gpu: Expose internal format R8 instead of RED.

ui/gl/gl_image_memory.cc

 // 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 "ui/gl/gl_image_memory.h"
 
 #include <stdint.h>
 
 #include "base/logging.h"
 #include "base/numerics/safe_conversions.h"
 #include "base/trace_event/trace_event.h"
 #include "ui/gfx/buffer_format_util.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_version_info.h"
 
 using gfx::BufferFormat;
 
 namespace gl {
 namespace {
 
 bool ValidInternalFormat(unsigned internalformat) {
   switch (internalformat) {
     case GL_ATC_RGB_AMD:
     case GL_ATC_RGBA_INTERPOLATED_ALPHA_AMD:
     case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
     case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
     case GL_ETC1_RGB8_OES:
-    case GL_RED:
+    case GL_R8:

[Zhenyao Mo, 2016/02/22 22:53:08]

Please also keep GL_RED

     case GL_RGB:
     case GL_RGBA:
     case GL_BGRA_EXT:
       return true;
     default:
       return false;
   }
 }
 
 bool ValidFormat(BufferFormat format) {
@@ skipping 52 matching lines @@
       return GL_ATC_RGB_AMD;
     case BufferFormat::ATCIA:
       return GL_ATC_RGBA_INTERPOLATED_ALPHA_AMD;
     case BufferFormat::DXT1:
       return GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
     case BufferFormat::DXT5:
       return GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
     case BufferFormat::ETC1:
       return GL_ETC1_RGB8_OES;
     case BufferFormat::R_8:
-      return GL_RED;
+      return gfx::GLContext::GetCurrent()->GetVersionInfo()->IsES3Capable()
+                 ? GL_R8
+                 : GL_RED;
     case BufferFormat::RGBA_4444:
     case BufferFormat::RGBA_8888:
       return GL_RGBA;
     case BufferFormat::BGRA_8888:
       return GL_BGRA_EXT;
     case BufferFormat::RGBX_8888:
     case BufferFormat::BGRX_8888:
       return GL_RGB;
     case BufferFormat::YUV_420:
     case BufferFormat::YUV_420_BIPLANAR:
     case BufferFormat::UYVY_422:
       NOTREACHED();
       return 0;
   }
 
   NOTREACHED();
   return 0;
 }
 
 GLenum DataFormat(BufferFormat format) {
   switch (format) {
     case BufferFormat::RGBX_8888:
       return GL_RGBA;
     case BufferFormat::BGRX_8888:
       return GL_BGRA_EXT;
+    case BufferFormat::R_8:
+      return GL_RED;

[Zhenyao Mo, 2016/02/22 22:53:08]

Why not let TextureFormat() deal with it here?

[Daniele Castagna, 2016/02/22 23:16:33]

TextureFormat returns GL_R8 for ES3.
IIUC DataFormat (that is passed to teximage2d as format) can't be R8 but should
be RED in ES3:
https://www.khronos.org/opengles/sdk/docs/man3/html/glTexImage2D.xhtml
I might be wrong and this seems pretty confusing since they allowed sized
formats in ES2 (they had to since format had to be the same as internalformat)
but it seems like in ES3 they restricted the values for format.

     case BufferFormat::RGBA_4444:
     case BufferFormat::RGBA_8888:
     case BufferFormat::BGRA_8888:
-    case BufferFormat::R_8:
     case BufferFormat::ATC:
     case BufferFormat::ATCIA:
     case BufferFormat::DXT1:
     case BufferFormat::DXT5:
     case BufferFormat::ETC1:
       return TextureFormat(format);
     case BufferFormat::YUV_420:
     case BufferFormat::YUV_420_BIPLANAR:
     case BufferFormat::UYVY_422:
       NOTREACHED();
@@ skipping 302 matching lines @@
   return false;
 }
 
 // static
 unsigned GLImageMemory::GetInternalFormatForTesting(BufferFormat format) {
   DCHECK(ValidFormat(format));
   return TextureFormat(format);
 }
 
 }  // namespace gl