text: //
  // Copyright 2016 The ANGLE Project Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  //
  
  // ColorMaskTest.cpp: Test GLES functionality related to color masks, particularly an AMD D3D9
  // driver bug.
  
  #include "test_utils/ANGLETest.h"
  
  namespace angle
  {
  class ColorMaskTest : public ANGLETest
  {
    protected:
      ColorMaskTest() : mProgram(0)
      {
          setWindowWidth(128);
          setWindowHeight(128);
          setConfigRedBits(8);
          setConfigGreenBits(8);
          setConfigBlueBits(8);
          setConfigAlphaBits(8);
          setConfigDepthBits(24);
      }
  
      void SetUp() override
      {
          ANGLETest::SetUp();
  
          const std::string vsSource =
              "precision highp float;\n"
              "attribute vec4 position;\n"
              "\n"
              "void main()\n"
              "{\n"
              "    gl_Position = position;\n"
              "}\n";
  
          const std::string fsSource =
              "precision highp float;\n"
              "uniform vec4 color;\n"
              "\n"
              "void main()\n"
              "{\n"
              "    gl_FragColor = color;\n"
              "}\n";
  
          mProgram = CompileProgram(vsSource, fsSource);
          ASSERT_NE(0u, mProgram) << "shader compilation failed.";
  
          mColorUniform = glGetUniformLocation(mProgram, "color");
      }
  
      void TearDown() override
      {
          glDeleteProgram(mProgram);
  
          ANGLETest::TearDown();
      }
  
      GLuint mProgram     = 0;
      GLint mColorUniform = -1;
  };
  
  // Some ATI cards have a bug where a draw with a zero color write mask can cause later draws to have
  // incorrect results. Test to make sure this bug is not exposed.
  TEST_P(ColorMaskTest, AMDZeroColorMaskBug)
  {
      int x = getWindowWidth() / 2;
      int y = getWindowHeight() / 2;
  
      // Clear to blue
      glClearColor(0.0f, 0.0f, 1.0f, 1.0f);
      glClear(GL_COLOR_BUFFER_BIT);
      EXPECT_PIXEL_EQ(x, y, 0, 0, 255, 255);
  
      // Draw a quad with all colors masked and blending disabled, should remain blue
      glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
      glDisable(GL_BLEND);
      glUseProgram(mProgram);
      glUniform4f(mColorUniform, 1.0f, 0.0f, 0.0f, 0.0f);
      EXPECT_GL_NO_ERROR();
      drawQuad(mProgram, "position", 0.5f);
      EXPECT_PIXEL_EQ(x, y, 0, 0, 255, 255);
  
      // Re-enable the color mask, should be red (with blend disabled, the red should overwrite
      // everything)
      glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
      glUseProgram(mProgram);
      glUniform4f(mColorUniform, 1.0f, 0.0f, 0.0f, 0.0f);
      EXPECT_GL_NO_ERROR();
      drawQuad(mProgram, "position", 0.5f);
      EXPECT_PIXEL_EQ(x, y, 255, 0, 0, 0);
  }
  
  // Use this to select which configurations (e.g. which renderer, which GLES major version) these
  // tests should be run against. D3D11 Feature Level 9_3 uses different D3D formats for vertex
  // attribs compared to Feature Levels 10_0+, so we should test them separately.
  ANGLE_INSTANTIATE_TEST(ColorMaskTest,
                         ES2_D3D9(),
                         ES2_D3D11(),
                         ES2_D3D11_FL9_3(),
                         ES2_OPENGL(),
                         ES3_OPENGL(),
                         ES2_OPENGLES(),
                         ES3_OPENGLES());
  
  }  // namespace angle
  