gpu: support R16 GPUMemoryBuffer

ui/gl/gl_image_io_surface.mm

 // Copyright 2013 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_io_surface.h"
 
 #include <map>
 
 #include "base/callback_helpers.h"
 #include "base/mac/bind_objc_block.h"
@@ skipping 14 matching lines @@
 #include <stddef.h>
 
 using gfx::BufferFormat;
 
 namespace gl {
 namespace {
 
 bool ValidInternalFormat(unsigned internalformat) {
   switch (internalformat) {
     case GL_RED:
+    case GL_R16_EXT:

[Ken Russell (switch to Gerrit), 2017/06/09 22:37:39]

Note: I checked CGLIOSurface.h and confirmed that the format/type/internal
format tuple (GL_UNSIGNED_SHORT, GL_RED, GL_R16) is supported. However, it was
only subsumed into the Core Profile in OpenGL 3.0. If Chrome happens to fall
back to the OpenGL compatibility profile (which is feature level 2.1 on macOS),
do we need to feature detect its availability (via GL_ARB_texture_rg)?

[riju_, 2017/06/13 15:34:14]

Thanks, I am doing the check here->
https://codereview.chromium.org/2933313003

[Ken Russell (switch to Gerrit), 2017/06/13 23:52:36]

Thanks. Reviewed that other change; it isn't necessary, since the other code
path checks for is_desktop_core_profile, which implies a minimum version of
OpenGL 3.2.

[riju_, 2017/06/14 07:14:46]

Acknowledged.

     case GL_RG:
     case GL_BGRA_EXT:
     case GL_RGB:
     case GL_RGB_YCBCR_420V_CHROMIUM:
     case GL_RGB_YCBCR_422_CHROMIUM:
     case GL_RGBA:
       return true;
     default:
       return false;
   }
 }
 
 bool ValidFormat(gfx::BufferFormat format) {
   switch (format) {
     case gfx::BufferFormat::R_8:
     case gfx::BufferFormat::BGRA_8888:
     case gfx::BufferFormat::BGRX_8888:
     case gfx::BufferFormat::RGBA_8888:
     case gfx::BufferFormat::RGBA_F16:
     case gfx::BufferFormat::UYVY_422:
     case gfx::BufferFormat::YUV_420_BIPLANAR:
       return true;
+    case gfx::BufferFormat::R_16:
     case gfx::BufferFormat::RG_88:
     case gfx::BufferFormat::ATC:
     case gfx::BufferFormat::ATCIA:
     case gfx::BufferFormat::DXT1:
     case gfx::BufferFormat::DXT5:
     case gfx::BufferFormat::ETC1:
     case gfx::BufferFormat::BGR_565:
     case gfx::BufferFormat::RGBA_4444:
     case gfx::BufferFormat::RGBX_8888:
     case gfx::BufferFormat::YVU_420:
       return false;
   }
 
   NOTREACHED();
   return false;
 }
 
 GLenum TextureFormat(gfx::BufferFormat format) {
   switch (format) {
     case gfx::BufferFormat::R_8:
       return GL_RED;
+    case gfx::BufferFormat::R_16:
+      return GL_R16_EXT;
     case gfx::BufferFormat::RG_88:
       return GL_RG;
     case gfx::BufferFormat::BGRA_8888:
     case gfx::BufferFormat::BGRX_8888:
     case gfx::BufferFormat::RGBA_8888:
     case gfx::BufferFormat::RGBA_F16:
       return GL_RGBA;
     case gfx::BufferFormat::UYVY_422:
       return GL_RGB;
     case gfx::BufferFormat::YUV_420_BIPLANAR:
@@ skipping 12 matching lines @@
   }
 
   NOTREACHED();
   return 0;
 }
 
 GLenum DataFormat(gfx::BufferFormat format) {
   switch (format) {
     case gfx::BufferFormat::R_8:
       return GL_RED;
+    case gfx::BufferFormat::R_16:
+      return GL_R16_EXT;
     case gfx::BufferFormat::RG_88:
       return GL_RG;
     case gfx::BufferFormat::BGRA_8888:
     case gfx::BufferFormat::BGRX_8888:
     case gfx::BufferFormat::RGBA_8888:
       return GL_BGRA;
     case gfx::BufferFormat::RGBA_F16:
       return GL_RGBA;
     case gfx::BufferFormat::UYVY_422:
       return GL_YCBCR_422_APPLE;
@@ skipping 13 matching lines @@
 
   NOTREACHED();
   return 0;
 }
 
 GLenum DataType(gfx::BufferFormat format) {
   switch (format) {
     case gfx::BufferFormat::R_8:
     case gfx::BufferFormat::RG_88:
       return GL_UNSIGNED_BYTE;
+    case gfx::BufferFormat::R_16:
+      return GL_UNSIGNED_SHORT;
     case gfx::BufferFormat::BGRA_8888:
     case gfx::BufferFormat::BGRX_8888:
     case gfx::BufferFormat::RGBA_8888:
       return GL_UNSIGNED_INT_8_8_8_8_REV;
     case gfx::BufferFormat::RGBA_F16:
       return GL_HALF_APPLE;
     case gfx::BufferFormat::UYVY_422:
       return GL_UNSIGNED_SHORT_8_8_APPLE;
       break;
     case gfx::BufferFormat::ATC:
@@ skipping 264 matching lines @@
 }
 
 // static
 GLImageIOSurface* GLImageIOSurface::FromGLImage(GLImage* image) {
   if (!image || image->GetType() != Type::IOSURFACE)
     return nullptr;
   return static_cast<GLImageIOSurface*>(image);
 }
 
 }  // namespace gl