Addition of unpremultiply setting to GL_CHROMIUM_copy_texture.

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 <stdio.h>
 
 #include <algorithm>
 #include <list>
@@ skipping 1370 matching lines @@
 
   // pack alignment as last set by glPixelStorei
   GLint pack_alignment_;
 
   // unpack alignment as last set by glPixelStorei
   GLint unpack_alignment_;
 
   // unpack flip y as last set by glPixelStorei
   bool unpack_flip_y_;
 
-  // unpack premultiply alpha as last set by glPixelStorei
+  // unpack (un)premultiply alpha as last set by glPixelStorei
   bool unpack_premultiply_alpha_;
+  bool unpack_unpremultiply_alpha_;
 
   // The currently bound array buffer. If this is 0 it is illegal to call
   // glVertexAttribPointer.
   BufferManager::BufferInfo::Ref bound_array_buffer_;
 
   // The currently bound element array buffer. If this is 0 it is illegal
   // to call glDrawElements.
   BufferManager::BufferInfo::Ref bound_element_array_buffer_;
 
   // Class that manages vertex attribs.
@@ skipping 494 matching lines @@
 }
 
 GLES2DecoderImpl::GLES2DecoderImpl(ContextGroup* group)
     : GLES2Decoder(),
       group_(group),
       error_bits_(0),
       pack_alignment_(4),
       unpack_alignment_(4),
       unpack_flip_y_(false),
       unpack_premultiply_alpha_(false),
+      unpack_unpremultiply_alpha_(false),
       attrib_0_buffer_id_(0),
       attrib_0_buffer_matches_value_(true),
       attrib_0_size_(0),
       fixed_attrib_buffer_id_(0),
       fixed_attrib_buffer_size_(0),
       active_texture_unit_(0),
       clear_red_(0),
       clear_green_(0),
       clear_blue_(0),
       clear_alpha_(0),
@@ skipping 4438 matching lines @@
     case GL_UNPACK_ALIGNMENT:
         if (!validators_->pixel_store_alignment.IsValid(param)) {
             SetGLError(GL_INVALID_VALUE,
                        "glPixelStore", "param GL_INVALID_VALUE");
             return error::kNoError;
         }
         break;
     case GL_UNPACK_FLIP_Y_CHROMIUM:
         unpack_flip_y_ = (param != 0);
         return error::kNoError;
     case GL_UNPACK_PREMULTIPLY_ALPHA_CHROMIUM:

[greggman, 2012/06/15 00:11:45]

When you add a new type here you also need to add a new type to
GLES2DecoderImpl::GetHelper and also the GLState list in
build_gles2_cmd_buffer.py

Did we forget the previous ones?

Should probably add a test

[Jeff Timanus, 2012/06/18 14:50:24]

I think a few settings are missing from GetHelper:
GL_UNPACK_FLIP_Y_CHROMIUM
GL_UNPACK_PREMULTIPLY_ALPHA_CHROMIUM
GL_PACK_REVERSE_ROW_ORDER_ANGLE

These are also missing from the GLState list.

Adding them.

         unpack_premultiply_alpha_ = (param != 0);
+        unpack_unpremultiply_alpha_ =

[greggman, 2012/06/15 00:11:45]

This logic seems strange to me. 

If I go pre=1, un=1, un=0 now pre = 0 but I, as a user, never explicitly set it
to 0

Do you want to just set to the 2 flags here and decide which takes precedence
when you apply them?

[Jeff Timanus, 2012/06/18 14:50:24]

Yeah, I mulled how to best handle this situation.  Maybe the simplest (and most
obvious) solution would be set the precedence such that if both are enabled,
then they nullify each other.

+            unpack_unpremultiply_alpha_ && !unpack_premultiply_alpha_;
+        return error::kNoError;
+    case GL_UNPACK_UNPREMULTIPLY_ALPHA_CHROMIUM:
+        unpack_unpremultiply_alpha_ = (param != 0);
+        unpack_premultiply_alpha_ =
+            unpack_premultiply_alpha_ && !unpack_unpremultiply_alpha_;
         return error::kNoError;
     default:
         break;
   }
   glPixelStorei(pname, param);
   switch (pname) {
     case GL_PACK_ALIGNMENT:
         pack_alignment_ = param;
         break;
     case GL_PACK_REVERSE_ROW_ORDER_ANGLE:
@@ skipping 2441 matching lines @@
         source_height, 1, 0, internal_format, dest_type, true);
   } else {
     texture_manager()->SetLevelCleared(dest_info, GL_TEXTURE_2D, level);
   }
 
   state_dirty_ = true;
   glViewport(0, 0, source_width, source_height);
   copy_texture_CHROMIUM_->DoCopyTexture(target, source_info->service_id(),
                                         dest_info->service_id(), level,
                                         unpack_flip_y_,
-                                        unpack_premultiply_alpha_);
+                                        unpack_premultiply_alpha_,
+                                        unpack_unpremultiply_alpha_);
   glViewport(viewport_x_, viewport_y_, viewport_width_, viewport_height_);
 
   // Restore all of the state touched by the extension.
   if (current_program_)
     glUseProgram(current_program_->service_id());
   else
     glUseProgram(0);
 
   RestoreCurrentFramebufferBindings();
   RestoreCurrentTexture2DBindings();
@@ skipping 169 matching lines @@
   BindAndApplyTextureParameters(info);
 }
 
 // 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 "gpu/command_buffer/service/gles2_cmd_decoder_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu