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

gpu/command_buffer/service/context_state.h

Index: gpu/command_buffer/service/context_state.h
diff --git a/gpu/command_buffer/service/context_state.h b/gpu/command_buffer/service/context_state.h
index d026df9a06fd38c22f76e0d508d994063614921c..f2016359c2cc69743f155671d51a7924dc127598 100644
--- a/gpu/command_buffer/service/context_state.h
+++ b/gpu/command_buffer/service/context_state.h
@@ -243,6 +243,22 @@ struct GPU_EXPORT ContextState {
   void SetBoundBuffer(GLenum target, Buffer* buffer);
   void RemoveBoundBuffer(Buffer* buffer);
 
+  void SetGenericVertexAttribBaseType(GLuint index, GLenum base_type) {
+    DCHECK(index >=0 && index < 16);
+    int shift_bits = index * 2;
+    generic_attrib_type_written_mask_ |= ~(0x3 << shift_bits);

[Zhenyao Mo, 2016/07/20 17:54:56]

You don't need this written mask.

Every vertex attrib has a default type (FLOAT), you should just initialize it,
and written mask should just be all true (therefore you don't need it).

[yunchao, 2016/07/22 13:43:53]

Done.

+    generic_attrib_base_type_ &= ~(0x3 << shift_bits);
+    generic_attrib_base_type_ |= base_type << shift_bits;
+  }
+
+  uint32_t GetGenericVertexAttribBaseType() {
+    return generic_attrib_base_type_;
+  }
+
+  uint32_t GetGenericVertexAttribTypeMask() {
+    return generic_attrib_type_written_mask_;
+  }
+
   void UnbindTexture(TextureRef* texture);
   void UnbindSampler(Sampler* sampler);
 
@@ -320,6 +336,14 @@ struct GPU_EXPORT ContextState {
 
   bool framebuffer_srgb_;
 
+  // Generic vertex attrib base types: FLOAT, INT, or UINT.
+  // We have up to 16 attribs, each is encoded into 2 bits, total 32 bits

[Zhenyao Mo, 2016/07/20 17:54:56]

You can't really limit it to 16.  Instead, it should be GL_MAX_VERTEX_ATTRIBS. 
This mask should be uint32_t[ceil(GL_MAX_VERTEX_ATTRIBS / 16)].

[yunchao, 2016/07/22 13:43:53]

Done.

+  // the lowest 2 bits for location 0, the highest 2 bits for location 15.
+  uint32_t generic_attrib_base_type_;

[Zhenyao Mo, 2016/07/20 17:54:56]

I really think we should keep the type_mask_ instead of just type_.  mask_
indicates it's encoded bits.

[yunchao, 2016/07/22 13:43:53]

Acknowledged.

+  // Same layout as above, 2 bits per location, 0x03 if a location is set
+  // by vertexAttrib API, 0x00 if not.
+  uint32_t generic_attrib_type_written_mask_;
+
   FeatureInfo* feature_info_;
   std::unique_ptr<ErrorState> error_state_;
 };