src/tests/gl_tests/BlitFramebufferANGLETest.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 "test_utils/gl_raii.h"

using namespace angle;

class BlitFramebufferANGLETest : public ANGLETest
{
  protected:
    BlitFramebufferANGLETest()
    {
        setWindowWidth(256);
        setWindowHeight(256);
        setConfigRedBits(8);
        setConfigGreenBits(8);
        setConfigBlueBits(8);
        setConfigAlphaBits(8);
        setConfigDepthBits(24);
        setConfigStencilBits(8);

        mCheckerProgram = 0;
        mBlueProgram = 0;

        mOriginalFBO = 0;

        mUserFBO = 0;
        mUserColorBuffer = 0;
        mUserDepthStencilBuffer = 0;

        mSmallFBO = 0;
        mSmallColorBuffer = 0;
        mSmallDepthStencilBuffer = 0;

        mColorOnlyFBO = 0;
        mColorOnlyColorBuffer = 0;

        mDiffFormatFBO = 0;
        mDiffFormatColorBuffer = 0;

        mDiffSizeFBO = 0;
        mDiffSizeColorBuffer = 0;

        mMRTFBO = 0;
        mMRTColorBuffer0 = 0;
        mMRTColorBuffer1 = 0;

        mRGBAColorbuffer = 0;
        mRGBAFBO = 0;
        mRGBAMultisampledRenderbuffer = 0;
        mRGBAMultisampledFBO          = 0;

        mBGRAColorbuffer              = 0;
        mBGRAFBO                      = 0;
        mBGRAMultisampledRenderbuffer = 0;
        mBGRAMultisampledFBO = 0;
    }

    virtual void SetUp()
    {
        ANGLETest::SetUp();

        mCheckerProgram =
            CompileProgram(essl1_shaders::vs::Passthrough(), essl1_shaders::fs::Checkered());
        mBlueProgram = CompileProgram(essl1_shaders::vs::Simple(), essl1_shaders::fs::Blue());
        if (mCheckerProgram == 0 || mBlueProgram == 0)
        {
            FAIL() << "shader compilation failed.";
        }

        EXPECT_GL_NO_ERROR();

        GLint originalFBO;
        glGetIntegerv(GL_FRAMEBUFFER_BINDING, &originalFBO);
        if (originalFBO >= 0)
        {
            mOriginalFBO = (GLuint)originalFBO;
        }

        GLenum format = GL_BGRA_EXT;

        glGenFramebuffers(1, &mUserFBO);
        glBindFramebuffer(GL_FRAMEBUFFER, mUserFBO);
        glGenTextures(1, &mUserColorBuffer);
        glGenRenderbuffers(1, &mUserDepthStencilBuffer);
        glBindTexture(GL_TEXTURE_2D, mUserColorBuffer);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mUserColorBuffer, 0);
        glTexImage2D(GL_TEXTURE_2D, 0, format, getWindowWidth(), getWindowHeight(), 0, format,
                     GL_UNSIGNED_BYTE, nullptr);
        glBindRenderbuffer(GL_RENDERBUFFER, mUserDepthStencilBuffer);
        glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8_OES, getWindowWidth(), getWindowHeight());
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, mUserDepthStencilBuffer);
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, mUserDepthStencilBuffer);

        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
        ASSERT_GL_NO_ERROR();

        glGenFramebuffers(1, &mSmallFBO);
        glBindFramebuffer(GL_FRAMEBUFFER, mSmallFBO);
        glGenTextures(1, &mSmallColorBuffer);
        glGenRenderbuffers(1, &mSmallDepthStencilBuffer);
        glBindTexture(GL_TEXTURE_2D, mSmallColorBuffer);
        glTexImage2D(GL_TEXTURE_2D, 0, format, getWindowWidth() / 2, getWindowHeight() / 2, 0,
                     format, GL_UNSIGNED_BYTE, nullptr);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mSmallColorBuffer, 0);
        glBindRenderbuffer(GL_RENDERBUFFER, mSmallDepthStencilBuffer);
        glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8_OES, getWindowWidth() / 2, getWindowHeight() / 2);
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, mSmallDepthStencilBuffer);
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, mSmallDepthStencilBuffer);

        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
        ASSERT_GL_NO_ERROR();

        glGenFramebuffers(1, &mColorOnlyFBO);
        glBindFramebuffer(GL_FRAMEBUFFER, mColorOnlyFBO);
        glGenTextures(1, &mColorOnlyColorBuffer);
        glBindTexture(GL_TEXTURE_2D, mColorOnlyColorBuffer);
        glTexImage2D(GL_TEXTURE_2D, 0, format, getWindowWidth(), getWindowHeight(), 0, format,
                     GL_UNSIGNED_BYTE, nullptr);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mColorOnlyColorBuffer, 0);

        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
        ASSERT_GL_NO_ERROR();

        glGenFramebuffers(1, &mDiffFormatFBO);
        glBindFramebuffer(GL_FRAMEBUFFER, mDiffFormatFBO);
        glGenTextures(1, &mDiffFormatColorBuffer);
        glBindTexture(GL_TEXTURE_2D, mDiffFormatColorBuffer);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, getWindowWidth(), getWindowHeight(), 0, GL_RGB,
                     GL_UNSIGNED_SHORT_5_6_5, nullptr);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mDiffFormatColorBuffer, 0);

        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
        ASSERT_GL_NO_ERROR();

        glGenFramebuffers(1, &mDiffSizeFBO);
        glBindFramebuffer(GL_FRAMEBUFFER, mDiffSizeFBO);
        glGenTextures(1, &mDiffSizeColorBuffer);
        glBindTexture(GL_TEXTURE_2D, mDiffSizeColorBuffer);
        glTexImage2D(GL_TEXTURE_2D, 0, format, getWindowWidth() * 2, getWindowHeight() * 2, 0,
                     format, GL_UNSIGNED_BYTE, nullptr);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mDiffSizeColorBuffer, 0);

        ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
        ASSERT_GL_NO_ERROR();

        if (extensionEnabled("GL_EXT_draw_buffers"))
        {
            glGenFramebuffers(1, &mMRTFBO);
            glBindFramebuffer(GL_FRAMEBUFFER, mMRTFBO);
            glGenTextures(1, &mMRTColorBuffer0);
            glGenTextures(1, &mMRTColorBuffer1);
            glBindTexture(GL_TEXTURE_2D, mMRTColorBuffer0);
            glTexImage2D(GL_TEXTURE_2D, 0, format, getWindowWidth(), getWindowHeight(), 0, format,
                         GL_UNSIGNED_BYTE, nullptr);
            glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, mMRTColorBuffer0, 0);
            glBindTexture(GL_TEXTURE_2D, mMRTColorBuffer1);
            glTexImage2D(GL_TEXTURE_2D, 0, format, getWindowWidth(), getWindowHeight(), 0, format,
                         GL_UNSIGNED_BYTE, nullptr);
            glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1_EXT, GL_TEXTURE_2D, mMRTColorBuffer1, 0);

            ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
            ASSERT_GL_NO_ERROR();
        }

        if (extensionEnabled("GL_ANGLE_framebuffer_multisample") &&
            extensionEnabled("GL_OES_rgb8_rgba8"))
        {
            // RGBA single-sampled framebuffer
            glGenTextures(1, &mRGBAColorbuffer);
            glBindTexture(GL_TEXTURE_2D, mRGBAColorbuffer);
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, getWindowWidth(), getWindowHeight(), 0, GL_RGBA,
                         GL_UNSIGNED_BYTE, nullptr);

            glGenFramebuffers(1, &mRGBAFBO);
            glBindFramebuffer(GL_FRAMEBUFFER, mRGBAFBO);
            glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mRGBAColorbuffer, 0);

            ASSERT_GL_NO_ERROR();
            ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));

            // RGBA multisampled framebuffer
            glGenRenderbuffers(1, &mRGBAMultisampledRenderbuffer);
            glBindRenderbuffer(GL_RENDERBUFFER, mRGBAMultisampledRenderbuffer);
            glRenderbufferStorageMultisampleANGLE(GL_RENDERBUFFER, 1, GL_RGBA8, getWindowWidth(),
                                                  getWindowHeight());

            glGenFramebuffers(1, &mRGBAMultisampledFBO);
            glBindFramebuffer(GL_FRAMEBUFFER, mRGBAMultisampledFBO);
            glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER,
                                      mRGBAMultisampledRenderbuffer);

            ASSERT_GL_NO_ERROR();
            ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));

            if (extensionEnabled("GL_EXT_texture_format_BGRA8888"))
            {
                // BGRA single-sampled framebuffer
                glGenTextures(1, &mBGRAColorbuffer);
                glBindTexture(GL_TEXTURE_2D, mBGRAColorbuffer);
                glTexImage2D(GL_TEXTURE_2D, 0, GL_BGRA_EXT, getWindowWidth(), getWindowHeight(), 0,
                             GL_BGRA_EXT, GL_UNSIGNED_BYTE, nullptr);

                glGenFramebuffers(1, &mBGRAFBO);
                glBindFramebuffer(GL_FRAMEBUFFER, mBGRAFBO);
                glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
                                       mBGRAColorbuffer, 0);

                ASSERT_GL_NO_ERROR();
                ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));

                // BGRA multisampled framebuffer
                glGenRenderbuffers(1, &mBGRAMultisampledRenderbuffer);
                glBindRenderbuffer(GL_RENDERBUFFER, mBGRAMultisampledRenderbuffer);
                glRenderbufferStorageMultisampleANGLE(GL_RENDERBUFFER, 1, GL_BGRA8_EXT,
                                                      getWindowWidth(), getWindowHeight());

                glGenFramebuffers(1, &mBGRAMultisampledFBO);
                glBindFramebuffer(GL_FRAMEBUFFER, mBGRAMultisampledFBO);
                glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER,
                                          mBGRAMultisampledRenderbuffer);

                ASSERT_GL_NO_ERROR();
                ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));
            }
        }

        glBindFramebuffer(GL_FRAMEBUFFER, mOriginalFBO);
    }

    virtual void TearDown()
    {
        glDeleteProgram(mCheckerProgram);
        glDeleteProgram(mBlueProgram);

        glDeleteFramebuffers(1, &mUserFBO);
        glDeleteTextures(1, &mUserColorBuffer);
        glDeleteRenderbuffers(1, &mUserDepthStencilBuffer);

        glDeleteFramebuffers(1, &mSmallFBO);
        glDeleteTextures(1, &mSmallColorBuffer);
        glDeleteRenderbuffers(1, &mSmallDepthStencilBuffer);

        glDeleteFramebuffers(1, &mColorOnlyFBO);
        glDeleteTextures(1, &mSmallDepthStencilBuffer);

        glDeleteFramebuffers(1, &mDiffFormatFBO);
        glDeleteTextures(1, &mDiffFormatColorBuffer);

        glDeleteFramebuffers(1, &mDiffSizeFBO);
        glDeleteTextures(1, &mDiffSizeColorBuffer);

        if (extensionEnabled("GL_EXT_draw_buffers"))
        {
            glDeleteFramebuffers(1, &mMRTFBO);
            glDeleteTextures(1, &mMRTColorBuffer0);
            glDeleteTextures(1, &mMRTColorBuffer1);
        }

        if (mRGBAColorbuffer != 0)
        {
            glDeleteTextures(1, &mRGBAColorbuffer);
        }

        if (mRGBAFBO != 0)
        {
            glDeleteFramebuffers(1, &mRGBAFBO);
        }

        if (mRGBAMultisampledRenderbuffer != 0)
        {
            glDeleteRenderbuffers(1, &mRGBAMultisampledRenderbuffer);
        }

        if (mRGBAMultisampledFBO != 0)
        {
            glDeleteFramebuffers(1, &mRGBAMultisampledFBO);
        }

        if (mBGRAColorbuffer != 0)
        {
            glDeleteTextures(1, &mBGRAColorbuffer);
        }

        if (mBGRAFBO != 0)
        {
            glDeleteFramebuffers(1, &mBGRAFBO);
        }

        if (mBGRAMultisampledRenderbuffer != 0)
        {
            glDeleteRenderbuffers(1, &mBGRAMultisampledRenderbuffer);
        }

        if (mBGRAMultisampledFBO != 0)
        {
            glDeleteFramebuffers(1, &mBGRAMultisampledFBO);
        }

        ANGLETest::TearDown();
    }

    void multisampleTestHelper(GLuint readFramebuffer, GLuint drawFramebuffer)
    {
        glClearColor(0.0, 1.0, 0.0, 1.0);
        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, readFramebuffer);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
        EXPECT_GL_NO_ERROR();

        glBindFramebuffer(GL_READ_FRAMEBUFFER, readFramebuffer);
        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, drawFramebuffer);
        glBlitFramebufferANGLE(0, 0, getWindowWidth(), getWindowHeight(), 0, 0, getWindowWidth(),
                               getWindowHeight(), GL_COLOR_BUFFER_BIT, GL_NEAREST);
        EXPECT_GL_NO_ERROR();

        glBindFramebuffer(GL_READ_FRAMEBUFFER, drawFramebuffer);
        EXPECT_PIXEL_EQ(getWindowWidth() / 4, getWindowHeight() / 4, 0, 255, 0, 255);
        EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4, getWindowHeight() / 4, 0, 255, 0, 255);
        EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4, 3 * getWindowHeight() / 4, 0, 255, 0, 255);
        EXPECT_PIXEL_EQ(getWindowWidth() / 4, 3 * getWindowHeight() / 4, 0, 255, 0, 255);
    }

    bool checkExtension(const std::string &extension)
    {
        if (!extensionEnabled(extension))
        {
            std::cout << "Test skipped because " << extension << " not supported." << std::endl;
            return false;
        }

        return true;
    }

    GLuint mCheckerProgram;
    GLuint mBlueProgram;

    GLuint mOriginalFBO;

    GLuint mUserFBO;
    GLuint mUserColorBuffer;
    GLuint mUserDepthStencilBuffer;

    GLuint mSmallFBO;
    GLuint mSmallColorBuffer;
    GLuint mSmallDepthStencilBuffer;

    GLuint mColorOnlyFBO;
    GLuint mColorOnlyColorBuffer;

    GLuint mDiffFormatFBO;
    GLuint mDiffFormatColorBuffer;

    GLuint mDiffSizeFBO;
    GLuint mDiffSizeColorBuffer;

    GLuint mMRTFBO;
    GLuint mMRTColorBuffer0;
    GLuint mMRTColorBuffer1;

    GLuint mRGBAColorbuffer;
    GLuint mRGBAFBO;
    GLuint mRGBAMultisampledRenderbuffer;
    GLuint mRGBAMultisampledFBO;

    GLuint mBGRAColorbuffer;
    GLuint mBGRAFBO;
    GLuint mBGRAMultisampledRenderbuffer;
    GLuint mBGRAMultisampledFBO;
};

// Draw to user-created framebuffer, blit whole-buffer color to original framebuffer.
TEST_P(BlitFramebufferANGLETest, BlitColorToDefault)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mUserFBO);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.8f);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, mUserFBO);
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mOriginalFBO);

    glBlitFramebufferANGLE(0, 0, getWindowWidth(), getWindowHeight(), 0, 0, getWindowWidth(), getWindowHeight(), 
                           GL_COLOR_BUFFER_BIT, GL_NEAREST);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, mOriginalFBO);

    EXPECT_PIXEL_EQ(    getWindowWidth() / 4,     getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4,     getWindowHeight() / 4,   0, 255,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4, 3 * getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(    getWindowWidth() / 4, 3 * getWindowHeight() / 4,   0, 255,   0, 255);
}

// Draw to system framebuffer, blit whole-buffer color to user-created framebuffer.
TEST_P(BlitFramebufferANGLETest, ReverseColorBlit)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mOriginalFBO);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.8f);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, mOriginalFBO);
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mUserFBO);

    glBlitFramebufferANGLE(0, 0, getWindowWidth(), getWindowHeight(), 0, 0, getWindowWidth(), getWindowHeight(),
                           GL_COLOR_BUFFER_BIT, GL_NEAREST);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, mUserFBO);

    EXPECT_PIXEL_EQ(    getWindowWidth() / 4,     getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4,     getWindowHeight() / 4,   0, 255,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4, 3 * getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(    getWindowWidth() / 4, 3 * getWindowHeight() / 4,   0, 255,   0, 255);
}

// blit from user-created FBO to system framebuffer, with the scissor test enabled.
TEST_P(BlitFramebufferANGLETest, ScissoredBlit)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mUserFBO);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.8f);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mOriginalFBO);
    glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, mUserFBO);

    glClearColor(1.0, 1.0, 1.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    glScissor(getWindowWidth() / 2, 0, getWindowWidth() / 2, getWindowHeight());
    glEnable(GL_SCISSOR_TEST);

    glBlitFramebufferANGLE(0, 0, getWindowWidth(), getWindowHeight(), 0, 0, getWindowWidth(), getWindowHeight(), 
                           GL_COLOR_BUFFER_BIT, GL_NEAREST);

    EXPECT_GL_NO_ERROR();

    glDisable(GL_SCISSOR_TEST);

    glBindFramebuffer(GL_FRAMEBUFFER, mOriginalFBO);

    EXPECT_PIXEL_EQ(    getWindowWidth() / 4,     getWindowHeight() / 4, 255, 255, 255, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4,     getWindowHeight() / 4,   0, 255,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4, 3 * getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(    getWindowWidth() / 4, 3 * getWindowHeight() / 4, 255, 255, 255, 255);
}

// blit from system FBO to user-created framebuffer, with the scissor test enabled.
TEST_P(BlitFramebufferANGLETest, ReverseScissoredBlit)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mOriginalFBO);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.8f);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mUserFBO);
    glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, mOriginalFBO);

    glClearColor(1.0, 1.0, 1.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
    
    glScissor(getWindowWidth() / 2, 0, getWindowWidth() / 2, getWindowHeight());
    glEnable(GL_SCISSOR_TEST);

    glBlitFramebufferANGLE(0, 0, getWindowWidth(), getWindowHeight(), 0, 0, getWindowWidth(), getWindowHeight(), 
                           GL_COLOR_BUFFER_BIT, GL_NEAREST);

    EXPECT_GL_NO_ERROR();

    glDisable(GL_SCISSOR_TEST);

    glBindFramebuffer(GL_FRAMEBUFFER, mUserFBO);
    
    EXPECT_PIXEL_EQ(    getWindowWidth() / 4,     getWindowHeight() / 4, 255, 255, 255, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4,     getWindowHeight() / 4,   0, 255,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4, 3 * getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(    getWindowWidth() / 4, 3 * getWindowHeight() / 4, 255, 255, 255, 255);
}

// blit from user-created FBO to system framebuffer, using region larger than buffer.
TEST_P(BlitFramebufferANGLETest, OversizedBlit)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mUserFBO);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.8f);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mOriginalFBO);
    glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, mUserFBO);

    glClearColor(1.0, 1.0, 1.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    glBlitFramebufferANGLE(0, 0, getWindowWidth() * 2, getWindowHeight() * 2, 0, 0, getWindowWidth() * 2, getWindowHeight() * 2, 
                           GL_COLOR_BUFFER_BIT, GL_NEAREST);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, mOriginalFBO);

    EXPECT_PIXEL_EQ(    getWindowWidth() / 4,     getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4,     getWindowHeight() / 4,   0, 255,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4, 3 * getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(    getWindowWidth() / 4, 3 * getWindowHeight() / 4,   0, 255,   0, 255);
}

// blit from system FBO to user-created framebuffer, using region larger than buffer.
TEST_P(BlitFramebufferANGLETest, ReverseOversizedBlit)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mOriginalFBO);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.8f);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mUserFBO);
    glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, mOriginalFBO);

    glClearColor(1.0, 1.0, 1.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    glBlitFramebufferANGLE(0, 0, getWindowWidth() * 2, getWindowHeight() * 2, 0, 0, getWindowWidth() * 2, getWindowHeight() * 2, 
                           GL_COLOR_BUFFER_BIT, GL_NEAREST);
    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, mUserFBO);

    EXPECT_PIXEL_EQ(    getWindowWidth() / 4,     getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4,     getWindowHeight() / 4,   0, 255,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4, 3 * getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(    getWindowWidth() / 4, 3 * getWindowHeight() / 4,   0, 255,   0, 255);
}

// blit from user-created FBO to system framebuffer, with depth buffer.
TEST_P(BlitFramebufferANGLETest, BlitWithDepth)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mUserFBO);

    glDepthMask(GL_TRUE);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    glEnable(GL_DEPTH_TEST);

    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.3f);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mOriginalFBO);
    glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, mUserFBO);

    glClearColor(1.0, 1.0, 1.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    glBlitFramebufferANGLE(0, 0, getWindowWidth(), getWindowHeight(), 0, 0, getWindowWidth(), getWindowHeight(), 
                           GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT, GL_NEAREST);
    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, mOriginalFBO);

    // if blit is happening correctly, this quad will not draw, because it is behind the blitted one
    drawQuad(mBlueProgram, essl1_shaders::PositionAttrib(), 0.8f);

    glDisable(GL_DEPTH_TEST);

    EXPECT_PIXEL_EQ(    getWindowWidth() / 4,     getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4,     getWindowHeight() / 4,   0, 255,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4, 3 * getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(    getWindowWidth() / 4, 3 * getWindowHeight() / 4,   0, 255,   0, 255);
}

// blit from system FBO to user-created framebuffer, with depth buffer.
TEST_P(BlitFramebufferANGLETest, ReverseBlitWithDepth)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mOriginalFBO);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    glEnable(GL_DEPTH_TEST);

    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.3f);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mUserFBO);
    glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, mOriginalFBO);

    glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    glBlitFramebufferANGLE(0, 0, getWindowWidth(), getWindowHeight(), 0, 0, getWindowWidth(), getWindowHeight(), 
                           GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT, GL_NEAREST);
    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, mUserFBO);

    // if blit is happening correctly, this quad will not draw, because it is behind the blitted one

    drawQuad(mBlueProgram, essl1_shaders::PositionAttrib(), 0.8f);

    glDisable(GL_DEPTH_TEST);

    EXPECT_PIXEL_EQ(    getWindowWidth() / 4,     getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4,     getWindowHeight() / 4,   0, 255,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4, 3 * getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(    getWindowWidth() / 4, 3 * getWindowHeight() / 4,   0, 255,   0, 255);
}

// blit from one region of the system fbo to another-- this should fail.
TEST_P(BlitFramebufferANGLETest, BlitSameBufferOriginal)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mOriginalFBO);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.3f);

    EXPECT_GL_NO_ERROR();

    glBlitFramebufferANGLE(0, 0, getWindowWidth() / 2, getWindowHeight(), getWindowWidth() / 2, 0, getWindowWidth(), getWindowHeight(), 
                           GL_COLOR_BUFFER_BIT, GL_NEAREST);
    EXPECT_GL_ERROR(GL_INVALID_OPERATION);
}

// blit from one region of the system fbo to another.
TEST_P(BlitFramebufferANGLETest, BlitSameBufferUser)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mUserFBO);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.3f);

    EXPECT_GL_NO_ERROR();

    glBlitFramebufferANGLE(0, 0, getWindowWidth() / 2, getWindowHeight(), getWindowWidth() / 2, 0, getWindowWidth(), getWindowHeight(), 
                           GL_COLOR_BUFFER_BIT, GL_NEAREST);
    EXPECT_GL_ERROR(GL_INVALID_OPERATION);
}

TEST_P(BlitFramebufferANGLETest, BlitPartialColor)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mUserFBO);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.5f);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mOriginalFBO);
    glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, mUserFBO);

    glClearColor(1.0, 1.0, 1.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT| GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    glBlitFramebufferANGLE(0, 0, getWindowWidth() / 2, getWindowHeight() / 2, 0, getWindowHeight() / 2, getWindowWidth() / 2, getWindowHeight(),
                           GL_COLOR_BUFFER_BIT, GL_NEAREST);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, mOriginalFBO);

    EXPECT_PIXEL_EQ(    getWindowWidth() / 4,     getWindowHeight() / 4, 255, 255, 255, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4,     getWindowHeight() / 4, 255, 255, 255, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4, 3 * getWindowHeight() / 4, 255, 255, 255, 255);
    EXPECT_PIXEL_EQ(    getWindowWidth() / 4, 3 * getWindowHeight() / 4, 255,   0,   0, 255);
}

TEST_P(BlitFramebufferANGLETest, BlitDifferentSizes)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mUserFBO);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.5f);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mSmallFBO);
    glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, mUserFBO);

    glClearColor(1.0, 1.0, 1.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT| GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    glBlitFramebufferANGLE(0, 0, getWindowWidth(), getWindowHeight(), 0, 0, getWindowWidth(), getWindowHeight(),
                           GL_COLOR_BUFFER_BIT, GL_NEAREST);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, mSmallFBO);

    EXPECT_PIXEL_EQ(    getWindowWidth() / 4,     getWindowHeight() / 4, 255,   0,   0, 255);

    EXPECT_GL_NO_ERROR();
}

TEST_P(BlitFramebufferANGLETest, BlitWithMissingAttachments)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mColorOnlyFBO);

    glClear(GL_COLOR_BUFFER_BIT);
    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.3f);

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mOriginalFBO);
    glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, mColorOnlyFBO);

    glClearColor(1.0, 1.0, 1.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT| GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    // generate INVALID_OPERATION if the read FBO has no depth attachment
    glBlitFramebufferANGLE(0, 0, getWindowWidth(), getWindowHeight(), 0, 0, getWindowWidth(),
                           getWindowHeight(), GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT,
                           GL_NEAREST);

    EXPECT_GL_ERROR(GL_INVALID_OPERATION);

    // generate INVALID_OPERATION if the read FBO has no stencil attachment
    glBlitFramebufferANGLE(0, 0, getWindowWidth(), getWindowHeight(), 0, 0, getWindowWidth(),
                           getWindowHeight(), GL_COLOR_BUFFER_BIT | GL_STENCIL_BUFFER_BIT,
                           GL_NEAREST);

    EXPECT_GL_ERROR(GL_INVALID_OPERATION);

    // generate INVALID_OPERATION if we read from a missing color attachment
    glReadBuffer(GL_COLOR_ATTACHMENT1);
    glBlitFramebufferANGLE(0, 0, getWindowWidth(), getWindowHeight(), 0, 0, getWindowWidth(),
                           getWindowHeight(), GL_COLOR_BUFFER_BIT, GL_NEAREST);

    EXPECT_GL_ERROR(GL_INVALID_OPERATION);
}

TEST_P(BlitFramebufferANGLETest, BlitStencil)
{
    // TODO(jmadill): Figure out if we can fix this on D3D9.
    // https://code.google.com/p/angleproject/issues/detail?id=2205
    ANGLE_SKIP_TEST_IF(IsIntel() && IsD3D9());

    glBindFramebuffer(GL_FRAMEBUFFER, mUserFBO);

    glClear(GL_COLOR_BUFFER_BIT);
    // fill the stencil buffer with 0x1
    glStencilFunc(GL_ALWAYS, 0x1, 0xFF);
    glStencilOp(GL_REPLACE, GL_REPLACE, GL_REPLACE);
    glEnable(GL_STENCIL_TEST);
    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.3f);

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mOriginalFBO);
    glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, mUserFBO);

    glClearColor(1.0, 1.0, 1.0, 1.0);
    glClearStencil(0x0);
    glClear(GL_COLOR_BUFFER_BIT| GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    // depth blit request should be silently ignored, because the read FBO has no depth attachment
    glBlitFramebufferANGLE(0, 0, getWindowWidth(), getWindowHeight(), 0, 0, getWindowWidth(), getWindowHeight(),
                           GL_COLOR_BUFFER_BIT | GL_STENCIL_BUFFER_BIT, GL_NEAREST); 

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, mOriginalFBO);

    EXPECT_PIXEL_EQ(    getWindowWidth() / 4,     getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4,     getWindowHeight() / 4,   0, 255,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4, 3 * getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(    getWindowWidth() / 4, 3 * getWindowHeight() / 4,   0, 255,   0, 255);

    glStencilFunc(GL_EQUAL, 0x1, 0xFF); // only pass if stencil buffer at pixel reads 0x1
    drawQuad(mBlueProgram, essl1_shaders::PositionAttrib(),
             0.8f);  // blue quad will draw if stencil buffer was copied
    glDisable(GL_STENCIL_TEST);

    EXPECT_PIXEL_EQ(    getWindowWidth() / 4,     getWindowHeight() / 4,   0,   0, 255, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4,     getWindowHeight() / 4,   0,   0, 255, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4, 3 * getWindowHeight() / 4,   0,   0, 255, 255);
    EXPECT_PIXEL_EQ(    getWindowWidth() / 4, 3 * getWindowHeight() / 4,   0,   0, 255, 255);
}

// make sure that attempting to blit a partial depth buffer issues an error
TEST_P(BlitFramebufferANGLETest, BlitPartialDepthStencil)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mUserFBO);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.5f);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mOriginalFBO);
    glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, mUserFBO);

    glBlitFramebufferANGLE(0, 0, getWindowWidth() / 2, getWindowHeight() / 2, 0, 0, 
                           getWindowWidth() / 2, getWindowHeight() / 2, GL_DEPTH_BUFFER_BIT, GL_NEAREST);
    EXPECT_GL_ERROR(GL_INVALID_OPERATION);
}

// Test blit with MRT framebuffers
TEST_P(BlitFramebufferANGLETest, BlitMRT)
{
    if (!extensionEnabled("GL_EXT_draw_buffers"))
    {
        return;
    }

    GLenum drawBuffers[] = { GL_COLOR_ATTACHMENT0_EXT, GL_COLOR_ATTACHMENT1_EXT };

    glBindFramebuffer(GL_FRAMEBUFFER, mMRTFBO);
    glDrawBuffersEXT(2, drawBuffers);

    glBindFramebuffer(GL_FRAMEBUFFER, mColorOnlyFBO);

    glClear(GL_COLOR_BUFFER_BIT);

    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.8f);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, mColorOnlyFBO);
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mMRTFBO);

    glBlitFramebufferANGLE(0, 0, getWindowWidth(), getWindowHeight(), 0, 0, getWindowWidth(), getWindowHeight(), 
                           GL_COLOR_BUFFER_BIT, GL_NEAREST);
    
    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, mMRTFBO);

    EXPECT_PIXEL_EQ(    getWindowWidth() / 4,     getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4,     getWindowHeight() / 4,   0, 255,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4, 3 * getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(    getWindowWidth() / 4, 3 * getWindowHeight() / 4,   0, 255,   0, 255);

    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1_EXT, GL_TEXTURE_2D, 0, 0);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mMRTColorBuffer0, 0);

    EXPECT_PIXEL_EQ(    getWindowWidth() / 4,     getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4,     getWindowHeight() / 4,   0, 255,   0, 255);
    EXPECT_PIXEL_EQ(3 * getWindowWidth() / 4, 3 * getWindowHeight() / 4, 255,   0,   0, 255);
    EXPECT_PIXEL_EQ(    getWindowWidth() / 4, 3 * getWindowHeight() / 4,   0, 255,   0, 255);

    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mMRTColorBuffer0, 0);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1_EXT, GL_TEXTURE_2D, mMRTColorBuffer1, 0);
}

// Test multisampled framebuffer blits if supported
TEST_P(BlitFramebufferANGLETest, MultisampledRGBAToRGBA)
{
    if (!checkExtension("GL_ANGLE_framebuffer_multisample"))
        return;

    if (!checkExtension("GL_OES_rgb8_rgba8"))
        return;

    multisampleTestHelper(mRGBAMultisampledFBO, mRGBAFBO);
}

TEST_P(BlitFramebufferANGLETest, MultisampledRGBAToBGRA)
{
    if (!checkExtension("GL_ANGLE_framebuffer_multisample"))
        return;

    if (!checkExtension("GL_OES_rgb8_rgba8"))
        return;

    if (!checkExtension("GL_EXT_texture_format_BGRA8888"))
        return;

    multisampleTestHelper(mRGBAMultisampledFBO, mBGRAFBO);
}

TEST_P(BlitFramebufferANGLETest, MultisampledBGRAToRGBA)
{
    if (!checkExtension("GL_ANGLE_framebuffer_multisample"))
        return;

    if (!checkExtension("GL_OES_rgb8_rgba8"))
        return;

    if (!checkExtension("GL_EXT_texture_format_BGRA8888"))
        return;

    multisampleTestHelper(mBGRAMultisampledFBO, mRGBAFBO);
}

TEST_P(BlitFramebufferANGLETest, MultisampledBGRAToBGRA)
{
    if (!checkExtension("GL_ANGLE_framebuffer_multisample"))
        return;

    if (!checkExtension("GL_OES_rgb8_rgba8"))
        return;

    if (!checkExtension("GL_EXT_texture_format_BGRA8888"))
        return;

    multisampleTestHelper(mBGRAMultisampledFBO, mBGRAFBO);
}

// Make sure that attempts to stretch in a blit call issue an error
TEST_P(BlitFramebufferANGLETest, ErrorStretching)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mUserFBO);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.5f);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mOriginalFBO);
    glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, mUserFBO);

    glBlitFramebufferANGLE(0, 0, getWindowWidth() / 2, getWindowHeight() / 2, 0, 0, 
                           getWindowWidth(), getWindowHeight(), GL_COLOR_BUFFER_BIT, GL_NEAREST);
    EXPECT_GL_ERROR(GL_INVALID_OPERATION);
}

// Make sure that attempts to flip in a blit call issue an error
TEST_P(BlitFramebufferANGLETest, ErrorFlipping)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mUserFBO);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.5f);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mOriginalFBO);
    glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, mUserFBO);

    glBlitFramebufferANGLE(0, 0, getWindowWidth() / 2, getWindowHeight() / 2, getWindowWidth() / 2, getWindowHeight() / 2, 
                           0, 0, GL_COLOR_BUFFER_BIT, GL_NEAREST);
    EXPECT_GL_ERROR(GL_INVALID_OPERATION);
}

TEST_P(BlitFramebufferANGLETest, Errors)
{
    glBindFramebuffer(GL_FRAMEBUFFER, mUserFBO);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    drawQuad(mCheckerProgram, essl1_shaders::PositionAttrib(), 0.5f);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mOriginalFBO);
    glBindFramebuffer(GL_READ_FRAMEBUFFER_ANGLE, mUserFBO);

    glBlitFramebufferANGLE(0, 0, getWindowWidth(), getWindowHeight(), 0, 0, getWindowWidth(), getWindowHeight(), 
                           GL_COLOR_BUFFER_BIT, GL_LINEAR);
    EXPECT_GL_ERROR(GL_INVALID_ENUM);

    glBlitFramebufferANGLE(0, 0, getWindowWidth(), getWindowHeight(), 0, 0, getWindowWidth(), getWindowHeight(),
                           GL_COLOR_BUFFER_BIT | 234, GL_NEAREST);
    EXPECT_GL_ERROR(GL_INVALID_VALUE);

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_ANGLE, mDiffFormatFBO);

    glBlitFramebufferANGLE(0, 0, getWindowWidth(), getWindowHeight(), 0, 0, getWindowWidth(), getWindowHeight(),
                           GL_COLOR_BUFFER_BIT, GL_NEAREST);
    EXPECT_GL_ERROR(GL_INVALID_OPERATION);
}

// TODO(geofflang): Fix the dependence on glBlitFramebufferANGLE without checks and assuming the
// default framebuffer is BGRA to enable the GL and GLES backends. (http://anglebug.com/1289)

class BlitFramebufferTest : public ANGLETest
{
  protected:
    BlitFramebufferTest()
    {
        setWindowWidth(256);
        setWindowHeight(256);
        setConfigRedBits(8);
        setConfigGreenBits(8);
        setConfigBlueBits(8);
        setConfigAlphaBits(8);
        setConfigDepthBits(24);
        setConfigStencilBits(8);
    }

    void initColorFBO(GLFramebuffer *fbo,
                      GLRenderbuffer *rbo,
                      GLenum rboFormat,
                      GLsizei width,
                      GLsizei height)
    {
        glBindRenderbuffer(GL_RENDERBUFFER, *rbo);
        glRenderbufferStorage(GL_RENDERBUFFER, rboFormat, width, height);

        glBindFramebuffer(GL_FRAMEBUFFER, *fbo);
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, *rbo);
    }

    void initColorFBOWithCheckerPattern(GLFramebuffer *fbo,
                                        GLRenderbuffer *rbo,
                                        GLenum rboFormat,
                                        GLsizei width,
                                        GLsizei height)
    {
        initColorFBO(fbo, rbo, rboFormat, width, height);

        ANGLE_GL_PROGRAM(checkerProgram, essl1_shaders::vs::Passthrough(),
                         essl1_shaders::fs::Checkered());
        glViewport(0, 0, width, height);
        glBindFramebuffer(GL_FRAMEBUFFER, *fbo);
        drawQuad(checkerProgram.get(), essl1_shaders::PositionAttrib(), 0.5f);
    }
};

// Tests resolving a multisample depth buffer.
TEST_P(BlitFramebufferTest, MultisampleDepth)
{
    // TODO(oetuaho@nvidia.com): http://crbug.com/837717
    ANGLE_SKIP_TEST_IF(IsOpenGL() && IsOSX());

    GLRenderbuffer renderbuf;
    glBindRenderbuffer(GL_RENDERBUFFER, renderbuf.get());
    glRenderbufferStorageMultisample(GL_RENDERBUFFER, 2, GL_DEPTH_COMPONENT24, 256, 256);

    const std::string &fragment =
        "#version 300 es\n"
        "out mediump vec4 red;\n"
        "void main() {\n"
        "   red = vec4(1.0, 0.0, 0.0, 1.0);\n"
        "   gl_FragDepth = 0.5;\n"
        "}";

    ANGLE_GL_PROGRAM(drawRed, essl3_shaders::vs::Simple(), fragment);

    GLFramebuffer framebuffer;
    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer.get());
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER,
                              renderbuf.get());

    ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));

    glClearDepthf(0.5f);
    glClear(GL_DEPTH_BUFFER_BIT);

    GLRenderbuffer destRenderbuf;
    glBindRenderbuffer(GL_RENDERBUFFER, destRenderbuf.get());
    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, 256, 256);

    GLFramebuffer resolved;
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, resolved.get());
    glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER,
                              destRenderbuf.get());

    glBindFramebuffer(GL_READ_FRAMEBUFFER, framebuffer.get());
    glBlitFramebuffer(0, 0, 256, 256, 0, 0, 256, 256, GL_DEPTH_BUFFER_BIT, GL_NEAREST);

    glBindFramebuffer(GL_FRAMEBUFFER, resolved.get());

    GLTexture colorbuf;
    glBindTexture(GL_TEXTURE_2D, colorbuf.get());
    glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA8, 256, 256);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, colorbuf.get(), 0);

    ASSERT_GL_NO_ERROR();

    // Clear to green
    glClearColor(0.0f, 1.0f, 0.0f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT);
    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);

    // Draw with 0.5f test and the test should pass.
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_EQUAL);
    drawQuad(drawRed.get(), essl3_shaders::PositionAttrib(), 0.5f);
    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::red);

    ASSERT_GL_NO_ERROR();
}

// Test resolving a multisampled stencil buffer.
TEST_P(BlitFramebufferTest, MultisampleStencil)
{
    // Incorrect rendering results seen on AMD Windows OpenGL. http://anglebug.com/2486
    ANGLE_SKIP_TEST_IF(IsAMD() && IsOpenGL() && IsWindows());

    GLRenderbuffer renderbuf;
    glBindRenderbuffer(GL_RENDERBUFFER, renderbuf.get());
    glRenderbufferStorageMultisample(GL_RENDERBUFFER, 2, GL_STENCIL_INDEX8, 256, 256);

    ANGLE_GL_PROGRAM(drawRed, essl3_shaders::vs::Simple(), essl3_shaders::fs::Red());

    GLFramebuffer framebuffer;
    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer.get());
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER,
                              renderbuf.get());

    ASSERT_GLENUM_EQ(GL_FRAMEBUFFER_COMPLETE, glCheckFramebufferStatus(GL_FRAMEBUFFER));

    // fill the stencil buffer with 0x1
    glStencilFunc(GL_ALWAYS, 0x1, 0xFF);
    glStencilOp(GL_REPLACE, GL_REPLACE, GL_REPLACE);
    glEnable(GL_STENCIL_TEST);
    drawQuad(drawRed.get(), essl3_shaders::PositionAttrib(), 0.5f);

    GLTexture destColorbuf;
    glBindTexture(GL_TEXTURE_2D, destColorbuf.get());
    glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA8, 256, 256);

    GLRenderbuffer destRenderbuf;
    glBindRenderbuffer(GL_RENDERBUFFER, destRenderbuf.get());
    glRenderbufferStorage(GL_RENDERBUFFER, GL_STENCIL_INDEX8, 256, 256);

    GLFramebuffer resolved;
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, resolved.get());
    glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
                           destColorbuf.get(), 0);
    glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER,
                              destRenderbuf.get());

    glBindFramebuffer(GL_READ_FRAMEBUFFER, framebuffer.get());
    glBlitFramebuffer(0, 0, 256, 256, 0, 0, 256, 256, GL_STENCIL_BUFFER_BIT, GL_NEAREST);

    glBindFramebuffer(GL_FRAMEBUFFER, resolved.get());

    ASSERT_GL_NO_ERROR();

    // Clear to green
    glClearColor(0.0f, 1.0f, 0.0f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT);
    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);

    // Draw red if the stencil is 0x1, which should be true after the blit/resolve.
    glStencilFunc(GL_EQUAL, 0x1, 0xFF);
    drawQuad(drawRed.get(), essl3_shaders::PositionAttrib(), 0.5f);
    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::red);

    ASSERT_GL_NO_ERROR();
}

// Blit an SRGB framebuffer and scale it.
TEST_P(BlitFramebufferTest, BlitSRGBToRGBAndScale)
{
    constexpr const GLsizei kWidth  = 256;
    constexpr const GLsizei kHeight = 256;

    GLRenderbuffer sourceRBO, targetRBO;
    GLFramebuffer sourceFBO, targetFBO;
    initColorFBOWithCheckerPattern(&sourceFBO, &sourceRBO, GL_SRGB8_ALPHA8, kWidth * 2,
                                   kHeight * 2);
    initColorFBO(&targetFBO, &targetRBO, GL_RGBA8, kWidth, kHeight);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_READ_FRAMEBUFFER, sourceFBO);
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, targetFBO);

    glViewport(0, 0, kWidth, kHeight);

    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
    glClear(GL_COLOR_BUFFER_BIT);

    // Scale down without flipping.
    glBlitFramebuffer(0, 0, kWidth * 2, kHeight * 2, 0, 0, kWidth, kHeight, GL_COLOR_BUFFER_BIT,
                      GL_NEAREST);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, targetFBO);

    EXPECT_PIXEL_COLOR_EQ(kWidth / 4, kHeight / 4, GLColor::red);
    EXPECT_PIXEL_COLOR_EQ(3 * kWidth / 4, kHeight / 4, GLColor::green);
    EXPECT_PIXEL_COLOR_EQ(3 * kWidth / 4, 3 * kHeight / 4, GLColor::red);
    EXPECT_PIXEL_COLOR_EQ(kWidth / 4, 3 * kHeight / 4, GLColor::green);

    glBindFramebuffer(GL_READ_FRAMEBUFFER, sourceFBO);
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, targetFBO);

    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
    glClear(GL_COLOR_BUFFER_BIT);

    // Scale down and flip in the X direction.
    glBlitFramebuffer(0, 0, kWidth * 2, kHeight * 2, kWidth, 0, 0, kHeight, GL_COLOR_BUFFER_BIT,
                      GL_NEAREST);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, targetFBO);

    EXPECT_PIXEL_COLOR_EQ(kWidth / 4, kHeight / 4, GLColor::green);
    EXPECT_PIXEL_COLOR_EQ(3 * kWidth / 4, kHeight / 4, GLColor::red);
    EXPECT_PIXEL_COLOR_EQ(3 * kWidth / 4, 3 * kHeight / 4, GLColor::green);
    EXPECT_PIXEL_COLOR_EQ(kWidth / 4, 3 * kHeight / 4, GLColor::red);
}

// Blit a subregion of an SRGB framebuffer to an RGB framebuffer.
TEST_P(BlitFramebufferTest, PartialBlitSRGBToRGB)
{
    constexpr const GLsizei kWidth  = 256;
    constexpr const GLsizei kHeight = 256;

    GLRenderbuffer sourceRBO, targetRBO;
    GLFramebuffer sourceFBO, targetFBO;
    initColorFBOWithCheckerPattern(&sourceFBO, &sourceRBO, GL_SRGB8_ALPHA8, kWidth * 2,
                                   kHeight * 2);
    initColorFBO(&targetFBO, &targetRBO, GL_RGBA8, kWidth, kHeight);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_READ_FRAMEBUFFER, sourceFBO);
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, targetFBO);

    glViewport(0, 0, kWidth, kHeight);

    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
    glClear(GL_COLOR_BUFFER_BIT);

    // Blit a part of the source FBO without flipping.
    glBlitFramebuffer(kWidth, kHeight, kWidth * 2, kHeight * 2, 0, 0, kWidth, kHeight,
                      GL_COLOR_BUFFER_BIT, GL_NEAREST);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, targetFBO);

    EXPECT_PIXEL_COLOR_EQ(kWidth / 4, kHeight / 4, GLColor::red);
    EXPECT_PIXEL_COLOR_EQ(3 * kWidth / 4, kHeight / 4, GLColor::red);
    EXPECT_PIXEL_COLOR_EQ(3 * kWidth / 4, 3 * kHeight / 4, GLColor::red);
    EXPECT_PIXEL_COLOR_EQ(kWidth / 4, 3 * kHeight / 4, GLColor::red);

    glBindFramebuffer(GL_READ_FRAMEBUFFER, sourceFBO);
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, targetFBO);

    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
    glClear(GL_COLOR_BUFFER_BIT);

    // Blit a part of the source FBO and flip in the X direction.
    glBlitFramebuffer(kWidth * 2, 0, kWidth, kHeight, kWidth, 0, 0, kHeight, GL_COLOR_BUFFER_BIT,
                      GL_NEAREST);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, targetFBO);

    EXPECT_PIXEL_COLOR_EQ(kWidth / 4, kHeight / 4, GLColor::green);
    EXPECT_PIXEL_COLOR_EQ(3 * kWidth / 4, kHeight / 4, GLColor::green);
    EXPECT_PIXEL_COLOR_EQ(3 * kWidth / 4, 3 * kHeight / 4, GLColor::green);
    EXPECT_PIXEL_COLOR_EQ(kWidth / 4, 3 * kHeight / 4, GLColor::green);
}

// Blit an SRGB framebuffer with an oversized source area (parts outside the source area should be
// clipped out).
TEST_P(BlitFramebufferTest, BlitSRGBToRGBOversizedSourceArea)
{
    // D3D11 blit implementation seems to have a bug where the blit rectangles are computed
    // incorrectly. http://anglebug.com/2521
    ANGLE_SKIP_TEST_IF(IsD3D11());

    constexpr const GLsizei kWidth  = 256;
    constexpr const GLsizei kHeight = 256;

    GLRenderbuffer sourceRBO, targetRBO;
    GLFramebuffer sourceFBO, targetFBO;
    initColorFBOWithCheckerPattern(&sourceFBO, &sourceRBO, GL_SRGB8_ALPHA8, kWidth, kHeight);
    initColorFBO(&targetFBO, &targetRBO, GL_RGBA8, kWidth, kHeight);

    EXPECT_GL_NO_ERROR();

    glViewport(0, 0, kWidth, kHeight);

    glBindFramebuffer(GL_READ_FRAMEBUFFER, sourceFBO);
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, targetFBO);

    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT);

    // Blit so that the source area gets placed at the center of the target FBO.
    // The width of the source area is 1/4 of the width of the target FBO.
    glBlitFramebuffer(-3 * kWidth / 2, -3 * kHeight / 2, 5 * kWidth / 2, 5 * kHeight / 2, 0, 0,
                      kWidth, kHeight, GL_COLOR_BUFFER_BIT, GL_NEAREST);

    EXPECT_GL_NO_ERROR();

    glBindFramebuffer(GL_FRAMEBUFFER, targetFBO);

    // Source FBO colors can be found in the middle of the target FBO.
    EXPECT_PIXEL_COLOR_EQ(7 * kWidth / 16, 7 * kHeight / 16, GLColor::red);
    EXPECT_PIXEL_COLOR_EQ(9 * kWidth / 16, 7 * kHeight / 16, GLColor::green);
    EXPECT_PIXEL_COLOR_EQ(9 * kWidth / 16, 9 * kHeight / 16, GLColor::red);
    EXPECT_PIXEL_COLOR_EQ(7 * kWidth / 16, 9 * kHeight / 16, GLColor::green);

    // Clear color should remain around the edges of the target FBO (WebGL 2.0 spec explicitly
    // requires this and ANGLE is expected to follow that).
    EXPECT_PIXEL_COLOR_EQ(kWidth / 4, kHeight / 4, GLColor::black);
    EXPECT_PIXEL_COLOR_EQ(3 * kWidth / 4, kHeight / 4, GLColor::black);
    EXPECT_PIXEL_COLOR_EQ(3 * kWidth / 4, 3 * kHeight / 4, GLColor::black);
    EXPECT_PIXEL_COLOR_EQ(kWidth / 4, 3 * kHeight / 4, GLColor::black);
}

// Use this to select which configurations (e.g. which renderer, which GLES major version) these tests should be run against.
ANGLE_INSTANTIATE_TEST(BlitFramebufferANGLETest,
                       ES2_D3D9(),
                       ES2_D3D11(EGL_EXPERIMENTAL_PRESENT_PATH_COPY_ANGLE),
                       ES2_D3D11(EGL_EXPERIMENTAL_PRESENT_PATH_FAST_ANGLE),
                       ES2_OPENGL(),
                       ES3_OPENGL());

// We're specifically testing GL 4.4 and GL 4.3 since on versions earlier than 4.4 FramebufferGL
// takes a different path for blitting SRGB textures.
ANGLE_INSTANTIATE_TEST(BlitFramebufferTest, ES3_D3D11(), ES3_OPENGL(4, 4), ES3_OPENGL(4, 3));