#pragma once


struct MeshVertex
{
	vec4 Position;
	vec4 Normal;
};


struct Instance
{
	Matrix transform;
};


class Mesh
{
public:
	Mesh();

	struct VertexInfo
	{
		int Pos;
		int Normal;
		int UV;

		bool operator < (const VertexInfo& v) const
		{
			if (Pos == v.Pos)
			{
				if (Normal == v.Normal)
				{
					return UV < v.UV;
				}
				return Normal < v.Normal;
			}
			return Pos < v.Pos;
		} 
	};	

	int VertexCount;
	int IndexCount;
	int FaceCount;

	static const int MaxVertexBuffer = 65536;
	static const int MaxIndexBuffer = 65536 * 9 / 2;

	MeshVertex* VertexBuffer;
	unsigned short* IndexBuffer;

	struct OpInfo
	{
		void Reset();

		MeshVertex NextVB[Mesh::MaxVertexBuffer];
		unsigned short int NextIB[Mesh::MaxIndexBuffer];
		int NextVertexCount;
		int NextIndexCount;
		int NextFaceCount;
		
		int EdgeCount;
		unsigned int EdgeConfiguration[Mesh::MaxIndexBuffer];
		unsigned char EdgeUsage[Mesh::MaxIndexBuffer];
		int MakeEdgeID(unsigned short VertexA, unsigned short VertexB);
		unsigned short int EdgeID[Mesh::MaxIndexBuffer];
	};

	OpInfo OP;

	unsigned int VertexArrayObject;
	unsigned int VertexArrayBuffer;
	unsigned int IndexBufferObject;

	void Render();
	void Lock();
	void Unlock();

	void Transform(const Matrix& transform);
	void CreateCube();
	void CreateSphere(unsigned int lod);

private:
	void Homogenize();
	void GenerateNormals();
	void NormalizeNormals();
	void CatmullClarkSubdivide();
	void StandardSubdivide();
	void Extrude(float extend);
	void Bevel(float extend, float minAngle);
	void Triangulate();
};