Proposed changes for Pepper 3D API.

ppapi/c/dev/pp_graphics_3d_dev.h

 /* Copyright (c) 2011 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.
  */
 
 #ifndef PPAPI_C_DEV_PP_GRAPHICS_3D_DEV_H_
 #define PPAPI_C_DEV_PP_GRAPHICS_3D_DEV_H_
 
 #include "ppapi/c/pp_stdint.h"
 
 enum PP_Graphics3DError_Dev {
-  PP_GRAPHICS3DERROR_BAD_ATTRIBUTE = 0x3004,
   PP_GRAPHICS3DERROR_CONTEXT_LOST = 0x300E
 };
 
 enum PP_Graphics3DAttrib_Dev {
   // Bits of Alpha in the color buffer.
   PP_GRAPHICS3DATTRIB_ALPHA_SIZE = 0x3021,
   // Bits of Blue in the color buffer.
   PP_GRAPHICS3DATTRIB_BLUE_SIZE = 0x3022,
   // Bits of Green in the color buffer.
   PP_GRAPHICS3DATTRIB_GREEN_SIZE = 0x3023,
   // Bits of Red in the color buffer.
   PP_GRAPHICS3DATTRIB_RED_SIZE = 0x3024,
   // Bits of Z in the depth buffer.
   PP_GRAPHICS3DATTRIB_DEPTH_SIZE = 0x3025,
   // Bits of Stencil in the stencil buffer.
   PP_GRAPHICS3DATTRIB_STENCIL_SIZE = 0x3026,
   // Number of samples per pixel.
   PP_GRAPHICS3DATTRIB_SAMPLES = 0x3031,
   // Number of multisample buffers.
   PP_GRAPHICS3DATTRIB_SAMPLE_BUFFERS = 0x3032,
   // Attrib list terminator.
   PP_GRAPHICS3DATTRIB_NONE = 0x3038,
-
-  // Surface-specific attributes.
+  // Boolean to ignore the alpha channel of RGBA color buffer.
+  // The value of this attribute is ignored for RGB color buffer.
+  PP_GRAPHICS3DATTRIB_BIND_RGB = 0x3039,

[piman, 2011/08/25 19:58:09]

I think we want more flexibility than this here. At least:
- pre-multiplied alpha (what is the default today)
- non-premul alpha (what many games would typically do, also available on WebGL)
- ignore alpha

See bug http://code.google.com/p/chromium/issues/detail?id=74209

I think we'd want specifying the complete blending function, as 2 enum values
for source and destination, providing the most flexibility, without adding
complexity (since we can do it all in the compositor).

[greggman, 2011/09/22 21:01:25]

Do we need that functionality here?

I'm pretty sure that's all being added to css so if you want it blended
different you just set the css.

Adding it here would then add complexity since you'd have to combine them with
the css blending modes to get the correct result.

   // Height of surface in pixels.
   PP_GRAPHICS3DATTRIB_HEIGHT = 0x3056,
   // Width of surface in pixels.
   PP_GRAPHICS3DATTRIB_WIDTH = 0x3057,
 
   // Specifies the effect on the color buffer of posting a surface
   // with SwapBuffers. The initial value is chosen by the implementation.
   PP_GRAPHICS3DATTRIB_SWAP_BEHAVIOR = 0x3093,
   // Indicates that color buffer contents are unaffected.
   PP_GRAPHICS3DATTRIB_BUFFER_PRESERVED = 0x3094,
   // Indicates that color buffer contents may be destroyed or changed.
   PP_GRAPHICS3DATTRIB_BUFFER_DESTROYED = 0x3095
 };
 
 // TODO(alokp): Remove this when PPB_Context3D_Dev and PPB_Surface3D_Dev
 // are deprecated.
 typedef int32_t PP_Config3D_Dev;
 
 #endif  // PPAPI_C_DEV_PP_GRAPHICS_3D_DEV_H_