VertexDeclarationOpenGL.h

#pragma once

namespace ParaEngine
{
    struct VertexElement
    {
        //VertexElement();

        bool IsEndDeclare() const;
        uint32 GetSize() const;
    public:
        WORD    Stream;     // Stream index
        WORD    Offset;     // Offset in the stream in bytes
        BYTE    Type;       // Data type
        BYTE    Method;     // Processing method
        BYTE    Usage;      // Semantics
        BYTE    UsageIndex; // Semantic index
    };
    
    class CVertexDeclaration
    {
    public:
        CVertexDeclaration(const VertexElement* elems);
        virtual ~CVertexDeclaration();
    public:
        virtual void Release();

        void ApplyAttribute(const void* pVertexStreamZeroData = 0);
        void EnableAttribute();

        void SetVertexElement(const VertexElement* elems);
        
    protected:
        std::vector<VertexElement> m_elements;
        uint32 m_nSize;
        uint32 m_dwAttributes;
        //use opengl vertext array object (vao) if possible, same concept as vertex declaration in directX
        GLuint m_vao; 
    };
}