Command buffer: Fix bugs for drawing when the type of vertex attrib is a packed type

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 <limits.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
@@ skipping 8901 matching lines @@
         GL_INVALID_VALUE, "glVertexAttribPointer", "stride > 255");
     return error::kNoError;
   }
   if (offset < 0) {
     LOCAL_SET_GL_ERROR(
         GL_INVALID_VALUE, "glVertexAttribPointer", "offset < 0");
     return error::kNoError;
   }
   GLsizei component_size =
       GLES2Util::GetGLTypeSizeForTexturesAndBuffers(type);
-  // component_size must be a power of two to use & as optimized modulo.
-  DCHECK(GLES2Util::IsPOT(component_size));
-  if (offset & (component_size - 1)) {
+  GLsizei data_size = component_size;
+  if (type == GL_INT_2_10_10_10_REV || type == GL_UNSIGNED_INT_2_10_10_10_REV) {
+    data_size = component_size * size;
+  }
+  // data_size must be a power of two to use & as optimized modulo.
+  DCHECK(GLES2Util::IsPOT(data_size));
+  if (offset & (data_size - 1)) {
     LOCAL_SET_GL_ERROR(
         GL_INVALID_OPERATION,
         "glVertexAttribPointer", "offset not valid for type");
     return error::kNoError;
   }
-  if (stride & (component_size - 1)) {
+  if (stride & (data_size - 1)) {

[yunchao, 2016/02/18 14:55:30]

The offset and stride should be aligned with the element_size (component_size *
component_count) for packed types(INT_2_10_10_10_REV and
UNSIGNED_2_10_10_10_REV).

     LOCAL_SET_GL_ERROR(
         GL_INVALID_OPERATION,
         "glVertexAttribPointer", "stride not valid for type");
     return error::kNoError;
   }
   state_.vertex_attrib_manager
       ->SetAttribInfo(indx,
                       state_.bound_array_buffer.get(),
                       size,
                       type,
@@ skipping 6713 matching lines @@
 }
 
 // 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 "base/macros.h"
 #include "gpu/command_buffer/service/gles2_cmd_decoder_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu