SRGB_EXT is a valid format of texture in WebGL1.0 and ES2.0 contexts

gpu/command_buffer/service/gles2_cmd_decoder.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.
 
 #include "gpu/command_buffer/service/gles2_cmd_decoder.h"
 
 #include <limits.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
@@ skipping 11424 matching lines @@
   } else {
     if (!pixels_shm_id && pixels_shm_offset)
       return error::kInvalidArguments;
     // When reading from client buffer, the command buffer client side took
     // the responsibility to take the pixels from the client buffer and
     // unpack them according to the full ES3 pack parameters as source, all
     // parameters for 0 (except for alignment) as destination mem for the
     // service side.
     params.alignment = state_.unpack_alignment;
   }
+
+  // When the client is providing ES 2.0 or WebGL 1.0 contexts, but the
+  // command buffer is running on top of desktop GL or ES 3.0, it would
+  // have to translate these unsized internal formats to the appropriate
+  // sized internal formats.
+  if ((internal_format == GL_SRGB_EXT ||
+      internal_format == GL_SRGB_ALPHA_EXT) &&
+      (feature_info_->context_type() == CONTEXT_TYPE_WEBGL2 ||
+      feature_info_->context_type() == CONTEXT_TYPE_OPENGLES3)) {

[Zhenyao Mo, 2016/04/27 17:12:26]

I just realized we have a different place for such mapping:
ui/gl/gl_gl_api_implementation.cc::GetTexInternalFormat()

Although I think we should just move that function into command buffer, but at
the moment let's put such mapping all in one place.

On a separate note, and it doesn't matter if this code is moved to the ui/gl,
your current code is incorrect.  feature_info_->context_type() is the command
buffer's context type, whereas you should check the underlying GL driver's type,
which is feature_info_->gl_version_info().

[xinghua.cao, 2016/04/28 09:59:27]

I have put this mapping in gl_gl_api_implementation.cc.
Zhenyao, you are right. here should identify the GL driver's type when mapping
internal format and format.

+    if (internal_format == GL_SRGB_EXT) {
+      internal_format = GL_SRGB8;
+      format = GL_RGB;
+    } else if (internal_format == GL_SRGB_ALPHA_EXT) {
+      internal_format = GL_SRGB8_ALPHA8;
+      format = GL_RGBA;
+    }
+  }
+
   uint32_t pixels_size;
   uint32_t skip_size;
   uint32_t padding;
   if (!GLES2Util::ComputeImageDataSizesES3(width, height, 1,
                                            format, type,
                                            params,
                                            &pixels_size,
                                            nullptr,
                                            nullptr,
                                            &skip_size,
@@ skipping 546 matching lines @@
       return error::kInvalidArguments;
     params = state_.GetUnpackParams(ContextState::k2D);
   } else {
     // When reading from client buffer, the command buffer client side took
     // the responsibility to take the pixels from the client buffer and
     // unpack them according to the full ES3 pack parameters as source, all
     // parameters for 0 (except for alignment) as destination mem for the
     // service side.
     params.alignment = state_.unpack_alignment;
   }
+
+  // When the client is providing ES 2.0 or WebGL 1.0 contexts, but the
+  // command buffer is running on top of desktop GL or ES 3.0, it would
+  // have to translate these unsized internal formats to the appropriate
+  // sized internal formats.
+  if ((format == GL_SRGB_EXT || format == GL_SRGB_ALPHA_EXT) &&

[Zhenyao Mo, 2016/04/27 17:12:26]

Same here. Let's do the mapping in ui/gl/gl_gl_api_implementation.cc

+      (feature_info_->context_type() == CONTEXT_TYPE_WEBGL2 ||
+      feature_info_->context_type() == CONTEXT_TYPE_OPENGLES3)) {
+    if (format == GL_SRGB_EXT) {
+      format = GL_RGB;
+    } else if (format == GL_SRGB_ALPHA_EXT) {
+      format = GL_RGBA;
+    }
+  }
+
   uint32_t pixels_size;
   uint32_t skip_size;
   uint32_t padding;
   if (!GLES2Util::ComputeImageDataSizesES3(width, height, 1,
                                            format, type,
                                            params,
                                            &pixels_size,
                                            nullptr,
                                            nullptr,
                                            &skip_size,
@@ skipping 4336 matching lines @@
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "base/macros.h"
 #include "gpu/command_buffer/service/gles2_cmd_decoder_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu