Work around CopyTexImage2D issue on Intel Mac OSX 10.12

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 13296 matching lines @@
             GetBoundReadFramebufferServiceId(),
             GetBoundReadFramebufferInternalFormat());
       } else {
         glCopyTexSubImage2D(target, level, destX, destY, copyX, copyY,
                             copyWidth, copyHeight);
       }
     }
   } else {
     GLenum final_internal_format = TextureManager::AdjustTexInternalFormat(
         feature_info_.get(), internal_format);
+    if (workarounds().init_cube_map_before_copyteximage &&
+        texture->target() == GL_TEXTURE_CUBE_MAP &&
+        target != GL_TEXTURE_CUBE_MAP_POSITIVE_X) {
+      for (int i = 0; i < 2; ++i) {
+        TextureManager::DoTexImageArguments args = {
+          target, i, final_internal_format, 1, 1, 1, border,
+          format, type, nullptr, 1, 0,
+          TextureManager::DoTexImageArguments::kTexImage2D };
+        texture_manager()->WorkaroundCopyTexImageCubeMap(&texture_state_,
+            &state_, &framebuffer_state_, texture_ref, func_name, args);
+      }

[Zhenyao Mo, 2016/09/28 21:14:23]

This gets complicated when we also need to emulate for LUMINANCE_ALPHA formats.

Could you at least add a TODO and create a bug to track it?

[qiankun, 2016/09/29 00:51:27]

What kinds of TODO, something like to handle this workaround and LUMINANCE_ALPHA
emulation correctly?

[Zhenyao Mo, 2016/09/29 20:30:16]

What I mean is, if the src texture format is LUMINANCE/ALPHA, then
WorkaroundCopyTexImageCubeMap() will generate GL errors on platforms where these
formats are not supported.

[qiankun, 2016/09/30 05:47:39]

Sorry, I didn't get this. Can you explain it further? Where does the GL errors
come from? I think WorkaroundCopyTexImageCubeMap doens't use src texture format.
Does LUMINANCE/ALPHA emulation patch land chromium already?

[qiankun, 2016/10/11 01:56:20]

Zhenyao&Ken, do I still need to add this TODO according my last comment as
below:

Format is also mapped when doing glTexImage2D, see:
https://cs.chromium.org/chromium/src/gpu/command_buffer/service/texture_manag...

+    }
 
     // The service id and target of the texture attached to READ_FRAMEBUFFER.
     GLuint source_texture_service_id = 0;
     GLenum source_texture_target = 0;
     uint32_t channels_exist = GLES2Util::GetChannelsForFormat(read_format);
     bool use_workaround = NeedsCopyTextureImageWorkaround(
         final_internal_format, channels_exist, &source_texture_service_id,
         &source_texture_target);
     if (requires_luma_blit) {
       copy_tex_image_blit_->DoCopyTexImage2DToLUMACompatibilityTexture(
           this, texture->service_id(), texture->target(), target, format,
           type, level, internal_format, copyX, copyY, copyWidth, copyHeight,
           GetBoundReadFramebufferServiceId(),
           GetBoundReadFramebufferInternalFormat());

[qiankun, 2016/09/29 00:51:27]

FYI: This path requires the init_cube_map_before_copyteximage workaround.
Otherwise, luminance related dEQP tests will fail.

     } else if (use_workaround) {
       GLenum dest_texture_target = target;
       GLenum framebuffer_target = features().chromium_framebuffer_multisample
                                       ? GL_READ_FRAMEBUFFER_EXT
                                       : GL_FRAMEBUFFER;
 
       GLenum temp_internal_format = 0;
       if (channels_exist == GLES2Util::kRGBA) {
         temp_internal_format = GL_RGBA;
       } else if (channels_exist == GLES2Util::kRGB) {
@@ skipping 4742 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