Add OES_texture_half_float extension support in Chromium for desktop GL implementation.

gpu/command_buffer/tests/gl_oes_texture_half_float_unittest.cc

+// Copyright (c) 2012 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.
+
+#ifndef GL_GLEXT_PROTOTYPES
+#define GL_GLEXT_PROTOTYPES
+#endif
+
+#include <GLES2/gl2.h>
+#include <GLES2/gl2ext.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"
+
+#define SHADER(Src) #Src
+
+namespace gpu {
+
+static const char* v_shader_str = SHADER(
+  attribute vec4 v_position;

[greggman, 2013/05/02 16:37:26]

nit: a_ for attribute, v_ for varying?

+  void main() {
+    gl_Position = v_position;
+  }
+);
+
+static const char* f_shader_str = SHADER(
+  uniform sampler2D u_texture;
+  void main() {
+    gl_FragColor = texture2D(u_texture, vec2(0.5, 0.5)) *
+                             vec4(4.0, 2.0, 0.5, 0.25);
+  }
+);
+
+class GLOesTextureHalfFloatTest : public testing::Test {
+ protected:
+  virtual void SetUp() {
+    gl_.Initialize(GLManager::Options());
+
+    glGenTextures(2, textures);
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_2D, textures[1]);
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+
+    glGenFramebuffers(1, &fbo);
+    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
+                         textures[1], 0);

[greggman, 2013/05/02 16:37:26]

nit: indenting

+  }
+
+  virtual void TearDown() {
+    glDeleteTextures(2, textures);
+    glDeleteFramebuffers(1, &fbo);
+    gl_.Destroy();
+  }
+
+  GLuint SetupUnitQuad(GLint position_location);
+
+  GLManager gl_;
+  GLuint textures[2];
+  GLuint fbo;
+};
+
+GLuint GLOesTextureHalfFloatTest::SetupUnitQuad(GLint position_location) {

[greggman, 2013/05/02 16:37:26]

Can you just use GLTestHelper::SetupUnitQuad?

+  GLuint vbo = 0;
+  glGenBuffers(1, &vbo);
+  glBindBuffer(GL_ARRAY_BUFFER, vbo);
+  static float vertices[] = {
+      1.0f,  1.0f,  1.0f,
+     -1.0f,  1.0f,  0.0f,
+     -1.0f, -1.0f, -1.0f,
+      1.0f,  1.0f,  1.0f,
+     -1.0f, -1.0f, -1.0f,
+      1.0f, -1.0f,  0.0f,
+  };
+  glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+  glEnableVertexAttribArray(position_location);
+  glVertexAttribPointer(position_location, 3, GL_FLOAT, GL_FALSE, 0, 0);
+
+  return vbo;
+}
+
+TEST_F(GLOesTextureHalfFloatTest, TexImage2DAndTexSubImage2D) {
+  if (!GLTestHelper::HasExtension("GL_OES_texture_half_float")) {
+    return;
+  }
+
+  // (0.25, 0.5, 2.0, 4.0)
+  int16 pixels[1 * 4] = { 0x3400, 0x3800, 0x4000, 0x4400 };

[greggman, 2013/05/02 16:37:26]

static?

+  glBindTexture(GL_TEXTURE_2D, textures[0]);
+
+  GLenum formats[5] = { GL_RGBA, GL_RGB, GL_LUMINANCE_ALPHA,
+                          GL_LUMINANCE, GL_ALPHA };
+  for (unsigned int i = 0; i < 5; i++) {
+    glTexImage2D(GL_TEXTURE_2D, 0, formats[i], 1, 1, 0, formats[i],
+                 GL_HALF_FLOAT_OES, pixels);
+    EXPECT_TRUE(glGetError() == GL_NO_ERROR);
+    glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 1, 1, formats[i],
+                    GL_HALF_FLOAT_OES, pixels);
+    EXPECT_TRUE(glGetError() == GL_NO_ERROR);
+  }
+}
+
+TEST_F(GLOesTextureHalfFloatTest, ReadPixels) {
+  if (!GLTestHelper::HasExtension("GL_OES_texture_half_float")) {
+    return;
+  }
+
+  GLuint program = GLTestHelper::LoadProgram(v_shader_str, f_shader_str);
+  glUseProgram(program);
+  EXPECT_TRUE(glGetError() == GL_NO_ERROR);
+
+  GLint position_loc = glGetAttribLocation(program, "v_position");
+  SetupUnitQuad(position_loc);
+  EXPECT_TRUE(glGetError() == GL_NO_ERROR);
+
+  glBindTexture(GL_TEXTURE_2D, textures[1]);
+  glTexImage2D(
+      GL_TEXTURE_2D, 0, GL_RGBA, 4, 4,
+      0, GL_RGBA, GL_HALF_FLOAT_OES, NULL);
+  // Direct return if GL_HALF_FLOAT_OES if not a renderable type.
+  if (glCheckFramebufferStatus(GL_FRAMEBUFFER)
+      != static_cast<GLenum>(GL_FRAMEBUFFER_COMPLETE))
+    return;
+
+  // (0.25, 0.5, 0.5, 4.0) / (0x3400, 0x3800, 0x3800, 0x4400)
+  int16 pixels[1 * 4] = { 0x3400, 0x3800, 0x3800, 0x4400 };
+  glBindTexture(GL_TEXTURE_2D, textures[0]);
+  glTexImage2D(
+      GL_TEXTURE_2D, 0, GL_RGBA, 1, 1,
+      0, GL_RGBA, GL_HALF_FLOAT_OES, pixels);
+
+  glDrawArrays(GL_TRIANGLES, 0, 6);
+
+  uint16 actual_pixels[1 * 4] = { 0 };
+  glReadPixels(
+        0, 0, 1, 1, GL_RGBA, GL_HALF_FLOAT_OES,

[greggman, 2013/05/02 16:37:26]

AFAIK in GL ES 2.0 ReadPixels does not have to support GL_HALF_FLOAT_OES. In
fact I believe we don't allow anything but GL_RGBA, GL_UNSIGNED_BYTE so the
final result needs to be GL_RGBA, GL_UNSIGNED_BYTE in which case you can just
use GLTestHelper::CheckRect

+        actual_pixels);
+  EXPECT_TRUE(glGetError() == GL_NO_ERROR);
+
+  // (1.0, 1.0, 0.25, 1.0) / (15360, 15360, 13312, 15360)
+  EXPECT_EQ(15360, actual_pixels[0]);
+  EXPECT_EQ(15360, actual_pixels[1]);
+  EXPECT_EQ(13312, actual_pixels[2]);
+  EXPECT_EQ(15360, actual_pixels[3]);
+}
+
+
+TEST_F(GLOesTextureHalfFloatTest, OesTextureHalfFloatTest) {
+  if (!GLTestHelper::HasExtension("GL_OES_texture_half_float")) {
+    return;
+  }
+
+  GLuint program = GLTestHelper::LoadProgram(v_shader_str, f_shader_str);
+  glUseProgram(program);
+  EXPECT_TRUE(glGetError() == GL_NO_ERROR);
+
+  GLint position_loc = glGetAttribLocation(program, "v_position");
+  SetupUnitQuad(position_loc);
+  EXPECT_TRUE(glGetError() == GL_NO_ERROR);
+
+  glBindTexture(GL_TEXTURE_2D, textures[1]);
+  glTexImage2D(
+      GL_TEXTURE_2D, 0, GL_RGBA, 4, 4,
+      0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+  EXPECT_EQ(static_cast<GLenum>(GL_FRAMEBUFFER_COMPLETE),
+            glCheckFramebufferStatus(GL_FRAMEBUFFER));
+
+  // (0.25, 0.5, 2.0, 4.0) / (0x3400, 0x3800, 0x4000, 0x4400)
+  int16 pixels[1 * 4] = { 0x3400, 0x3800, 0x4000, 0x4400 };

[greggman, 2013/05/02 16:37:26]

static?

+  glBindTexture(GL_TEXTURE_2D, textures[0]);
+  glTexImage2D(
+      GL_TEXTURE_2D, 0, GL_RGBA, 1, 1,
+      0, GL_RGBA, GL_HALF_FLOAT_OES, pixels);
+  glDrawArrays(GL_TRIANGLES, 0, 6);
+  // check pixels
+  uint8 actual_pixels[1 * 4] = { 0 };

[greggman, 2013/05/02 16:37:26]

use GLTestHelper::CheckRect?

+  glReadPixels(
+        0, 0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE,
+        actual_pixels);
+  for (unsigned int i = 0; i < 4; i++) {
+    EXPECT_EQ(255, actual_pixels[i]);
+  }
+
+  glTexSubImage2D(
+      GL_TEXTURE_2D, 0, 0, 0, 1, 1,
+      GL_RGBA, GL_HALF_FLOAT_OES, pixels);
+  glDrawArrays(GL_TRIANGLES, 0, 6);
+  // check pixels
+  uint8 actual_pixels_sub[1 * 4] = { 0 };
+  glReadPixels(
+        0, 0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE,
+        actual_pixels_sub);
+  EXPECT_TRUE(glGetError() == GL_NO_ERROR);
+
+  for (unsigned int i = 0; i < 4; i++) {

[greggman, 2013/05/02 16:37:26]

use GLTestHelper::CheckRect?

+    EXPECT_EQ(255, actual_pixels_sub[i]);
+  }
+}
+
+}  // namespace gpu