WebGL 2: make sure VertexAttrib type match the corresponding attrib type in shader

gpu/command_buffer/service/vertex_attrib_manager.h

Index: gpu/command_buffer/service/vertex_attrib_manager.h
diff --git a/gpu/command_buffer/service/vertex_attrib_manager.h b/gpu/command_buffer/service/vertex_attrib_manager.h
index f3fae6d2d8f2e98ab144da10dad5f1ba210cfe1a..7491a56113a7a9732abb6c61cff5ca359d6d8e5e 100644
--- a/gpu/command_buffer/service/vertex_attrib_manager.h
+++ b/gpu/command_buffer/service/vertex_attrib_manager.h
@@ -200,6 +200,28 @@ class GPU_EXPORT VertexAttribManager :
     return NULL;
   }
 
+  void UpdateAttribBaseTypeAndMask(GLuint loc, GLenum base_type) {
+    DCHECK(loc < max_vertex_attribs_);
+    int shift_bits = (loc % 16) * 2;
+    attrib_type_written_mask_[loc / 16] |= (0x3 << shift_bits);
+    attrib_base_type_mask_[loc / 16] &= ~(0x3 << shift_bits);
+    attrib_base_type_mask_[loc / 16] |= base_type << shift_bits;
+  }
+
+  // Return 16 attributes' base types, in which the attribute
+  // specified by argument 'loc' located.
+  uint32_t attrib_base_type_mask(GLuint loc) const {
+    DCHECK(loc < max_vertex_attribs_);
+    return attrib_base_type_mask_[loc / 16];
+  }
+
+  // Return 16 attributes' type written masks, in which the
+  // attribute specified by argument 'loc' located.
+  uint32_t attrib_type_written_mask(GLuint loc) const {
+    DCHECK(loc < max_vertex_attribs_);
+    return attrib_type_written_mask_[loc / 16];
+  }
+
   void SetAttribInfo(
       GLuint index,
       Buffer* buffer,
@@ -284,6 +306,15 @@ class GPU_EXPORT VertexAttribManager :
   // if it is safe to draw.
   std::vector<VertexAttrib> vertex_attribs_;
 
+  uint32_t max_vertex_attribs_;
+  // Vertex attrib base types: FLOAT, INT, or UINT.
+  // Each base type is encoded into 2 bits, the lowest 2 bits for location 0,
+  // the highest 2 bits for location (max_vertex_attribs_ - 1).
+  std::vector<uint32_t> attrib_base_type_mask_;
+  // Same layout as above, 2 bits per location, 0x03 if a location is set
+  // by vertexAttrib API, 0x00 if not.
+  std::vector<uint32_t> attrib_type_written_mask_;

[Zhenyao Mo, 2016/07/22 14:36:47]

You don't need this written mask.  If it's not written, the type_mask bits will
be 00, so that's enough information.

Instead, you will need a enable_mask, indication if this vertex attrib array is
enabled or not.  We only use the corresponding bits if it is enabled. 
Otherwise, we will look into generic vertex attrib value type from
context_state.

+
   // The currently bound element array buffer. If this is 0 it is illegal
   // to call glDrawElements.
   scoped_refptr<Buffer> element_array_buffer_;