Reland of "webgl: optimize webgl.texSubImage2D(video) path."

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 <cmath>
@@ skipping 13185 matching lines @@
       return;
     }
   } else {
     if (!source_texture->GetLevelSize(source_texture->target(), 0,
                                       &source_width, &source_height, nullptr)) {
       LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "glCopySubTextureCHROMIUM",
                          "source texture has no level 0");
       return;
     }
 
+    if (!source_texture->ValidForTexture(source_texture->target(), 0, x, y, 0,
+                                         width, height, 1)) {
+      LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "glCopySubTextureCHROMIUM",
+                         "source texture bad dimensions.");
+      return;
+    }
+

[dshwang, 2015/10/29 09:18:09]

As kbr reviewed, I fold https://codereview.chromium.org/1417913004/ into here.
It's fixed as part of cube map CL in
https://codereview.chromium.org/1275773003/diff/80001/gpu/command_buffer/serv...
,
but the CL was reverted.

zmo, piman, could you review?

[piman, 2015/10/30 00:16:30]

Can you explain? It seems that we would want to make sure that the source
contains the rectangle we're trying to copy, even for the GLImage case. Why are
we removing the check?

What would happen if x/y/width/height were out of range?

[dshwang, 2015/10/30 11:06:28]

That's good concern. Currently GLES2DecoderImpl cannot validation bad dimensions
as well as valid target, because some methods (e.g.
GetLevelSize/ValidForTexture/ValidForTarget) in Texture class are not valid for
GLImage. Let me solve it in
https://code.google.com/p/chromium/issues/detail?id=549531 and then remove this
unfortunate branch together.

     // Check that this type of texture is allowed.
     if (!texture_manager()->ValidForTarget(source_texture->target(), 0,
                                            source_width, source_height, 1)) {
       LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "glCopySubTextureCHROMIUM",
                          "source texture bad dimensions");
       return;
     }
   }
 
   GLenum source_type = 0;
   GLenum source_internal_format = 0;
   source_texture->GetLevelType(source_texture->target(), 0, &source_type,
                                &source_internal_format);
-  if (!source_texture->ValidForTexture(source_texture->target(), 0, x, y, 0,
-                                       width, height, 1)) {
-    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "glCopySubTextureCHROMIUM",
-                       "source texture bad dimensions.");
-    return;
-  }
 
   GLenum dest_type = 0;
   GLenum dest_internal_format = 0;
   bool dest_level_defined = dest_texture->GetLevelType(
       dest_texture->target(), 0, &dest_type, &dest_internal_format);
   if (!dest_level_defined) {
     LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION, "glCopySubTextureCHROMIUM",
                        "destination texture is not defined");
     return;
   }
@@ skipping 283 matching lines @@
       return;
     }
   } else {
     if (!source_texture->GetLevelSize(source_texture->target(), 0,
                                       &source_width, &source_height, nullptr)) {
       LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "glCompressedCopySubTextureCHROMIUM",
                          "source texture has no level 0");
       return;
     }
 
+    if (!source_texture->ValidForTexture(source_texture->target(), 0, x, y, 0,
+                                         width, height, 1)) {
+      LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "glCompressedCopySubTextureCHROMIUM",
+                         "source texture bad dimensions.");
+      return;
+    }
+
     // Check that this type of texture is allowed.
     if (!texture_manager()->ValidForTarget(source_texture->target(), 0,
                                            source_width, source_height, 1)) {
       LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "glCompressedCopySubTextureCHROMIUM",
                          "source texture bad dimensions");
       return;
     }
   }
 
   GLenum source_type = 0;
   GLenum source_internal_format = 0;
   source_texture->GetLevelType(source_texture->target(), 0, &source_type,
                                &source_internal_format);
-  if (!source_texture->ValidForTexture(source_texture->target(), 0, x, y, 0,
-                                       width, height, 1)) {
-    LOCAL_SET_GL_ERROR(GL_INVALID_VALUE, "glCompressedCopySubTextureCHROMIUM",
-                       "source texture bad dimensions.");
-    return;
-  }
 
   GLenum dest_type = 0;
   GLenum dest_internal_format = 0;
   bool dest_level_defined = dest_texture->GetLevelType(
       dest_texture->target(), 0, &dest_type, &dest_internal_format);
   if (!dest_level_defined) {
     LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION,
                        "glCompressedCopySubTextureCHROMIUM",
                        "destination texture is not defined");
     return;
@@ skipping 1885 matching lines @@
   return error::kNoError;
 }
 
 // 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