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

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• Author : Le Hoang Quyen
  Date : 2020-09-26 19:22:00
  Hash : 80d4901a
  Message : Metal: Support integer textures. Bug: angleproject:2634 Bug: angleproject:5154 Change-Id: Iffea26fe2c683557b4fa7c13fddf3523294b47d4 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2433329 Commit-Queue: Le Hoang Quyen <le.hoang.q@gmail.com> Reviewed-by: Jonah Ryan-Davis <jonahr@google.com> Reviewed-by: Jamie Madill <jmadill@chromium.org>

• src/tests/gl_tests/DrawBuffersTest.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 DrawBuffersTest : public ANGLETest
  {
    protected:
      DrawBuffersTest()
      {
          setWindowWidth(128);
          setWindowHeight(128);
          setConfigRedBits(8);
          setConfigGreenBits(8);
          setConfigBlueBits(8);
          setConfigAlphaBits(8);
          setConfigDepthBits(24);
      }
  
      void testTearDown() override
      {
          glDeleteFramebuffers(1, &mFBO);
          glDeleteFramebuffers(1, &mReadFramebuffer);
          glDeleteTextures(4, mTextures);
      }
  
      // We must call a different DrawBuffers method depending on extension support. Use this
      // method instead of calling on directly.
      void setDrawBuffers(GLsizei n, const GLenum *drawBufs)
      {
          if (IsGLExtensionEnabled("GL_EXT_draw_buffers"))
          {
              glDrawBuffersEXT(n, drawBufs);
          }
          else
          {
              ASSERT_GE(getClientMajorVersion(), 3);
              glDrawBuffers(n, drawBufs);
          }
      }
  
      // Use this method to filter if we can support these tests.
      bool setupTest()
      {
          if (getClientMajorVersion() < 3 && (!EnsureGLExtensionEnabled("GL_EXT_draw_buffers") ||
                                              !EnsureGLExtensionEnabled("GL_ANGLE_framebuffer_blit")))
          {
              return false;
          }
  
          // This test seems to fail on an nVidia machine when the window is hidden
          setWindowVisible(getOSWindow(), true);
  
          glGenFramebuffers(1, &mFBO);
          glBindFramebuffer(GL_DRAW_FRAMEBUFFER, mFBO);
  
          glGenTextures(4, mTextures);
  
          for (size_t texIndex = 0; texIndex < ArraySize(mTextures); texIndex++)
          {
              glBindTexture(GL_TEXTURE_2D, mTextures[texIndex]);
              glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, getWindowWidth(), getWindowHeight(), 0, GL_RGBA,
                           GL_UNSIGNED_BYTE, nullptr);
          }
  
          glGetIntegerv(GL_MAX_DRAW_BUFFERS, &mMaxDrawBuffers);
  
          glGenFramebuffers(1, &mReadFramebuffer);
          glBindFramebuffer(GL_READ_FRAMEBUFFER, mReadFramebuffer);
  
          return true;
      }
  
      void setupMRTProgramESSL3(bool bufferEnabled[8], GLuint *programOut)
      {
          std::stringstream strstr;
  
          strstr << "#version 300 es\n"
                    "precision highp float;\n";
  
          for (unsigned int index = 0; index < 8; index++)
          {
              if (bufferEnabled[index])
              {
                  strstr << "layout(location = " << index
                         << ") "
                            "out vec4 value"
                         << index << ";\n";
              }
          }
  
          strstr << "void main()\n"
                    "{\n";
  
          for (unsigned int index = 0; index < 8; index++)
          {
              if (bufferEnabled[index])
              {
                  unsigned int r = (index + 1) & 1;
                  unsigned int g = (index + 1) & 2;
                  unsigned int b = (index + 1) & 4;
  
                  strstr << "    value" << index << " = vec4(" << r << ".0, " << g << ".0, " << b
                         << ".0, 1.0);\n";
              }
          }
  
          strstr << "}\n";
  
          *programOut = CompileProgram(essl3_shaders::vs::Simple(), strstr.str().c_str());
          if (*programOut == 0)
          {
              FAIL() << "shader compilation failed.";
          }
      }
  
      void setupMRTProgramESSL1(bool bufferEnabled[8], GLuint *programOut)
      {
          std::stringstream strstr;
  
          strstr << "#extension GL_EXT_draw_buffers : enable\n"
                    "precision highp float;\n"
                    "void main()\n"
                    "{\n";
  
          for (unsigned int index = 0; index < 8; index++)
          {
              if (bufferEnabled[index])
              {
                  unsigned int r = (index + 1) & 1;
                  unsigned int g = (index + 1) & 2;
                  unsigned int b = (index + 1) & 4;
  
                  strstr << "    gl_FragData[" << index << "] = vec4(" << r << ".0, " << g << ".0, "
                         << b << ".0, 1.0);\n";
              }
          }
  
          strstr << "}\n";
  
          *programOut = CompileProgram(essl1_shaders::vs::Simple(), strstr.str().c_str());
          if (*programOut == 0)
          {
              FAIL() << "shader compilation failed.";
          }
      }
  
      void setupMRTProgram(bool bufferEnabled[8], GLuint *programOut)
      {
          if (getClientMajorVersion() == 3)
          {
              setupMRTProgramESSL3(bufferEnabled, programOut);
          }
          else
          {
              ASSERT_EQ(getClientMajorVersion(), 2);
              setupMRTProgramESSL1(bufferEnabled, programOut);
          }
      }
  
      const char *positionAttrib()
      {
          if (getClientMajorVersion() == 3)
          {
              return essl3_shaders::PositionAttrib();
          }
          else
          {
              return essl1_shaders::PositionAttrib();
          }
      }
  
      static GLColor getColorForIndex(unsigned int index)
      {
          GLubyte r = (((index + 1) & 1) > 0) ? 255 : 0;
          GLubyte g = (((index + 1) & 2) > 0) ? 255 : 0;
          GLubyte b = (((index + 1) & 4) > 0) ? 255 : 0;
          return GLColor(r, g, b, 255u);
      }
  
      void verifyAttachment2DColor(unsigned int index,
                                   GLuint textureName,
                                   GLenum target,
                                   GLint level,
                                   GLColor color)
      {
          glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, target, textureName,
                                 level);
          EXPECT_PIXEL_COLOR_EQ(getWindowWidth() / 2, getWindowHeight() / 2, color)
              << "index " << index;
      }
  
      void verifyAttachment2DUnwritten(unsigned int index, GLuint texture, GLenum target, GLint level)
      {
          verifyAttachment2DColor(index, texture, target, level, GLColor::transparentBlack);
      }
  
      void verifyAttachment2D(unsigned int index, GLuint texture, GLenum target, GLint level)
      {
          verifyAttachment2DColor(index, texture, target, level, getColorForIndex(index));
      }
  
      void verifyAttachment3DOES(unsigned int index, GLuint texture, GLint level, GLint layer)
      {
          ANGLE_SKIP_TEST_IF(!IsGLExtensionEnabled("GL_OES_texture_3D"));
  
          glFramebufferTexture3DOES(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_3D, texture,
                                    level, layer);
          EXPECT_PIXEL_COLOR_EQ(getWindowWidth() / 2, getWindowHeight() / 2, getColorForIndex(index));
      }
  
      void verifyAttachmentLayer(unsigned int index, GLuint texture, GLint level, GLint layer)
      {
          glFramebufferTextureLayer(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, texture, level, layer);
          EXPECT_PIXEL_COLOR_EQ(getWindowWidth() / 2, getWindowHeight() / 2, getColorForIndex(index));
      }
  
      GLuint mFBO             = 0;
      GLuint mReadFramebuffer = 0;
      GLuint mTextures[4]     = {};
      GLint mMaxDrawBuffers   = 0;
  };
  
  class DrawBuffersWebGL2Test : public DrawBuffersTest
  {
    public:
      DrawBuffersWebGL2Test()
      {
          setWebGLCompatibilityEnabled(true);
          setRobustResourceInit(true);
      }
  };
  
  // Verify that GL_MAX_DRAW_BUFFERS returns the expected values for D3D11
  TEST_P(DrawBuffersTest, VerifyD3DLimits)
  {
      EGLPlatformParameters platform = GetParam().eglParameters;
  
      ANGLE_SKIP_TEST_IF(platform.renderer != EGL_PLATFORM_ANGLE_TYPE_D3D11_ANGLE);
  
      glGetIntegerv(GL_MAX_DRAW_BUFFERS, &mMaxDrawBuffers);
  
      if (platform.majorVersion == 9 && platform.minorVersion == 3)
      {
          // D3D11 Feature Level 9_3 supports 4 draw buffers
          ASSERT_EQ(mMaxDrawBuffers, 4);
      }
      else
      {
          // D3D11 Feature Level 10_0+ supports 8 draw buffers
          ASSERT_EQ(mMaxDrawBuffers, 8);
      }
  }
  
  TEST_P(DrawBuffersTest, Gaps)
  {
      ANGLE_SKIP_TEST_IF(!setupTest());
  
      // TODO(ynovikov): Investigate the failure (http://anglebug.com/1535)
      ANGLE_SKIP_TEST_IF(IsWindows() && IsAMD() && IsDesktopOpenGL());
  
      // TODO(syoussefi): Qualcomm driver crashes in the presence of VK_ATTACHMENT_UNUSED.
      // http://anglebug.com/3423
      ANGLE_SKIP_TEST_IF(IsVulkan() && IsAndroid());
  
      // Fails on Intel Ubuntu 19.04 Mesa 19.0.2 Vulkan. http://anglebug.com/3616
      ANGLE_SKIP_TEST_IF(IsLinux() && IsIntel() && IsVulkan());
  
      glBindTexture(GL_TEXTURE_2D, mTextures[0]);
      glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, mTextures[0], 0);
  
      bool flags[8] = {false, true};
  
      GLuint program;
      setupMRTProgram(flags, &program);
  
      const GLenum bufs[] = {GL_NONE, GL_COLOR_ATTACHMENT1};
      setDrawBuffers(2, bufs);
      drawQuad(program, positionAttrib(), 0.5);
  
      verifyAttachment2D(1, mTextures[0], GL_TEXTURE_2D, 0);
  
      glDeleteProgram(program);
  }
  
  // Test that blend works with gaps
  TEST_P(DrawBuffersTest, BlendWithGaps)
  {
      ANGLE_SKIP_TEST_IF(!setupTest());
  
      // Qualcomm driver crashes in the presence of VK_ATTACHMENT_UNUSED.
      // http://anglebug.com/3423
      ANGLE_SKIP_TEST_IF(IsVulkan() && IsAndroid());
  
      // Fails on Intel Ubuntu 19.04 Mesa 19.0.2 Vulkan. http://anglebug.com/3616
      ANGLE_SKIP_TEST_IF(IsLinux() && IsIntel() && IsVulkan());
  
      // http://anglebug.com/5154
      ANGLE_SKIP_TEST_IF(IsOSX() && IsIntel() && IsDesktopOpenGL());
  
      glBindTexture(GL_TEXTURE_2D, mTextures[0]);
      glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, mTextures[0], 0);
  
      ASSERT_GL_NO_ERROR();
  
      bool flags[8] = {false, true};
  
      GLuint program;
      setupMRTProgram(flags, &program);
  
      const GLenum bufs[] = {GL_NONE, GL_COLOR_ATTACHMENT1};
      setDrawBuffers(2, bufs);
  
      // Draws green into attachment 1
      drawQuad(program, positionAttrib(), 0.5);
      verifyAttachment2D(1, mTextures[0], GL_TEXTURE_2D, 0);
      ASSERT_GL_NO_ERROR();
  
      // Clear with red
      glClearColor(1.0, 0.0, 0.0, 1.0);
      glClear(GL_COLOR_BUFFER_BIT);
      verifyAttachment2DColor(1, mTextures[0], GL_TEXTURE_2D, 0, GLColor(255u, 0, 0, 255u));
  
      // Draw green into attachment 1 again but with blending, expecting yellow
      glEnable(GL_BLEND);
      glBlendFunc(GL_ONE, GL_ONE);
      drawQuad(program, positionAttrib(), 0.5);
      verifyAttachment2DColor(1, mTextures[0], GL_TEXTURE_2D, 0, GLColor(255u, 255u, 0, 255u));
      ASSERT_GL_NO_ERROR();
  
      glDeleteProgram(program);
  }
  
  // Test that clear works with gaps
  TEST_P(DrawBuffersTest, ClearWithGaps)
  {
      // TODO(syoussefi): Qualcomm driver crashes in the presence of VK_ATTACHMENT_UNUSED.
      // http://anglebug.com/3423
      ANGLE_SKIP_TEST_IF(IsVulkan() && IsAndroid());
  
      ANGLE_SKIP_TEST_IF(!setupTest());
  
      glGetIntegerv(GL_MAX_DRAW_BUFFERS, &mMaxDrawBuffers);
      ASSERT_GE(mMaxDrawBuffers, 4);
  
      glBindTexture(GL_TEXTURE_2D, mTextures[0]);
      glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mTextures[0], 0);
  
      glBindTexture(GL_TEXTURE_2D, mTextures[1]);
      glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT3, GL_TEXTURE_2D, mTextures[1], 0);
  
      const GLenum bufs[] = {GL_COLOR_ATTACHMENT0, GL_NONE, GL_NONE, GL_COLOR_ATTACHMENT3};
  
      bool flags[8] = {true, false, false, true};
      GLuint program;
      setupMRTProgram(flags, &program);
  
      setDrawBuffers(4, bufs);
  
      glClearColor(1.0f, 1.0f, 0.0f, 1.0f);
      glClear(GL_COLOR_BUFFER_BIT);
  
      // A bogus draw to make sure clears are done with a render pass in the Vulkan backend.
      glEnable(GL_BLEND);
      glBlendFunc(GL_ZERO, GL_ONE);
      drawQuad(program, positionAttrib(), 0.5);
      EXPECT_GL_NO_ERROR();
  
      verifyAttachment2DColor(0, mTextures[0], GL_TEXTURE_2D, 0, GLColor::yellow);
      verifyAttachment2DColor(3, mTextures[1], GL_TEXTURE_2D, 0, GLColor::yellow);
  
      EXPECT_GL_NO_ERROR();
  }
  
  TEST_P(DrawBuffersTest, FirstAndLast)
  {
      ANGLE_SKIP_TEST_IF(!setupTest());
  
      // TODO(ynovikov): Investigate the failure (https://anglebug.com/1533)
      ANGLE_SKIP_TEST_IF(IsWindows() && IsAMD() && IsDesktopOpenGL());
  
      // TODO(syoussefi): Qualcomm driver crashes in the presence of VK_ATTACHMENT_UNUSED.
      // http://anglebug.com/3423
      ANGLE_SKIP_TEST_IF(IsVulkan() && IsAndroid());
  
      glBindTexture(GL_TEXTURE_2D, mTextures[0]);
      glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mTextures[0], 0);
  
      glBindTexture(GL_TEXTURE_2D, mTextures[1]);
      glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT3, GL_TEXTURE_2D, mTextures[1], 0);
  
      bool flags[8] = {true, false, false, true};
  
      GLuint program;
      setupMRTProgram(flags, &program);
  
      const GLenum bufs[] = {GL_COLOR_ATTACHMENT0, GL_NONE, GL_NONE, GL_COLOR_ATTACHMENT3};
  
      setDrawBuffers(4, bufs);
      drawQuad(program, positionAttrib(), 0.5);
  
      verifyAttachment2D(0, mTextures[0], GL_TEXTURE_2D, 0);
      verifyAttachment2D(3, mTextures[1], GL_TEXTURE_2D, 0);
  
      EXPECT_GL_NO_ERROR();
  
      glDeleteProgram(program);
  }
  
  TEST_P(DrawBuffersTest, FirstHalfNULL)
  {
      ANGLE_SKIP_TEST_IF(!setupTest());
  
      // TODO(ynovikov): Investigate the failure (https://anglebug.com/1533)
      ANGLE_SKIP_TEST_IF(IsWindows() && IsAMD() && IsDesktopOpenGL());
  
      // TODO(syoussefi): Qualcomm driver crashes in the presence of VK_ATTACHMENT_UNUSED.
      // http://anglebug.com/3423
      ANGLE_SKIP_TEST_IF(IsVulkan() && IsAndroid());
  
      // Fails on Intel Ubuntu 19.04 Mesa 19.0.2 Vulkan. http://anglebug.com/3616
      ANGLE_SKIP_TEST_IF(IsLinux() && IsIntel() && IsVulkan());
  
      bool flags[8]  = {false};
      GLenum bufs[8] = {GL_NONE};
  
      GLuint halfMaxDrawBuffers = static_cast<GLuint>(mMaxDrawBuffers) / 2;
  
      for (GLuint texIndex = 0; texIndex < halfMaxDrawBuffers; texIndex++)
      {
          glBindTexture(GL_TEXTURE_2D, mTextures[texIndex]);
          glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + halfMaxDrawBuffers + texIndex,
                                 GL_TEXTURE_2D, mTextures[texIndex], 0);
          flags[texIndex + halfMaxDrawBuffers] = true;
          bufs[texIndex + halfMaxDrawBuffers]  = GL_COLOR_ATTACHMENT0 + halfMaxDrawBuffers + texIndex;
      }
  
      GLuint program;
      setupMRTProgram(flags, &program);
  
      setDrawBuffers(mMaxDrawBuffers, bufs);
      drawQuad(program, positionAttrib(), 0.5);
  
      for (GLuint texIndex = 0; texIndex < halfMaxDrawBuffers; texIndex++)
      {
          verifyAttachment2D(texIndex + halfMaxDrawBuffers, mTextures[texIndex], GL_TEXTURE_2D, 0);
      }
  
      EXPECT_GL_NO_ERROR();
  
      glDeleteProgram(program);
  }
  
  // Test that non-zero draw buffers can be queried on the default framebuffer
  TEST_P(DrawBuffersTest, DefaultFramebufferDrawBufferQuery)
  {
      ANGLE_SKIP_TEST_IF(!setupTest());
  
      glBindFramebuffer(GL_FRAMEBUFFER, 0);
  
      GLint drawbuffer = 0;
      glGetIntegerv(GL_DRAW_BUFFER1, &drawbuffer);
      EXPECT_GL_NO_ERROR();
  
      EXPECT_EQ(GL_NONE, drawbuffer);
  }
  
  // Same as above but adds a state change from a program with different masks after a clear.
  TEST_P(DrawBuffersWebGL2Test, TwoProgramsWithDifferentOutputsAndClear)
  {
      // TODO(http://anglebug.com/2872): Broken on the GL back-end.
      ANGLE_SKIP_TEST_IF(IsOpenGL());
  
      // TODO(ynovikov): Investigate the failure (https://anglebug.com/1533)
      ANGLE_SKIP_TEST_IF(IsWindows() && IsAMD() && IsDesktopOpenGL());
  
      // TODO(syoussefi): Qualcomm driver crashes in the presence of VK_ATTACHMENT_UNUSED.
      // http://anglebug.com/3423
      ANGLE_SKIP_TEST_IF(IsVulkan() && IsAndroid());
  
      ANGLE_SKIP_TEST_IF(!setupTest());
  
      glGetIntegerv(GL_MAX_DRAW_BUFFERS, &mMaxDrawBuffers);
      ASSERT_GE(mMaxDrawBuffers, 4);
  
      bool flags[8]      = {false};
      GLenum someBufs[4] = {GL_NONE};
      GLenum allBufs[4]  = {GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2,
                           GL_COLOR_ATTACHMENT3};
  
      constexpr GLuint kMaxBuffers     = 4;
      constexpr GLuint kHalfMaxBuffers = 2;
  
      // Enable all draw buffers.
      for (GLuint texIndex = 0; texIndex < kMaxBuffers; texIndex++)
      {
          glBindTexture(GL_TEXTURE_2D, mTextures[texIndex]);
          glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + texIndex, GL_TEXTURE_2D,
                                 mTextures[texIndex], 0);
          someBufs[texIndex] =
              texIndex >= kHalfMaxBuffers ? GL_COLOR_ATTACHMENT0 + texIndex : GL_NONE;
  
          // Mask out the first two buffers.
          flags[texIndex] = texIndex >= kHalfMaxBuffers;
      }
  
      GLuint program;
      setupMRTProgram(flags, &program);
  
      // Now set up a second simple program that draws to FragColor. Should be broadcast.
      ANGLE_GL_PROGRAM(simpleProgram, essl1_shaders::vs::Simple(), essl1_shaders::fs::Red());
  
      // Draw with simple program.
      drawQuad(simpleProgram, essl1_shaders::PositionAttrib(), 0.5f, 1.0f, true);
      ASSERT_GL_NO_ERROR();
  
      // Clear draw buffers.
      setDrawBuffers(kMaxBuffers, someBufs);
      glClearColor(0.0f, 1.0f, 0.0f, 1.0f);
      glClear(GL_COLOR_BUFFER_BIT);
  
      ASSERT_GL_NO_ERROR();
  
      // Verify first is drawn red, second is untouched, and last two are cleared green.
      verifyAttachment2DColor(0, mTextures[0], GL_TEXTURE_2D, 0, GLColor::red);
      verifyAttachment2DColor(1, mTextures[1], GL_TEXTURE_2D, 0, GLColor::transparentBlack);
      verifyAttachment2DColor(2, mTextures[2], GL_TEXTURE_2D, 0, GLColor::green);
      verifyAttachment2DColor(3, mTextures[3], GL_TEXTURE_2D, 0, GLColor::green);
  
      // Draw with MRT program.
      setDrawBuffers(kMaxBuffers, someBufs);
      drawQuad(program, positionAttrib(), 0.5, 1.0f, true);
      ASSERT_GL_NO_ERROR();
  
      // Only the last two attachments should be updated.
      verifyAttachment2DColor(0, mTextures[0], GL_TEXTURE_2D, 0, GLColor::red);
      verifyAttachment2DColor(1, mTextures[1], GL_TEXTURE_2D, 0, GLColor::transparentBlack);
      verifyAttachment2D(2, mTextures[2], GL_TEXTURE_2D, 0);
      verifyAttachment2D(3, mTextures[3], GL_TEXTURE_2D, 0);
  
      // Active draw buffers with no fragment output is not allowed.
      setDrawBuffers(kMaxBuffers, allBufs);
      drawQuad(program, positionAttrib(), 0.5, 1.0f, true);
      ASSERT_GL_ERROR(GL_INVALID_OPERATION);
      // Exception: when RASTERIZER_DISCARD is enabled.
      glEnable(GL_RASTERIZER_DISCARD);
      drawQuad(program, positionAttrib(), 0.5, 1.0f, true);
      ASSERT_GL_NO_ERROR();
      glDisable(GL_RASTERIZER_DISCARD);
      // Exception: when all 4 channels of color mask are set to false.
      glColorMask(false, false, false, false);
      drawQuad(program, positionAttrib(), 0.5, 1.0f, true);
      ASSERT_GL_NO_ERROR();
      glColorMask(false, true, false, false);
      drawQuad(program, positionAttrib(), 0.5, 1.0f, true);
      ASSERT_GL_ERROR(GL_INVALID_OPERATION);
      glColorMask(true, true, true, true);
      drawQuad(program, positionAttrib(), 0.5, 1.0f, true);
      ASSERT_GL_ERROR(GL_INVALID_OPERATION);
  
      // Clear again. All attachments should be cleared.
      glClear(GL_COLOR_BUFFER_BIT);
      verifyAttachment2DColor(0, mTextures[0], GL_TEXTURE_2D, 0, GLColor::green);
      verifyAttachment2DColor(1, mTextures[1], GL_TEXTURE_2D, 0, GLColor::green);
      verifyAttachment2DColor(2, mTextures[2], GL_TEXTURE_2D, 0, GLColor::green);
      verifyAttachment2DColor(3, mTextures[3], GL_TEXTURE_2D, 0, GLColor::green);
  
      glDeleteProgram(program);
  }
  
  // Test clear with gaps in draw buffers, originally show up as
  // webgl_conformance_vulkan_passthrough_tests conformance/extensions/webgl-draw-buffers.html
  // failure. This is added for ease of debugging.
  TEST_P(DrawBuffersWebGL2Test, Clear)
  {
      ANGLE_SKIP_TEST_IF(!setupTest());
  
      constexpr GLint kMaxBuffers = 4;
  
      glGetIntegerv(GL_MAX_DRAW_BUFFERS, &mMaxDrawBuffers);
      ASSERT_GE(mMaxDrawBuffers, kMaxBuffers);
  
      GLenum drawBufs[kMaxBuffers] = {GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1,
                                      GL_COLOR_ATTACHMENT2, GL_COLOR_ATTACHMENT3};
  
      // Enable all draw buffers.
      for (GLuint texIndex = 0; texIndex < kMaxBuffers; texIndex++)
      {
          glBindTexture(GL_TEXTURE_2D, mTextures[texIndex]);
          glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + texIndex, GL_TEXTURE_2D,
                                 mTextures[texIndex], 0);
      }
  
      // Clear with all draw buffers.
      setDrawBuffers(kMaxBuffers, drawBufs);
      glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
      glClear(GL_COLOR_BUFFER_BIT);
  
      // Clear with first half none draw buffers.
      drawBufs[0] = GL_NONE;
      drawBufs[1] = GL_NONE;
      setDrawBuffers(kMaxBuffers, drawBufs);
      glClearColor(0.0f, 1.0f, 0.0f, 1.0f);
      glClear(GL_COLOR_BUFFER_BIT);
  
      ASSERT_GL_NO_ERROR();
  
      // Verify first is drawn red, second is untouched, and last two are cleared green.
      verifyAttachment2DColor(0, mTextures[0], GL_TEXTURE_2D, 0, GLColor::red);
      verifyAttachment2DColor(1, mTextures[1], GL_TEXTURE_2D, 0, GLColor::red);
      verifyAttachment2DColor(2, mTextures[2], GL_TEXTURE_2D, 0, GLColor::green);
      verifyAttachment2DColor(3, mTextures[3], GL_TEXTURE_2D, 0, GLColor::green);
  }
  
  TEST_P(DrawBuffersTest, UnwrittenOutputVariablesShouldNotCrash)
  {
      ANGLE_SKIP_TEST_IF(!setupTest());
  
      // Bind two render targets but use a shader which writes only to the first one.
      glBindTexture(GL_TEXTURE_2D, mTextures[0]);
      glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mTextures[0], 0);
  
      glBindTexture(GL_TEXTURE_2D, mTextures[1]);
      glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, mTextures[1], 0);
  
      bool flags[8] = {true, false};
  
      GLuint program;
      setupMRTProgram(flags, &program);
  
      const GLenum bufs[] = {
          GL_COLOR_ATTACHMENT0,
          GL_COLOR_ATTACHMENT1,
          GL_NONE,
          GL_NONE,
      };
  
      setDrawBuffers(4, bufs);
  
      // This call should not crash when we dynamically generate the HLSL code.
      drawQuad(program, positionAttrib(), 0.5);
  
      verifyAttachment2D(0, mTextures[0], GL_TEXTURE_2D, 0);
  
      EXPECT_GL_NO_ERROR();
  
      glDeleteProgram(program);
  }
  
  TEST_P(DrawBuffersTest, BroadcastGLFragColor)
  {
      // Broadcast is not supported on GLES 3.0.
      ANGLE_SKIP_TEST_IF(getClientMajorVersion() >= 3);
      ANGLE_SKIP_TEST_IF(!setupTest());
  
      // Bind two render targets. gl_FragColor should be broadcast to both.
      glBindTexture(GL_TEXTURE_2D, mTextures[0]);
      glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mTextures[0], 0);
  
      glBindTexture(GL_TEXTURE_2D, mTextures[1]);
      glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, mTextures[1], 0);
  
      const GLenum bufs[] = {GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1};
  
      constexpr char kFS[] =
          "#extension GL_EXT_draw_buffers : enable\n"
          "precision highp float;\n"
          "uniform float u_zero;\n"
          "void main()\n"
          "{\n"
          "    gl_FragColor = vec4(1, 0, 0, 1);\n"
          "    if (u_zero < 1.0)\n"
          "    {\n"
          "        return;\n"
          "    }\n"
          "}\n";
  
      GLuint program = CompileProgram(essl1_shaders::vs::Simple(), kFS);
      if (program == 0)
      {
          FAIL() << "shader compilation failed.";
      }
  
      setDrawBuffers(2, bufs);
      drawQuad(program, essl1_shaders::PositionAttrib(), 0.5);
  
      verifyAttachment2D(0, mTextures[0], GL_TEXTURE_2D, 0);
      verifyAttachment2D(0, mTextures[1], GL_TEXTURE_2D, 0);
  
      EXPECT_GL_NO_ERROR();
  
      glDeleteProgram(program);
  }
  
  // Test that binding multiple layers of a 3D texture works correctly.
  // This is the same as DrawBuffersTestES3.3DTextures but is used for GL_OES_texture_3D extension
  // on GLES 2.0 instead.
  TEST_P(DrawBuffersTest, 3DTexturesOES)
  {
      ANGLE_SKIP_TEST_IF(!setupTest());
      ANGLE_SKIP_TEST_IF(!IsGLExtensionEnabled("GL_OES_texture_3D"));
  
      GLTexture texture;
      glBindTexture(GL_TEXTURE_3D, texture.get());
      glTexImage3DOES(GL_TEXTURE_3D, 0, GL_RGBA, getWindowWidth(), getWindowHeight(),
                      getWindowWidth(), 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
  
      glFramebufferTexture3DOES(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_3D, texture.get(), 0,
                                0);
      glFramebufferTexture3DOES(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_3D, texture.get(), 0,
                                1);
      glFramebufferTexture3DOES(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, GL_TEXTURE_3D, texture.get(), 0,
                                2);
      glFramebufferTexture3DOES(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT3, GL_TEXTURE_3D, texture.get(), 0,
                                3);
  
      bool flags[8] = {true, true, true, true, false};
  
      GLuint program;
      setupMRTProgram(flags, &program);
  
      const GLenum bufs[] = {
          GL_COLOR_ATTACHMENT0,
          GL_COLOR_ATTACHMENT1,
          GL_COLOR_ATTACHMENT2,
          GL_COLOR_ATTACHMENT3,
      };
  
      setDrawBuffers(4, bufs);
      drawQuad(program, positionAttrib(), 0.5);
  
      verifyAttachment3DOES(0, texture.get(), 0, 0);
      verifyAttachment3DOES(1, texture.get(), 0, 1);
      verifyAttachment3DOES(2, texture.get(), 0, 2);
      verifyAttachment3DOES(3, texture.get(), 0, 3);
  
      EXPECT_GL_NO_ERROR();
  
      glDeleteProgram(program);
  }
  
  class DrawBuffersTestES3 : public DrawBuffersTest
  {};
  
  // Test that binding multiple layers of a 3D texture works correctly
  TEST_P(DrawBuffersTestES3, 3DTextures)
  {
      ANGLE_SKIP_TEST_IF(!setupTest());
  
      GLTexture texture;
      glBindTexture(GL_TEXTURE_3D, texture.get());
      glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA, getWindowWidth(), getWindowHeight(), getWindowWidth(),
                   0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
  
      glFramebufferTextureLayer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, texture.get(), 0, 0);
      glFramebufferTextureLayer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, texture.get(), 0, 1);
      glFramebufferTextureLayer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, texture.get(), 0, 2);
      glFramebufferTextureLayer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT3, texture.get(), 0, 3);
  
      bool flags[8] = {true, true, true, true, false};
  
      GLuint program;
      setupMRTProgram(flags, &program);
  
      const GLenum bufs[] = {
          GL_COLOR_ATTACHMENT0,
          GL_COLOR_ATTACHMENT1,
          GL_COLOR_ATTACHMENT2,
          GL_COLOR_ATTACHMENT3,
      };
  
      glDrawBuffers(4, bufs);
      drawQuad(program, positionAttrib(), 0.5);
  
      verifyAttachmentLayer(0, texture.get(), 0, 0);
      verifyAttachmentLayer(1, texture.get(), 0, 1);
      verifyAttachmentLayer(2, texture.get(), 0, 2);
      verifyAttachmentLayer(3, texture.get(), 0, 3);
  
      EXPECT_GL_NO_ERROR();
  
      glDeleteProgram(program);
  }
  
  // Test that binding multiple layers of a 2D array texture works correctly
  TEST_P(DrawBuffersTestES3, 2DArrayTextures)
  {
      ANGLE_SKIP_TEST_IF(!setupTest());
  
      GLTexture texture;
      glBindTexture(GL_TEXTURE_2D_ARRAY, texture.get());
      glTexImage3D(GL_TEXTURE_2D_ARRAY, 0, GL_RGBA, getWindowWidth(), getWindowHeight(),
                   getWindowWidth(), 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
  
      glFramebufferTextureLayer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, texture.get(), 0, 0);
      glFramebufferTextureLayer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, texture.get(), 0, 1);
      glFramebufferTextureLayer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, texture.get(), 0, 2);
      glFramebufferTextureLayer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT3, texture.get(), 0, 3);
  
      bool flags[8] = {true, true, true, true, false};
  
      GLuint program;
      setupMRTProgram(flags, &program);
  
      const GLenum bufs[] = {
          GL_COLOR_ATTACHMENT0,
          GL_COLOR_ATTACHMENT1,
          GL_COLOR_ATTACHMENT2,
          GL_COLOR_ATTACHMENT3,
      };
  
      glDrawBuffers(4, bufs);
      drawQuad(program, positionAttrib(), 0.5);
  
      verifyAttachmentLayer(0, texture.get(), 0, 0);
      verifyAttachmentLayer(1, texture.get(), 0, 1);
      verifyAttachmentLayer(2, texture.get(), 0, 2);
      verifyAttachmentLayer(3, texture.get(), 0, 3);
  
      EXPECT_GL_NO_ERROR();
  
      glDeleteProgram(program);
  }
  
  // Vulkan backend is setting per buffer color mask to false for draw buffers that set to GL_NONE.
  // These set of tests are to test draw buffer change followed by draw/clear/blit and followed by
  // draw buffer change are behaving correctly.
  class ColorMaskForDrawBuffersTest : public DrawBuffersTest
  {
    protected:
      void setupColorMaskForDrawBuffersTest()
      {
          glBindTexture(GL_TEXTURE_2D, mTextures[0]);
          glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mTextures[0],
                                 0);
          glBindTexture(GL_TEXTURE_2D, mTextures[1]);
          glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, mTextures[1],
                                 0);
          glBindTexture(GL_TEXTURE_2D, mTextures[2]);
          glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, GL_TEXTURE_2D, mTextures[2],
                                 0);
  
          constexpr char kFS_ESSL3[] =
              "#version 300 es\n"
              "precision highp float;\n"
              "uniform mediump vec4 u_color0;\n"
              "uniform mediump vec4 u_color1;\n"
              "uniform mediump vec4 u_color2;\n"
              "layout(location = 0) out vec4 out_color0;\n"
              "layout(location = 1) out vec4 out_color1;\n"
              "layout(location = 2) out vec4 out_color2;\n"
              "void main()\n"
              "{\n"
              "    out_color0 = u_color0;\n"
              "    out_color1 = u_color1;\n"
              "    out_color2 = u_color2;\n"
              "}\n";
          program = CompileProgram(essl3_shaders::vs::Simple(), kFS_ESSL3);
          glUseProgram(program);
  
          positionLocation = glGetAttribLocation(program, positionAttrib());
          ASSERT_NE(-1, positionLocation);
          color0UniformLocation = glGetUniformLocation(program, "u_color0");
          ASSERT_NE(color0UniformLocation, -1);
          color1UniformLocation = glGetUniformLocation(program, "u_color1");
          ASSERT_NE(color1UniformLocation, -1);
          color2UniformLocation = glGetUniformLocation(program, "u_color2");
          ASSERT_NE(color2UniformLocation, -1);
  
          glUniform4fv(color0UniformLocation, 1, GLColor::red.toNormalizedVector().data());
          glUniform4fv(color1UniformLocation, 1, GLColor::green.toNormalizedVector().data());
          glUniform4fv(color2UniformLocation, 1, GLColor::yellow.toNormalizedVector().data());
  
          // First draw into both buffers so that buffer0 is red and buffer1 is green
          resetDrawBuffers();
          drawQuad(program, positionAttrib(), 0.5);
          EXPECT_GL_NO_ERROR();
  
          for (int i = 0; i < 4; i++)
          {
              drawBuffers[i] = GL_NONE;
          }
      }
  
      void resetDrawBuffers()
      {
          drawBuffers[0] = GL_COLOR_ATTACHMENT0;
          drawBuffers[1] = GL_COLOR_ATTACHMENT1;
          drawBuffers[2] = GL_COLOR_ATTACHMENT2;
          drawBuffers[3] = GL_NONE;
          setDrawBuffers(4, drawBuffers);
      }
  
      GLenum drawBuffers[4];
      GLuint program;
      GLint positionLocation;
      GLint color0UniformLocation;
      GLint color1UniformLocation;
      GLint color2UniformLocation;
  };
  
  // Test draw buffer state change followed draw call
  TEST_P(ColorMaskForDrawBuffersTest, DrawQuad)
  {
      ANGLE_SKIP_TEST_IF(!setupTest());
      setupColorMaskForDrawBuffersTest();
  
      // Draw blue into attachment0. Buffer0 should be blue and buffer1 should remain green
      drawBuffers[0] = GL_COLOR_ATTACHMENT0;
      setDrawBuffers(4, drawBuffers);
      glUniform4fv(color0UniformLocation, 1, GLColor::blue.toNormalizedVector().data());
      glUniform4fv(color1UniformLocation, 1, GLColor::cyan.toNormalizedVector().data());
      glViewport(0, 0, getWindowWidth() / 2, getWindowHeight() / 2);
      drawQuad(program, positionAttrib(), 0.5);
  
      resetDrawBuffers();
      glUniform4fv(color0UniformLocation, 1, GLColor::magenta.toNormalizedVector().data());
      glUniform4fv(color1UniformLocation, 1, GLColor::white.toNormalizedVector().data());
      glViewport(getWindowWidth() / 2, 0, getWindowWidth() / 2, getWindowHeight() / 2);
      drawQuad(program, positionAttrib(), 0.5);
      EXPECT_GL_NO_ERROR();
  
      glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mTextures[0],
                             0);
      EXPECT_PIXEL_COLOR_EQ(getWindowWidth() / 4, getWindowHeight() / 4, GLColor::blue);
      EXPECT_PIXEL_COLOR_EQ(getWindowWidth() * 3 / 4, getWindowHeight() / 4, GLColor::magenta);
      EXPECT_PIXEL_COLOR_EQ(getWindowWidth() / 4, getWindowHeight() * 3 / 4, GLColor::red);
      glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mTextures[1],
                             0);
      EXPECT_PIXEL_COLOR_EQ(getWindowWidth() / 4, getWindowHeight() / 4, GLColor::green);
      EXPECT_PIXEL_COLOR_EQ(getWindowWidth() * 3 / 4, getWindowHeight() / 4, GLColor::white);
      EXPECT_PIXEL_COLOR_EQ(getWindowWidth() / 4, getWindowHeight() * 3 / 4, GLColor::green);
      EXPECT_GL_NO_ERROR();
  }
  
  // Test draw buffer state change followed clear
  TEST_P(ColorMaskForDrawBuffersTest, Clear)
  {
      ANGLE_SKIP_TEST_IF(!setupTest());
      setupColorMaskForDrawBuffersTest();
  
      // Clear attachment1. Buffer0 should retain red and buffer1 should be blue
      drawBuffers[1] = GL_COLOR_ATTACHMENT1;
      setDrawBuffers(4, drawBuffers);
      GLfloat *clearColor = GLColor::blue.toNormalizedVector().data();
      glClearColor(clearColor[0], clearColor[1], clearColor[2], clearColor[3]);
      glClear(GL_COLOR_BUFFER_BIT);
      verifyAttachment2DColor(0, mTextures[0], GL_TEXTURE_2D, 0, GLColor::red);
      verifyAttachment2DColor(1, mTextures[1], GL_TEXTURE_2D, 0, GLColor::blue);
      EXPECT_GL_NO_ERROR();
  }
  
  // Test draw buffer state change followed scissored clear
  TEST_P(ColorMaskForDrawBuffersTest, ScissoredClear)
  {
      ANGLE_SKIP_TEST_IF(!setupTest());
      setupColorMaskForDrawBuffersTest();
  
      // Clear attachment1. Buffer0 should retain red and buffer1 should be blue
      drawBuffers[1] = GL_COLOR_ATTACHMENT1;
      setDrawBuffers(4, drawBuffers);
      GLfloat *clearColor = GLColor::blue.toNormalizedVector().data();
      glClearColor(clearColor[0], clearColor[1], clearColor[2], clearColor[3]);
      glScissor(0, 0, getWindowWidth() / 2, getWindowHeight() / 2);
      glEnable(GL_SCISSOR_TEST);
      glClear(GL_COLOR_BUFFER_BIT);
  
      resetDrawBuffers();
      clearColor = GLColor::magenta.toNormalizedVector().data();
      glClearColor(clearColor[0], clearColor[1], clearColor[2], clearColor[3]);
      glScissor(getWindowWidth() / 2, 0, getWindowWidth() / 2, getWindowHeight() / 2);
      glClear(GL_COLOR_BUFFER_BIT);
      EXPECT_GL_NO_ERROR();
  
      glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mTextures[0],
                             0);
      EXPECT_PIXEL_COLOR_EQ(getWindowWidth() / 4, getWindowHeight() / 4, GLColor::red);
      EXPECT_PIXEL_COLOR_EQ(getWindowWidth() * 3 / 4, getWindowHeight() / 4, GLColor::magenta);
      EXPECT_PIXEL_COLOR_EQ(getWindowWidth() / 4, getWindowHeight() * 3 / 4, GLColor::red);
      glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mTextures[1],
                             0);
      EXPECT_PIXEL_COLOR_EQ(getWindowWidth() / 4, getWindowHeight() / 4, GLColor::blue);
      EXPECT_PIXEL_COLOR_EQ(getWindowWidth() * 3 / 4, getWindowHeight() / 4, GLColor::magenta);
      EXPECT_PIXEL_COLOR_EQ(getWindowWidth() / 4, getWindowHeight() * 3 / 4, GLColor::green);
      EXPECT_GL_NO_ERROR();
  }
  
  // Test draw buffer state change followed FBO blit
  TEST_P(ColorMaskForDrawBuffersTest, Blit)
  {
      ANGLE_SKIP_TEST_IF(!setupTest());
      setupColorMaskForDrawBuffersTest();
  
      glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mTextures[2],
                             0);
  
      // BLIT mTexture[2] to attachment0. Buffer0 should remain red and buffer1 should be yellow
      drawBuffers[0] = GL_COLOR_ATTACHMENT0;
      setDrawBuffers(4, drawBuffers);
      glBlitFramebuffer(0, 0, getWindowWidth(), getWindowHeight(), 0, 0, getWindowWidth(),
                        getWindowHeight(), GL_COLOR_BUFFER_BIT, GL_NEAREST);
      verifyAttachment2DColor(0, mTextures[0], GL_TEXTURE_2D, 0, GLColor::yellow);
      verifyAttachment2DColor(1, mTextures[1], GL_TEXTURE_2D, 0, GLColor::green);
      EXPECT_GL_NO_ERROR();
  }
  
  // Use this to select which configurations (e.g. which renderer, which GLES major version) these
  // tests should be run against.
  ANGLE_INSTANTIATE_TEST(DrawBuffersTest,
                         ANGLE_ALL_TEST_PLATFORMS_ES2,
                         ANGLE_ALL_TEST_PLATFORMS_ES3,
                         WithNoTransformFeedback(ES2_VULKAN()));
  ANGLE_INSTANTIATE_TEST_ES3(DrawBuffersWebGL2Test);
  
  ANGLE_INSTANTIATE_TEST_ES3(DrawBuffersTestES3);
  
  ANGLE_INSTANTIATE_TEST_ES3(ColorMaskForDrawBuffersTest);