Add support for GL_EXT_read_format_bgra.

I think this is all that is needed.

TEST=unit tests
BUG=none

Review URL: http://codereview.chromium.org/3109008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@55860 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 40 insertions, 2 deletions

diff --git a/gpu/command_buffer/service/context_group.cc b/gpu/command_buffer/service/context_group.cc
index 4e625c41..c0a9a98 100644
--- a/gpu/command_buffer/service/context_group.cc
+++ b/gpu/command_buffer/service/context_group.cc
@@ -65,15 +65,34 @@ bool ContextGroup::Initialize() {
         GL_COMPRESSED_RGBA_S3TC_DXT1_EXT);
   }
 
+  bool enable_texture_format_bgra8888 = false;
+  bool enable_read_format_bgra = false;
   // Check if we should allow GL_EXT_texture_format_BGRA8888
   if (strstr(extensions, "GL_EXT_texture_format_BGRA8888") ||
-      strstr(extensions, "GL_APPLE_texture_format_BGRA8888") ||
-      strstr(extensions, "GL_EXT_bgra")) {
+      strstr(extensions, "GL_APPLE_texture_format_BGRA8888")) {
+    enable_texture_format_bgra8888 = true;
+  }
+
+  if (strstr(extensions, "GL_EXT_bgra")) {
+    enable_texture_format_bgra8888 = true;
+    enable_read_format_bgra = true;
+  }
+
+  if (strstr(extensions, "GL_EXT_read_format_bgra")) {
+    enable_read_format_bgra = true;
+  }
+
+  if (enable_texture_format_bgra8888) {
     AddExtensionString("GL_EXT_texture_format_BGRA8888");
     validators_.texture_internal_format.AddValue(GL_BGRA_EXT);
     validators_.texture_format.AddValue(GL_BGRA_EXT);
   }
 
+  if (enable_read_format_bgra) {
+    AddExtensionString("GL_EXT_read_format_bgra");
+    validators_.read_pixel_format.AddValue(GL_BGRA_EXT);
+  }
+
   // Check if we should allow GL_OES_texture_npot
   if (strstr(extensions, "GL_ARB_texture_non_power_of_two") ||
       strstr(extensions, "GL_OES_texture_npot")) {
diff --git a/gpu/command_buffer/service/context_group_unittest.cc b/gpu/command_buffer/service/context_group_unittest.cc
index 3f8c65e..34c8adc 100644
--- a/gpu/command_buffer/service/context_group_unittest.cc
+++ b/gpu/command_buffer/service/context_group_unittest.cc
@@ -136,6 +136,8 @@ TEST_F(ContextGroupTest, InitializeNoExtensions) {
       GL_COMPRESSED_RGB_S3TC_DXT1_EXT));
   EXPECT_FALSE(group_.validators()->compressed_texture_format.IsValid(
       GL_COMPRESSED_RGBA_S3TC_DXT1_EXT));
+  EXPECT_FALSE(group_.validators()->read_pixel_format.IsValid(
+      GL_BGRA_EXT));
 }
 
 TEST_F(ContextGroupTest, InitializeNPOTExtensionGLES) {
@@ -190,10 +192,14 @@ TEST_F(ContextGroupTest, InitializeEXT_texture_format_BGRA8888GL) {
   group_.Initialize();
   EXPECT_THAT(group_.extensions(),
               HasSubstr("GL_EXT_texture_format_BGRA8888"));
+  EXPECT_THAT(group_.extensions(),
+              HasSubstr("GL_EXT_read_format_bgra"));
   EXPECT_TRUE(group_.validators()->texture_format.IsValid(
       GL_BGRA_EXT));
   EXPECT_TRUE(group_.validators()->texture_internal_format.IsValid(
       GL_BGRA_EXT));
+  EXPECT_TRUE(group_.validators()->read_pixel_format.IsValid(
+      GL_BGRA_EXT));
 }
 
 TEST_F(ContextGroupTest, InitializeEXT_texture_format_BGRA8888Apple) {
@@ -207,6 +213,19 @@ TEST_F(ContextGroupTest, InitializeEXT_texture_format_BGRA8888Apple) {
       GL_BGRA_EXT));
 }
 
+TEST_F(ContextGroupTest, InitializeEXT_read_format_bgra) {
+  SetupInitExpectations("GL_EXT_read_format_bgra");
+  group_.Initialize();
+  EXPECT_THAT(group_.extensions(),
+              HasSubstr("GL_EXT_read_format_bgra"));
+  EXPECT_FALSE(group_.validators()->texture_format.IsValid(
+      GL_BGRA_EXT));
+  EXPECT_FALSE(group_.validators()->texture_internal_format.IsValid(
+      GL_BGRA_EXT));
+  EXPECT_TRUE(group_.validators()->read_pixel_format.IsValid(
+      GL_BGRA_EXT));
+}
+
 TEST_F(ContextGroupTest, InitializeOES_texture_floatGLES2) {
   SetupInitExpectations("GL_OES_texture_float");
   group_.Initialize();