gpu, cmaa: improve |do_copy| condition logic

gpu/command_buffer/service/gles2_cmd_apply_framebuffer_attachment_cmaa_intel.cc

 // Copyright 2016 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_apply_framebuffer_attachment_cmaa_intel.h"
 
 #include "base/logging.h"
 #include "gpu/command_buffer/service/framebuffer_manager.h"
 #include "gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.h"
 #include "gpu/command_buffer/service/gles2_cmd_decoder.h"
+#include "gpu/command_buffer/service/texture_manager.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_gl_api_implementation.h"
 #include "ui/gl/gl_version_info.h"
 
 #define SHADER(Src) #Src
 
 namespace gpu {
 namespace gles2 {
 
 ApplyFramebufferAttachmentCMAAINTELResourceManager::
@@ skipping 179 matching lines @@
   glDeleteProgram(debug_display_edges_shader_);
 
   initialized_ = false;
 }
 
 // Apply CMAA(Conservative Morphological Anti-Aliasing) algorithm to the
 // color attachments of currently bound draw framebuffer.
 // Reference GL_INTEL_framebuffer_CMAA for details.
 void ApplyFramebufferAttachmentCMAAINTELResourceManager::
     ApplyFramebufferAttachmentCMAAINTEL(
-        gles2::GLES2Decoder* decoder,
-        gles2::Framebuffer* framebuffer,
-        gles2::CopyTextureCHROMIUMResourceManager* copier) {
+        GLES2Decoder* decoder,
+        Framebuffer* framebuffer,
+        CopyTextureCHROMIUMResourceManager* copier,
+        TextureManager* texture_manager) {
   DCHECK(decoder);
   DCHECK(initialized_);
   if (!framebuffer)
     return;
 
   glDisable(GL_SCISSOR_TEST);
   glDisable(GL_STENCIL_TEST);
   glDisable(GL_CULL_FACE);
   glDisable(GL_BLEND);
 
@@ skipping 11 matching lines @@
         continue;
       GLsizei width = attachment->width();
       GLsizei height = attachment->height();
       GLenum internal_format = attachment->internal_format();
 
       // Resize internal structures - only if needed.
       OnSize(width, height);
 
       // CMAA internally expects GL_RGBA8 textures.
       // Process using a GL_RGBA8 copy if this is not the case.
-      bool do_copy = internal_format != GL_RGBA8;
+      DCHECK(attachment->object_name());
+      TextureRef* texture =
+          texture_manager->GetTexture(attachment->object_name());
+      const bool rgba_immutable =
+          texture->texture()->IsImmutable() &&
+          TextureManager::ExtractFormatFromStorageFormat(internal_format) ==
+              GL_RGBA;
+      const bool do_copy = !rgba_immutable;
 
       // CMAA Effect
       if (do_copy) {
         ApplyCMAAEffectTexture(source_texture, rgba8_texture_, do_copy);
 
         copier->DoCopySubTexture(

[qiankun, 2017/02/08 03:19:56]

Hi DS,

DoCopySubTexture only supported GLES2 formats at this point. I extended it to
support part of ES3 formats: https://codereview.chromium.org/2479513002/. A few
ES3 formats is still not supported yet, e.g. RGBA16I, RGBA16UI, RGBA32I,
RGBA32UI, because that it is not clear how to translate 8-bit format to 16-bit
or 32-bit format, see the Rationale under texImage2D section in WebGL 2.0 spec:
https://www.khronos.org/registry/webgl/specs/latest/2.0/index.html#3.7.6. So it
may have potential issues using DoCopySubTexture here. What do you think? I
proposed a CL to fix part issue:https://codereview.chromium.org/2680703003/. But
I think we still need to support other ES3 formats if we use DoCopySubTexture
here or find other methods to do copy.

[dshwang, 2017/02/10 01:13:38]

Hi Qiankun,

CMAA requires only RGB, RGBA, and probably SRGBA. Only default framebuffer
object for DrawingBuffer uses CMAA. So your
https://codereview.chromium.org/2479513002/ is enough for CMAA. Thank you!

             decoder, GL_TEXTURE_2D, rgba8_texture_, GL_RGBA8, GL_TEXTURE_2D,
             source_texture, internal_format, 0, 0, 0, 0, width_, height_,
             width_, height_, width_, height_, false, false, false);
       } else {
         ApplyCMAAEffectTexture(source_texture, source_texture, do_copy);
       }
 
       decoder->RestoreTextureState(source_texture);
     }
   }
@@ skipping 1580 matching lines @@
     \n#endif\n
     \n#if defined DISPLAY_EDGES\n
       DisplayEdges();
     \n#endif\n
     }
   );
 /* clang-format on */
 
 }  // namespace gles2
 }  // namespace gpu