Edit

kc3-lang/angle/src/tests/compiler_tests/WEBGL_multiview_test.cpp

Branch :

  • Show log

    Commit

  • Author : Martin Radev
    Date : 2017-07-07 18:52:09
    Hash : c39a19aa
    Message : Select viewport index in the GLSL/ESSL vertex shader The patch enables viewport selection for multiview rendering in the GLSL/ESSL vertex shader through the use of the GL_NV_viewport_array2 extension. The AST is modified only for GLSL and ESSL to include the viewport selection expression after ViewID_OVR's initialization. BUG=angleproject:2062 TEST=angle_unittests Change-Id: Iee05bb5a4b687ed53ddbdd466f1572227b1f0cde

  • src/tests/compiler_tests/WEBGL_multiview_test.cpp
  • //
    // Copyright (c) 2016 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.
    //
    // WEBGL_multiview_test.cpp:
    //   Test that shaders with gl_ViewID_OVR are validated correctly.
    //
    
    #include "GLSLANG/ShaderLang.h"
    #include "compiler/translator/IntermTraverse.h"
    #include "tests/test_utils/ShaderCompileTreeTest.h"
    #include "tests/test_utils/compiler_test.h"
    
    using namespace sh;
    
    namespace
    {
    
    class SymbolOccurrenceCounter : public TIntermTraverser
    {
      public:
        SymbolOccurrenceCounter() : TIntermTraverser(true, false, false), mNumberOfOccurrences(0u) {}
    
        void visitSymbol(TIntermSymbol *node) override
        {
            if (shouldCountSymbol(node))
            {
                ++mNumberOfOccurrences;
            }
        }
    
        virtual bool shouldCountSymbol(const TIntermSymbol *node) const = 0;
    
        unsigned getNumberOfOccurrences() const { return mNumberOfOccurrences; }
    
      private:
        unsigned mNumberOfOccurrences;
    };
    
    class SymbolOccurrenceCounterByQualifier : public SymbolOccurrenceCounter
    {
      public:
        SymbolOccurrenceCounterByQualifier(TQualifier symbolQualifier)
            : mSymbolQualifier(symbolQualifier)
        {
        }
    
        bool shouldCountSymbol(const TIntermSymbol *node) const override
        {
            return node->getQualifier() == mSymbolQualifier;
        }
    
      private:
        TQualifier mSymbolQualifier;
    };
    
    class SymbolOccurrenceCounterByName : public SymbolOccurrenceCounter
    {
      public:
        SymbolOccurrenceCounterByName(const TString &symbolName) : mSymbolName(symbolName) {}
    
        bool shouldCountSymbol(const TIntermSymbol *node) const override
        {
            return node->getName().getString() == mSymbolName;
        }
    
      private:
        TString mSymbolName;
    };
    
    class SymbolOccurrenceCounterByNameAndQualifier : public SymbolOccurrenceCounter
    {
      public:
        SymbolOccurrenceCounterByNameAndQualifier(const TString &symbolName, TQualifier qualifier)
            : mSymbolName(symbolName), mSymbolQualifier(qualifier)
        {
        }
    
        bool shouldCountSymbol(const TIntermSymbol *node) const override
        {
            return node->getName().getString() == mSymbolName &&
                   node->getQualifier() == mSymbolQualifier;
        }
    
      private:
        TString mSymbolName;
        TQualifier mSymbolQualifier;
    };
    
    class WEBGLMultiviewVertexShaderTest : public ShaderCompileTreeTest
    {
      public:
        WEBGLMultiviewVertexShaderTest() {}
      protected:
        ::GLenum getShaderType() const override { return GL_VERTEX_SHADER; }
        ShShaderSpec getShaderSpec() const override { return SH_WEBGL3_SPEC; }
        void initResources(ShBuiltInResources *resources) override
        {
            resources->OVR_multiview = 1;
            resources->MaxViewsOVR   = 4;
        }
    };
    
    class WEBGLMultiviewFragmentShaderTest : public ShaderCompileTreeTest
    {
      public:
        WEBGLMultiviewFragmentShaderTest() {}
      protected:
        ::GLenum getShaderType() const override { return GL_FRAGMENT_SHADER; }
        ShShaderSpec getShaderSpec() const override { return SH_WEBGL3_SPEC; }
        void initResources(ShBuiltInResources *resources) override
        {
            resources->OVR_multiview = 1;
            resources->MaxViewsOVR   = 4;
        }
    };
    
    class WEBGLMultiviewOutputCodeTest : public MatchOutputCodeTest
    {
      public:
        WEBGLMultiviewOutputCodeTest(sh::GLenum shaderType)
            : MatchOutputCodeTest(shaderType, 0, SH_ESSL_OUTPUT)
        {
            addOutputType(SH_GLSL_COMPATIBILITY_OUTPUT);
    
            getResources()->OVR_multiview = 1;
            getResources()->MaxViewsOVR   = 4;
        }
    
        void requestHLSLOutput()
        {
    #if defined(ANGLE_ENABLE_HLSL)
            addOutputType(SH_HLSL_4_1_OUTPUT);
    #endif
        }
    
        bool foundInAllGLSLCode(const char *str)
        {
            return foundInGLSLCode(str) && foundInESSLCode(str);
        }
    
        bool foundInHLSLCode(const char *stringToFind) const
        {
    #if defined(ANGLE_ENABLE_HLSL)
            return foundInCode(SH_HLSL_4_1_OUTPUT, stringToFind);
    #else
            return true;
    #endif
        }
    };
    
    class WEBGLMultiviewVertexShaderOutputCodeTest : public WEBGLMultiviewOutputCodeTest
    {
      public:
        WEBGLMultiviewVertexShaderOutputCodeTest() : WEBGLMultiviewOutputCodeTest(GL_VERTEX_SHADER) {}
    };
    
    class WEBGLMultiviewFragmentShaderOutputCodeTest : public WEBGLMultiviewOutputCodeTest
    {
      public:
        WEBGLMultiviewFragmentShaderOutputCodeTest() : WEBGLMultiviewOutputCodeTest(GL_FRAGMENT_SHADER)
        {
        }
    };
    
    class WEBGLMultiviewComputeShaderOutputCodeTest : public WEBGLMultiviewOutputCodeTest
    {
      public:
        WEBGLMultiviewComputeShaderOutputCodeTest() : WEBGLMultiviewOutputCodeTest(GL_COMPUTE_SHADER) {}
    };
    
    void VariableOccursNTimes(TIntermBlock *root,
                              const TString &varName,
                              const TQualifier varQualifier,
                              unsigned n)
    {
        // Check that there are n occurrences of the variable with the given name and qualifier.
        SymbolOccurrenceCounterByNameAndQualifier viewIDByNameAndQualifier(varName, varQualifier);
        root->traverse(&viewIDByNameAndQualifier);
        EXPECT_EQ(n, viewIDByNameAndQualifier.getNumberOfOccurrences());
    
        // Check that there are n occurrences of the variable with the given name. By this we guarantee
        // that there are no other occurrences of the variable with the same name but different
        // qualifier.
        SymbolOccurrenceCounterByName viewIDByName(varName);
        root->traverse(&viewIDByName);
        EXPECT_EQ(n, viewIDByName.getNumberOfOccurrences());
    }
    
    // Invalid combination of extensions (restricted in the WEBGL_multiview spec).
    TEST_F(WEBGLMultiviewVertexShaderTest, InvalidBothMultiviewAndMultiview2)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "#extension GL_OVR_multiview2 : enable\n"
            "layout(num_views = 2) in;\n"
            "void main()\n"
            "{\n"
            "    gl_Position.x = (gl_ViewID_OVR == 0u) ? 1.0 : 0.0;\n"
            "    gl_Position.yzw = vec3(0, 0, 1);\n"
            "}\n";
        if (compile(shaderString))
        {
            FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
        }
    }
    
    // Invalid combination of non-matching num_views declarations.
    TEST_F(WEBGLMultiviewVertexShaderTest, InvalidNumViewsMismatch)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview2 : require\n"
            "layout(num_views = 2) in;\n"
            "layout(num_views = 1) in;\n"
            "void main()\n"
            "{\n"
            "    gl_Position.x = (gl_ViewID_OVR == 0u) ? 1.0 : 0.0;\n"
            "    gl_Position.yzw = vec3(0, 0, 1);\n"
            "}\n";
        if (compile(shaderString))
        {
            FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
        }
    }
    
    // Invalid value zero for num_views.
    TEST_F(WEBGLMultiviewVertexShaderTest, InvalidNumViewsZero)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview2 : require\n"
            "layout(num_views = 0) in;\n"
            "void main()\n"
            "{\n"
            "    gl_Position.x = (gl_ViewID_OVR == 0u) ? 1.0 : 0.0;\n"
            "    gl_Position.yzw = vec3(0, 0, 1);\n"
            "}\n";
        if (compile(shaderString))
        {
            FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
        }
    }
    
    // Too large value for num_views.
    TEST_F(WEBGLMultiviewVertexShaderTest, InvalidNumViewsGreaterThanMax)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview2 : require\n"
            "layout(num_views = 5) in;\n"
            "void main()\n"
            "{\n"
            "    gl_Position.x = (gl_ViewID_OVR == 0u) ? 1.0 : 0.0;\n"
            "    gl_Position.yzw = vec3(0, 0, 1);\n"
            "}\n";
        if (compile(shaderString))
        {
            FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
        }
    }
    
    // Valid use of gl_ViewID_OVR in a ternary operator.
    TEST_F(WEBGLMultiviewVertexShaderTest, ValidViewIDInTernary)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "layout(num_views = 2) in;\n"
            "layout(num_views = 2) in;  // Duplicated on purpose\n"
            "void main()\n"
            "{\n"
            "    gl_Position.x = (gl_ViewID_OVR == 0u) ? 1.0 : 0.0;\n"
            "    gl_Position.yzw = vec3(0, 0, 1);\n"
            "}\n";
        if (!compile(shaderString))
        {
            FAIL() << "Shader compilation failed, expecting success:\n" << mInfoLog;
        }
    }
    
    // Valid use of gl_ViewID_OVR in an if statement.
    TEST_F(WEBGLMultiviewVertexShaderTest, ValidViewIDInIf)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "layout(num_views = 2) in;\n"
            "precision highp float;\n"
            "in vec4 pos;\n"
            "void main()\n"
            "{\n"
            "    if (gl_ViewID_OVR == 0u)\n"
            "    {\n"
            "        gl_Position.x = pos.x;\n"
            "    }\n"
            "    else\n"
            "    {\n"
            "        gl_Position.x = 1.0;\n"
            "    }\n"
            "    gl_Position.yzw = pos.yzw;\n"
            "}\n";
        if (!compile(shaderString))
        {
            FAIL() << "Shader compilation failed, expecting success:\n" << mInfoLog;
        }
    }
    
    // Valid normal write of gl_Position in addition to the write that's dependent on gl_ViewID_OVR.
    TEST_F(WEBGLMultiviewVertexShaderTest, ValidWriteOfGlPosition)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "layout(num_views = 2) in;\n"
            "void main()\n"
            "{\n"
            "    if (0u == gl_ViewID_OVR)\n"
            "    {\n"
            "        gl_Position.x = 1.0;\n"
            "    }\n"
            "    else\n"
            "    {\n"
            "        gl_Position.x = 1.0;\n"
            "    }\n"
            "    gl_Position = vec4(1, 1, 1, 1);\n"
            "}\n";
        if (!compile(shaderString))
        {
            FAIL() << "Shader compilation failed, expecting success:\n" << mInfoLog;
        }
    }
    
    // Invalid assignment to gl_Position.y inside if dependent on gl_ViewID_OVR.
    TEST_F(WEBGLMultiviewVertexShaderTest, InvalidGlPositionAssignmentInIf)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "layout(num_views = 2) in;\n"
            "void main()\n"
            "{\n"
            "    if (gl_ViewID_OVR == 0u)\n"
            "    {\n"
            "        gl_Position.y = 1.0;\n"
            "    }\n"
            "    else\n"
            "    {\n"
            "        gl_Position.y = 1.0;\n"
            "    }\n"
            "    gl_Position.xzw = vec3(0, 0, 1);\n"
            "}\n";
        if (compile(shaderString))
        {
            FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
        }
    }
    
    // Invalid multiple assignments inside if dependent on gl_ViewID_OVR.
    TEST_F(WEBGLMultiviewVertexShaderTest, InvalidMultipleGlPositionXAssignmentsInIf)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "layout(num_views = 2) in;\n"
            "void main()\n"
            "{\n"
            "    if (gl_ViewID_OVR == 0u)\n"
            "    {\n"
            "        gl_Position.x = 1.0;\n"
            "        gl_Position.x = 2.0;\n"
            "    }\n"
            "    else\n"
            "    {\n"
            "        gl_Position.x = 1.0;\n"
            "    }\n"
            "    gl_Position.yzw = vec3(0, 0, 1);\n"
            "}\n";
        if (compile(shaderString))
        {
            FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
        }
    }
    
    // Invalid read of gl_Position
    TEST_F(WEBGLMultiviewVertexShaderTest, InvalidReadOfGlPosition)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "layout(num_views = 2) in;\n"
            "void main()\n"
            "{\n"
            "    if (gl_ViewID_OVR == 0u) {\n"
            "        gl_Position.x = 1.0;\n"
            "    } else {\n"
            "        gl_Position.x = 1.0;\n"
            "    }\n"
            "    gl_Position.yzw = vec3(0, 0, 1);\n"
            "    float f = gl_Position.y;\n"
            "}\n";
        if (compile(shaderString))
        {
            FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
        }
    }
    
    // Read gl_Position when the shader does not refer to gl_ViewID_OVR.
    TEST_F(WEBGLMultiviewVertexShaderTest, ValidReadOfGlPosition)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "layout(num_views = 2) in;\n"
            "uniform float u;\n"
            "void main()\n"
            "{\n"
            "    gl_Position = vec4(0, 0, 0, 1);\n"
            "    gl_Position.y = gl_Position.x * u;\n"
            "}\n";
        if (!compile(shaderString))
        {
            FAIL() << "Shader compilation failed, expecting success:\n" << mInfoLog;
        }
    }
    
    // Read gl_FragCoord in a OVR_multiview fragment shader.
    TEST_F(WEBGLMultiviewFragmentShaderTest, InvalidReadOfFragCoord)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "precision highp float;\n"
            "out vec4 outColor;\n"
            "void main()\n"
            "{\n"
            "    outColor = vec4(gl_FragCoord.xy, 0, 1);\n"
            "}\n";
        if (compile(shaderString))
        {
            FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
        }
    }
    
    // Read gl_ViewID_OVR in an OVR_multiview fragment shader.
    TEST_F(WEBGLMultiviewFragmentShaderTest, InvalidReadOfViewID)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "precision highp float;\n"
            "out vec4 outColor;\n"
            "void main()\n"
            "{\n"
            "    outColor = vec4(gl_ViewID_OVR, 0, 0, 1);\n"
            "}\n";
        if (compile(shaderString))
        {
            FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
        }
    }
    
    // Tricky invalid read of view ID.
    TEST_F(WEBGLMultiviewVertexShaderTest, InvalidConsumingExpressionForAssignGLPositionX)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "layout(num_views = 2) in;\n"
            "void main()\n"
            "{\n"
            "    float f = (gl_Position.x = (gl_ViewID_OVR == 0u) ? 1.0 : 0.0);\n"
            "    gl_Position.yzw = vec3(f, f, f);\n"
            "}\n";
        if (compile(shaderString))
        {
            FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
        }
    }
    
    // Using the OVR_multiview2 extension directive lifts restrictions of OVR_multiview.
    TEST_F(WEBGLMultiviewVertexShaderTest, RestrictionsLiftedMultiview2)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview2 : require\n"
            "layout(num_views = 2) in;\n"
            "out float out_f;\n"
            "void main()\n"
            "{\n"
            "    if (gl_ViewID_OVR == 0u)\n"
            "    {\n"
            "        gl_Position.x = 1.0;\n"
            "        gl_Position.x = 2.0;\n"
            "    }\n"
            "    else\n"
            "    {\n"
            "        gl_Position.x = 1.0;\n"
            "    }\n"
            "    gl_Position.yzw = vec3(0, 0, 1);\n"
            "    gl_Position += vec4(1, 0, 0, 1);\n"
            "    out_f = float(gl_ViewID_OVR * 2u);\n"
            "}\n";
        if (!compile(shaderString))
        {
            FAIL() << "Shader compilation failed, expecting success:\n" << mInfoLog;
        }
    }
    
    // Correct use of GL_OVR_multiview macros.
    TEST_F(WEBGLMultiviewVertexShaderTest, ValidUseOfExtensionMacros)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#ifdef GL_OVR_multiview\n"
            "#ifdef GL_OVR_multiview2\n"
            "#if (GL_OVR_multiview == 1) && (GL_OVR_multiview2 == 1)\n"
            "void main()\n"
            "{\n"
            "    gl_Position = vec4(0.0, 0.0, 0.0, 1.0);\n"
            "}\n"
            "#endif\n"
            "#endif\n"
            "#endif\n";
        if (!compile(shaderString))
        {
            FAIL() << "Shader compilation failed, expecting success:\n" << mInfoLog;
        }
    }
    
    // Test that the parent node is tracked correctly when validating assignment to gl_Position.
    TEST_F(WEBGLMultiviewVertexShaderTest, AssignmentWithViewIDInsideAssignment)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "layout(num_views = 2) in;\n"
            "void main()\n"
            "{\n"
            "    gl_Position.y = (gl_Position.x = (gl_ViewID_OVR == 0u) ? 1.0 : 0.0);\n"
            "}\n";
        if (compile(shaderString))
        {
            FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
        }
    }
    
    // Test that gl_ViewID_OVR can't be used as an l-value.
    TEST_F(WEBGLMultiviewVertexShaderTest, ViewIdAsLValue)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview2 : require\n"
            "layout(num_views = 2) in;\n"
            "void foo(out uint u)\n"
            "{\n"
            "    u = 3u;\n"
            "}\n"
            "void main()\n"
            "{\n"
            "    foo(gl_ViewID_OVR);\n"
            "    gl_Position = vec4(0.0, 0.0, 0.0, 1.0);\n"
            "}\n";
        if (compile(shaderString))
        {
            FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
        }
    }
    
    // Test that compiling an ESSL 1.00 shader with multiview support succeeds.
    TEST_F(WEBGLMultiviewVertexShaderTest, ESSL1Shader)
    {
        const std::string &shaderString =
            "#extension GL_OVR_multiview2 : require\n"
            "layout(num_views = 2) in;\n"
            "void main()\n"
            "{\n"
            "    if (gl_ViewID_OVR == 0)\n"
            "    {\n"
            "        gl_Position = vec4(-1.0, 0.0, 0.0, 1.0);\n"
            "    }\n"
            "    else\n"
            "    {\n"
            "        gl_Position = vec4(1.0, 0.0, 0.0, 1.0);\n"
            "    }\n"
            "}\n";
        if (!compile(shaderString))
        {
            FAIL() << "Shader compilation failed, expecting success:\n" << mInfoLog;
        }
    }
    
    // Test that compiling an ESSL 1.00 shader with an unsupported global layout qualifier fails.
    TEST_F(WEBGLMultiviewVertexShaderTest, ESSL1ShaderUnsupportedGlobalLayoutQualifier)
    {
        const std::string &shaderString =
            "#extension GL_OVR_multiview2 : require\n"
            "layout(num_views = 2) in;\n"
            "layout(std140) uniform;\n"
            "void main()\n"
            "{\n"
            "    if (gl_ViewID_OVR == 0)\n"
            "    {\n"
            "        gl_Position = vec4(-1.0, 0.0, 0.0, 1.0);\n"
            "    }\n"
            "    else\n"
            "    {\n"
            "        gl_Position = vec4(1.0, 0.0, 0.0, 1.0);\n"
            "    }\n"
            "}\n";
        if (compile(shaderString))
        {
            FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
        }
    }
    
    // Test that compiling an ESSL 1.00 vertex shader with an unsupported input storage qualifier fails.
    TEST_F(WEBGLMultiviewVertexShaderTest, ESSL1ShaderUnsupportedInputStorageQualifier)
    {
        const std::string &shaderString =
            "#extension GL_OVR_multiview2 : require\n"
            "layout(num_views = 2) in;\n"
            "in vec4 pos;\n"
            "void main()\n"
            "{\n"
            "    if (gl_ViewID_OVR == 0)\n"
            "    {\n"
            "        gl_Position = vec4(-1.0, 0.0, 0.0, 1.0);\n"
            "    }\n"
            "    else\n"
            "    {\n"
            "        gl_Position = vec4(1.0, 0.0, 0.0, 1.0);\n"
            "    }\n"
            "}\n";
        if (compile(shaderString))
        {
            FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
        }
    }
    
    // Test that compiling an ESSL 1.00 fragment shader with an unsupported input storage qualifier
    // fails.
    TEST_F(WEBGLMultiviewFragmentShaderTest, ESSL1ShaderUnsupportedInStorageQualifier)
    {
        const std::string &shaderString =
            "#extension GL_OVR_multiview2 : require\n"
            "precision highp float;\n"
            "in vec4 color;\n"
            "void main()\n"
            "{\n"
            "    if (gl_ViewID_OVR == 0)\n"
            "    {\n"
            "        gl_FragColor = color;\n"
            "    }\n"
            "    else\n"
            "    {\n"
            "        gl_FragColor = color + vec4(1.0, 0.0, 0.0, 1.0);\n"
            "    }\n"
            "}\n";
        if (compile(shaderString))
        {
            FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
        }
    }
    
    // Test that gl_InstanceID gets correctly replaced by InstanceID. gl_InstanceID should only be used
    // twice: once to initialize ViewID_OVR and once for InstanceID. The number of occurrences of
    // InstanceID in the AST should be the sum of two and the number of occurrences of gl_InstanceID
    // before any renaming.
    TEST_F(WEBGLMultiviewVertexShaderTest, GLInstanceIDIsRenamed)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "layout(num_views = 2) in;\n"
            "flat out int myInstance;\n"
            "out float myInstanceF;\n"
            "out float myInstanceF2;\n"
            "void main()\n"
            "{\n"
            "   gl_Position.x = gl_ViewID_OVR == 0u ? 0. : 1.;\n"
            "   gl_Position.yzw = vec3(0., 0., 1.);\n"
            "   myInstance = gl_InstanceID;\n"
            "   myInstanceF = float(gl_InstanceID) + .5;\n"
            "   myInstanceF2 = float(gl_InstanceID) + .1;\n"
            "}\n";
        mExtraCompileOptions |= SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW;
        compileAssumeSuccess(shaderString);
    
        SymbolOccurrenceCounterByName glInstanceIDByName("gl_InstanceID");
        mASTRoot->traverse(&glInstanceIDByName);
        EXPECT_EQ(2u, glInstanceIDByName.getNumberOfOccurrences());
    
        SymbolOccurrenceCounterByQualifier glInstanceIDByQualifier(EvqInstanceID);
        mASTRoot->traverse(&glInstanceIDByQualifier);
        EXPECT_EQ(2u, glInstanceIDByQualifier.getNumberOfOccurrences());
    
        SymbolOccurrenceCounterByName instanceIDByName("InstanceID");
        mASTRoot->traverse(&instanceIDByName);
        EXPECT_EQ(5u, instanceIDByName.getNumberOfOccurrences());
    }
    
    // Test that gl_ViewID_OVR gets correctly replaced by ViewID_OVR. gl_ViewID_OVR should not be found
    // by either name or qualifier. The number of occurrences of ViewID_OVR in the AST should be the sum
    // of two and the number of occurrences of gl_ViewID_OVR before any renaming.
    TEST_F(WEBGLMultiviewVertexShaderTest, GLViewIDIsRenamed)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview2 : require\n"
            "layout(num_views = 2) in;\n"
            "flat out uint a;\n"
            "void main()\n"
            "{\n"
            "   gl_Position.x = gl_ViewID_OVR == 0u ? 0. : 1.;\n"
            "   gl_Position.yzw = vec3(0., 0., 1.);\n"
            "   a = gl_ViewID_OVR == 0u ? (gl_ViewID_OVR+2u) : gl_ViewID_OVR;\n"
            "}\n";
        mExtraCompileOptions |= SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW;
        compileAssumeSuccess(shaderString);
    
        SymbolOccurrenceCounterByName glViewIDOVRByName("gl_ViewID_OVR");
        mASTRoot->traverse(&glViewIDOVRByName);
        EXPECT_EQ(0u, glViewIDOVRByName.getNumberOfOccurrences());
    
        SymbolOccurrenceCounterByQualifier glViewIDOVRByQualifier(EvqViewIDOVR);
        mASTRoot->traverse(&glViewIDOVRByQualifier);
        EXPECT_EQ(0u, glViewIDOVRByQualifier.getNumberOfOccurrences());
    
        SymbolOccurrenceCounterByNameAndQualifier viewIDByNameAndQualifier("ViewID_OVR", EvqFlatOut);
        mASTRoot->traverse(&viewIDByNameAndQualifier);
        EXPECT_EQ(6u, viewIDByNameAndQualifier.getNumberOfOccurrences());
    }
    
    // The test checks that ViewID_OVR and InstanceID have the correct initializers based on the
    // number of views.
    TEST_F(WEBGLMultiviewVertexShaderOutputCodeTest, ViewIDAndInstanceIDHaveCorrectValues)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "layout(num_views = 3) in;\n"
            "flat out int myInstance;\n"
            "void main()\n"
            "{\n"
            "   gl_Position.x = gl_ViewID_OVR == 0u ? 0. : 1.;\n"
            "   gl_Position.yzw = vec3(0., 0., 1.);\n"
            "   myInstance = gl_InstanceID;\n"
            "}\n";
        requestHLSLOutput();
        compile(shaderString, SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW);
    
        EXPECT_TRUE(foundInAllGLSLCode("webgl_angle_ViewID_OVR = (uint(gl_InstanceID) % 3u)"));
        EXPECT_TRUE(foundInAllGLSLCode("webgl_angle_InstanceID = (gl_InstanceID / 3)"));
    
        EXPECT_TRUE(foundInHLSLCode("ViewID_OVR = (uvec1(gl_InstanceID) % 3)"));
        EXPECT_TRUE(foundInHLSLCode("InstanceID = (gl_InstanceID / 3)"));
    }
    
    // The test checks that the directive enabling GL_OVR_multiview is not outputted if the extension is
    // emulated.
    TEST_F(WEBGLMultiviewVertexShaderOutputCodeTest, StrippedOVRMultiviewDirective)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "layout(num_views = 3) in;\n"
            "void main()\n"
            "{\n"
            "}\n";
        // The directive must not be present if any of the multiview emulation options are set.
        compile(shaderString, SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW);
        EXPECT_FALSE(foundInESSLCode("GL_OVR_multiview"));
        EXPECT_FALSE(foundInGLSLCode("GL_OVR_multiview"));
    
        compile(shaderString, SH_TRANSLATE_VIEWID_OVR_TO_UNIFORM);
        EXPECT_FALSE(foundInESSLCode("GL_OVR_multiview"));
        EXPECT_FALSE(foundInGLSLCode("GL_OVR_multiview"));
    
        // The directive should be outputted from the ESSL translator with none of the options being
        // set.
        compile(shaderString);
        EXPECT_TRUE(foundInESSLCode("GL_OVR_multiview"));
    }
    
    // Test that gl_InstanceID is collected in an ESSL1 shader if the
    // SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW option is set.
    TEST_F(WEBGLMultiviewVertexShaderTest, InstaceIDCollectedESSL1)
    {
        const std::string &shaderString =
            "#extension GL_OVR_multiview2 : require\n"
            "layout(num_views = 2) in;\n"
            "void main()\n"
            "{\n"
            "   gl_Position.x = gl_ViewID_OVR == 0 ? 0. : 1.;\n"
            "   gl_Position.yzw = vec3(0., 0., 1.);\n"
            "}\n";
        mExtraCompileOptions |= SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW;
        mExtraCompileOptions |= SH_VARIABLES;
        compileAssumeSuccess(shaderString);
    
        const std::vector<Attribute> &attributes = getAttributes();
        bool isGLInstanceIDFound                 = false;
        for (size_t i = 0u; i < attributes.size() && !isGLInstanceIDFound; ++i)
        {
            isGLInstanceIDFound = (attributes[i].name == "gl_InstanceID");
        }
        EXPECT_TRUE(isGLInstanceIDFound);
    }
    
    // Test that ViewID_OVR is declared as a flat input variable in an ESSL 3.00 fragment shader.
    TEST_F(WEBGLMultiviewFragmentShaderTest, ViewIDDeclaredAsFlatInput)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview2 : require\n"
            "void main()\n"
            "{\n"
            "}\n";
        mExtraCompileOptions |= SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW;
        compileAssumeSuccess(shaderString);
        VariableOccursNTimes(mASTRoot, "ViewID_OVR", EvqFlatIn, 1u);
    }
    
    // Test that ViewID_OVR is declared as a flat output variable in an ESSL 1.00 vertex shader.
    TEST_F(WEBGLMultiviewVertexShaderTest, ViewIDDeclaredAsFlatOutput)
    {
        const std::string &shaderString =
            "#extension GL_OVR_multiview2 : require\n"
            "void main()\n"
            "{\n"
            "}\n";
        mExtraCompileOptions |= SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW;
        compileAssumeSuccess(shaderString);
        VariableOccursNTimes(mASTRoot, "ViewID_OVR", EvqFlatOut, 2u);
    }
    
    // The test checks that the GL_NV_viewport_array2 extension is emitted in a vertex shader if the
    // SH_SELECT_VIEW_IN_NV_GLSL_VERTEX_SHADER option is set.
    TEST_F(WEBGLMultiviewVertexShaderOutputCodeTest, ViewportArray2IsEmitted)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "layout(num_views = 3) in;\n"
            "void main()\n"
            "{\n"
            "}\n";
        compile(shaderString, SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW |
                                  SH_SELECT_VIEW_IN_NV_GLSL_VERTEX_SHADER);
        EXPECT_TRUE(foundInAllGLSLCode("#extension GL_NV_viewport_array2 : require"));
    }
    
    // The test checks that the GL_NV_viewport_array2 extension is not emitted in a vertex shader if the
    // OVR_multiview extension is not requested in the shader source even if the
    // SH_SELECT_VIEW_IN_NV_GLSL_VERTEX_SHADER option is set.
    TEST_F(WEBGLMultiviewVertexShaderOutputCodeTest, ViewportArray2IsNotEmitted)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "void main()\n"
            "{\n"
            "}\n";
        compile(shaderString, SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW |
                                  SH_SELECT_VIEW_IN_NV_GLSL_VERTEX_SHADER);
        EXPECT_FALSE(foundInGLSLCode("#extension GL_NV_viewport_array2"));
        EXPECT_FALSE(foundInESSLCode("#extension GL_NV_viewport_array2"));
    }
    
    // The test checks that the GL_NV_viewport_array2 extension is not emitted in a fragment shader if
    // the SH_SELECT_VIEW_IN_NV_GLSL_VERTEX_SHADER option is set.
    TEST_F(WEBGLMultiviewFragmentShaderOutputCodeTest, ViewportArray2IsNotEmitted)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "void main()\n"
            "{\n"
            "}\n";
        compile(shaderString, SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW |
                                  SH_SELECT_VIEW_IN_NV_GLSL_VERTEX_SHADER);
        EXPECT_FALSE(foundInGLSLCode("#extension GL_NV_viewport_array2"));
        EXPECT_FALSE(foundInESSLCode("#extension GL_NV_viewport_array2"));
    }
    
    // The test checks that the GL_NV_viewport_array2 extension is not emitted in a compute shader if
    // the SH_SELECT_VIEW_IN_NV_GLSL_VERTEX_SHADER option is set.
    TEST_F(WEBGLMultiviewComputeShaderOutputCodeTest, ViewportArray2IsNotEmitted)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "void main()\n"
            "{\n"
            "}\n";
        compile(shaderString, SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW |
                                  SH_SELECT_VIEW_IN_NV_GLSL_VERTEX_SHADER);
        EXPECT_FALSE(foundInGLSLCode("#extension GL_NV_viewport_array2"));
        EXPECT_FALSE(foundInESSLCode("#extension GL_NV_viewport_array2"));
    }
    
    // The test checks that the viewport index is selected after the initialization of ViewID_OVR for
    // GLSL and ESSL ouputs.
    TEST_F(WEBGLMultiviewVertexShaderOutputCodeTest, GlViewportIndexIsSet)
    {
        const std::string &shaderString =
            "#version 300 es\n"
            "#extension GL_OVR_multiview : require\n"
            "layout(num_views = 3) in;\n"
            "void main()\n"
            "{\n"
            "}\n";
        compile(shaderString, SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW |
                                  SH_SELECT_VIEW_IN_NV_GLSL_VERTEX_SHADER);
        const char glViewportIndexAssignment[] = "gl_ViewportIndex = int(webgl_angle_ViewID_OVR)";
    
        // Check that the viewport index is selected.
        EXPECT_TRUE(foundInAllGLSLCode(glViewportIndexAssignment));
    
        // Setting gl_ViewportIndex must happen after ViewID_OVR's initialization.
        const char viewIDOVRAssignment[] = "webgl_angle_ViewID_OVR = (uint(gl_InstanceID) % 3u)";
        size_t viewIDOVRAssignmentLoc = findInCode(SH_GLSL_COMPATIBILITY_OUTPUT, viewIDOVRAssignment);
        size_t glViewportIndexAssignmentLoc =
            findInCode(SH_GLSL_COMPATIBILITY_OUTPUT, glViewportIndexAssignment);
        EXPECT_LT(viewIDOVRAssignmentLoc, glViewportIndexAssignmentLoc);
    
        viewIDOVRAssignmentLoc       = findInCode(SH_ESSL_OUTPUT, viewIDOVRAssignment);
        glViewportIndexAssignmentLoc = findInCode(SH_ESSL_OUTPUT, glViewportIndexAssignment);
        EXPECT_LT(viewIDOVRAssignmentLoc, glViewportIndexAssignmentLoc);
    }
    
    }  // namespace