ClearTest.cpp

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Author : Jamie Madill
Date : 2020-01-24 09:54:31
Hash : 0a3f58f1
Message : Fix undefined behaviour in ClearTest. We were expecting an uninitialized texture to contain black. However the contents of the texture data may be undefined. Discovered when working with the Vulkan command stream refactor. Bug: angleproject:4029 Change-Id: Ia5d24707746819b116ac0053fabb48033574569a Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2017978 Reviewed-by: Jonah Ryan-Davis <jonahr@google.com> Commit-Queue: Jamie Madill <jmadill@chromium.org>
src/tests/gl_tests/ClearTest.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.
//

#include "test_utils/ANGLETest.h"

#include "platform/FeaturesVk.h"
#include "test_utils/gl_raii.h"
#include "util/random_utils.h"
#include "util/shader_utils.h"

using namespace angle;

namespace
{

Vector4 RandomVec4(int seed, float minValue, float maxValue)
{
    RNG rng(seed);
    srand(seed);
    return Vector4(
        rng.randomFloatBetween(minValue, maxValue), rng.randomFloatBetween(minValue, maxValue),
        rng.randomFloatBetween(minValue, maxValue), rng.randomFloatBetween(minValue, maxValue));
}

GLColor Vec4ToColor(const Vector4 &vec)
{
    GLColor color;
    color.R = static_cast<uint8_t>(vec.x() * 255.0f);
    color.G = static_cast<uint8_t>(vec.y() * 255.0f);
    color.B = static_cast<uint8_t>(vec.z() * 255.0f);
    color.A = static_cast<uint8_t>(vec.w() * 255.0f);
    return color;
}

class ClearTestBase : public ANGLETest
{
  protected:
    ClearTestBase()
    {
        setWindowWidth(128);
        setWindowHeight(128);
        setConfigRedBits(8);
        setConfigGreenBits(8);
        setConfigBlueBits(8);
        setConfigAlphaBits(8);
        setConfigDepthBits(24);
        setConfigStencilBits(8);
    }

    void testSetUp() override
    {
        mFBOs.resize(2, 0);
        glGenFramebuffers(2, mFBOs.data());

        ASSERT_GL_NO_ERROR();
    }

    void testTearDown() override
    {
        if (!mFBOs.empty())
        {
            glDeleteFramebuffers(static_cast<GLsizei>(mFBOs.size()), mFBOs.data());
        }

        if (!mTextures.empty())
        {
            glDeleteTextures(static_cast<GLsizei>(mTextures.size()), mTextures.data());
        }
    }

    std::vector<GLuint> mFBOs;
    std::vector<GLuint> mTextures;
};

class ClearTest : public ClearTestBase
{};

class ClearTestES3 : public ClearTestBase
{
  protected:
    void verifyDepth(float depthValue, uint32_t size)
    {
        // Use a small shader to verify depth.
        ANGLE_GL_PROGRAM(depthTestProgram, essl1_shaders::vs::Passthrough(),
                         essl1_shaders::fs::Blue());
        ANGLE_GL_PROGRAM(depthTestProgramFail, essl1_shaders::vs::Passthrough(),
                         essl1_shaders::fs::Red());
        glEnable(GL_DEPTH_TEST);
        glDepthFunc(GL_LESS);
        drawQuad(depthTestProgram, essl1_shaders::PositionAttrib(), depthValue * 2 - 1 - 0.01f);
        drawQuad(depthTestProgramFail, essl1_shaders::PositionAttrib(), depthValue * 2 - 1 + 0.01f);
        glDisable(GL_DEPTH_TEST);
        ASSERT_GL_NO_ERROR();

        EXPECT_PIXEL_COLOR_NEAR(0, 0, GLColor::blue, 1);
        EXPECT_PIXEL_COLOR_NEAR(size - 1, 0, GLColor::blue, 1);
        EXPECT_PIXEL_COLOR_NEAR(0, size - 1, GLColor::blue, 1);
        EXPECT_PIXEL_COLOR_NEAR(size - 1, size - 1, GLColor::blue, 1);
    }

    void verifyStencil(uint32_t stencilValue, uint32_t size)
    {
        // Use another small shader to verify stencil.
        ANGLE_GL_PROGRAM(stencilTestProgram, essl1_shaders::vs::Passthrough(),
                         essl1_shaders::fs::Green());
        glEnable(GL_STENCIL_TEST);
        glStencilFunc(GL_EQUAL, stencilValue, 0xFF);
        drawQuad(stencilTestProgram, essl1_shaders::PositionAttrib(), 0.0f);
        glDisable(GL_STENCIL_TEST);
        ASSERT_GL_NO_ERROR();

        EXPECT_PIXEL_COLOR_NEAR(0, 0, GLColor::green, 1);
        EXPECT_PIXEL_COLOR_NEAR(size - 1, 0, GLColor::green, 1);
        EXPECT_PIXEL_COLOR_NEAR(0, size - 1, GLColor::green, 1);
        EXPECT_PIXEL_COLOR_NEAR(size - 1, size - 1, GLColor::green, 1);
    }
};

class ClearTestRGB : public ANGLETest
{
  protected:
    ClearTestRGB()
    {
        setWindowWidth(128);
        setWindowHeight(128);
        setConfigRedBits(8);
        setConfigGreenBits(8);
        setConfigBlueBits(8);
    }
};

// Each int parameter can have three values: don't clear, clear, or masked clear.  The bool
// parameter controls scissor.
using MaskedScissoredClearVariationsTestParams =
    std::tuple<angle::PlatformParameters, int, int, int, bool>;

void ParseMaskedScissoredClearVariationsTestParams(
    const MaskedScissoredClearVariationsTestParams &params,
    bool *clearColor,
    bool *clearDepth,
    bool *clearStencil,
    bool *maskColor,
    bool *maskDepth,
    bool *maskStencil,
    bool *scissor)
{
    int colorClearInfo   = std::get<1>(params);
    int depthClearInfo   = std::get<2>(params);
    int stencilClearInfo = std::get<3>(params);

    *clearColor   = colorClearInfo > 0;
    *clearDepth   = depthClearInfo > 0;
    *clearStencil = stencilClearInfo > 0;

    *maskColor   = colorClearInfo > 1;
    *maskDepth   = depthClearInfo > 1;
    *maskStencil = stencilClearInfo > 1;

    *scissor = std::get<4>(params);
}

std::string MaskedScissoredClearVariationsTestPrint(
    const ::testing::TestParamInfo<MaskedScissoredClearVariationsTestParams> &paramsInfo)
{
    const MaskedScissoredClearVariationsTestParams &params = paramsInfo.param;
    std::ostringstream out;

    out << std::get<0>(params);

    bool clearColor, clearDepth, clearStencil;
    bool maskColor, maskDepth, maskStencil;
    bool scissor;

    ParseMaskedScissoredClearVariationsTestParams(params, &clearColor, &clearDepth, &clearStencil,
                                                  &maskColor, &maskDepth, &maskStencil, &scissor);

    if (scissor)
    {
        out << "_scissored";
    }

    if (clearColor || clearDepth || clearStencil)
    {
        out << "_clear_";
        if (clearColor)
        {
            out << "c";
        }
        if (clearDepth)
        {
            out << "d";
        }
        if (clearStencil)
        {
            out << "s";
        }
    }

    if (maskColor || maskDepth || maskStencil)
    {
        out << "_mask_";
        if (maskColor)
        {
            out << "c";
        }
        if (maskDepth)
        {
            out << "d";
        }
        if (maskStencil)
        {
            out << "s";
        }
    }

    return out.str();
}

class MaskedScissoredClearTestBase
    : public ANGLETestWithParam<MaskedScissoredClearVariationsTestParams>
{
  protected:
    MaskedScissoredClearTestBase()
    {
        setWindowWidth(128);
        setWindowHeight(128);
        setConfigRedBits(8);
        setConfigGreenBits(8);
        setConfigBlueBits(8);
        setConfigAlphaBits(8);
        setConfigDepthBits(24);
        setConfigStencilBits(8);
    }

    void MaskedScissoredColorDepthStencilClear(
        const MaskedScissoredClearVariationsTestParams &params);

    bool mHasDepth   = true;
    bool mHasStencil = true;
};

class MaskedScissoredClearTest : public MaskedScissoredClearTestBase
{};

class VulkanClearTest : public MaskedScissoredClearTestBase
{
  protected:
    void testSetUp() override
    {
        glBindTexture(GL_TEXTURE_2D, mColorTexture);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, getWindowWidth(), getWindowHeight(), 0, GL_RGBA,
                     GL_UNSIGNED_BYTE, nullptr);

        // Setup Color/Stencil FBO with a stencil format that's emulated with packed depth/stencil.
        glBindFramebuffer(GL_FRAMEBUFFER, mColorStencilFBO);

        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mColorTexture,
                               0);
        glBindRenderbuffer(GL_RENDERBUFFER, mStencilTexture);
        glRenderbufferStorage(GL_RENDERBUFFER, GL_STENCIL_INDEX8, getWindowWidth(),
                              getWindowHeight());
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER,
                                  mStencilTexture);

        ASSERT_GL_NO_ERROR();

        // Note: GL_DEPTH_COMPONENT24 is not allowed in GLES2.
        if (getClientMajorVersion() >= 3)
        {
            // Setup Color/Depth FBO with a depth format that's emulated with packed depth/stencil.
            glBindFramebuffer(GL_FRAMEBUFFER, mColorDepthFBO);

            glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
                                   mColorTexture, 0);
            glBindRenderbuffer(GL_RENDERBUFFER, mDepthTexture);
            glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, getWindowWidth(),
                                  getWindowHeight());
            glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER,
                                      mDepthTexture);
        }

        ASSERT_GL_NO_ERROR();
    }

    void bindColorStencilFBO()
    {
        glBindFramebuffer(GL_FRAMEBUFFER, mColorStencilFBO);
        mHasDepth = false;
    }

    void bindColorDepthFBO()
    {
        glBindFramebuffer(GL_FRAMEBUFFER, mColorDepthFBO);
        mHasStencil = false;
    }

    // Override a feature to force emulation of stencil-only and depth-only formats with a packed
    // depth/stencil format
    void overrideFeaturesVk(FeaturesVk *featuresVk) override
    {
        featuresVk->overrideFeatures({"force_fallback_format"}, true);
    }

  private:
    GLFramebuffer mColorStencilFBO;
    GLFramebuffer mColorDepthFBO;
    GLTexture mColorTexture;
    GLRenderbuffer mDepthTexture;
    GLRenderbuffer mStencilTexture;
};

// Test clearing the default framebuffer
TEST_P(ClearTest, DefaultFramebuffer)
{
    glClearColor(0.25f, 0.5f, 0.5f, 0.5f);
    glClear(GL_COLOR_BUFFER_BIT);
    EXPECT_PIXEL_NEAR(0, 0, 64, 128, 128, 128, 1.0);
}

// Test clearing the default framebuffer with scissor and mask
// This forces down path that uses draw to do clear
TEST_P(ClearTest, EmptyScissor)
{
    // These configs have bug that fails this test.
    // These configs are unmaintained so skipping.
    ANGLE_SKIP_TEST_IF(IsIntel() && IsD3D9());
    ANGLE_SKIP_TEST_IF(IsOSX());
    glClearColor(0.25f, 0.5f, 0.5f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT);
    glEnable(GL_SCISSOR_TEST);
    glScissor(-10, 0, 5, 5);
    glClearColor(0.5f, 0.25f, 0.75f, 0.5f);
    glColorMask(GL_TRUE, GL_FALSE, GL_TRUE, GL_TRUE);
    glClear(GL_COLOR_BUFFER_BIT);
    glDisable(GL_SCISSOR_TEST);
    glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
    EXPECT_PIXEL_NEAR(0, 0, 64, 128, 128, 255, 1.0);
}

// Test clearing the RGB default framebuffer and verify that the alpha channel is not cleared
TEST_P(ClearTestRGB, DefaultFramebufferRGB)
{
    glClearColor(0.25f, 0.5f, 0.5f, 0.5f);
    glClear(GL_COLOR_BUFFER_BIT);
    EXPECT_PIXEL_NEAR(0, 0, 64, 128, 128, 255, 1.0);
}

// Test clearing a RGBA8 Framebuffer
TEST_P(ClearTest, RGBA8Framebuffer)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mFBOs[0]);

    GLTexture texture;

    glBindTexture(GL_TEXTURE_2D, texture);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, getWindowWidth(), getWindowHeight(), 0, GL_RGBA,
                 GL_UNSIGNED_BYTE, nullptr);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);

    glClearColor(0.5f, 0.5f, 0.5f, 0.5f);
    glClear(GL_COLOR_BUFFER_BIT);

    EXPECT_PIXEL_NEAR(0, 0, 128, 128, 128, 128, 1.0);
}

// Test to validate that we can go from an RGBA framebuffer attachment, to an RGB one and still
// have a correct behavior after.
TEST_P(ClearTest, ChangeFramebufferAttachmentFromRGBAtoRGB)
{
    // http://anglebug.com/2689
    ANGLE_SKIP_TEST_IF(IsD3D9() || IsD3D11() || (IsOzone() && IsOpenGLES()));
    ANGLE_SKIP_TEST_IF(IsOSX() && (IsNVIDIA() || IsIntel()) && IsDesktopOpenGL());
    ANGLE_SKIP_TEST_IF(IsAndroid() && IsAdreno() && IsOpenGLES());

    ANGLE_GL_PROGRAM(program, angle::essl1_shaders::vs::Simple(),
                     angle::essl1_shaders::fs::UniformColor());
    setupQuadVertexBuffer(0.5f, 1.0f);
    glUseProgram(program);
    GLint positionLocation = glGetAttribLocation(program, angle::essl1_shaders::PositionAttrib());
    ASSERT_NE(positionLocation, -1);
    glVertexAttribPointer(positionLocation, 3, GL_FLOAT, GL_FALSE, 0, nullptr);
    glEnableVertexAttribArray(positionLocation);

    GLint colorUniformLocation =
        glGetUniformLocation(program, angle::essl1_shaders::ColorUniform());
    ASSERT_NE(colorUniformLocation, -1);

    glUniform4f(colorUniformLocation, 1.0f, 1.0f, 1.0f, 0.5f);

    glBindFramebuffer(GL_FRAMEBUFFER, mFBOs[0]);

    GLTexture texture;
    glBindTexture(GL_TEXTURE_2D, texture);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, getWindowWidth(), getWindowHeight(), 0, GL_RGBA,
                 GL_UNSIGNED_BYTE, nullptr);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);

    // Initially clear to black.
    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT);

    // Clear with masked color.
    glColorMask(GL_TRUE, GL_FALSE, GL_TRUE, GL_TRUE);
    glClearColor(0.5f, 0.5f, 0.5f, 0.75f);
    glClear(GL_COLOR_BUFFER_BIT);
    ASSERT_GL_NO_ERROR();

    // So far so good, we have an RGBA framebuffer that we've cleared to 0.5 everywhere.
    EXPECT_PIXEL_NEAR(0, 0, 128, 0, 128, 192, 1.0);

    // In the Vulkan backend, RGB textures are emulated with an RGBA texture format
    // underneath and we keep a special mask to know that we shouldn't touch the alpha
    // channel when we have that emulated texture. This test exists to validate that
    // this mask gets updated correctly when the framebuffer attachment changes.
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, getWindowWidth(), getWindowHeight(), 0, GL_RGB,
                 GL_UNSIGNED_BYTE, nullptr);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);
    ASSERT_GL_NO_ERROR();

    glDrawArrays(GL_TRIANGLES, 0, 6);
    ASSERT_GL_NO_ERROR();

    EXPECT_PIXEL_RECT_EQ(0, 0, getWindowWidth(), getWindowHeight(), GLColor::magenta);
}

// Test clearing a RGB8 Framebuffer with a color mask.
TEST_P(ClearTest, RGB8WithMaskFramebuffer)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mFBOs[0]);

    GLTexture texture;

    glBindTexture(GL_TEXTURE_2D, texture);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, getWindowWidth(), getWindowHeight(), 0, GL_RGB,
                 GL_UNSIGNED_BYTE, nullptr);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);

    glClearColor(0.2f, 0.4f, 0.6f, 0.8f);
    glClear(GL_COLOR_BUFFER_BIT);

    // Since there's no alpha, we expect to get 255 back instead of the clear value (204).
    EXPECT_PIXEL_NEAR(0, 0, 51, 102, 153, 255, 1.0);

    glColorMask(GL_TRUE, GL_TRUE, GL_FALSE, GL_TRUE);
    glClearColor(0.1f, 0.3f, 0.5f, 0.7f);
    glClear(GL_COLOR_BUFFER_BIT);

    // The blue channel was masked so its value should be unchanged.
    EXPECT_PIXEL_NEAR(0, 0, 26, 77, 153, 255, 1.0);

    // Restore default.
    glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
}

TEST_P(ClearTest, ClearIssue)
{
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LEQUAL);

    glClearColor(0.0, 1.0, 0.0, 1.0);
    glClearDepthf(0.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, mFBOs[0]);

    GLRenderbuffer rbo;
    glBindRenderbuffer(GL_RENDERBUFFER, rbo);
    glRenderbufferStorage(GL_RENDERBUFFER, GL_RGB565, 16, 16);

    EXPECT_GL_NO_ERROR();

    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, rbo);

    EXPECT_GL_NO_ERROR();

    glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
    glClearDepthf(1.0f);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, 0);
    glBindBuffer(GL_ARRAY_BUFFER, 0);

    ANGLE_GL_PROGRAM(blueProgram, essl1_shaders::vs::Simple(), essl1_shaders::fs::Blue());
    drawQuad(blueProgram, essl1_shaders::PositionAttrib(), 0.5f);

    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
}

// Regression test for a bug where "glClearDepthf"'s argument was not clamped
// In GLES 2 they where declared as GLclampf and the behaviour is the same in GLES 3.2
TEST_P(ClearTest, ClearIsClamped)
{
    glClearDepthf(5.0f);

    GLfloat clear_depth;
    glGetFloatv(GL_DEPTH_CLEAR_VALUE, &clear_depth);
    EXPECT_EQ(1.0f, clear_depth);
}

// Regression test for a bug where "glDepthRangef"'s arguments were not clamped
// In GLES 2 they where declared as GLclampf and the behaviour is the same in GLES 3.2
TEST_P(ClearTest, DepthRangefIsClamped)
{
    glDepthRangef(1.1f, -4.0f);

    GLfloat depth_range[2];
    glGetFloatv(GL_DEPTH_RANGE, depth_range);
    EXPECT_EQ(1.0f, depth_range[0]);
    EXPECT_EQ(0.0f, depth_range[1]);
}

// Test scissored clears on Depth16
TEST_P(ClearTest, Depth16Scissored)
{
    GLRenderbuffer renderbuffer;
    glBindRenderbuffer(GL_RENDERBUFFER, renderbuffer);
    constexpr int kRenderbufferSize = 64;
    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, kRenderbufferSize,
                          kRenderbufferSize);

    GLFramebuffer fbo;
    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, renderbuffer);

    glClearDepthf(0.0f);
    glClear(GL_DEPTH_BUFFER_BIT);

    glEnable(GL_SCISSOR_TEST);
    constexpr int kNumSteps = 13;
    for (int ndx = 1; ndx < kNumSteps; ndx++)
    {
        float perc = static_cast<float>(ndx) / static_cast<float>(kNumSteps);
        glScissor(0, 0, static_cast<int>(kRenderbufferSize * perc),
                  static_cast<int>(kRenderbufferSize * perc));
        glClearDepthf(perc);
        glClear(GL_DEPTH_BUFFER_BIT);
    }
}

// Test scissored clears on Stencil8
TEST_P(ClearTest, Stencil8Scissored)
{
    GLRenderbuffer renderbuffer;
    glBindRenderbuffer(GL_RENDERBUFFER, renderbuffer);
    constexpr int kRenderbufferSize = 64;
    glRenderbufferStorage(GL_RENDERBUFFER, GL_STENCIL_INDEX8, kRenderbufferSize, kRenderbufferSize);

    GLFramebuffer fbo;
    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, renderbuffer);

    glClearStencil(0);
    glClear(GL_STENCIL_BUFFER_BIT);

    glEnable(GL_SCISSOR_TEST);
    constexpr int kNumSteps = 13;
    for (int ndx = 1; ndx < kNumSteps; ndx++)
    {
        float perc = static_cast<float>(ndx) / static_cast<float>(kNumSteps);
        glScissor(0, 0, static_cast<int>(kRenderbufferSize * perc),
                  static_cast<int>(kRenderbufferSize * perc));
        glClearStencil(static_cast<int>(perc * 255.0f));
        glClear(GL_STENCIL_BUFFER_BIT);
    }
}

// Covers a bug in the Vulkan back-end where starting a new command buffer in
// the masked clear would not trigger descriptor sets to be re-bound.
TEST_P(ClearTest, MaskedClearThenDrawWithUniform)
{
    // Initialize a program with a uniform.
    ANGLE_GL_PROGRAM(program, essl1_shaders::vs::Simple(), essl1_shaders::fs::UniformColor());
    glUseProgram(program);

    GLint uniLoc = glGetUniformLocation(program, essl1_shaders::ColorUniform());
    ASSERT_NE(-1, uniLoc);
    glUniform4f(uniLoc, 0.0f, 1.0f, 0.0f, 1.0f);

    // Initialize position attribute.
    GLint posLoc = glGetAttribLocation(program, essl1_shaders::PositionAttrib());
    ASSERT_NE(-1, posLoc);
    setupQuadVertexBuffer(0.5f, 1.0f);
    glVertexAttribPointer(posLoc, 3, GL_FLOAT, GL_FALSE, 0, nullptr);
    glEnableVertexAttribArray(posLoc);

    // Initialize a simple FBO.
    constexpr GLsizei kSize = 2;
    GLTexture clearTexture;
    glBindTexture(GL_TEXTURE_2D, clearTexture);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, kSize, kSize, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);

    GLFramebuffer fbo;
    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, clearTexture, 0);

    glViewport(0, 0, kSize, kSize);

    // Clear and draw to flush out dirty bits.
    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT);

    glDrawArrays(GL_TRIANGLES, 0, 6);

    // Flush to trigger a new serial.
    glFlush();

    // Enable color mask and draw again to trigger the bug.
    glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_FALSE);
    glClearColor(1.0f, 0.0f, 0.0f, 0.0f);
    glClear(GL_COLOR_BUFFER_BIT);

    glDrawArrays(GL_TRIANGLES, 0, 6);

    ASSERT_GL_NO_ERROR();
    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
}

// Test that clearing all buffers through glClearColor followed by a clear of a specific buffer
// clears to the correct values.
TEST_P(ClearTestES3, ClearMultipleAttachmentsFollowedBySpecificOne)
{
    // http://anglebug.com/4092
    ANGLE_SKIP_TEST_IF(isSwiftshader());
    constexpr uint32_t kSize            = 16;
    constexpr uint32_t kAttachmentCount = 4;
    std::vector<unsigned char> pixelData(kSize * kSize * 4, 255);

    glBindFramebuffer(GL_FRAMEBUFFER, mFBOs[0]);

    GLTexture textures[kAttachmentCount];
    GLenum drawBuffers[kAttachmentCount];
    GLColor clearValues[kAttachmentCount];

    for (uint32_t i = 0; i < kAttachmentCount; ++i)
    {
        glBindTexture(GL_TEXTURE_2D, textures[i]);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, kSize, kSize, 0, GL_RGBA, GL_UNSIGNED_BYTE,
                     pixelData.data());
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + i, GL_TEXTURE_2D, textures[i],
                               0);
        drawBuffers[i] = GL_COLOR_ATTACHMENT0 + i;

        clearValues[i].R = static_cast<GLubyte>(1 + i * 20);
        clearValues[i].G = static_cast<GLubyte>(7 + i * 20);
        clearValues[i].B = static_cast<GLubyte>(12 + i * 20);
        clearValues[i].A = static_cast<GLubyte>(16 + i * 20);
    }

    glDrawBuffers(kAttachmentCount, drawBuffers);

    ASSERT_GL_NO_ERROR();
    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::white);

    // Clear all targets.
    angle::Vector4 clearColor = clearValues[0].toNormalizedVector();
    glClearColor(clearColor[0], clearColor[1], clearColor[2], clearColor[3]);
    glClear(GL_COLOR_BUFFER_BIT);
    ASSERT_GL_NO_ERROR();

    // Clear odd targets individually.
    for (uint32_t i = 1; i < kAttachmentCount; i += 2)
    {
        clearColor = clearValues[i].toNormalizedVector();
        glClearBufferfv(GL_COLOR, i, clearColor.data());
    }

    // Even attachments should be cleared to color 0, while odd attachments are cleared to their
    // respective color.
    for (uint32_t i = 0; i < kAttachmentCount; ++i)
    {
        glReadBuffer(GL_COLOR_ATTACHMENT0 + i);
        ASSERT_GL_NO_ERROR();

        uint32_t clearIndex   = i % 2 == 0 ? 0 : i;
        const GLColor &expect = clearValues[clearIndex];

        EXPECT_PIXEL_COLOR_EQ(0, 0, expect);
        EXPECT_PIXEL_COLOR_EQ(0, kSize - 1, expect);
        EXPECT_PIXEL_COLOR_EQ(kSize - 1, 0, expect);
        EXPECT_PIXEL_COLOR_EQ(kSize - 1, kSize - 1, expect);
    }
}

// Test that clearing each render target individually works.  In the Vulkan backend, this should be
// done in a single render pass.
TEST_P(ClearTestES3, ClearMultipleAttachmentsIndividually)
{
    constexpr uint32_t kSize             = 16;
    constexpr uint32_t kAttachmentCount  = 2;
    constexpr float kDepthClearValue     = 0.125f;
    constexpr int32_t kStencilClearValue = 0x67;
    std::vector<unsigned char> pixelData(kSize * kSize * 4, 255);

    glBindFramebuffer(GL_FRAMEBUFFER, mFBOs[0]);

    GLTexture textures[kAttachmentCount];
    GLRenderbuffer depthStencil;
    GLenum drawBuffers[kAttachmentCount];
    GLColor clearValues[kAttachmentCount];

    for (uint32_t i = 0; i < kAttachmentCount; ++i)
    {
        glBindTexture(GL_TEXTURE_2D, textures[i]);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, kSize, kSize, 0, GL_RGBA, GL_UNSIGNED_BYTE,
                     pixelData.data());
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + i, GL_TEXTURE_2D, textures[i],
                               0);
        drawBuffers[i] = GL_COLOR_ATTACHMENT0 + i;

        clearValues[i].R = static_cast<GLubyte>(1 + i * 20);
        clearValues[i].G = static_cast<GLubyte>(7 + i * 20);
        clearValues[i].B = static_cast<GLubyte>(12 + i * 20);
        clearValues[i].A = static_cast<GLubyte>(16 + i * 20);
    }

    glBindRenderbuffer(GL_RENDERBUFFER, depthStencil);
    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, kSize, kSize);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER,
                              depthStencil);

    glDrawBuffers(kAttachmentCount, drawBuffers);

    ASSERT_GL_NO_ERROR();
    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::white);

    for (uint32_t i = 0; i < kAttachmentCount; ++i)
    {
        glClearBufferfv(GL_COLOR, i, clearValues[i].toNormalizedVector().data());
    }

    glClearBufferfv(GL_DEPTH, 0, &kDepthClearValue);
    glClearBufferiv(GL_STENCIL, 0, &kStencilClearValue);
    ASSERT_GL_NO_ERROR();

    for (uint32_t i = 0; i < kAttachmentCount; ++i)
    {
        glReadBuffer(GL_COLOR_ATTACHMENT0 + i);
        ASSERT_GL_NO_ERROR();

        const GLColor &expect = clearValues[i];

        EXPECT_PIXEL_COLOR_EQ(0, 0, expect);
        EXPECT_PIXEL_COLOR_EQ(0, kSize - 1, expect);
        EXPECT_PIXEL_COLOR_EQ(kSize - 1, 0, expect);
        EXPECT_PIXEL_COLOR_EQ(kSize - 1, kSize - 1, expect);
    }

    glReadBuffer(GL_COLOR_ATTACHMENT0);
    for (uint32_t i = 1; i < kAttachmentCount; ++i)
        drawBuffers[i] = GL_NONE;
    glDrawBuffers(kAttachmentCount, drawBuffers);

    verifyDepth(kDepthClearValue, kSize);
    verifyStencil(kStencilClearValue, kSize);
}

// Test that clearing multiple attachments in the presence of a color mask, scissor or both
// correctly clears all the attachments.
TEST_P(ClearTestES3, MaskedScissoredClearMultipleAttachments)
{
    constexpr uint32_t kSize            = 16;
    constexpr uint32_t kAttachmentCount = 2;
    std::vector<unsigned char> pixelData(kSize * kSize * 4, 255);

    glBindFramebuffer(GL_FRAMEBUFFER, mFBOs[0]);

    GLTexture textures[kAttachmentCount];
    GLenum drawBuffers[kAttachmentCount];

    for (uint32_t i = 0; i < kAttachmentCount; ++i)
    {
        glBindTexture(GL_TEXTURE_2D, textures[i]);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, kSize, kSize, 0, GL_RGBA, GL_UNSIGNED_BYTE,
                     pixelData.data());
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + i, GL_TEXTURE_2D, textures[i],
                               0);
        drawBuffers[i] = GL_COLOR_ATTACHMENT0 + i;
    }

    glDrawBuffers(kAttachmentCount, drawBuffers);

    ASSERT_GL_NO_ERROR();
    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::white);

    // Masked clear
    GLColor clearColorMasked(31, 63, 255, 191);
    angle::Vector4 clearColor = GLColor(31, 63, 127, 191).toNormalizedVector();

    glColorMask(GL_TRUE, GL_TRUE, GL_FALSE, GL_TRUE);
    glClearColor(clearColor[0], clearColor[1], clearColor[2], clearColor[3]);
    glClear(GL_COLOR_BUFFER_BIT);
    ASSERT_GL_NO_ERROR();

    // All attachments should be cleared, with the blue channel untouched
    for (uint32_t i = 0; i < kAttachmentCount; ++i)
    {
        glReadBuffer(GL_COLOR_ATTACHMENT0 + i);
        ASSERT_GL_NO_ERROR();

        EXPECT_PIXEL_COLOR_EQ(0, 0, clearColorMasked);
        EXPECT_PIXEL_COLOR_EQ(0, kSize - 1, clearColorMasked);
        EXPECT_PIXEL_COLOR_EQ(kSize - 1, 0, clearColorMasked);
        EXPECT_PIXEL_COLOR_EQ(kSize - 1, kSize - 1, clearColorMasked);
        EXPECT_PIXEL_COLOR_EQ(kSize / 2, kSize / 2, clearColorMasked);
    }

    // Masked scissored clear
    GLColor clearColorMaskedScissored(63, 127, 255, 31);
    clearColor = GLColor(63, 127, 191, 31).toNormalizedVector();

    glClearColor(clearColor[0], clearColor[1], clearColor[2], clearColor[3]);
    glEnable(GL_SCISSOR_TEST);
    glScissor(kSize / 6, kSize / 6, kSize / 3, kSize / 3);
    glClear(GL_COLOR_BUFFER_BIT);
    ASSERT_GL_NO_ERROR();

    // The corners should keep the previous value while the center is cleared, except its blue
    // channel.
    for (uint32_t i = 0; i < kAttachmentCount; ++i)
    {
        glReadBuffer(GL_COLOR_ATTACHMENT0 + i);
        ASSERT_GL_NO_ERROR();

        EXPECT_PIXEL_COLOR_EQ(0, 0, clearColorMasked);
        EXPECT_PIXEL_COLOR_EQ(0, kSize - 1, clearColorMasked);
        EXPECT_PIXEL_COLOR_EQ(kSize - 1, 0, clearColorMasked);
        EXPECT_PIXEL_COLOR_EQ(kSize - 1, kSize - 1, clearColorMasked);
        EXPECT_PIXEL_COLOR_EQ(kSize / 3, 2 * kSize / 3, clearColorMasked);
        EXPECT_PIXEL_COLOR_EQ(2 * kSize / 3, kSize / 3, clearColorMasked);
        EXPECT_PIXEL_COLOR_EQ(2 * kSize / 3, 2 * kSize / 3, clearColorMasked);

        EXPECT_PIXEL_COLOR_EQ(kSize / 3, kSize / 3, clearColorMaskedScissored);
    }

    // Scissored clear
    GLColor clearColorScissored(127, 191, 31, 63);
    clearColor = GLColor(127, 191, 31, 63).toNormalizedVector();

    glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
    glClearColor(clearColor[0], clearColor[1], clearColor[2], clearColor[3]);
    glClear(GL_COLOR_BUFFER_BIT);
    ASSERT_GL_NO_ERROR();

    // The corners should keep the old value while all channels of the center are cleared.
    for (uint32_t i = 0; i < kAttachmentCount; ++i)
    {
        glReadBuffer(GL_COLOR_ATTACHMENT0 + i);
        ASSERT_GL_NO_ERROR();

        EXPECT_PIXEL_COLOR_EQ(0, 0, clearColorMasked);
        EXPECT_PIXEL_COLOR_EQ(0, kSize - 1, clearColorMasked);
        EXPECT_PIXEL_COLOR_EQ(kSize - 1, 0, clearColorMasked);
        EXPECT_PIXEL_COLOR_EQ(kSize - 1, kSize - 1, clearColorMasked);
        EXPECT_PIXEL_COLOR_EQ(kSize / 3, 2 * kSize / 3, clearColorMasked);
        EXPECT_PIXEL_COLOR_EQ(2 * kSize / 3, kSize / 3, clearColorMasked);
        EXPECT_PIXEL_COLOR_EQ(2 * kSize / 3, 2 * kSize / 3, clearColorMasked);

        EXPECT_PIXEL_COLOR_EQ(kSize / 3, kSize / 3, clearColorScissored);
    }
}

// Test that clearing multiple attachments of different nature (float, int and uint) in the
// presence of a color mask works correctly.  In the Vulkan backend, this exercises clearWithDraw
// and the relevant internal shaders.
TEST_P(ClearTestES3, MaskedClearHeterogeneousAttachments)
{
    constexpr uint32_t kSize                              = 16;
    constexpr uint32_t kAttachmentCount                   = 3;
    constexpr float kDepthClearValue                      = 0.256f;
    constexpr int32_t kStencilClearValue                  = 0x1D;
    constexpr GLenum kAttachmentFormats[kAttachmentCount] = {
        GL_RGBA8,
        GL_RGBA8I,
        GL_RGBA8UI,
    };
    constexpr GLenum kDataFormats[kAttachmentCount] = {
        GL_RGBA,
        GL_RGBA_INTEGER,
        GL_RGBA_INTEGER,
    };
    constexpr GLenum kDataTypes[kAttachmentCount] = {
        GL_UNSIGNED_BYTE,
        GL_BYTE,
        GL_UNSIGNED_BYTE,
    };

    std::vector<unsigned char> pixelData(kSize * kSize * 4, 0);

    glBindFramebuffer(GL_FRAMEBUFFER, mFBOs[0]);

    GLTexture textures[kAttachmentCount];
    GLRenderbuffer depthStencil;
    GLenum drawBuffers[kAttachmentCount];

    for (uint32_t i = 0; i < kAttachmentCount; ++i)
    {
        glBindTexture(GL_TEXTURE_2D, textures[i]);
        glTexImage2D(GL_TEXTURE_2D, 0, kAttachmentFormats[i], kSize, kSize, 0, kDataFormats[i],
                     kDataTypes[i], pixelData.data());
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + i, GL_TEXTURE_2D, textures[i],
                               0);
        drawBuffers[i] = GL_COLOR_ATTACHMENT0 + i;
    }

    glBindRenderbuffer(GL_RENDERBUFFER, depthStencil);
    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, kSize, kSize);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER,
                              depthStencil);

    glDrawBuffers(kAttachmentCount, drawBuffers);

    ASSERT_GL_NO_ERROR();
    EXPECT_PIXEL_EQ(0, 0, 0, 0, 0, 0);

    // Mask out red for all clears
    glColorMask(GL_FALSE, GL_TRUE, GL_TRUE, GL_TRUE);

    glClearBufferfv(GL_DEPTH, 0, &kDepthClearValue);
    glClearBufferiv(GL_STENCIL, 0, &kStencilClearValue);

    GLColor clearValuef = {25, 50, 75, 100};
    glClearBufferfv(GL_COLOR, 0, clearValuef.toNormalizedVector().data());

    int clearValuei[4] = {10, -20, 30, -40};
    glClearBufferiv(GL_COLOR, 1, clearValuei);

    uint32_t clearValueui[4] = {50, 60, 70, 80};
    glClearBufferuiv(GL_COLOR, 2, clearValueui);

    ASSERT_GL_NO_ERROR();

    {
        glReadBuffer(GL_COLOR_ATTACHMENT0);
        ASSERT_GL_NO_ERROR();

        GLColor expect = clearValuef;
        expect.R       = 0;

        EXPECT_PIXEL_COLOR_EQ(0, 0, expect);
        EXPECT_PIXEL_COLOR_EQ(0, kSize - 1, expect);
        EXPECT_PIXEL_COLOR_EQ(kSize - 1, 0, expect);
        EXPECT_PIXEL_COLOR_EQ(kSize - 1, kSize - 1, expect);
    }

    {
        glReadBuffer(GL_COLOR_ATTACHMENT1);
        ASSERT_GL_NO_ERROR();

        EXPECT_PIXEL_8I(0, 0, 0, clearValuei[1], clearValuei[2], clearValuei[3]);
        EXPECT_PIXEL_8I(0, kSize - 1, 0, clearValuei[1], clearValuei[2], clearValuei[3]);
        EXPECT_PIXEL_8I(kSize - 1, 0, 0, clearValuei[1], clearValuei[2], clearValuei[3]);
        EXPECT_PIXEL_8I(kSize - 1, kSize - 1, 0, clearValuei[1], clearValuei[2], clearValuei[3]);
    }

    {
        glReadBuffer(GL_COLOR_ATTACHMENT2);
        ASSERT_GL_NO_ERROR();

        EXPECT_PIXEL_8UI(0, 0, 0, clearValueui[1], clearValueui[2], clearValueui[3]);
        EXPECT_PIXEL_8UI(0, kSize - 1, 0, clearValueui[1], clearValueui[2], clearValueui[3]);
        EXPECT_PIXEL_8UI(kSize - 1, 0, 0, clearValueui[1], clearValueui[2], clearValueui[3]);
        EXPECT_PIXEL_8UI(kSize - 1, kSize - 1, 0, clearValueui[1], clearValueui[2],
                         clearValueui[3]);
    }

    glReadBuffer(GL_COLOR_ATTACHMENT0);
    for (uint32_t i = 1; i < kAttachmentCount; ++i)
        drawBuffers[i] = GL_NONE;
    glDrawBuffers(kAttachmentCount, drawBuffers);

    verifyDepth(kDepthClearValue, kSize);
    verifyStencil(kStencilClearValue, kSize);
}

// This tests a bug where in a masked clear when calling "ClearBuffer", we would
// mistakenly clear every channel (including the masked-out ones)
TEST_P(ClearTestES3, MaskedClearBufferBug)
{
    // TODO(syoussefi): Qualcomm driver crashes in the presence of VK_ATTACHMENT_UNUSED.
    // http://anglebug.com/3423
    ANGLE_SKIP_TEST_IF(IsVulkan() && IsAndroid());

    unsigned char pixelData[] = {255, 255, 255, 255};

    glBindFramebuffer(GL_FRAMEBUFFER, mFBOs[0]);

    GLTexture textures[2];

    glBindTexture(GL_TEXTURE_2D, textures[0]);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixelData);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[0], 0);

    glBindTexture(GL_TEXTURE_2D, textures[1]);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixelData);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, textures[1], 0);

    ASSERT_GL_NO_ERROR();
    EXPECT_PIXEL_EQ(0, 0, 255, 255, 255, 255);

    float clearValue[]   = {0, 0.5f, 0.5f, 1.0f};
    GLenum drawBuffers[] = {GL_NONE, GL_COLOR_ATTACHMENT1};
    glDrawBuffers(2, drawBuffers);
    glColorMask(GL_TRUE, GL_TRUE, GL_FALSE, GL_TRUE);
    glClearBufferfv(GL_COLOR, 1, clearValue);

    ASSERT_GL_NO_ERROR();
    EXPECT_PIXEL_EQ(0, 0, 255, 255, 255, 255);

    glReadBuffer(GL_COLOR_ATTACHMENT1);
    ASSERT_GL_NO_ERROR();

    EXPECT_PIXEL_NEAR(0, 0, 0, 127, 255, 255, 1);
}

TEST_P(ClearTestES3, BadFBOSerialBug)
{
    // First make a simple framebuffer, and clear it to green
    glBindFramebuffer(GL_FRAMEBUFFER, mFBOs[0]);

    GLTexture textures[2];

    glBindTexture(GL_TEXTURE_2D, textures[0]);
    glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA8, getWindowWidth(), getWindowHeight());
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[0], 0);

    GLenum drawBuffers[] = {GL_COLOR_ATTACHMENT0};
    glDrawBuffers(1, drawBuffers);

    float clearValues1[] = {0.0f, 1.0f, 0.0f, 1.0f};
    glClearBufferfv(GL_COLOR, 0, clearValues1);

    ASSERT_GL_NO_ERROR();
    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);

    // Next make a second framebuffer, and draw it to red
    // (Triggers bad applied render target serial)
    GLFramebuffer fbo2;
    glBindFramebuffer(GL_FRAMEBUFFER, fbo2);
    ASSERT_GL_NO_ERROR();

    glBindTexture(GL_TEXTURE_2D, textures[1]);
    glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA8, getWindowWidth(), getWindowHeight());
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[1], 0);

    glDrawBuffers(1, drawBuffers);

    ANGLE_GL_PROGRAM(blueProgram, essl1_shaders::vs::Simple(), essl1_shaders::fs::Red());
    drawQuad(blueProgram, essl1_shaders::PositionAttrib(), 0.5f);

    ASSERT_GL_NO_ERROR();
    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::red);

    // Check that the first framebuffer is still green.
    glBindFramebuffer(GL_FRAMEBUFFER, mFBOs[0]);
    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
}

// Test that SRGB framebuffers clear to the linearized clear color
TEST_P(ClearTestES3, SRGBClear)
{
    // First make a simple framebuffer, and clear it
    glBindFramebuffer(GL_FRAMEBUFFER, mFBOs[0]);

    GLTexture texture;

    glBindTexture(GL_TEXTURE_2D, texture);
    glTexStorage2D(GL_TEXTURE_2D, 1, GL_SRGB8_ALPHA8, getWindowWidth(), getWindowHeight());
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);

    glClearColor(0.5f, 0.5f, 0.5f, 0.5f);
    glClear(GL_COLOR_BUFFER_BIT);

    EXPECT_PIXEL_NEAR(0, 0, 188, 188, 188, 128, 1.0);
}

// Test that framebuffers with mixed SRGB/Linear attachments clear to the correct color for each
// attachment
TEST_P(ClearTestES3, MixedSRGBClear)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mFBOs[0]);

    GLTexture textures[2];

    glBindTexture(GL_TEXTURE_2D, textures[0]);
    glTexStorage2D(GL_TEXTURE_2D, 1, GL_SRGB8_ALPHA8, getWindowWidth(), getWindowHeight());
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[0], 0);

    glBindTexture(GL_TEXTURE_2D, textures[1]);
    glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA8, getWindowWidth(), getWindowHeight());
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, textures[1], 0);

    GLenum drawBuffers[] = {GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1};
    glDrawBuffers(2, drawBuffers);

    // Clear both textures
    glClearColor(0.5f, 0.5f, 0.5f, 0.5f);
    glClear(GL_COLOR_BUFFER_BIT);

    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, 0, 0);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, 0, 0);

    // Check value of texture0
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[0], 0);
    EXPECT_PIXEL_NEAR(0, 0, 188, 188, 188, 128, 1.0);

    // Check value of texture1
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textures[1], 0);
    EXPECT_PIXEL_NEAR(0, 0, 128, 128, 128, 128, 1.0);
}

// This test covers a D3D11 bug where calling ClearRenderTargetView sometimes wouldn't sync
// before a draw call. The test draws small quads to a larger FBO (the default back buffer).
// Before each blit to the back buffer it clears the quad to a certain color using
// ClearBufferfv to give a solid color. The sync problem goes away if we insert a call to
// flush or finish after ClearBufferfv or each draw.
TEST_P(ClearTestES3, RepeatedClear)
{
    // Fails on 431.02 driver. http://anglebug.com/3748
    ANGLE_SKIP_TEST_IF(IsWindows() && IsNVIDIA() && IsVulkan());

    constexpr char kVS[] =
        "#version 300 es\n"
        "in highp vec2 position;\n"
        "out highp vec2 v_coord;\n"
        "void main(void)\n"
        "{\n"
        "    gl_Position = vec4(position, 0, 1);\n"
        "    vec2 texCoord = (position * 0.5) + 0.5;\n"
        "    v_coord = texCoord;\n"
        "}\n";

    constexpr char kFS[] =
        "#version 300 es\n"
        "in highp vec2 v_coord;\n"
        "out highp vec4 color;\n"
        "uniform sampler2D tex;\n"
        "void main()\n"
        "{\n"
        "    color = texture(tex, v_coord);\n"
        "}\n";

    ANGLE_GL_PROGRAM(program, kVS, kFS);

    mTextures.resize(1, 0);
    glGenTextures(1, mTextures.data());

    GLenum format           = GL_RGBA8;
    const int numRowsCols   = 3;
    const int cellSize      = 32;
    const int fboSize       = cellSize;
    const int backFBOSize   = cellSize * numRowsCols;
    const float fmtValueMin = 0.0f;
    const float fmtValueMax = 1.0f;

    glBindTexture(GL_TEXTURE_2D, mTextures[0]);
    glTexStorage2D(GL_TEXTURE_2D, 1, format, fboSize, fboSize);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    ASSERT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, mFBOs[0]);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mTextures[0], 0);
    ASSERT_GL_NO_ERROR();

    ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));

    // larger fbo bound -- clear to transparent black
    glUseProgram(program);
    GLint uniLoc = glGetUniformLocation(program, "tex");
    ASSERT_NE(-1, uniLoc);
    glUniform1i(uniLoc, 0);
    glBindTexture(GL_TEXTURE_2D, mTextures[0]);

    GLint positionLocation = glGetAttribLocation(program, "position");
    ASSERT_NE(-1, positionLocation);

    glUseProgram(program);

    for (int cellY = 0; cellY < numRowsCols; cellY++)
    {
        for (int cellX = 0; cellX < numRowsCols; cellX++)
        {
            int seed            = cellX + cellY * numRowsCols;
            const Vector4 color = RandomVec4(seed, fmtValueMin, fmtValueMax);

            glBindFramebuffer(GL_FRAMEBUFFER, mFBOs[0]);
            glClearBufferfv(GL_COLOR, 0, color.data());

            glBindFramebuffer(GL_FRAMEBUFFER, 0);

            // Method 1: Set viewport and draw full-viewport quad
            glViewport(cellX * cellSize, cellY * cellSize, cellSize, cellSize);
            drawQuad(program, "position", 0.5f);

            // Uncommenting the glFinish call seems to make the test pass.
            // glFinish();
        }
    }

    std::vector<GLColor> pixelData(backFBOSize * backFBOSize);
    glReadPixels(0, 0, backFBOSize, backFBOSize, GL_RGBA, GL_UNSIGNED_BYTE, pixelData.data());

    for (int cellY = 0; cellY < numRowsCols; cellY++)
    {
        for (int cellX = 0; cellX < numRowsCols; cellX++)
        {
            int seed              = cellX + cellY * numRowsCols;
            const Vector4 color   = RandomVec4(seed, fmtValueMin, fmtValueMax);
            GLColor expectedColor = Vec4ToColor(color);

            int testN = cellX * cellSize + cellY * backFBOSize * cellSize + backFBOSize + 1;
            GLColor actualColor = pixelData[testN];
            EXPECT_NEAR(expectedColor.R, actualColor.R, 1);
            EXPECT_NEAR(expectedColor.G, actualColor.G, 1);
            EXPECT_NEAR(expectedColor.B, actualColor.B, 1);
            EXPECT_NEAR(expectedColor.A, actualColor.A, 1);
        }
    }

    ASSERT_GL_NO_ERROR();
}

void MaskedScissoredClearTestBase::MaskedScissoredColorDepthStencilClear(
    const MaskedScissoredClearVariationsTestParams &params)
{
    // Flaky on Android Nexus 5x and Pixel 2, possible Qualcomm driver bug.
    // TODO(jmadill): Re-enable when possible. http://anglebug.com/2548
    ANGLE_SKIP_TEST_IF(IsOpenGLES() && IsAndroid());

    const int w      = getWindowWidth();
    const int h      = getWindowHeight();
    const int wthird = w / 3;
    const int hthird = h / 3;

    constexpr float kPreClearDepth     = 0.9f;
    constexpr float kClearDepth        = 0.5f;
    constexpr uint8_t kPreClearStencil = 0xFF;
    constexpr uint8_t kClearStencil    = 0x16;
    constexpr uint8_t kStencilMask     = 0x59;
    constexpr uint8_t kMaskedClearStencil =
        (kPreClearStencil & ~kStencilMask) | (kClearStencil & kStencilMask);

    bool clearColor, clearDepth, clearStencil;
    bool maskColor, maskDepth, maskStencil;
    bool scissor;

    ParseMaskedScissoredClearVariationsTestParams(params, &clearColor, &clearDepth, &clearStencil,
                                                  &maskColor, &maskDepth, &maskStencil, &scissor);

    // clearDepth && !maskDepth fails on Intel Ubuntu 19.04 Mesa 19.0.2 GL. http://anglebug.com/3614
    ANGLE_SKIP_TEST_IF(IsLinux() && IsIntel() && IsDesktopOpenGL() && clearDepth && !maskDepth);

    // Clear to a random color, 0.9 depth and 0x00 stencil
    Vector4 color1(0.1f, 0.2f, 0.3f, 0.4f);
    GLColor color1RGB(color1);

    glClearColor(color1[0], color1[1], color1[2], color1[3]);
    glClearDepthf(kPreClearDepth);
    glClearStencil(kPreClearStencil);

    if (!clearColor)
    {
        // If not asked to clear color, clear it anyway, but individually.  The clear value is
        // still used to verify that the depth/stencil clear happened correctly.  This allows
        // testing for depth/stencil-only clear implementations.
        glClear(GL_COLOR_BUFFER_BIT);
    }

    glClear((clearColor ? GL_COLOR_BUFFER_BIT : 0) | (clearDepth ? GL_DEPTH_BUFFER_BIT : 0) |
            (clearStencil ? GL_STENCIL_BUFFER_BIT : 0));
    ASSERT_GL_NO_ERROR();

    // Verify color was cleared correctly.
    EXPECT_PIXEL_COLOR_NEAR(0, 0, color1RGB, 1);

    if (scissor)
    {
        glEnable(GL_SCISSOR_TEST);
        glScissor(wthird / 2, hthird / 2, wthird, hthird);
    }

    // Use color and stencil masks to clear to a second color, 0.5 depth and 0x59 stencil.
    Vector4 color2(0.2f, 0.4f, 0.6f, 0.8f);
    GLColor color2RGB(color2);
    glClearColor(color2[0], color2[1], color2[2], color2[3]);
    glClearDepthf(kClearDepth);
    glClearStencil(kClearStencil);
    if (maskColor)
    {
        glColorMask(GL_TRUE, GL_FALSE, GL_TRUE, GL_FALSE);
    }
    if (maskDepth)
    {
        glDepthMask(GL_FALSE);
    }
    if (maskStencil)
    {
        glStencilMask(kStencilMask);
    }
    glClear((clearColor ? GL_COLOR_BUFFER_BIT : 0) | (clearDepth ? GL_DEPTH_BUFFER_BIT : 0) |
            (clearStencil ? GL_STENCIL_BUFFER_BIT : 0));
    glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
    glDepthMask(GL_TRUE);
    glStencilMask(0xFF);
    glDisable(GL_DEPTH_TEST);
    glDisable(GL_STENCIL_TEST);
    glDisable(GL_SCISSOR_TEST);
    ASSERT_GL_NO_ERROR();

    GLColor color2MaskedRGB(color2RGB[0], color1RGB[1], color2RGB[2], color1RGB[3]);

    // If not clearing color, the original color should be left both in the center and corners.  If
    // using a scissor, the corners should be left to the original color, while the center is
    // possibly changed.  If using a mask, the center (and corners if not scissored), changes to
    // the masked results.
    GLColor expectedCenterColorRGB =
        !clearColor ? color1RGB : maskColor ? color2MaskedRGB : color2RGB;
    GLColor expectedCornerColorRGB = scissor ? color1RGB : expectedCenterColorRGB;

    // Verify second clear color mask worked as expected.
    EXPECT_PIXEL_COLOR_NEAR(wthird, hthird, expectedCenterColorRGB, 1);

    EXPECT_PIXEL_COLOR_NEAR(0, 0, expectedCornerColorRGB, 1);
    EXPECT_PIXEL_COLOR_NEAR(w - 1, 0, expectedCornerColorRGB, 1);
    EXPECT_PIXEL_COLOR_NEAR(0, h - 1, expectedCornerColorRGB, 1);
    EXPECT_PIXEL_COLOR_NEAR(w - 1, h - 1, expectedCornerColorRGB, 1);
    EXPECT_PIXEL_COLOR_NEAR(wthird, 2 * hthird, expectedCornerColorRGB, 1);
    EXPECT_PIXEL_COLOR_NEAR(2 * wthird, hthird, expectedCornerColorRGB, 1);
    EXPECT_PIXEL_COLOR_NEAR(2 * wthird, 2 * hthird, expectedCornerColorRGB, 1);

    // If there is depth, but depth is not asked to be cleared, the depth buffer contains garbage,
    // so no particular behavior can be expected.
    if (clearDepth || !mHasDepth)
    {
        // We use a small shader to verify depth.
        ANGLE_GL_PROGRAM(depthTestProgram, essl1_shaders::vs::Passthrough(),
                         essl1_shaders::fs::Blue());
        glEnable(GL_DEPTH_TEST);
        glDepthFunc(maskDepth ? GL_GREATER : GL_EQUAL);
        // - If depth is cleared, but it's masked, kPreClearDepth should be in the depth buffer.
        // - If depth is cleared, but it's not masked, kClearDepth should be in the depth buffer.
        // - If depth is not cleared, the if above ensures there is no depth buffer at all,
        //   which means depth test will always pass.
        drawQuad(depthTestProgram, essl1_shaders::PositionAttrib(), maskDepth ? 1.0f : 0.0f);
        glDisable(GL_DEPTH_TEST);
        ASSERT_GL_NO_ERROR();

        // Either way, we expect blue to be written to the center.
        expectedCenterColorRGB = GLColor::blue;
        // If there is no depth, depth test always passes so the whole image must be blue.  Same if
        // depth write is masked.
        expectedCornerColorRGB =
            mHasDepth && scissor && !maskDepth ? expectedCornerColorRGB : GLColor::blue;

        EXPECT_PIXEL_COLOR_NEAR(wthird, hthird, expectedCenterColorRGB, 1);

        EXPECT_PIXEL_COLOR_NEAR(0, 0, expectedCornerColorRGB, 1);
        EXPECT_PIXEL_COLOR_NEAR(w - 1, 0, expectedCornerColorRGB, 1);
        EXPECT_PIXEL_COLOR_NEAR(0, h - 1, expectedCornerColorRGB, 1);
        EXPECT_PIXEL_COLOR_NEAR(w - 1, h - 1, expectedCornerColorRGB, 1);
        EXPECT_PIXEL_COLOR_NEAR(wthird, 2 * hthird, expectedCornerColorRGB, 1);
        EXPECT_PIXEL_COLOR_NEAR(2 * wthird, hthird, expectedCornerColorRGB, 1);
        EXPECT_PIXEL_COLOR_NEAR(2 * wthird, 2 * hthird, expectedCornerColorRGB, 1);
    }

    // If there is stencil, but it's not asked to be cleared, there is similarly no expectation.
    if (clearStencil || !mHasStencil)
    {
        // And another small shader to verify stencil.
        ANGLE_GL_PROGRAM(stencilTestProgram, essl1_shaders::vs::Passthrough(),
                         essl1_shaders::fs::Green());
        glEnable(GL_STENCIL_TEST);
        // - If stencil is cleared, but it's masked, kMaskedClearStencil should be in the stencil
        //   buffer.
        // - If stencil is cleared, but it's not masked, kClearStencil should be in the stencil
        //   buffer.
        // - If stencil is not cleared, the if above ensures there is no stencil buffer at all,
        //   which means stencil test will always pass.
        glStencilFunc(GL_EQUAL, maskStencil ? kMaskedClearStencil : kClearStencil, 0xFF);
        drawQuad(stencilTestProgram, essl1_shaders::PositionAttrib(), 0.0f);
        glDisable(GL_STENCIL_TEST);
        ASSERT_GL_NO_ERROR();

        // Either way, we expect green to be written to the center.
        expectedCenterColorRGB = GLColor::green;
        // If there is no stencil, stencil test always passes so the whole image must be green.
        expectedCornerColorRGB = mHasStencil && scissor ? expectedCornerColorRGB : GLColor::green;

        EXPECT_PIXEL_COLOR_NEAR(wthird, hthird, expectedCenterColorRGB, 1);

        EXPECT_PIXEL_COLOR_NEAR(0, 0, expectedCornerColorRGB, 1);
        EXPECT_PIXEL_COLOR_NEAR(w - 1, 0, expectedCornerColorRGB, 1);
        EXPECT_PIXEL_COLOR_NEAR(0, h - 1, expectedCornerColorRGB, 1);
        EXPECT_PIXEL_COLOR_NEAR(w - 1, h - 1, expectedCornerColorRGB, 1);
        EXPECT_PIXEL_COLOR_NEAR(wthird, 2 * hthird, expectedCornerColorRGB, 1);
        EXPECT_PIXEL_COLOR_NEAR(2 * wthird, hthird, expectedCornerColorRGB, 1);
        EXPECT_PIXEL_COLOR_NEAR(2 * wthird, 2 * hthird, expectedCornerColorRGB, 1);
    }
}

// Tests combinations of color, depth, stencil clears with or without masks or scissor.
TEST_P(MaskedScissoredClearTest, Test)
{
    MaskedScissoredColorDepthStencilClear(GetParam());
}

// Tests combinations of color, depth, stencil clears with or without masks or scissor.
//
// This uses depth/stencil attachments that are single-channel, but are emulated with a format
// that has both channels.
TEST_P(VulkanClearTest, Test)
{
    bool clearColor, clearDepth, clearStencil;
    bool maskColor, maskDepth, maskStencil;
    bool scissor;

    ParseMaskedScissoredClearVariationsTestParams(GetParam(), &clearColor, &clearDepth,
                                                  &clearStencil, &maskColor, &maskDepth,
                                                  &maskStencil, &scissor);

    // We only care about clearing depth xor stencil.
    if (clearDepth == clearStencil)
    {
        return;
    }

    if (clearDepth)
    {
        // Creating a depth-only renderbuffer is an ES3 feature.
        ANGLE_SKIP_TEST_IF(getClientMajorVersion() < 3);
        bindColorDepthFBO();
    }
    else
    {
        bindColorStencilFBO();
    }

    MaskedScissoredColorDepthStencilClear(GetParam());
}

// Test that just clearing a nonexistent drawbuffer of the default framebuffer doesn't cause an
// assert.
TEST_P(ClearTestES3, ClearBuffer1OnDefaultFramebufferNoAssert)
{
    std::vector<GLuint> testUint(4);
    glClearBufferuiv(GL_COLOR, 1, testUint.data());
    std::vector<GLint> testInt(4);
    glClearBufferiv(GL_COLOR, 1, testInt.data());
    std::vector<GLfloat> testFloat(4);
    glClearBufferfv(GL_COLOR, 1, testFloat.data());
    EXPECT_GL_NO_ERROR();
}

#ifdef Bool
// X11 craziness.
#    undef Bool
#endif

// 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(ClearTest);
ANGLE_INSTANTIATE_TEST_ES3(ClearTestES3);
ANGLE_INSTANTIATE_TEST_COMBINE_4(MaskedScissoredClearTest,
                                 MaskedScissoredClearVariationsTestPrint,
                                 testing::Range(0, 3),
                                 testing::Range(0, 3),
                                 testing::Range(0, 3),
                                 testing::Bool(),
                                 ES2_D3D9(),
                                 ES2_D3D11(),
                                 ES3_D3D11(),
                                 ES2_OPENGL(),
                                 ES3_OPENGL(),
                                 ES2_OPENGLES(),
                                 ES3_OPENGLES(),
                                 ES2_VULKAN(),
                                 ES3_VULKAN());
ANGLE_INSTANTIATE_TEST_COMBINE_4(VulkanClearTest,
                                 MaskedScissoredClearVariationsTestPrint,
                                 testing::Range(0, 3),
                                 testing::Range(0, 3),
                                 testing::Range(0, 3),
                                 testing::Bool(),
                                 ES2_VULKAN(),
                                 ES3_VULKAN());

// Not all ANGLE backends support RGB backbuffers
ANGLE_INSTANTIATE_TEST(ClearTestRGB, ES2_D3D11(), ES3_D3D11(), ES2_VULKAN(), ES3_VULKAN());

}  // anonymous namespace
kc3-lang/angle/src/tests/gl_tests/ClearTest.cpp

Commit

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