL_FLOAT, texture, filter, render,
                                       textureData, readPixelData);
            }
        }
    }
    
    TEST_P(WebGLCompatibilityTest, LA32FTextures)
    {
        constexpr float textureData[]   = {-0.21f, 15.1f, 0.0f, 0.0f};
        constexpr float readPixelData[] = {textureData[0], textureData[0], textureData[0],
                                           textureData[1]};
    
        for (auto extension : FloatingPointTextureExtensions)
        {
            if (strlen(extension) > 0 && IsGLExtensionRequestable(extension))
            {
                glRequestExtensionANGLE(extension);
                ASSERT_GL_NO_ERROR();
            }
    
            // Unsized LA 32F
            {
                bool texture = IsGLExtensionEnabled("GL_OES_texture_float");
                bool filter  = IsGLExtensionEnabled("GL_OES_texture_float_linear");
                bool render  = false;
                TestFloatTextureFormat(GL_LUMINANCE_ALPHA, GL_LUMINANCE_ALPHA, GL_FLOAT, texture,
                                       filter, render, textureData, readPixelData);
            }
    
            if (getClientMajorVersion() >= 3 || IsGLExtensionEnabled("GL_EXT_texture_storage"))
            {
                // Sized LA 32F
                bool texture = IsGLExtensionEnabled("GL_OES_texture_float") &&
                               IsGLExtensionEnabled("GL_EXT_texture_storage");
                bool filter = IsGLExtensionEnabled("GL_OES_texture_float_linear");
                bool render = false;
                TestFloatTextureFormat(GL_LUMINANCE_ALPHA32F_EXT, GL_LUMINANCE_ALPHA, GL_FLOAT, texture,
                                       filter, render, textureData, readPixelData);
            }
        }
    }
    
    TEST_P(WebGLCompatibilityTest, R32FTextures)
    {
        constexpr float data[] = {1000.0f, 0.0f, 0.0f, 1.0f};
    
        for (auto extension : FloatingPointTextureExtensions)
        {
            if (strlen(extension) > 0 && IsGLExtensionRequestable(extension))
            {
                glRequestExtensionANGLE(extension);
                ASSERT_GL_NO_ERROR();
            }
    
            // Unsized R 32F
            {
                bool texture = IsGLExtensionEnabled("GL_OES_texture_float") &&
                               IsGLExtensionEnabled("GL_EXT_texture_rg");
                bool filter = IsGLExtensionEnabled("GL_OES_texture_float_linear");
                bool render = IsGLExtensionEnabled("GL_EXT_color_buffer_float");
                TestFloatTextureFormat(GL_RED, GL_RED, GL_FLOAT, texture, filter, render, data, data);
            }
    
            if (getClientMajorVersion() >= 3 || IsGLExtensionEnabled("GL_EXT_texture_storage"))
            {
                // Sized R 32F
                bool texture =
                    (getClientMajorVersion() >= 3) || (IsGLExtensionEnabled("GL_OES_texture_float") &&
                                                       IsGLExtensionEnabled("GL_EXT_texture_rg") &&
                                                       IsGLExtensionEnabled("GL_EXT_texture_storage"));
                bool filter = IsGLExtensionEnabled("GL_OES_texture_float_linear");
                bool render = IsGLExtensionEnabled("GL_EXT_color_buffer_float");
                TestFloatTextureFormat(GL_R32F, GL_RED, GL_FLOAT, texture, filter, render, data, data);
            }
        }
    }
    
    TEST_P(WebGLCompatibilityTest, RG32FTextures)
    {
        constexpr float data[] = {1000.0f, -0.001f, 0.0f, 1.0f};
    
        for (auto extension : FloatingPointTextureExtensions)
        {
            if (strlen(extension) > 0 && IsGLExtensionRequestable(extension))
            {
                glRequestExtensionANGLE(extension);
                ASSERT_GL_NO_ERROR();
            }
    
            // Unsized RG 32F
            {
                bool texture = (IsGLExtensionEnabled("GL_OES_texture_float") &&
                                IsGLExtensionEnabled("GL_EXT_texture_rg"));
                bool filter  = IsGLExtensionEnabled("GL_OES_texture_float_linear");
                bool render  = IsGLExtensionEnabled("GL_EXT_color_buffer_float");
                TestFloatTextureFormat(GL_RG, GL_RG, GL_FLOAT, texture, filter, render, data, data);
            }
    
            if (getClientMajorVersion() >= 3 || IsGLExtensionEnabled("GL_EXT_texture_storage"))
            {
                // Sized RG 32F
                bool texture =
                    (getClientMajorVersion() >= 3) || (IsGLExtensionEnabled("GL_OES_texture_float") &&
                                                       IsGLExtensionEnabled("GL_EXT_texture_rg") &&
                                                       IsGLExtensionEnabled("GL_EXT_texture_storage"));
                bool filter = IsGLExtensionEnabled("GL_OES_texture_float_linear");
                bool render = IsGLExtensionEnabled("GL_EXT_color_buffer_float");
                TestFloatTextureFormat(GL_RG32F, GL_RG, GL_FLOAT, texture, filter, render, data, data);
            }
        }
    }
    
    TEST_P(WebGLCompatibilityTest, RGB32FTextures)
    {
        // TODO(syoussefi): Missing format support.  http://anglebug.com/2898
        ANGLE_SKIP_TEST_IF(IsVulkan());
    
        constexpr float data[] = {1000.0f, -500.0f, 10.0f, 1.0f};
    
        for (auto extension : FloatingPointTextureExtensions)
        {
            if (strlen(extension) > 0 && IsGLExtensionRequestable(extension))
            {
                glRequestExtensionANGLE(extension);
                ASSERT_GL_NO_ERROR();
            }
    
            // Unsized RGB 32F
            {
                bool texture = IsGLExtensionEnabled("GL_OES_texture_float");
                bool filter  = IsGLExtensionEnabled("GL_OES_texture_float_linear");
                bool render  = false;
                TestFloatTextureFormat(GL_RGB, GL_RGB, GL_FLOAT, texture, filter, render, data, data);
            }
    
            if (getClientMajorVersion() >= 3 || IsGLExtensionEnabled("GL_EXT_texture_storage"))
            {
                // Sized RGB 32F
                bool texture =
                    (getClientMajorVersion() >= 3) || (IsGLExtensionEnabled("GL_OES_texture_float") &&
                                                       IsGLExtensionEnabled("GL_EXT_texture_storage"));
                bool filter = IsGLExtensionEnabled("GL_OES_texture_float_linear");
                bool render = IsGLExtensionEnabled("GL_CHROMIUM_color_buffer_float_rgb");
                TestFloatTextureFormat(GL_RGB32F, GL_RGB, GL_FLOAT, texture, filter, render, data,
                                       data);
            }
        }
    }
    
    TEST_P(WebGLCompatibilityTest, RGBA32FTextures)
    {
        // TODO(syoussefi): Missing format support.  http://anglebug.com/2898
        ANGLE_SKIP_TEST_IF(IsVulkan());
    
        constexpr float data[] = {7000.0f, 100.0f, 33.0f, -1.0f};
    
        for (auto extension : FloatingPointTextureExtensions)
        {
            if (strlen(extension) > 0 && IsGLExtensionRequestable(extension))
            {
                glRequestExtensionANGLE(extension);
                ASSERT_GL_NO_ERROR();
            }
    
            // Unsized RGBA 32F
            {
                bool texture = IsGLExtensionEnabled("GL_OES_texture_float");
                bool filter  = IsGLExtensionEnabled("GL_OES_texture_float_linear");
                bool render  = false;
                TestFloatTextureFormat(GL_RGBA, GL_RGBA, GL_FLOAT, texture, filter, render, data, data);
            }
    
            if (getClientMajorVersion() >= 3 || IsGLExtensionEnabled("GL_EXT_texture_storage"))
            {
                // Sized RGBA 32F
                bool texture =
                    (getClientMajorVersion() >= 3) || (IsGLExtensionEnabled("GL_OES_texture_float") &&
                                                       IsGLExtensionEnabled("GL_EXT_texture_storage"));
                bool filter = IsGLExtensionEnabled("GL_OES_texture_float_linear");
                bool render = IsGLExtensionEnabled("GL_EXT_color_buffer_float") ||
                              IsGLExtensionEnabled("GL_CHROMIUM_color_buffer_float_rgba");
                TestFloatTextureFormat(GL_RGBA32F, GL_RGBA, GL_FLOAT, texture, filter, render, data,
                                       data);
            }
        }
    }
    
    // Test that has float color attachment caching works when color attachments change, by calling draw
    // command when blending is enabled
    TEST_P(WebGLCompatibilityTest, FramebufferFloatColorAttachment)
    {
        if (getClientMajorVersion() >= 3)
        {
            ANGLE_SKIP_TEST_IF(!EnsureGLExtensionEnabled("GL_EXT_color_buffer_float"));
        }
        else
        {
            ANGLE_SKIP_TEST_IF(!EnsureGLExtensionEnabled("GL_OES_texture_float"));
            ANGLE_SKIP_TEST_IF(!EnsureGLExtensionEnabled("GL_CHROMIUM_color_buffer_float_rgba"));
        }
    
        constexpr char kVS[] =
            R"(void main()
    {
        gl_Position = vec4(0, 0, 0, 1);
    })";
    
        constexpr char kFS[] =
            R"(void main()
    {
        gl_FragColor = vec4(0, 1, 0, 1);
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, kFS);
        glUseProgram(program);
    
        glEnable(GL_BLEND);
    
        GLTexture texture1;
        glBindTexture(GL_TEXTURE_2D, texture1);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        EXPECT_GL_NO_ERROR();
    
        GLTexture texture2;
        glBindTexture(GL_TEXTURE_2D, texture2);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, 1, 1, 0, GL_RGBA, GL_FLOAT, nullptr);
        EXPECT_GL_NO_ERROR();
    
        GLFramebuffer fbo1;
        glBindFramebuffer(GL_FRAMEBUFFER, fbo1);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture1, 0);
        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
    
        GLFramebuffer fbo2;
        glBindFramebuffer(GL_FRAMEBUFFER, fbo2);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture2, 0);
        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
        glDrawArrays(GL_POINTS, 0, 1);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glDisable(GL_BLEND);
        glDrawArrays(GL_POINTS, 0, 1);
        EXPECT_GL_NO_ERROR();
        glEnable(GL_BLEND);
    
        glBindFramebuffer(GL_FRAMEBUFFER, fbo1);
        glDrawArrays(GL_POINTS, 0, 1);
    
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, 0,
                               0);  // test unbind
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture2, 0);
        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
    
        glDrawArrays(GL_POINTS, 0, 1);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glDisable(GL_BLEND);
        glDrawArrays(GL_POINTS, 0, 1);
        EXPECT_GL_NO_ERROR();
        glEnable(GL_BLEND);
    
        glBindTexture(GL_TEXTURE_2D, texture2);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
    
        glDrawArrays(GL_POINTS, 0, 1);
        EXPECT_GL_NO_ERROR();
    }
    
    // Test that has float color attachment caching works with multiple color attachments bound to a
    // Framebuffer
    TEST_P(WebGLCompatibilityTest, FramebufferFloatColorAttachmentMRT)
    {
        bool isWebGL2 = getClientMajorVersion() >= 3;
        if (isWebGL2)
        {
            ANGLE_SKIP_TEST_IF(!EnsureGLExtensionEnabled("GL_EXT_color_buffer_float"));
    
            constexpr char kVS[] =
                R"(#version 300 es
    void main()
    {
        gl_Position = vec4(0, 0, 0, 1);
    })";
    
            constexpr char kFS[] =
                R"(#version 300 es
    precision lowp float;
    layout(location = 0) out vec4 o_color0;
    layout(location = 1) out vec4 o_color1;
    void main()
    {
        o_color0 = vec4(1, 0, 0, 1);
        o_color1 = vec4(0, 1, 0, 1);
    })";
    
            ANGLE_GL_PROGRAM(program, kVS, kFS);
            glUseProgram(program);
        }
        else
        {
            ANGLE_SKIP_TEST_IF(!EnsureGLExtensionEnabled("GL_OES_texture_float"));
            ANGLE_SKIP_TEST_IF(!EnsureGLExtensionEnabled("GL_CHROMIUM_color_buffer_float_rgba"));
            ANGLE_SKIP_TEST_IF(!EnsureGLExtensionEnabled("GL_EXT_draw_buffers"));
    
            constexpr char kVS[] =
                R"(void main()
    {
        gl_Position = vec4(0, 0, 0, 1);
    })";
    
            constexpr char kFS[] =
                R"(#extension GL_EXT_draw_buffers : require
    precision lowp float;
    void main()
    {
        gl_FragData[0] = vec4(1, 0, 0, 1);
        gl_FragData[1] = vec4(0, 1, 0, 1);
    })";
    
            ANGLE_GL_PROGRAM(program, kVS, kFS);
            glUseProgram(program);
        }
    
        glEnable(GL_BLEND);
    
        GLTexture texture1;
        glBindTexture(GL_TEXTURE_2D, texture1);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        EXPECT_GL_NO_ERROR();
    
        GLTexture texture2;
        glBindTexture(GL_TEXTURE_2D, texture2);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        EXPECT_GL_NO_ERROR();
    
        GLTexture textureF1;
        glBindTexture(GL_TEXTURE_2D, textureF1);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, 1, 1, 0, GL_RGBA, GL_FLOAT, nullptr);
        EXPECT_GL_NO_ERROR();
    
        GLTexture textureF2;
        glBindTexture(GL_TEXTURE_2D, textureF2);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, 1, 1, 0, GL_RGBA, GL_FLOAT, nullptr);
        EXPECT_GL_NO_ERROR();
    
        GLFramebuffer fbo;
        glBindFramebuffer(GL_FRAMEBUFFER, fbo);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture1, 0);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, texture2, 0);
        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
    
        GLenum drawbuffers[] = {GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1};
        if (isWebGL2)
        {
            glDrawBuffers(2, drawbuffers);
        }
        else
        {
            glDrawBuffersEXT(2, drawbuffers);
        }
    
        glDrawArrays(GL_POINTS, 0, 1);
        EXPECT_GL_NO_ERROR();
    
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textureF1, 0);
        glDrawArrays(GL_POINTS, 0, 1);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, textureF2, 0);
        glDrawArrays(GL_POINTS, 0, 1);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture1, 0);
        glDrawArrays(GL_POINTS, 0, 1);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        if (isWebGL2)
        {
            // WebGL 1 will report a FRAMEBUFFER_UNSUPPORTED for one unsigned_byte and one float
            // attachment bound to one FBO at the same time
            glDrawBuffers(1, drawbuffers);
            ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
            glDrawArrays(GL_POINTS, 0, 1);
            EXPECT_GL_NO_ERROR();
            glDrawBuffers(2, drawbuffers);
        }
    
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, texture2, 0);
        glDrawArrays(GL_POINTS, 0, 1);
        EXPECT_GL_NO_ERROR();
    }
    
    static void TestBlendColor(const bool shouldClamp)
    {
        auto expected = GLColor32F(5, 0, 0, 0);
        glBlendColor(expected.R, expected.G, expected.B, expected.A);
        if (shouldClamp)
        {
            expected.R = 1;
        }
    
        float arr[4] = {};
        glGetFloatv(GL_BLEND_COLOR, arr);
        const auto actual = GLColor32F(arr[0], arr[1], arr[2], arr[3]);
        EXPECT_COLOR_NEAR(expected, actual, 0.001);
    }
    
    // Test if blending of float32 color attachment generates GL_INVALID_OPERATION when
    // GL_EXT_float_blend is not enabled
    TEST_P(WebGLCompatibilityTest, FloatBlend)
    {
        if (getClientMajorVersion() >= 3)
        {
            TestBlendColor(false);
            ANGLE_SKIP_TEST_IF(!EnsureGLExtensionEnabled("GL_EXT_color_buffer_float"));
        }
        else
        {
            TestBlendColor(true);
            ANGLE_SKIP_TEST_IF(!EnsureGLExtensionEnabled("GL_OES_texture_float"));
            ANGLE_SKIP_TEST_IF(!EnsureGLExtensionEnabled("GL_CHROMIUM_color_buffer_float_rgba"));
        }
    
        TestBlendColor(false);
    
        // -
    
        TestExtFloatBlend(GL_RGBA32F, GL_FLOAT, false);
    
        ANGLE_SKIP_TEST_IF(!EnsureGLExtensionEnabled("GL_EXT_float_blend"));
        ASSERT_GL_NO_ERROR();
    
        // D3D9 supports float rendering explicitly, supports blending operations in practice,
        // but cannot support float blend colors.
        ANGLE_SKIP_TEST_IF(IsD3D9());
    
        TestExtFloatBlend(GL_RGBA32F, GL_FLOAT, true);
    }
    
    // Test the blending of float16 color attachments
    TEST_P(WebGLCompatibilityTest, HalfFloatBlend)
    {
        GLenum internalFormat = GL_RGBA16F;
        GLenum type           = GL_FLOAT;
        if (getClientMajorVersion() >= 3)
        {
            TestBlendColor(false);
            ANGLE_SKIP_TEST_IF(!EnsureGLExtensionEnabled("GL_EXT_color_buffer_float"));
        }
        else
        {
            TestBlendColor(true);
            ANGLE_SKIP_TEST_IF(!EnsureGLExtensionEnabled("GL_OES_texture_half_float"));
            ANGLE_SKIP_TEST_IF(!EnsureGLExtensionEnabled("GL_EXT_color_buffer_half_float"));
            internalFormat = GL_RGBA;
            type           = GL_HALF_FLOAT_OES;
        }
    
        TestBlendColor(false);
    
        // -
    
        // D3D9 supports float rendering explicitly, supports blending operations in practice,
        // but cannot support float blend colors.
        ANGLE_SKIP_TEST_IF(IsD3D9());
    
        TestExtFloatBlend(internalFormat, type, true);
    }
    
    TEST_P(WebGLCompatibilityTest, R16FTextures)
    {
        constexpr float readPixelsData[] = {-5000.0f, 0.0f, 0.0f, 1.0f};
        const GLushort textureData[]     = {
            gl::float32ToFloat16(readPixelsData[0]), gl::float32ToFloat16(readPixelsData[1]),
            gl::float32ToFloat16(readPixelsData[2]), gl::float32ToFloat16(readPixelsData[3])};
    
        for (auto extension : FloatingPointTextureExtensions)
        {
            if (strlen(extension) > 0 && IsGLExtensionRequestable(extension))
            {
                glRequestExtensionANGLE(extension);
                ASSERT_GL_NO_ERROR();
            }
    
            // Unsized R 16F (OES)
            {
                bool texture = IsGLExtensionEnabled("GL_OES_texture_half_float") &&
                               IsGLExtensionEnabled("GL_EXT_texture_rg");
                bool filter = IsGLExtensionEnabled("GL_OES_texture_half_float_linear");
                bool render = false;
                TestFloatTextureFormat(GL_RED, GL_RED, GL_HALF_FLOAT_OES, texture, filter, render,
                                       textureData, readPixelsData);
            }
    
            // Unsized R 16F
            {
                bool texture = false;
                bool filter  = false;
                bool render  = false;
                TestFloatTextureFormat(GL_RED, GL_RED, GL_HALF_FLOAT, texture, filter, render,
                                       textureData, readPixelsData);
            }
    
            if (getClientMajorVersion() >= 3)
            {
                // Sized R 16F
                bool texture = true;
                bool filter  = true;
                bool render  = IsGLExtensionEnabled("GL_EXT_color_buffer_float") ||
                              IsGLExtensionEnabled("GL_EXT_color_buffer_half_float");
                TestFloatTextureFormat(GL_R16F, GL_RED, GL_HALF_FLOAT, texture, filter, render,
                                       textureData, readPixelsData);
            }
            else if (IsGLExtensionEnabled("GL_EXT_texture_storage"))
            {
                // Sized R 16F (OES)
                bool texture = IsGLExtensionEnabled("GL_OES_texture_half_float") &&
                               IsGLExtensionEnabled("GL_EXT_texture_rg");
                bool filter = IsGLExtensionEnabled("GL_OES_texture_half_float_linear");
                bool render = IsGLExtensionEnabled("GL_EXT_color_buffer_half_float");
                TestFloatTextureFormat(GL_R16F, GL_RED, GL_HALF_FLOAT_OES, texture, filter, render,
                                       textureData, readPixelsData);
            }
        }
    }
    
    TEST_P(WebGLCompatibilityTest, RG16FTextures)
    {
        constexpr float readPixelsData[] = {7108.0f, -10.0f, 0.0f, 1.0f};
        const GLushort textureData[]     = {
            gl::float32ToFloat16(readPixelsData[0]), gl::float32ToFloat16(readPixelsData[1]),
            gl::float32ToFloat16(readPixelsData[2]), gl::float32ToFloat16(readPixelsData[3])};
    
        for (auto extension : FloatingPointTextureExtensions)
        {
            if (strlen(extension) > 0 && IsGLExtensionRequestable(extension))
            {
                glRequestExtensionANGLE(extension);
                ASSERT_GL_NO_ERROR();
            }
    
            // Unsized RG 16F (OES)
            {
                bool texture = IsGLExtensionEnabled("GL_OES_texture_half_float") &&
                               IsGLExtensionEnabled("GL_EXT_texture_rg");
                bool filter = IsGLExtensionEnabled("GL_OES_texture_half_float_linear");
                bool render = false;
                TestFloatTextureFormat(GL_RG, GL_RG, GL_HALF_FLOAT_OES, texture, filter, render,
                                       textureData, readPixelsData);
            }
    
            // Unsized RG 16F
            {
                bool texture = false;
                bool filter  = false;
                bool render  = false;
                TestFloatTextureFormat(GL_RG, GL_RG, GL_HALF_FLOAT, texture, filter, render,
                                       textureData, readPixelsData);
            }
    
            if (getClientMajorVersion() >= 3)
            {
                // Sized RG 16F
                bool texture = true;
                bool filter  = true;
                bool render  = IsGLExtensionEnabled("GL_EXT_color_buffer_float") ||
                              IsGLExtensionEnabled("GL_EXT_color_buffer_half_float");
                TestFloatTextureFormat(GL_RG16F, GL_RG, GL_HALF_FLOAT, texture, filter, render,
                                       textureData, readPixelsData);
            }
            else if (IsGLExtensionEnabled("GL_EXT_texture_storage"))
            {
                // Sized RG 16F (OES)
                bool texture = IsGLExtensionEnabled("GL_OES_texture_half_float") &&
                               IsGLExtensionEnabled("GL_EXT_texture_rg");
                bool filter = IsGLExtensionEnabled("GL_OES_texture_half_float_linear");
                bool render = IsGLExtensionEnabled("GL_EXT_color_buffer_half_float");
                TestFloatTextureFormat(GL_RG16F, GL_RG, GL_HALF_FLOAT_OES, texture, filter, render,
                                       textureData, readPixelsData);
            }
        }
    }
    
    TEST_P(WebGLCompatibilityTest, RGB16FTextures)
    {
        // TODO(syoussefi): Missing format support.  http://anglebug.com/2898
        ANGLE_SKIP_TEST_IF(IsVulkan());
    
        ANGLE_SKIP_TEST_IF(IsOzone() && IsIntel());
    
        constexpr float readPixelsData[] = {7000.0f, 100.0f, 33.0f, 1.0f};
        const GLushort textureData[]     = {
            gl::float32ToFloat16(readPixelsData[0]), gl::float32ToFloat16(readPixelsData[1]),
            gl::float32ToFloat16(readPixelsData[2]), gl::float32ToFloat16(readPixelsData[3])};
    
        for (auto extension : FloatingPointTextureExtensions)
        {
            if (strlen(extension) > 0 && IsGLExtensionRequestable(extension))
            {
                glRequestExtensionANGLE(extension);
                ASSERT_GL_NO_ERROR();
            }
    
            // Unsized RGB 16F (OES)
            {
                bool texture = IsGLExtensionEnabled("GL_OES_texture_half_float");
                bool filter  = IsGLExtensionEnabled("GL_OES_texture_half_float_linear");
                // WebGL says that Unsized RGB 16F (OES) can be renderable with
                // GL_EXT_color_buffer_half_float.
                bool render = IsGLExtensionEnabled("GL_EXT_color_buffer_half_float");
                TestFloatTextureFormat(GL_RGB, GL_RGB, GL_HALF_FLOAT_OES, texture, filter, render,
                                       textureData, readPixelsData);
            }
    
            // Unsized RGB 16F
            {
                bool texture = false;
                bool filter  = false;
                bool render  = false;
                TestFloatTextureFormat(GL_RGB, GL_RGB, GL_HALF_FLOAT, texture, filter, render,
                                       textureData, readPixelsData);
            }
    
            if (getClientMajorVersion() >= 3)
            {
                // Sized RGB 16F
                bool texture = true;
                bool filter  = true;
                // Renderability of RGB is forbidden by GL_EXT_color_buffer_half_float in WebGL 2.
                bool render = false;
                TestFloatTextureFormat(GL_RGB16F, GL_RGB, GL_HALF_FLOAT, texture, filter, render,
                                       textureData, readPixelsData);
            }
            else if (IsGLExtensionEnabled("GL_EXT_texture_storage"))
            {
                // Sized RGB 16F (OES)
                bool texture = IsGLExtensionEnabled("GL_OES_texture_half_float");
                bool filter  = IsGLExtensionEnabled("GL_OES_texture_half_float_linear");
                bool render  = IsGLExtensionEnabled("GL_EXT_color_buffer_half_float");
                TestFloatTextureFormat(GL_RGB16F, GL_RGB, GL_HALF_FLOAT_OES, texture, filter, render,
                                       textureData, readPixelsData);
            }
        }
    }
    
    TEST_P(WebGLCompatibilityTest, RGBA16FTextures)
    {
        ANGLE_SKIP_TEST_IF(IsOzone() && IsIntel());
    
        constexpr float readPixelsData[] = {7000.0f, 100.0f, 33.0f, -1.0f};
        const GLushort textureData[]     = {
            gl::float32ToFloat16(readPixelsData[0]), gl::float32ToFloat16(readPixelsData[1]),
            gl::float32ToFloat16(readPixelsData[2]), gl::float32ToFloat16(readPixelsData[3])};
    
        for (auto extension : FloatingPointTextureExtensions)
        {
            if (strlen(extension) > 0 && IsGLExtensionRequestable(extension))
            {
                glRequestExtensionANGLE(extension);
                ASSERT_GL_NO_ERROR();
            }
    
            // Unsized RGBA 16F (OES)
            {
                bool texture = IsGLExtensionEnabled("GL_OES_texture_half_float");
                bool filter  = IsGLExtensionEnabled("GL_OES_texture_half_float_linear");
                bool render  = IsGLExtensionEnabled("GL_EXT_color_buffer_half_float");
                TestFloatTextureFormat(GL_RGBA, GL_RGBA, GL_HALF_FLOAT_OES, texture, filter, render,
                                       textureData, readPixelsData);
            }
    
            // Unsized RGBA 16F
            {
                bool texture = false;
                bool filter  = false;
                bool render  = false;
                TestFloatTextureFormat(GL_RGBA, GL_RGBA, GL_HALF_FLOAT, texture, filter, render,
                                       textureData, readPixelsData);
            }
    
            if (getClientMajorVersion() >= 3)
            {
                // Sized RGBA 16F
                bool texture = true;
                bool filter  = true;
                bool render  = IsGLExtensionEnabled("GL_EXT_color_buffer_float") ||
                              IsGLExtensionEnabled("GL_EXT_color_buffer_half_float");
                TestFloatTextureFormat(GL_RGBA16F, GL_RGBA, GL_HALF_FLOAT, texture, filter, render,
                                       textureData, readPixelsData);
            }
            else if (IsGLExtensionEnabled("GL_EXT_texture_storage"))
            {
                // Sized RGBA 16F (OES)
                bool texture = IsGLExtensionEnabled("GL_OES_texture_half_float");
                bool filter  = IsGLExtensionEnabled("GL_OES_texture_half_float_linear");
                bool render  = IsGLExtensionEnabled("GL_EXT_color_buffer_half_float");
                TestFloatTextureFormat(GL_RGBA16F, GL_RGBA, GL_HALF_FLOAT_OES, texture, filter, render,
                                       textureData, readPixelsData);
            }
        }
    }
    
    // Test that when GL_CHROMIUM_color_buffer_float_rgb[a] is enabled, sized GL_RGB[A]_32F formats are
    // accepted by glTexImage2D
    TEST_P(WebGLCompatibilityTest, SizedRGBA32FFormats)
    {
        // Test skipped because it is only valid for WebGL1 contexts.
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() != 2);
    
        ANGLE_SKIP_TEST_IF(!IsGLExtensionRequestable("GL_OES_texture_float"));
    
        glRequestExtensionANGLE("GL_OES_texture_float");
        ASSERT_GL_NO_ERROR();
    
        GLTexture texture;
        glBindTexture(GL_TEXTURE_2D, texture);
    
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, 1, 1, 0, GL_RGBA, GL_FLOAT, nullptr);
        // dEQP implicitly defines error code ordering
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F, 1, 1, 0, GL_RGB, GL_FLOAT, nullptr);
        // dEQP implicitly defines error code ordering
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        if (IsGLExtensionRequestable("GL_CHROMIUM_color_buffer_float_rgba"))
        {
            glRequestExtensionANGLE("GL_CHROMIUM_color_buffer_float_rgba");
            ASSERT_GL_NO_ERROR();
    
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, 1, 1, 0, GL_RGBA, GL_FLOAT, nullptr);
            EXPECT_GL_NO_ERROR();
        }
    
        if (IsGLExtensionRequestable("GL_CHROMIUM_color_buffer_float_rgb"))
        {
            glRequestExtensionANGLE("GL_CHROMIUM_color_buffer_float_rgb");
            ASSERT_GL_NO_ERROR();
    
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F, 1, 1, 0, GL_RGB, GL_FLOAT, nullptr);
            EXPECT_GL_NO_ERROR();
        }
    }
    
    // Verify GL_DEPTH_STENCIL_ATTACHMENT is a valid attachment point.
    TEST_P(WebGLCompatibilityTest, DepthStencilAttachment)
    {
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() > 2);
    
        // Test that attaching a bound texture succeeds.
        GLTexture texture;
        glBindTexture(GL_TEXTURE_2D, texture);
    
        GLFramebuffer fbo;
        glBindFramebuffer(GL_FRAMEBUFFER, fbo);
    
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_TEXTURE_2D, texture, 0);
    
        GLint attachmentType = 0;
        glGetFramebufferAttachmentParameteriv(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT,
                                              GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE, &attachmentType);
        EXPECT_GL_NO_ERROR();
        EXPECT_GLENUM_EQ(GL_TEXTURE, attachmentType);
    
        // Test when if no attach object at the named attachment point and pname is not OBJECT_TYPE.
        GLFramebuffer fbo2;
        glBindFramebuffer(GL_FRAMEBUFFER, fbo2);
    
        glGetFramebufferAttachmentParameteriv(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT,
                                              GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME, &attachmentType);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    }
    
    // Verify framebuffer attachments return expected types when in an inconsistant state.
    TEST_P(WebGLCompatibilityTest, FramebufferAttachmentConsistancy)
    {
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() > 2);
    
        GLFramebuffer fbo;
        glBindFramebuffer(GL_FRAMEBUFFER, fbo);
    
        GLRenderbuffer rb1;
        glBindRenderbuffer(GL_RENDERBUFFER, rb1);
    
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, rb1);
    
        GLint attachmentType = 0;
        glGetFramebufferAttachmentParameteriv(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT,
                                              GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE, &attachmentType);
    
        EXPECT_GL_NO_ERROR();
        EXPECT_GLENUM_EQ(GL_RENDERBUFFER, attachmentType);
    
        GLRenderbuffer rb2;
        glBindRenderbuffer(GL_RENDERBUFFER, rb2);
    
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, rb2);
    
        glGetFramebufferAttachmentParameteriv(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT,
                                              GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE, &attachmentType);
    
        EXPECT_GL_NO_ERROR();
        EXPECT_GLENUM_EQ(GL_RENDERBUFFER, attachmentType);
    
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, rb2);
    
        glGetFramebufferAttachmentParameteriv(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
                                              GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE, &attachmentType);
    
        EXPECT_GL_NO_ERROR();
        EXPECT_GLENUM_EQ(GL_RENDERBUFFER, attachmentType);
    
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, rb2);
    
        glGetFramebufferAttachmentParameteriv(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
                                              GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE, &attachmentType);
    
        EXPECT_GL_NO_ERROR();
        EXPECT_GLENUM_EQ(GL_RENDERBUFFER, attachmentType);
    }
    
    // This tests that rendering feedback loops works as expected with WebGL 2.
    // Based on WebGL test conformance2/rendering/rendering-sampling-feedback-loop.html
    TEST_P(WebGL2CompatibilityTest, RenderingFeedbackLoopWithDrawBuffers)
    {
        constexpr char kVS[] =
            R"(#version 300 es
    in vec4 aPosition;
    out vec2 texCoord;
    void main() {
        gl_Position = aPosition;
        texCoord = (aPosition.xy * 0.5) + 0.5;
    })";
    
        constexpr char kFS[] =
            R"(#version 300 es
    precision mediump float;
    uniform sampler2D tex;
    in vec2 texCoord;
    out vec4 oColor;
    void main() {
        oColor = texture(tex, texCoord);
    })";
    
        GLsizei width  = 8;
        GLsizei height = 8;
    
        GLint maxDrawBuffers = 0;
        glGetIntegerv(GL_MAX_DRAW_BUFFERS, &maxDrawBuffers);
        // ES3 requires a minimum value of 4 for MAX_DRAW_BUFFERS.
        ASSERT_GE(maxDrawBuffers, 2);
    
        ANGLE_GL_PROGRAM(program, kVS, kFS);
        glUseProgram(program.get());
        glViewport(0, 0, width, height);
    
        GLTexture tex0;
        GLTexture tex1;
        GLFramebuffer fbo;
        FillTexture2D(tex0.get(), width, height, GLColor::red, 0, GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE);
        FillTexture2D(tex1.get(), width, height, GLColor::green, 0, GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE);
        ASSERT_GL_NO_ERROR();
    
        glBindTexture(GL_TEXTURE_2D, tex1.get());
        GLint texLoc = glGetUniformLocation(program.get(), "tex");
        ASSERT_NE(-1, texLoc);
        glUniform1i(texLoc, 0);
    
        // The sampling texture is bound to COLOR_ATTACHMENT1 during resource allocation
        glBindFramebuffer(GL_FRAMEBUFFER, fbo.get());
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, tex0.get(), 0);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, tex1.get(), 0);
        ASSERT_GL_NO_ERROR();
    
        drawBuffersFeedbackLoop(program.get(), {{GL_NONE, GL_COLOR_ATTACHMENT1}}, GL_INVALID_OPERATION);
        drawBuffersFeedbackLoop(program.get(), {{GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1}},
                                GL_INVALID_OPERATION);
        // A feedback loop is formed regardless of drawBuffers settings.
        drawBuffersFeedbackLoop(program.get(), {{GL_COLOR_ATTACHMENT0, GL_NONE}}, GL_INVALID_OPERATION);
    }
    
    // This test covers detection of rendering feedback loops between the FBO and a depth Texture.
    // Based on WebGL test conformance2/rendering/depth-stencil-feedback-loop.html
    TEST_P(WebGL2CompatibilityTest, RenderingFeedbackLoopWithDepthStencil)
    {
        constexpr char kVS[] =
            R"(#version 300 es
    in vec4 aPosition;
    out vec2 texCoord;
    void main() {
        gl_Position = aPosition;
        texCoord = (aPosition.xy * 0.5) + 0.5;
    })";
    
        constexpr char kFS[] =
            R"(#version 300 es
    precision mediump float;
    uniform sampler2D tex;
    in vec2 texCoord;
    out vec4 oColor;
    void main() {
        oColor = texture(tex, texCoord);
    })";
    
        GLsizei width  = 8;
        GLsizei height = 8;
    
        ANGLE_GL_PROGRAM(program, kVS, kFS);
        glUseProgram(program.get());
    
        glViewport(0, 0, width, height);
    
        GLint texLoc = glGetUniformLocation(program.get(), "tex");
        glUniform1i(texLoc, 0);
    
        // Create textures and allocate storage
        GLTexture tex0;
        GLTexture tex1;
        GLTexture tex2;
        FillTexture2D(tex0.get(), width, height, GLColor::black, 0, GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE);
        FillTexture2D(tex1.get(), width, height, 0x80, 0, GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT,
                      GL_UNSIGNED_INT);
        FillTexture2D(tex2.get(), width, height, 0x40, 0, GL_DEPTH24_STENCIL8, GL_DEPTH_STENCIL,
                      GL_UNSIGNED_INT_24_8);
        ASSERT_GL_NO_ERROR();
    
        GLFramebuffer fbo;
        glBindFramebuffer(GL_FRAMEBUFFER, fbo.get());
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, tex0.get(), 0);
    
        // Test rendering and sampling feedback loop for depth buffer
        glBindTexture(GL_TEXTURE_2D, tex1.get());
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, tex1.get(), 0);
        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
    
        // The same image is used as depth buffer during rendering.
        glEnable(GL_DEPTH_TEST);
        drawQuad(program.get(), "aPosition", 0.5f, 1.0f, true);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION) << "Same image as depth buffer should fail";
    
        // The same image is used as depth buffer. But depth mask is false.
        // This is now considered a feedback loop and should generate an error. http://crbug.com/763695
        glDepthMask(GL_FALSE);
        drawQuad(program.get(), "aPosition", 0.5f, 1.0f, true);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION) << "Depth writes disabled should still fail";
    
        // The same image is used as depth buffer. But depth test is not enabled during rendering.
        // This is now considered a feedback loop and should generate an error. http://crbug.com/763695
        glDepthMask(GL_TRUE);
        glDisable(GL_DEPTH_TEST);
        drawQuad(program.get(), "aPosition", 0.5f, 1.0f, true);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION) << "Depth read disabled should still fail";
    
        // Test rendering and sampling feedback loop for stencil buffer
        glBindTexture(GL_TEXTURE_2D, tex2.get());
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, 0, 0);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_TEXTURE_2D, tex2.get(), 0);
        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
        constexpr GLint stencilClearValue = 0x40;
        glClearBufferiv(GL_STENCIL, 0, &stencilClearValue);
    
        // The same image is used as stencil buffer during rendering.
        glEnable(GL_STENCIL_TEST);
        drawQuad(program.get(), "aPosition", 0.5f, 1.0f, true);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION) << "Same image as stencil buffer should fail";
    
        // The same image is used as stencil buffer. But stencil mask is zero.
        // This is now considered a feedback loop and should generate an error. http://crbug.com/763695
        glStencilMask(0x0);
        drawQuad(program.get(), "aPosition", 0.5f, 1.0f, true);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION) << "Stencil mask zero should still fail";
    
        // The same image is used as stencil buffer. But stencil test is not enabled during rendering.
        // This is now considered a feedback loop and should generate an error. http://crbug.com/763695
        glStencilMask(0xffff);
        glDisable(GL_STENCIL_TEST);
        drawQuad(program.get(), "aPosition", 0.5f, 1.0f, true);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION) << "Stencil test disabled should still fail";
    }
    
    // The source and the target for CopyTexSubImage3D are the same 3D texture.
    // But the level of the 3D texture != the level of the read attachment.
    TEST_P(WebGL2CompatibilityTest, NoTextureCopyingFeedbackLoopBetween3DLevels)
    {
        // http://anglebug.com/4092
        ANGLE_SKIP_TEST_IF(IsVulkan());
        GLTexture texture;
        GLFramebuffer framebuffer;
    
        glBindTexture(GL_TEXTURE_3D, texture.get());
        glBindFramebuffer(GL_FRAMEBUFFER, framebuffer.get());
    
        glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA8, 2, 2, 2, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        glTexImage3D(GL_TEXTURE_3D, 1, GL_RGBA8, 2, 2, 2, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        glFramebufferTextureLayer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, texture.get(), 0, 0);
        ASSERT_GL_NO_ERROR();
    
        glCopyTexSubImage3D(GL_TEXTURE_3D, 1, 0, 0, 0, 0, 0, 2, 2);
        EXPECT_GL_NO_ERROR();
    }
    
    // The source and the target for CopyTexSubImage3D are the same 3D texture.
    // But the zoffset of the 3D texture != the layer of the read attachment.
    TEST_P(WebGL2CompatibilityTest, NoTextureCopyingFeedbackLoopBetween3DLayers)
    {
        // http://anglebug.com/4092
        ANGLE_SKIP_TEST_IF(IsVulkan());
        GLTexture texture;
        GLFramebuffer framebuffer;
    
        glBindTexture(GL_TEXTURE_3D, texture.get());
        glBindFramebuffer(GL_FRAMEBUFFER, framebuffer.get());
    
        glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA8, 2, 2, 2, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        glFramebufferTextureLayer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, texture.get(), 0, 1);
        ASSERT_GL_NO_ERROR();
    
        glCopyTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, 0, 0, 0, 2, 2);
        EXPECT_GL_NO_ERROR();
    }
    
    // The source and the target for CopyTexSubImage3D are the same 3D texture.
    // And the level / zoffset of the 3D texture is equal to the level / layer of the read attachment.
    TEST_P(WebGL2CompatibilityTest, TextureCopyingFeedbackLoop3D)
    {
        GLTexture texture;
        GLFramebuffer framebuffer;
    
        glBindTexture(GL_TEXTURE_3D, texture.get());
        glBindFramebuffer(GL_FRAMEBUFFER, framebuffer.get());
    
        glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA8, 4, 4, 4, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        glTexImage3D(GL_TEXTURE_3D, 1, GL_RGBA8, 2, 2, 2, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        glTexImage3D(GL_TEXTURE_3D, 2, GL_RGBA8, 1, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        glFramebufferTextureLayer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, texture.get(), 1, 0);
        ASSERT_GL_NO_ERROR();
    
        glCopyTexSubImage3D(GL_TEXTURE_3D, 1, 0, 0, 0, 0, 0, 2, 2);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // Verify that errors are generated when there isn't a defined conversion between the clear type and
    // the buffer type.
    TEST_P(WebGL2CompatibilityTest, ClearBufferTypeCompatibity)
    {
        // Test skipped for D3D11 because it generates D3D11 runtime warnings.
        ANGLE_SKIP_TEST_IF(IsD3D11());
    
        constexpr float clearFloat[]       = {0.0f, 0.0f, 0.0f, 0.0f};
        constexpr int clearInt[]           = {0, 0, 0, 0};
        constexpr unsigned int clearUint[] = {0, 0, 0, 0};
    
        GLTexture texture;
        GLFramebuffer framebuffer;
    
        glBindTexture(GL_TEXTURE_2D, texture.get());
        glBindFramebuffer(GL_FRAMEBUFFER, framebuffer.get());
    
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture.get(), 0);
        ASSERT_GL_NO_ERROR();
    
        // Unsigned integer buffer
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32UI, 1, 1, 0, GL_RGBA_INTEGER, GL_UNSIGNED_INT, nullptr);
        ASSERT_GL_NO_ERROR();
    
        glClearBufferfv(GL_COLOR, 0, clearFloat);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glClearBufferiv(GL_COLOR, 0, clearInt);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glClearBufferuiv(GL_COLOR, 0, clearUint);
        EXPECT_GL_NO_ERROR();
    
        glClear(GL_COLOR_BUFFER_BIT);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Integer buffer
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32I, 1, 1, 0, GL_RGBA_INTEGER, GL_INT, nullptr);
        ASSERT_GL_NO_ERROR();
    
        glClearBufferfv(GL_COLOR, 0, clearFloat);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glClearBufferiv(GL_COLOR, 0, clearInt);
        EXPECT_GL_NO_ERROR();
    
        glClearBufferuiv(GL_COLOR, 0, clearUint);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glClear(GL_COLOR_BUFFER_BIT);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Float buffer
        if (IsGLExtensionRequestable("GL_EXT_color_buffer_float"))
        {
            glRequestExtensionANGLE("GL_EXT_color_buffer_float");
        }
    
        if (IsGLExtensionEnabled("GL_EXT_color_buffer_float"))
        {
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, 1, 1, 0, GL_RGBA, GL_FLOAT, nullptr);
            ASSERT_GL_NO_ERROR();
    
            glClearBufferfv(GL_COLOR, 0, clearFloat);
            EXPECT_GL_NO_ERROR();
    
            glClearBufferiv(GL_COLOR, 0, clearInt);
            EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
            glClearBufferuiv(GL_COLOR, 0, clearUint);
            EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
            glClear(GL_COLOR_BUFFER_BIT);
            EXPECT_GL_NO_ERROR();
        }
    
        // Normalized uint buffer
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        ASSERT_GL_NO_ERROR();
    
        glClearBufferfv(GL_COLOR, 0, clearFloat);
        EXPECT_GL_NO_ERROR();
    
        glClearBufferiv(GL_COLOR, 0, clearInt);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glClearBufferuiv(GL_COLOR, 0, clearUint);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glClear(GL_COLOR_BUFFER_BIT);
        EXPECT_GL_NO_ERROR();
    }
    
    // Test the interaction of WebGL compatibility clears with default framebuffers
    TEST_P(WebGL2CompatibilityTest, ClearBufferDefaultFramebuffer)
    {
        constexpr float clearFloat[]       = {0.0f, 0.0f, 0.0f, 0.0f};
        constexpr int clearInt[]           = {0, 0, 0, 0};
        constexpr unsigned int clearUint[] = {0, 0, 0, 0};
    
        // glClear works as usual, this is also a regression test for a bug where we
        // iterated on maxDrawBuffers for default framebuffers, triggering an assert
        glClear(GL_COLOR_BUFFER_BIT);
        EXPECT_GL_NO_ERROR();
    
        // Default framebuffers are normalized uints, so only glClearBufferfv works.
        glClearBufferfv(GL_COLOR, 0, clearFloat);
        EXPECT_GL_NO_ERROR();
    
        glClearBufferiv(GL_COLOR, 0, clearInt);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        glClearBufferuiv(GL_COLOR, 0, clearUint);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // Verify that errors are generate when trying to blit from an image to itself
    TEST_P(WebGL2CompatibilityTest, BlitFramebufferSameImage)
    {
        GLTexture textures[2];
        glBindTexture(GL_TEXTURE_2D, textures[0]);
        glTexStorage2D(GL_TEXTURE_2D, 3, GL_RGBA8, 4, 4);
        glBindTexture(GL_TEXTURE_2D, textures[1]);
        glTexStorage2D(GL_TEXTURE_2D, 3, GL_RGBA8, 4, 4);
    
        GLRenderbuffer renderbuffers[2];
        glBindRenderbuffer(GL_RENDERBUFFER, renderbuffers[0]);
        glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, 4, 4);
        glBindRenderbuffer(GL_RENDERBUFFER, renderbuffers[1]);
        glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, 4, 4);
    
        GLFramebuffer framebuffers[2];
        glBindFramebuffer(GL_READ_FRAMEBUFFER, framebuffers[0]);
        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, framebuffers[1]);
    
        ASSERT_GL_NO_ERROR();
    
        // Same texture
        glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[0],
                               0);
        glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[0],
                               0);
        ASSERT_GL_NO_ERROR();
        glBlitFramebuffer(0, 0, 4, 4, 0, 0, 4, 4, GL_COLOR_BUFFER_BIT, GL_NEAREST);
        ASSERT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Same textures but different renderbuffers
        glFramebufferRenderbuffer(GL_READ_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER,
                                  renderbuffers[0]);
        glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER,
                                  renderbuffers[1]);
        ASSERT_GL_NO_ERROR();
        glBlitFramebuffer(0, 0, 4, 4, 0, 0, 4, 4, GL_DEPTH_BUFFER_BIT, GL_NEAREST);
        ASSERT_GL_NO_ERROR();
        glBlitFramebuffer(0, 0, 4, 4, 0, 0, 4, 4, GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT,
                          GL_NEAREST);
        ASSERT_GL_NO_ERROR();
        glBlitFramebuffer(0, 0, 4, 4, 0, 0, 4, 4,
                          GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT,
                          GL_NEAREST);
        ASSERT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Same renderbuffers but different textures
        glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[0],
                               0);
        glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[1],
                               0);
        glFramebufferRenderbuffer(GL_READ_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER,
                                  renderbuffers[0]);
        glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER,
                                  renderbuffers[0]);
        ASSERT_GL_NO_ERROR();
        glBlitFramebuffer(0, 0, 4, 4, 0, 0, 4, 4, GL_COLOR_BUFFER_BIT, GL_NEAREST);
        ASSERT_GL_NO_ERROR();
        glBlitFramebuffer(0, 0, 4, 4, 0, 0, 4, 4, GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT,
                          GL_NEAREST);
        ASSERT_GL_ERROR(GL_INVALID_OPERATION);
        glBlitFramebuffer(0, 0, 4, 4, 0, 0, 4, 4,
                          GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT,
                          GL_NEAREST);
        ASSERT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // Verify that errors are generated when the fragment shader output doesn't match the bound color
    // buffer types
    TEST_P(WebGL2CompatibilityTest, FragmentShaderColorBufferTypeMissmatch)
    {
        constexpr char kVS[] =
            R"(#version 300 es
    void main() {
        gl_Position = vec4(0, 0, 0, 1);
    })";
    
        constexpr char kFS[] =
            R"(#version 300 es
    precision mediump float;
    layout(location = 0) out vec4 floatOutput;
    layout(location = 1) out uvec4 uintOutput;
    layout(location = 2) out ivec4 intOutput;
    void main() {
        floatOutput = vec4(0, 0, 0, 1);
        uintOutput = uvec4(0, 0, 0, 1);
        intOutput = ivec4(0, 0, 0, 1);
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, kFS);
        glUseProgram(program.get());
    
        GLuint floatLocation = glGetFragDataLocation(program, "floatOutput");
        GLuint uintLocation  = glGetFragDataLocation(program, "uintOutput");
        GLuint intLocation   = glGetFragDataLocation(program, "intOutput");
    
        GLFramebuffer fbo;
        glBindFramebuffer(GL_FRAMEBUFFER, fbo);
    
        GLRenderbuffer floatRenderbuffer;
        glBindRenderbuffer(GL_RENDERBUFFER, floatRenderbuffer);
        glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8, 1, 1);
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + floatLocation, GL_RENDERBUFFER,
                                  floatRenderbuffer);
    
        GLRenderbuffer uintRenderbuffer;
        glBindRenderbuffer(GL_RENDERBUFFER, uintRenderbuffer);
        glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8UI, 1, 1);
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + uintLocation, GL_RENDERBUFFER,
                                  uintRenderbuffer);
    
        GLRenderbuffer intRenderbuffer;
        glBindRenderbuffer(GL_RENDERBUFFER, intRenderbuffer);
        glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8I, 1, 1);
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + intLocation, GL_RENDERBUFFER,
                                  intRenderbuffer);
    
        ASSERT_GL_NO_ERROR();
    
        GLint maxDrawBuffers = 0;
        glGetIntegerv(GL_MAX_DRAW_BUFFERS, &maxDrawBuffers);
        std::vector<GLenum> drawBuffers(static_cast<size_t>(maxDrawBuffers), GL_NONE);
        drawBuffers[floatLocation] = GL_COLOR_ATTACHMENT0 + floatLocation;
        drawBuffers[uintLocation]  = GL_COLOR_ATTACHMENT0 + uintLocation;
        drawBuffers[intLocation]   = GL_COLOR_ATTACHMENT0 + intLocation;
    
        glDrawBuffers(maxDrawBuffers, drawBuffers.data());
    
        // Check that the correct case generates no errors
        glDrawArrays(GL_TRIANGLES, 0, 6);
        EXPECT_GL_NO_ERROR();
    
        // Unbind some buffers and verify that there are still no errors
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + uintLocation, GL_RENDERBUFFER,
                                  0);
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + intLocation, GL_RENDERBUFFER,
                                  0);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        EXPECT_GL_NO_ERROR();
    
        // Swap the int and uint buffers to and verify that an error is generated
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + uintLocation, GL_RENDERBUFFER,
                                  intRenderbuffer);
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + intLocation, GL_RENDERBUFFER,
                                  uintRenderbuffer);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Swap the float and uint buffers to and verify that an error is generated
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + uintLocation, GL_RENDERBUFFER,
                                  floatRenderbuffer);
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + floatLocation, GL_RENDERBUFFER,
                                  uintRenderbuffer);
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + intLocation, GL_RENDERBUFFER,
                                  intRenderbuffer);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // Verify that errors are generated when the vertex shader intput doesn't match the bound attribute
    // types
    TEST_P(WebGL2CompatibilityTest, VertexShaderAttributeTypeMismatch)
    {
        constexpr char kVS[] =
            R"(#version 300 es
    in vec4 floatInput;
    in uvec4 uintInput;
    in ivec4 intInput;
    void main() {
        gl_Position = vec4(floatInput.x, uintInput.x, intInput.x, 1);
    })";
    
        constexpr char kFS[] =
            R"(#version 300 es
    precision mediump float;
    out vec4 outputColor;
    void main() {
        outputColor = vec4(0, 0, 0, 1);
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, kFS);
        glUseProgram(program.get());
    
        GLint floatLocation = glGetAttribLocation(program, "floatInput");
        GLint uintLocation  = glGetAttribLocation(program, "uintInput");
        GLint intLocation   = glGetAttribLocation(program, "intInput");
    
        // Default attributes are of float types
        glDrawArrays(GL_TRIANGLES, 0, 6);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Set the default attributes to the correct types, should succeed
        glVertexAttribI4ui(uintLocation, 0, 0, 0, 1);
        glVertexAttribI4i(intLocation, 0, 0, 0, 1);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        EXPECT_GL_NO_ERROR();
    
        // Change the default float attribute to an integer, should fail
        glVertexAttribI4ui(floatLocation, 0, 0, 0, 1);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Use a buffer for some attributes
        GLBuffer buffer;
        glBindBuffer(GL_ARRAY_BUFFER, buffer);
        glBufferData(GL_ARRAY_BUFFER, 1024, nullptr, GL_STATIC_DRAW);
        glEnableVertexAttribArray(floatLocation);
        glVertexAttribPointer(floatLocation, 4, GL_FLOAT, GL_FALSE, 0, nullptr);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        EXPECT_GL_NO_ERROR();
    
        // Use a float pointer attrib for a uint input
        glEnableVertexAttribArray(uintLocation);
        glVertexAttribPointer(uintLocation, 4, GL_FLOAT, GL_FALSE, 0, nullptr);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Use a uint pointer for the uint input
        glVertexAttribIPointer(uintLocation, 4, GL_UNSIGNED_INT, 0, nullptr);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        EXPECT_GL_NO_ERROR();
    }
    
    // Test that it's not possible to query the non-zero color attachments without the drawbuffers
    // extension in WebGL1
    TEST_P(WebGLCompatibilityTest, FramebufferAttachmentQuery)
    {
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() > 2);
        ANGLE_SKIP_TEST_IF(IsGLExtensionEnabled("GL_EXT_draw_buffers"));
    
        GLFramebuffer fbo;
        glBindFramebuffer(GL_FRAMEBUFFER, fbo);
        EXPECT_GL_NO_ERROR();
    
        GLint result;
        glGetFramebufferAttachmentParameteriv(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1,
                                              GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE, &result);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        GLRenderbuffer renderbuffer;
        glBindRenderbuffer(GL_RENDERBUFFER, renderbuffer);
        glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA4, 1, 1);
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_RENDERBUFFER, renderbuffer);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    }
    
    // Tests WebGL reports INVALID_OPERATION for mismatch of drawbuffers and fragment output
    TEST_P(WebGLCompatibilityTest, DrawBuffers)
    {
        // Fails on Intel Ubuntu 19.04 Mesa 19.0.2 Vulkan. http://anglebug.com/3616
        ANGLE_SKIP_TEST_IF(IsLinux() && IsIntel() && IsVulkan());
    
        // Make sure we can use at least 4 attachments for the tests.
        bool useEXT = false;
        if (getClientMajorVersion() < 3)
        {
            ANGLE_SKIP_TEST_IF(!IsGLExtensionRequestable("GL_EXT_draw_buffers"));
    
            glRequestExtensionANGLE("GL_EXT_draw_buffers");
            useEXT = true;
            EXPECT_GL_NO_ERROR();
        }
    
        GLint maxDrawBuffers = 0;
        glGetIntegerv(GL_MAX_DRAW_BUFFERS, &maxDrawBuffers);
        // Test skipped because MAX_DRAW_BUFFERS is too small.
        ANGLE_SKIP_TEST_IF(maxDrawBuffers < 4);
    
        // Clears all the renderbuffers to red.
        auto ClearEverythingToRed = [](GLRenderbuffer *renderbuffers) {
            GLFramebuffer clearFBO;
            glBindFramebuffer(GL_FRAMEBUFFER, clearFBO);
    
            glClearColor(1, 0, 0, 1);
            for (int i = 0; i < 4; ++i)
            {
                glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER,
                                          renderbuffers[i]);
                glClear(GL_COLOR_BUFFER_BIT);
            }
            ASSERT_GL_NO_ERROR();
        };
    
        // Checks that the renderbuffers specified by mask have the correct color
        auto CheckColors = [](GLRenderbuffer *renderbuffers, int mask, GLColor color) {
            GLFramebuffer readFBO;
            glBindFramebuffer(GL_FRAMEBUFFER, readFBO);
    
            for (int attachmentIndex = 0; attachmentIndex < 4; ++attachmentIndex)
            {
                if (mask & (1 << attachmentIndex))
                {
                    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER,
                                              renderbuffers[attachmentIndex]);
                    EXPECT_PIXEL_COLOR_EQ(0, 0, color) << "attachment " << attachmentIndex;
                }
            }
            ASSERT_GL_NO_ERROR();
        };
    
        // Depending on whether we are using the extension or ES3, a different entrypoint must be called
        auto DrawBuffers = [](bool useEXT, int numBuffers, GLenum *buffers) {
            if (useEXT)
            {
                glDrawBuffersEXT(numBuffers, buffers);
            }
            else
            {
                glDrawBuffers(numBuffers, buffers);
            }
        };
    
        // Initialized the test framebuffer
        GLFramebuffer drawFBO;
        glBindFramebuffer(GL_FRAMEBUFFER, drawFBO);
    
        GLRenderbuffer renderbuffers[4];
        for (int i = 0; i < 4; ++i)
        {
            glBindRenderbuffer(GL_RENDERBUFFER, renderbuffers[i]);
            glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA4, 1, 1);
            glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + i, GL_RENDERBUFFER,
                                      renderbuffers[i]);
        }
    
        ASSERT_GL_NO_ERROR();
    
        GLenum allDrawBuffers[] = {
            GL_COLOR_ATTACHMENT0,
            GL_COLOR_ATTACHMENT1,
            GL_COLOR_ATTACHMENT2,
            GL_COLOR_ATTACHMENT3,
        };
    
        GLenum halfDrawBuffers[] = {
            GL_NONE,
            GL_COLOR_ATTACHMENT1,
            GL_NONE,
            GL_COLOR_ATTACHMENT3,
        };
    
        // Test that when using gl_FragColor with no-array
        const char *fragESSL1 =
            R"(precision highp float;
    void main()
    {
        gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0);
    })";
        ANGLE_GL_PROGRAM(programESSL1, essl1_shaders::vs::Simple(), fragESSL1);
    
        {
            glBindFramebuffer(GL_FRAMEBUFFER, drawFBO);
            DrawBuffers(useEXT, 4, allDrawBuffers);
            drawQuad(programESSL1, essl1_shaders::PositionAttrib(), 0.5, 1.0, true);
            EXPECT_GL_ERROR(GL_INVALID_OPERATION);
        }
    
        // Test what happens when rendering to a subset of the outputs. There is a behavior difference
        // between the extension and ES3. In the extension gl_FragData is implicitly declared as an
        // array of size MAX_DRAW_BUFFERS, so the WebGL spec stipulates that elements not written to
        // should default to 0. On the contrary, in ES3 outputs are specified one by one, so
        // attachments not declared in the shader should not be written to.
        const char *positionAttrib;
        const char *writeOddOutputsVert;
        const char *writeOddOutputsFrag;
        if (useEXT)
        {
            positionAttrib      = essl1_shaders::PositionAttrib();
            writeOddOutputsVert = essl1_shaders::vs::Simple();
            writeOddOutputsFrag =
                R"(#extension GL_EXT_draw_buffers : require
    precision highp float;
    void main()
    {
        gl_FragData[1] = vec4(0.0, 1.0, 0.0, 1.0);
        gl_FragData[3] = vec4(0.0, 1.0, 0.0, 1.0);
    })";
        }
        else
        {
            positionAttrib      = essl3_shaders::PositionAttrib();
            writeOddOutputsVert = essl3_shaders::vs::Simple();
            writeOddOutputsFrag =
                R"(#version 300 es
    precision highp float;
    layout(location = 1) out vec4 output1;
    layout(location = 3) out vec4 output2;
    void main()
    {
        output1 = vec4(0.0, 1.0, 0.0, 1.0);
        output2 = vec4(0.0, 1.0, 0.0, 1.0);
    })";
        }
        ANGLE_GL_PROGRAM(writeOddOutputsProgram, writeOddOutputsVert, writeOddOutputsFrag);
    
        // Test that attachments not written to get the "unwritten" color (useEXT)
        // Or INVALID_OPERATION is generated if there's active draw buffer receive no output
        {
            ClearEverythingToRed(renderbuffers);
    
            glBindFramebuffer(GL_FRAMEBUFFER, drawFBO);
            DrawBuffers(useEXT, 4, allDrawBuffers);
            drawQuad(writeOddOutputsProgram, positionAttrib, 0.5, 1.0, true);
    
            if (useEXT)
            {
                ASSERT_GL_NO_ERROR();
                CheckColors(renderbuffers, 0b1010, GLColor::green);
                // In the extension, when an attachment isn't written to, it should get 0's
                CheckColors(renderbuffers, 0b0101, GLColor(0, 0, 0, 0));
            }
            else
            {
                EXPECT_GL_ERROR(GL_INVALID_OPERATION);
            }
        }
    
        // TODO(syoussefi): Qualcomm driver crashes in the presence of VK_ATTACHMENT_UNUSED.
        // http://anglebug.com/3423
        ANGLE_SKIP_TEST_IF(IsVulkan() && IsAndroid());
    
        // Test that attachments written to get the correct color from shader output but that even when
        // the extension is used, disabled attachments are not written at all and stay red.
        {
            ClearEverythingToRed(renderbuffers);
    
            glBindFramebuffer(GL_FRAMEBUFFER, drawFBO);
            DrawBuffers(useEXT, 4, halfDrawBuffers);
            drawQuad(writeOddOutputsProgram, positionAttrib, 0.5, 1.0, true);
            ASSERT_GL_NO_ERROR();
    
            CheckColors(renderbuffers, 0b1010, GLColor::green);
            CheckColors(renderbuffers, 0b0101, GLColor::red);
        }
    }
    
    // Test that it's possible to generate mipmaps on unsized floating point textures once the
    // extensions have been enabled
    TEST_P(WebGLCompatibilityTest, GenerateMipmapUnsizedFloatingPointTexture)
    {
        if (IsGLExtensionRequestable("GL_OES_texture_float"))
        {
            glRequestExtensionANGLE("GL_OES_texture_float");
        }
        ANGLE_SKIP_TEST_IF(!IsGLExtensionEnabled("GL_OES_texture_float"));
    
        GLTexture texture;
        glBindTexture(GL_TEXTURE_2D, texture);
    
        constexpr GLColor32F data[4] = {
            kFloatRed,
            kFloatRed,
            kFloatGreen,
            kFloatBlue,
        };
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 2, 2, 0, GL_RGBA, GL_FLOAT, data);
        ASSERT_GL_NO_ERROR();
    
        glGenerateMipmap(GL_TEXTURE_2D);
        EXPECT_GL_NO_ERROR();
    }
    // Test that it's possible to generate mipmaps on unsized floating point textures once the
    // extensions have been enabled
    TEST_P(WebGLCompatibilityTest, GenerateMipmapSizedFloatingPointTexture)
    {
        if (IsGLExtensionRequestable("GL_OES_texture_float"))
        {
            glRequestExtensionANGLE("GL_OES_texture_float");
        }
        ANGLE_SKIP_TEST_IF(!IsGLExtensionEnabled("GL_OES_texture_float"));
    
        if (IsGLExtensionRequestable("GL_EXT_texture_storage"))
        {
            glRequestExtensionANGLE("GL_EXT_texture_storage");
        }
        ANGLE_SKIP_TEST_IF(!IsGLExtensionEnabled("GL_EXT_texture_storage"));
    
        GLTexture texture;
        glBindTexture(GL_TEXTURE_2D, texture);
    
        constexpr GLColor32F data[4] = {
            kFloatRed,
            kFloatRed,
            kFloatGreen,
            kFloatBlue,
        };
        glTexStorage2DEXT(GL_TEXTURE_2D, 2, GL_RGBA32F, 2, 2);
        glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 2, 2, GL_RGBA, GL_FLOAT, data);
        ASSERT_GL_NO_ERROR();
    
        glGenerateMipmap(GL_TEXTURE_2D);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        if (IsGLExtensionRequestable("GL_EXT_color_buffer_float"))
        {
            // Format is renderable but not filterable
            glRequestExtensionANGLE("GL_EXT_color_buffer_float");
            glGenerateMipmap(GL_TEXTURE_2D);
            EXPECT_GL_ERROR(GL_INVALID_OPERATION);
        }
    
        if (IsGLExtensionRequestable("GL_EXT_color_buffer_float_linear"))
        {
            // Format is renderable but not filterable
            glRequestExtensionANGLE("GL_EXT_color_buffer_float_linear");
    
            if (IsGLExtensionEnabled("GL_EXT_color_buffer_float"))
            {
                // Format is filterable and renderable
                glGenerateMipmap(GL_TEXTURE_2D);
                EXPECT_GL_NO_ERROR();
            }
            else
            {
                // Format is filterable but not renderable
                glGenerateMipmap(GL_TEXTURE_2D);
                EXPECT_GL_ERROR(GL_INVALID_OPERATION);
            }
        }
    }
    
    // Verify that a texture format is only allowed with extension enabled.
    void WebGLCompatibilityTest::validateTexImageExtensionFormat(GLenum format,
                                                                 const std::string &extName)
    {
        // Verify texture format fails by default.
        glTexImage2D(GL_TEXTURE_2D, 0, format, 1, 1, 0, format, GL_UNSIGNED_BYTE, nullptr);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        if (IsGLExtensionRequestable(extName))
        {
            // Verify texture format is allowed once extension is enabled.
            glRequestExtensionANGLE(extName.c_str());
            EXPECT_TRUE(IsGLExtensionEnabled(extName));
    
            glTexImage2D(GL_TEXTURE_2D, 0, format, 1, 1, 0, format, GL_UNSIGNED_BYTE, nullptr);
            ASSERT_GL_NO_ERROR();
        }
    }
    
    // Test enabling various non-compressed texture format extensions
    TEST_P(WebGLCompatibilityTest, EnableTextureFormatExtensions)
    {
        ANGLE_SKIP_TEST_IF(IsOzone());
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() != 2);
    
        GLTexture texture;
        glBindTexture(GL_TEXTURE_2D, texture.get());
    
        // Verify valid format is allowed.
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
        ASSERT_GL_NO_ERROR();
    
        // Verify invalid format fails.
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, 1, 1, 0, GL_RGBA32F, GL_UNSIGNED_BYTE, nullptr);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        // Verify formats from enableable extensions.
        if (!IsOpenGLES())
        {
            validateTexImageExtensionFormat(GL_RED_EXT, "GL_EXT_texture_rg");
        }
    
        validateTexImageExtensionFormat(GL_SRGB_EXT, "GL_EXT_texture_sRGB");
        validateTexImageExtensionFormat(GL_BGRA_EXT, "GL_EXT_texture_format_BGRA8888");
    }
    
    void WebGLCompatibilityTest::validateCompressedTexImageExtensionFormat(GLenum format,
                                                                           GLsizei width,
                                                                           GLsizei height,
                                                                           GLsizei blockSize,
                                                                           const std::string &extName,
                                                                           bool subImageAllowed)
    {
        std::vector<GLubyte> data(blockSize, 0u);
    
        GLTexture texture;
        glBindTexture(GL_TEXTURE_2D, texture.get());
    
        // Verify texture format fails by default.
        glCompressedTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, blockSize, data.data());
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    
        if (IsGLExtensionRequestable(extName))
        {
            // Verify texture format is allowed once extension is enabled.
            glRequestExtensionANGLE(extName.c_str());
            EXPECT_TRUE(IsGLExtensionEnabled(extName));
    
            glCompressedTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, blockSize, data.data());
            EXPECT_GL_NO_ERROR();
    
            glCompressedTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, format, blockSize,
                                      data.data());
            if (subImageAllowed)
            {
                EXPECT_GL_NO_ERROR();
            }
            else
            {
                EXPECT_GL_ERROR(GL_INVALID_OPERATION);
            }
        }
    }
    
    // Test enabling GL_EXT_texture_compression_dxt1 for GL_COMPRESSED_RGB_S3TC_DXT1_EXT
    TEST_P(WebGLCompatibilityTest, EnableCompressedTextureExtensionDXT1RGB)
    {
        validateCompressedTexImageExtensionFormat(GL_COMPRESSED_RGB_S3TC_DXT1_EXT, 4, 4, 8,
                                                  "GL_EXT_texture_compression_dxt1", true);
    }
    
    // Test enabling GL_EXT_texture_compression_dxt1 for GL_COMPRESSED_RGBA_S3TC_DXT1_EXT
    TEST_P(WebGLCompatibilityTest, EnableCompressedTextureExtensionDXT1RGBA)
    {
        validateCompressedTexImageExtensionFormat(GL_COMPRESSED_RGBA_S3TC_DXT1_EXT, 4, 4, 8,
                                                  "GL_EXT_texture_compression_dxt1", true);
    }
    
    // Test enabling GL_ANGLE_texture_compression_dxt3
    TEST_P(WebGLCompatibilityTest, EnableCompressedTextureExtensionDXT3)
    {
        validateCompressedTexImageExtensionFormat(GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE, 4, 4, 16,
                                                  "GL_ANGLE_texture_compression_dxt3", true);
    }
    
    // Test enabling GL_ANGLE_texture_compression_dxt5
    TEST_P(WebGLCompatibilityTest, EnableCompressedTextureExtensionDXT5)
    {
        validateCompressedTexImageExtensionFormat(GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE, 4, 4, 16,
                                                  "GL_ANGLE_texture_compression_dxt5", true);
    }
    
    // Test enabling GL_EXT_texture_compression_s3tc_srgb for GL_COMPRESSED_SRGB_S3TC_DXT1_EXT
    TEST_P(WebGLCompatibilityTest, EnableCompressedTextureExtensionDXT1SRGB)
    {
        validateCompressedTexImageExtensionFormat(GL_COMPRESSED_SRGB_S3TC_DXT1_EXT, 4, 4, 8,
                                                  "GL_EXT_texture_compression_s3tc_srgb", true);
    }
    
    // Test enabling GL_EXT_texture_compression_s3tc_srgb for GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT
    TEST_P(WebGLCompatibilityTest, EnableCompressedTextureExtensionDXT1SRGBA)
    {
        validateCompressedTexImageExtensionFormat(GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT, 4, 4, 8,
                                                  "GL_EXT_texture_compression_s3tc_srgb", true);
    }
    
    // Test enabling GL_EXT_texture_compression_s3tc_srgb for GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT
    TEST_P(WebGLCompatibilityTest, EnableCompressedTextureExtensionDXT3SRGBA)
    {
        validateCompressedTexImageExtensionFormat(GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT, 4, 4, 16,
                                                  "GL_EXT_texture_compression_s3tc_srgb", true);
    }
    
    // Test enabling GL_EXT_texture_compression_s3tc_srgb for GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT
    TEST_P(WebGLCompatibilityTest, EnableCompressedTextureExtensionDXT5SRGBA)
    {
        validateCompressedTexImageExtensionFormat(GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT, 4, 4, 16,
                                                  "GL_EXT_texture_compression_s3tc_srgb", true);
    }
    
    // Test enabling GL_OES_compressed_ETC1_RGB8_texture
    TEST_P(WebGLCompatibilityTest, EnableCompressedTextureExtensionETC1)
    {
        validateCompressedTexImageExtensionFormat(
            GL_ETC1_RGB8_OES, 4, 4, 8, "GL_OES_compressed_ETC1_RGB8_texture",
            IsGLExtensionEnabled("GL_EXT_compressed_ETC1_RGB8_sub_texture"));
    }
    
    // Test enabling GL_ANGLE_lossy_etc_decode
    TEST_P(WebGLCompatibilityTest, EnableCompressedTextureExtensionLossyDecode)
    {
        validateCompressedTexImageExtensionFormat(GL_ETC1_RGB8_LOSSY_DECODE_ANGLE, 4, 4, 8,
                                                  "GL_ANGLE_lossy_etc_decode", true);
    }
    
    // Linking should fail when corresponding vertex/fragment uniform blocks have different precision
    // qualifiers.
    TEST_P(WebGL2CompatibilityTest, UniformBlockPrecisionMismatch)
    {
        constexpr char kVS[] =
            R"(#version 300 es
    uniform Block { mediump vec4 val; };
    void main() { gl_Position = val; })";
        constexpr char kFS[] =
            R"(#version 300 es
    uniform Block { highp vec4 val; };
    out highp vec4 out_FragColor;
    void main() { out_FragColor = val; })";
    
        GLuint vs = CompileShader(GL_VERTEX_SHADER, kVS);
        ASSERT_NE(0u, vs);
        GLuint fs = CompileShader(GL_FRAGMENT_SHADER, kFS);
        ASSERT_NE(0u, fs);
    
        GLuint program = glCreateProgram();
    
        glAttachShader(program, vs);
        glDeleteShader(vs);
        glAttachShader(program, fs);
        glDeleteShader(fs);
    
        glLinkProgram(program);
        GLint linkStatus;
        glGetProgramiv(program, GL_LINK_STATUS, &linkStatus);
        ASSERT_EQ(0, linkStatus);
    
        glDeleteProgram(program);
    }
    
    // Test no attribute vertex shaders
    TEST_P(WebGL2CompatibilityTest, NoAttributeVertexShader)
    {
        constexpr char kVS[] =
            R"(#version 300 es
    void main()
    {
    
        ivec2 xy = ivec2(gl_VertexID % 2, (gl_VertexID / 2 + gl_VertexID / 3) % 2);
        gl_Position = vec4(vec2(xy) * 2. - 1., 0, 1);
    })";
    
        ANGLE_GL_PROGRAM(program, kVS, essl3_shaders::fs::Red());
        glUseProgram(program);
    
        glDrawArrays(GL_TRIANGLES, 0, 6);
        ASSERT_GL_NO_ERROR();
        EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::red);
    }
    
    // Tests bindAttribLocations for length limit
    TEST_P(WebGL2CompatibilityTest, BindAttribLocationLimitation)
    {
        constexpr int maxLocStringLength = 1024;
        const std::string tooLongString(maxLocStringLength + 1, '_');
    
        glBindAttribLocation(0, 0, static_cast<const GLchar *>(tooLongString.c_str()));
    
        EXPECT_GL_ERROR(GL_INVALID_VALUE);
    }
    
    // Covers a bug in transform feedback loop detection.
    TEST_P(WebGL2CompatibilityTest, TransformFeedbackCheckNullDeref)
    {
        constexpr char kVS[] = R"(attribute vec4 color; void main() { color.r; })";
        constexpr char kFS[] = R"(void main(){})";
        ANGLE_GL_PROGRAM(program, kVS, kFS);
        glUseProgram(program);
    
        glEnableVertexAttribArray(0);
        glDrawArrays(GL_POINTS, 0, 1);
    
        // This should fail because it is trying to pull a vertex with no buffer.
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        GLBuffer buffer;
        glBindBuffer(GL_ARRAY_BUFFER, buffer);
        glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, nullptr);
    
        // This should fail because it is trying to pull a vertex from an empty buffer.
        glDrawArrays(GL_POINTS, 0, 1);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // We should forbid two transform feedback outputs going to the same buffer.
    TEST_P(WebGL2CompatibilityTest, TransformFeedbackDoubleBinding)
    {
        constexpr char kVS[] =
            R"(attribute float a; varying float b; varying float c; void main() { b = a; c = a; })";
        constexpr char kFS[] = R"(void main(){})";
        ANGLE_GL_PROGRAM(program, kVS, kFS);
        static const char *varyings[] = {"b", "c"};
        glTransformFeedbackVaryings(program, 2, varyings, GL_SEPARATE_ATTRIBS);
        glLinkProgram(program);
        glUseProgram(program);
        ASSERT_GL_NO_ERROR();
    
        // Bind the transform feedback varyings to non-overlapping regions of the same buffer.
        GLBuffer buffer;
        glBindBufferRange(GL_TRANSFORM_FEEDBACK_BUFFER, 0, buffer, 0, 4);
        glBindBufferRange(GL_TRANSFORM_FEEDBACK_BUFFER, 1, buffer, 4, 4);
        glBufferData(GL_TRANSFORM_FEEDBACK_BUFFER, 8, nullptr, GL_STATIC_DRAW);
        ASSERT_GL_NO_ERROR();
        // Two varyings bound to the same buffer should be an error.
        glBeginTransformFeedback(GL_POINTS);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // Check the return type of a given parameter upon getting the active uniforms.
    TEST_P(WebGL2CompatibilityTest, UniformVariablesReturnTypes)
    {
        ANGLE_GL_PROGRAM(program, essl1_shaders::vs::Simple(), essl1_shaders::fs::UniformColor());
    
        std::vector<GLuint> validUniformIndices = {0};
        std::vector<GLint> uniformNameLengthBuf(validUniformIndices.size());
    
        // This should fail because GL_UNIFORM_NAME_LENGTH cannot be used in WebGL2.
        glGetActiveUniformsiv(program, static_cast<GLsizei>(validUniformIndices.size()),
                              &validUniformIndices[0], GL_UNIFORM_NAME_LENGTH,
                              &uniformNameLengthBuf[0]);
        EXPECT_GL_ERROR(GL_INVALID_ENUM);
    }
    
    // Tests an error case to ensure we don't crash.
    TEST_P(WebGLCompatibilityTest, DrawWithNoProgram)
    {
        glDrawArrays(GL_TRIANGLES, 0, 6);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    }
    
    // Ensures that rendering to different texture levels of a sampled texture is supported.
    TEST_P(WebGL2CompatibilityTest, RenderToLevelsOfSampledTexture)
    {
        // TODO: Fix on Vulkan back-end. http://anglebug.com/4690
        ANGLE_SKIP_TEST_IF(IsVulkan());
    
        constexpr GLsizei kTexSize   = 2;
        constexpr GLsizei kTexLevels = 2;
    
        std::vector<GLColor> texData(kTexSize * kTexSize, GLColor::green);
    
        GLTexture sourceTexture;
        glBindTexture(GL_TEXTURE_2D, sourceTexture);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        glTexStorage2D(GL_TEXTURE_2D, kTexLevels, GL_RGBA8, kTexSize, kTexSize);
        glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, kTexSize, kTexSize, GL_RGBA, GL_UNSIGNED_BYTE,
                        texData.data());
    
        GLFramebuffer fbo;
        glBindFramebuffer(GL_FRAMEBUFFER, fbo);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, sourceTexture, 1);
        ASSERT_GL_FRAMEBUFFER_COMPLETE(GL_FRAMEBUFFER);
        glViewport(0, 0, kTexSize / 2, kTexSize / 2);
    
        ANGLE_GL_PROGRAM(program, essl1_shaders::vs::Texture2D(), essl1_shaders::fs::Texture2D());
        ASSERT_GL_NO_ERROR();
    
        // Should work - drawing from level 0 to level 1.
        drawQuad(program, essl1_shaders::PositionAttrib(), 0.5f, 1.0f, true);
        EXPECT_GL_NO_ERROR();
        EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
    
        // Should not work - drawing from levels [0,1] to level 1.
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST);
        drawQuad(program, essl1_shaders::PositionAttrib(), 0.5f, 1.0f, true);
        EXPECT_GL_ERROR(GL_INVALID_OPERATION);
    
        // Should work - drawing with levels [0,1] to default FBO.
        glBindFramebuffer(GL_FRAMEBUFFER, 0);
        glViewport(0, 0, getWindowWidth(), getWindowHeight());
    
        drawQuad(program, essl1_shaders::PositionAttrib(), 0.5f, 1.0f, true);
        EXPECT_GL_NO_ERROR();
        EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
    }
    
    // Use this to select which configurations (e.g. which renderer, which GLES major version) these
    // tests should be run against.
    ANGLE_INSTANTIATE_TEST_ES2_AND_ES3(WebGLCompatibilityTest);
    
    ANGLE_INSTANTIATE_TEST_ES3(WebGL2CompatibilityTest);
    }  // namespace angle