gpu/command_buffer/tests/gl_readback_unittest.cc - chromium/src - Git at Google

 // Copyright 2014 The Chromium 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 <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>
 #include <GLES2/gl2extchromium.h>
 #include <stddef.h>
 #include <stdint.h>

 #include <cmath>
 #include <memory>

 #include "base/bind.h"
 #include "base/bit_cast.h"
 #include "base/location.h"
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "gpu/command_buffer/tests/gl_manager.h"
 #include "gpu/command_buffer/tests/gl_test_utils.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"

 namespace gpu {

 class GLReadbackTest : public testing::Test {
  protected:
   void SetUp() override { gl_.Initialize(GLManager::Options()); }

   void TearDown() override { gl_.Destroy(); }

   static void WaitForQueryCallback(int q, base::Closure cb) {
     unsigned int done = 0;
     glGetQueryObjectuivEXT(q, GL_QUERY_RESULT_AVAILABLE_EXT, &done);
     if (done) {
       cb.Run();
     } else {
       base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
           FROM_HERE, base::Bind(&WaitForQueryCallback, q, cb),
           base::TimeDelta::FromMilliseconds(3));
     }
   }

   void WaitForQuery(int q) {
     base::RunLoop run_loop;
     WaitForQueryCallback(q, run_loop.QuitClosure());
     run_loop.Run();
   }

   GLManager gl_;
 };


 TEST_F(GLReadbackTest, ReadPixelsWithPBOAndQuery) {
   const GLint kBytesPerPixel = 4;
   const GLint kWidth = 2;
   const GLint kHeight = 2;

   GLuint b, q;
   glClearColor(0.0, 0.0, 1.0, 1.0);
   glClear(GL_COLOR_BUFFER_BIT);
   glGenBuffers(1, &b);
   glGenQueriesEXT(1, &q);
   glBindBuffer(GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM, b);
   glBufferData(GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM,
                kWidth * kHeight * kBytesPerPixel,
                NULL,
                GL_STREAM_READ);
   glBeginQueryEXT(GL_ASYNC_PIXEL_PACK_COMPLETED_CHROMIUM, q);
   glReadPixels(0, 0, kWidth, kHeight, GL_RGBA, GL_UNSIGNED_BYTE, 0);
   glEndQueryEXT(GL_ASYNC_PIXEL_PACK_COMPLETED_CHROMIUM);
   glFlush();
   WaitForQuery(q);

   // TODO(hubbe): Check that glMapBufferCHROMIUM does not block here.
   unsigned char *data = static_cast<unsigned char *>(
       glMapBufferCHROMIUM(
           GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM,
           GL_READ_ONLY));
   EXPECT_TRUE(data);
   EXPECT_EQ(data[0], 0);   // red
   EXPECT_EQ(data[1], 0);   // green
   EXPECT_EQ(data[2], 255); // blue
   glUnmapBufferCHROMIUM(GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM);
   glBindBuffer(GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM, 0);
   glDeleteBuffers(1, &b);
   glDeleteQueriesEXT(1, &q);
   GLTestHelper::CheckGLError("no errors", __LINE__);
 }

 static float HalfToFloat32(uint16_t value) {
   int32_t s = (value >> 15) & 0x00000001;
   int32_t e = (value >> 10) & 0x0000001f;
   int32_t m = value & 0x000003ff;

   if (e == 0) {
     if (m == 0) {
       uint32_t result = s << 31;
       return bit_cast<float>(result);
     } else {
       while (!(m & 0x00000400)) {
         m <<= 1;
         e -=  1;
       }

       e += 1;
       m &= ~0x00000400;
     }
   } else if (e == 31) {
     if (m == 0) {
       uint32_t result = (s << 31) | 0x7f800000;
       return bit_cast<float>(result);
     } else {
       uint32_t result = (s << 31) | 0x7f800000 | (m << 13);
       return bit_cast<float>(result);
     }
   }

   e = e + (127 - 15);
   m = m << 13;

   uint32_t result = (s << 31) | (e << 23) | m;
   return bit_cast<float>(result);
 }

 static GLuint CompileShader(GLenum type, const char *data) {
   const char *shaderStrings[1] = { data };

   GLuint shader = glCreateShader(type);
   glShaderSource(shader, 1, shaderStrings, NULL);
   glCompileShader(shader);

   GLint compile_status = 0;
   glGetShaderiv(shader, GL_COMPILE_STATUS, &compile_status);
   if (compile_status != GL_TRUE) {
     glDeleteShader(shader);
     shader = 0;
   }

   return shader;
 }

 // TODO(zmo): ReadPixels with float type isn't implemented in ANGLE ES2
 // backend. crbug.com/607283.
 // TODO(zmo): This test also fails on some android devices when the readback
 // type is HALF_FLOAT_OES. Likely it's due to a driver bug. crbug.com/607936.
 #if defined(OS_WIN) || defined(OS_ANDROID)
 #define MAYBE_ReadPixelsFloat DISABLED_ReadPixelsFloat
 #else
 #define MAYBE_ReadPixelsFloat ReadPixelsFloat
 #endif
 TEST_F(GLReadbackTest, MAYBE_ReadPixelsFloat) {
   const GLsizei kTextureSize = 4;
   const GLfloat kDrawColor[4] = { -10.9f, 0.5f, 10.5f, 100.12f };
   const GLfloat kEpsilon = 0.01f;

   struct TestFormat {
     GLint format;
     GLint type;
     uint32_t comp_count;
   };
   TestFormat test_formats[4];
   size_t test_count = 0;
   const char *extensions = reinterpret_cast<const char*>(
       glGetString(GL_EXTENSIONS));
   if (strstr(extensions, "GL_OES_texture_half_float") != NULL) {
       TestFormat rgb16f = { GL_RGB, GL_HALF_FLOAT_OES, 3 };
       test_formats[test_count++] = rgb16f;

       TestFormat rgba16f = { GL_RGBA, GL_HALF_FLOAT_OES, 4 };
       test_formats[test_count++] = rgba16f;
   }
   if (strstr(extensions, "GL_OES_texture_float") != NULL) {
       TestFormat rgb32f = { GL_RGB, GL_FLOAT, 3 };
       test_formats[test_count++] = rgb32f;

       TestFormat rgba32f = { GL_RGBA, GL_FLOAT, 4 };
       test_formats[test_count++] = rgba32f;
   }

   const char *vs_source =
       "precision mediump float;\n"
       "attribute vec4 a_position;\n"
       "void main() {\n"
       "  gl_Position =  a_position;\n"
       "}\n";

   GLuint vertex_shader = CompileShader(GL_VERTEX_SHADER, vs_source);
   ASSERT_NE(vertex_shader, GLuint(0));

   const char *fs_source =
       "precision mediump float;\n"
       "uniform vec4 u_color;\n"
       "void main() {\n"
       "  gl_FragColor = u_color;\n"
       "}\n";

   GLuint fragment_shader = CompileShader(GL_FRAGMENT_SHADER, fs_source);
   ASSERT_NE(fragment_shader, GLuint(0));

   GLuint program = glCreateProgram();
   glAttachShader(program, vertex_shader);
   glDeleteShader(vertex_shader);
   glAttachShader(program, fragment_shader);
   glDeleteShader(fragment_shader);
   glLinkProgram(program);

   GLint link_status = 0;
   glGetProgramiv(program, GL_LINK_STATUS, &link_status);
   if (link_status != GL_TRUE) {
     glDeleteProgram(program);
     program = 0;
   }
   ASSERT_NE(program, GLuint(0));

   EXPECT_EQ(glGetError(), GLenum(GL_NO_ERROR));

   float quad_vertices[] = {
       -1.0, -1.0,
       1.0, -1.0,
       1.0, 1.0,
       -1.0, 1.0
   };

   GLuint vertex_buffer;
   glGenBuffers(1, &vertex_buffer);
   glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer);
   glBufferData(
       GL_ARRAY_BUFFER, sizeof(quad_vertices),
       reinterpret_cast<void*>(quad_vertices), GL_STATIC_DRAW);

   GLint position_location = glGetAttribLocation(program, "a_position");
   glVertexAttribPointer(
       position_location, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), NULL);
   glEnableVertexAttribArray(position_location);

   glUseProgram(program);
   glUniform4fv(glGetUniformLocation(program, "u_color"), 1, kDrawColor);

   EXPECT_EQ(glGetError(), GLenum(GL_NO_ERROR));

   for (size_t ii = 0; ii < test_count; ++ii) {
     GLuint texture_id = 0;
     glGenTextures(1, &texture_id);
     glBindTexture(GL_TEXTURE_2D, texture_id);
     glTexImage2D(
         GL_TEXTURE_2D, 0, test_formats[ii].format, kTextureSize, kTextureSize,
         0, test_formats[ii].format, test_formats[ii].type, NULL);

     GLuint framebuffer = 0;
     glGenFramebuffers(1, &framebuffer);
     glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
     glFramebufferTexture2D(
         GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture_id, 0);

     EXPECT_EQ(glGetError(), GLenum(GL_NO_ERROR));

     // Make sure this floating point framebuffer is supported
     if (glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE) {
       // Check if this implementation supports reading floats back from this
       // framebuffer
       GLint read_format = 0;
       glGetIntegerv(GL_IMPLEMENTATION_COLOR_READ_FORMAT, &read_format);
       GLint read_type = 0;
       glGetIntegerv(GL_IMPLEMENTATION_COLOR_READ_TYPE, &read_type);

       EXPECT_EQ(glGetError(), GLenum(GL_NO_ERROR));

       if ((read_format == GL_RGB || read_format == GL_RGBA) &&
           read_type == test_formats[ii].type) {
         glClear(GL_COLOR_BUFFER_BIT);
         glDrawArrays(GL_TRIANGLE_FAN, 0, 4);

         uint32_t read_comp_count = 0;
         switch (read_format) {
           case GL_RGB:
             read_comp_count = 3;
             break;
           case GL_RGBA:
             read_comp_count = 4;
             break;
         }

         switch (read_type) {
           case GL_HALF_FLOAT_OES: {
             std::unique_ptr<GLushort[]> buf(
                 new GLushort[kTextureSize * kTextureSize * read_comp_count]);
             glReadPixels(
                 0, 0, kTextureSize, kTextureSize, read_format, read_type,
                 buf.get());
             EXPECT_EQ(glGetError(), GLenum(GL_NO_ERROR));
             for (uint32_t jj = 0; jj < kTextureSize * kTextureSize; ++jj) {
               for (uint32_t kk = 0; kk < test_formats[ii].comp_count; ++kk) {
                 EXPECT_LE(
                     std::abs(HalfToFloat32(buf[jj * read_comp_count + kk]) -
                         kDrawColor[kk]),
                     std::abs(kDrawColor[kk] * kEpsilon));
               }
             }
             break;
           }
           case GL_FLOAT: {
             std::unique_ptr<GLfloat[]> buf(
                 new GLfloat[kTextureSize * kTextureSize * read_comp_count]);
             glReadPixels(
                 0, 0, kTextureSize, kTextureSize, read_format, read_type,
                 buf.get());
             EXPECT_EQ(glGetError(), GLenum(GL_NO_ERROR));
             for (uint32_t jj = 0; jj < kTextureSize * kTextureSize; ++jj) {
               for (uint32_t kk = 0; kk < test_formats[ii].comp_count; ++kk) {
                 EXPECT_LE(
                     std::abs(buf[jj * read_comp_count + kk] - kDrawColor[kk]),
                     std::abs(kDrawColor[kk] * kEpsilon));
               }
             }
             break;
           }
         }
       }
     }

     glDeleteFramebuffers(1, &framebuffer);
     glDeleteTextures(1, &texture_id);
   }

   glDeleteBuffers(1, &vertex_buffer);
   glDeleteProgram(program);
 }

 }  // namespace gpu
	// Copyright 2014 The Chromium 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 <GLES2/gl2.h>
	#include <GLES2/gl2ext.h>
	#include <GLES2/gl2extchromium.h>
	#include <stddef.h>
	#include <stdint.h>

	#include <cmath>
	#include <memory>

	#include "base/bind.h"
	#include "base/bit_cast.h"
	#include "base/location.h"
	#include "base/run_loop.h"
	#include "base/single_thread_task_runner.h"
	#include "base/threading/thread_task_runner_handle.h"
	#include "gpu/command_buffer/tests/gl_manager.h"
	#include "gpu/command_buffer/tests/gl_test_utils.h"
	#include "testing/gmock/include/gmock/gmock.h"
	#include "testing/gtest/include/gtest/gtest.h"

	namespace gpu {

	class GLReadbackTest : public testing::Test {
	protected:
	void SetUp() override { gl_.Initialize(GLManager::Options()); }

	void TearDown() override { gl_.Destroy(); }

	static void WaitForQueryCallback(int q, base::Closure cb) {
	unsigned int done = 0;
	glGetQueryObjectuivEXT(q, GL_QUERY_RESULT_AVAILABLE_EXT, &done);
	if (done) {
	cb.Run();
	} else {
	base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
	FROM_HERE, base::Bind(&WaitForQueryCallback, q, cb),
	base::TimeDelta::FromMilliseconds(3));
	}
	}

	void WaitForQuery(int q) {
	base::RunLoop run_loop;
	WaitForQueryCallback(q, run_loop.QuitClosure());
	run_loop.Run();
	}

	GLManager gl_;
	};


	TEST_F(GLReadbackTest, ReadPixelsWithPBOAndQuery) {
	const GLint kBytesPerPixel = 4;
	const GLint kWidth = 2;
	const GLint kHeight = 2;

	GLuint b, q;
	glClearColor(0.0, 0.0, 1.0, 1.0);
	glClear(GL_COLOR_BUFFER_BIT);
	glGenBuffers(1, &b);
	glGenQueriesEXT(1, &q);
	glBindBuffer(GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM, b);
	glBufferData(GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM,
	kWidth * kHeight * kBytesPerPixel,
	NULL,
	GL_STREAM_READ);
	glBeginQueryEXT(GL_ASYNC_PIXEL_PACK_COMPLETED_CHROMIUM, q);
	glReadPixels(0, 0, kWidth, kHeight, GL_RGBA, GL_UNSIGNED_BYTE, 0);
	glEndQueryEXT(GL_ASYNC_PIXEL_PACK_COMPLETED_CHROMIUM);
	glFlush();
	WaitForQuery(q);

	// TODO(hubbe): Check that glMapBufferCHROMIUM does not block here.
	unsigned char data = static_cast<unsigned char >(
	glMapBufferCHROMIUM(
	GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM,
	GL_READ_ONLY));
	EXPECT_TRUE(data);
	EXPECT_EQ(data[0], 0); // red
	EXPECT_EQ(data[1], 0); // green
	EXPECT_EQ(data[2], 255); // blue
	glUnmapBufferCHROMIUM(GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM);
	glBindBuffer(GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM, 0);
	glDeleteBuffers(1, &b);
	glDeleteQueriesEXT(1, &q);
	GLTestHelper::CheckGLError("no errors", __LINE__);
	}

	static float HalfToFloat32(uint16_t value) {
	int32_t s = (value >> 15) & 0x00000001;
	int32_t e = (value >> 10) & 0x0000001f;
	int32_t m = value & 0x000003ff;

	if (e == 0) {
	if (m == 0) {
	uint32_t result = s << 31;
	return bit_cast<float>(result);
	} else {
	while (!(m & 0x00000400)) {
	m <<= 1;
	e -= 1;
	}

	e += 1;
	m &= ~0x00000400;
	}
	} else if (e == 31) {
	if (m == 0) {
	uint32_t result = (s << 31) \| 0x7f800000;
	return bit_cast<float>(result);
	} else {
	uint32_t result = (s << 31) \| 0x7f800000 \| (m << 13);
	return bit_cast<float>(result);
	}
	}

	e = e + (127 - 15);
	m = m << 13;

	uint32_t result = (s << 31) \| (e << 23) \| m;
	return bit_cast<float>(result);
	}

	static GLuint CompileShader(GLenum type, const char *data) {
	const char *shaderStrings[1] = { data };

	GLuint shader = glCreateShader(type);
	glShaderSource(shader, 1, shaderStrings, NULL);
	glCompileShader(shader);

	GLint compile_status = 0;
	glGetShaderiv(shader, GL_COMPILE_STATUS, &compile_status);
	if (compile_status != GL_TRUE) {
	glDeleteShader(shader);
	shader = 0;
	}

	return shader;
	}

	// TODO(zmo): ReadPixels with float type isn't implemented in ANGLE ES2
	// backend. crbug.com/607283.
	// TODO(zmo): This test also fails on some android devices when the readback
	// type is HALF_FLOAT_OES. Likely it's due to a driver bug. crbug.com/607936.
	#if defined(OS_WIN) \|\| defined(OS_ANDROID)
	#define MAYBE_ReadPixelsFloat DISABLED_ReadPixelsFloat
	#else
	#define MAYBE_ReadPixelsFloat ReadPixelsFloat
	#endif
	TEST_F(GLReadbackTest, MAYBE_ReadPixelsFloat) {
	const GLsizei kTextureSize = 4;
	const GLfloat kDrawColor[4] = { -10.9f, 0.5f, 10.5f, 100.12f };
	const GLfloat kEpsilon = 0.01f;

	struct TestFormat {
	GLint format;
	GLint type;
	uint32_t comp_count;
	};
	TestFormat test_formats[4];
	size_t test_count = 0;
	const char extensions = reinterpret_cast<const char>(
	glGetString(GL_EXTENSIONS));
	if (strstr(extensions, "GL_OES_texture_half_float") != NULL) {
	TestFormat rgb16f = { GL_RGB, GL_HALF_FLOAT_OES, 3 };
	test_formats[test_count++] = rgb16f;

	TestFormat rgba16f = { GL_RGBA, GL_HALF_FLOAT_OES, 4 };
	test_formats[test_count++] = rgba16f;
	}
	if (strstr(extensions, "GL_OES_texture_float") != NULL) {
	TestFormat rgb32f = { GL_RGB, GL_FLOAT, 3 };
	test_formats[test_count++] = rgb32f;

	TestFormat rgba32f = { GL_RGBA, GL_FLOAT, 4 };
	test_formats[test_count++] = rgba32f;
	}

	const char *vs_source =
	"precision mediump float;\n"
	"attribute vec4 a_position;\n"
	"void main() {\n"
	" gl_Position = a_position;\n"
	"}\n";

	GLuint vertex_shader = CompileShader(GL_VERTEX_SHADER, vs_source);
	ASSERT_NE(vertex_shader, GLuint(0));

	const char *fs_source =
	"precision mediump float;\n"
	"uniform vec4 u_color;\n"
	"void main() {\n"
	" gl_FragColor = u_color;\n"
	"}\n";

	GLuint fragment_shader = CompileShader(GL_FRAGMENT_SHADER, fs_source);
	ASSERT_NE(fragment_shader, GLuint(0));

	GLuint program = glCreateProgram();
	glAttachShader(program, vertex_shader);
	glDeleteShader(vertex_shader);
	glAttachShader(program, fragment_shader);
	glDeleteShader(fragment_shader);
	glLinkProgram(program);

	GLint link_status = 0;
	glGetProgramiv(program, GL_LINK_STATUS, &link_status);
	if (link_status != GL_TRUE) {
	glDeleteProgram(program);
	program = 0;
	}
	ASSERT_NE(program, GLuint(0));

	EXPECT_EQ(glGetError(), GLenum(GL_NO_ERROR));

	float quad_vertices[] = {
	-1.0, -1.0,
	1.0, -1.0,
	1.0, 1.0,
	-1.0, 1.0
	};

	GLuint vertex_buffer;
	glGenBuffers(1, &vertex_buffer);
	glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer);
	glBufferData(
	GL_ARRAY_BUFFER, sizeof(quad_vertices),
	reinterpret_cast<void*>(quad_vertices), GL_STATIC_DRAW);

	GLint position_location = glGetAttribLocation(program, "a_position");
	glVertexAttribPointer(
	position_location, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), NULL);
	glEnableVertexAttribArray(position_location);

	glUseProgram(program);
	glUniform4fv(glGetUniformLocation(program, "u_color"), 1, kDrawColor);

	EXPECT_EQ(glGetError(), GLenum(GL_NO_ERROR));

	for (size_t ii = 0; ii < test_count; ++ii) {
	GLuint texture_id = 0;
	glGenTextures(1, &texture_id);
	glBindTexture(GL_TEXTURE_2D, texture_id);
	glTexImage2D(
	GL_TEXTURE_2D, 0, test_formats[ii].format, kTextureSize, kTextureSize,
	0, test_formats[ii].format, test_formats[ii].type, NULL);

	GLuint framebuffer = 0;
	glGenFramebuffers(1, &framebuffer);
	glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
	glFramebufferTexture2D(
	GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture_id, 0);

	EXPECT_EQ(glGetError(), GLenum(GL_NO_ERROR));

	// Make sure this floating point framebuffer is supported
	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE) {
	// Check if this implementation supports reading floats back from this
	// framebuffer
	GLint read_format = 0;
	glGetIntegerv(GL_IMPLEMENTATION_COLOR_READ_FORMAT, &read_format);
	GLint read_type = 0;
	glGetIntegerv(GL_IMPLEMENTATION_COLOR_READ_TYPE, &read_type);

	EXPECT_EQ(glGetError(), GLenum(GL_NO_ERROR));

	if ((read_format == GL_RGB \|\| read_format == GL_RGBA) &&
	read_type == test_formats[ii].type) {
	glClear(GL_COLOR_BUFFER_BIT);
	glDrawArrays(GL_TRIANGLE_FAN, 0, 4);

	uint32_t read_comp_count = 0;
	switch (read_format) {
	case GL_RGB:
	read_comp_count = 3;
	break;
	case GL_RGBA:
	read_comp_count = 4;
	break;
	}

	switch (read_type) {
	case GL_HALF_FLOAT_OES: {
	std::unique_ptr<GLushort[]> buf(
	new GLushort[kTextureSize * kTextureSize * read_comp_count]);
	glReadPixels(
	0, 0, kTextureSize, kTextureSize, read_format, read_type,
	buf.get());
	EXPECT_EQ(glGetError(), GLenum(GL_NO_ERROR));
	for (uint32_t jj = 0; jj < kTextureSize * kTextureSize; ++jj) {
	for (uint32_t kk = 0; kk < test_formats[ii].comp_count; ++kk) {
	EXPECT_LE(
	std::abs(HalfToFloat32(buf[jj * read_comp_count + kk]) -
	kDrawColor[kk]),
	std::abs(kDrawColor[kk] * kEpsilon));
	}
	}
	break;
	}
	case GL_FLOAT: {
	std::unique_ptr<GLfloat[]> buf(
	new GLfloat[kTextureSize * kTextureSize * read_comp_count]);
	glReadPixels(
	0, 0, kTextureSize, kTextureSize, read_format, read_type,
	buf.get());
	EXPECT_EQ(glGetError(), GLenum(GL_NO_ERROR));
	for (uint32_t jj = 0; jj < kTextureSize * kTextureSize; ++jj) {
	for (uint32_t kk = 0; kk < test_formats[ii].comp_count; ++kk) {
	EXPECT_LE(
	std::abs(buf[jj * read_comp_count + kk] - kDrawColor[kk]),
	std::abs(kDrawColor[kk] * kEpsilon));
	}
	}
	break;
	}
	}
	}
	}

	glDeleteFramebuffers(1, &framebuffer);
	glDeleteTextures(1, &texture_id);
	}

	glDeleteBuffers(1, &vertex_buffer);
	glDeleteProgram(program);
	}

	} // namespace gpu