[ci skip]update comments CCVertexIndexData.h

cocos/renderer/CCVertexIndexData.h

@@ -31,7 +31,18 @@
 NS_CC_BEGIN
 
 class VertexBuffer;
+/**
+VertexStreamAttribute is used to specify the vertex attribute for drawing, which is correspondent to
+glVertexAttribPointer(GLuint indx, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const GLvoid* ptr)
 
+ _semantic  ->  index
+ _size      ->  size
+ _type      ->  type
+ _normalize ->  normalized
+ _offset is used to compute the start offset in a interleaved array, take a V3F_C4B_T2F array,
+ offset of vertex will be 0, offset of color would be 0 + sizeof(float) * 3 = 12, 
+ offset of texture coord would be 12 + sizeof(char) * 4 = 16
+*/
 struct CC_DLL VertexStreamAttribute
 {
     VertexStreamAttribute()
@@ -56,30 +67,66 @@ struct CC_DLL VertexStreamAttribute
     int _size;
 };
 
+/**
+VertexData is a class used for specify input streams for GPU rendering pipeline,
+a VertexData will be composed by several streams, every stream will contain a VertexStreamAttribute
+and the binding VertexBuffer. streams will be identified by semantic
+*/
+
 class CC_DLL VertexData : public Ref
 {
 public:
+    /**
+    Create function, used to create a instance of VertexData
+    */
     static VertexData* create();
     
+    /*Get the number of streams in the VertexData*/
     size_t getVertexStreamCount() const;
+    /**
+    Set a stream to VertexData,given that stream is identified by semantic, so if the semantic is not
+    specified before, it will add a stream, or it will override the old one
+    @param buffer The binding buffer of the stream
+    @param stream The binding vertex attribute, its member semantic will be used as the identifier.
+    */
     bool setStream(VertexBuffer* buffer, const VertexStreamAttribute& stream);
+    /**
+    Remove the given streams
+    @param semantic The semantic of the stream
+    */
     void removeStream(int semantic);
+    /**
+    Get the attribute of stream const version
+    @param semantic The semantic of the stream
+    */
     const VertexStreamAttribute* getStreamAttribute(int semantic) const;
+    /**
+    Get the attribute of stream
+    @param semantic The semantic of the stream
+    */
     VertexStreamAttribute* getStreamAttribute(int semantic);
-    
+    /**
+    Get the binded buffer of the stream
+    @param semantic The semantic of the stream
+    */
     VertexBuffer* getStreamBuffer(int semantic) const;
     
+    /*Called for rendering, it will bind the state of vertex data to current rendering pipeline*/
     void use();
 protected:
+    /*Constructor*/
     VertexData();
+    /*Destructor*/
     virtual ~VertexData();
 protected:
+    /*Simple struct to bundle buffer and attribute*/
     struct BufferAttribute
     {
         VertexBuffer* _buffer;
         VertexStreamAttribute _stream;
     };
     
+    /*Streams in the VertexData*/
     std::map<int, BufferAttribute> _vertexStreams;
 };