Implement client side PBOs for glReadPixel

gpu/GLES2/gl2extchromium.h

 // 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.
 
 // This file contains Chromium-specific GLES2 extensions declarations.
 
 #ifndef GPU_GLES2_GL2EXTCHROMIUM_H_
 #define GPU_GLES2_GL2EXTCHROMIUM_H_
 
 #include <GLES2/gl2.h>
@@ skipping 52 matching lines @@
     GLenum target, const GLbyte* mailbox);
 typedef void (GL_APIENTRYP PFNGLCONSUMETEXTURECHROMIUMPROC) (
     GLenum target, const GLbyte* mailbox);
 #endif  /* GL_CHROMIUM_texture_mailbox */
 
 /* GL_CHROMIUM_pixel_transfer_buffer_object */
 #ifndef GL_CHROMIUM_pixel_transfer_buffer_object
 #define GL_CHROMIUM_pixel_transfer_buffer_object 1
 
 #ifndef GL_PIXEL_UNPACK_TRANSFER_BUFFER_CHROMIUM
+// TODO(reveman): Get official numbers for this constants.
 #define GL_PIXEL_UNPACK_TRANSFER_BUFFER_CHROMIUM 0x78EC
+#define GL_PIXEL_PACK_TRANSFER_BUFFER_CHROMIUM 0x78ED
 
 #ifdef GL_GLEXT_PROTOTYPES
 GL_APICALL void* GL_APIENTRY glMapBufferCHROMIUM(GLuint target,GLenum access);
 GL_APICALL GLboolean GL_APIENTRY glUnmapBufferCHROMIUM(GLuint target);
 #endif
 typedef void* (GL_APIENTRY PFNGLMAPBUFFERCHROMIUM) (
     GLuint target,GLenum access);
 typedef GLboolean (GL_APIENTRY PFNGLUNMAPBUFFERCHROMIUM) (GLuint target);
 #endif  /* GL_CHROMIUM_pixel_transfer_buffer_object */
 
 #ifndef GL_PIXEL_UNPACK_TRANSFER_BUFFER_BINDING_CHROMIUM
+// TODO(reveman): Get official numbers for this constants.
 #define GL_PIXEL_UNPACK_TRANSFER_BUFFER_BINDING_CHROMIUM 0x78EF
+#define GL_PIXEL_PACK_TRANSFER_BUFFER_BINDING_CHROMIUM 0x78EE
+#endif
+
+#ifndef GL_STREAM_READ
+#define GL_STREAM_READ 0x88E1
 #endif
 #endif  /* GL_CHROMIUM_pixel_transfer_buffer_object */
 
 /* GL_CHROMIUM_map_sub */
 #ifndef GL_CHROMIUM_map_sub
 #define GL_CHROMIUM_map_sub 1
 
 #ifndef GL_READ_ONLY
 #define GL_READ_ONLY 0x88B8
 #endif
@@ skipping 473 matching lines @@
 #endif
 typedef GLuint (GL_APIENTRYP PFNGLINSERTSYNCPOINTCHROMIUMPROC) ();
 typedef void (GL_APIENTRYP PFNGLWAITSYNCPOINTCHROMIUMPROC) (GLuint sync_point);
 #endif  /* GL_CHROMIUM_sync_point */
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif  // GPU_GLES2_GL2EXTCHROMIUM_H_
-