/******************************************************************************
Class:Mesh
Implements:
Author:Rich Davison	<richard.davison4@newcastle.ac.uk>
Description:Wrapper around OpenGL primitives, geometry and related 
OGL functions.

There's a couple of extra functions in here that you didn't get in the tutorial
series, to draw debug normals and tangents. 


-_-_-_-_-_-_-_,------,   
_-_-_-_-_-_-_-|   /\_/\   NYANYANYAN
-_-_-_-_-_-_-~|__( ^ .^) /
_-_-_-_-_-_-_-""  ""   

*//////////////////////////////////////////////////////////////////////////////

#pragma once

#include "../nclgl/OGLRenderer.h"
#include <vector>
#include <string>
#include <fstream>

using std::ifstream;
using std::string;

//A handy enumerator, to determine which member of the bufferObject array
//holds which data
enum MeshBuffer {
	VERTEX_BUFFER	=0,
	COLOUR_BUFFER	=1, 
	TEXTURE_BUFFER	,
	NORMAL_BUFFER	, 
	TANGENT_BUFFER	,
	INDEX_BUFFER	,
	MAX_BUFFER
};

class Mesh	{
public:
	friend class MD5Mesh;
	Mesh(void);
	virtual ~Mesh(void);

	virtual void Draw();

	//Generates a single triangle, with RGB colours
	static Mesh* GenerateTriangle();
	static Mesh* GeneratePoints(unsigned int count);
	static Mesh* LoadMeshFile(const string &filename);
	static Mesh* GenerateQuadPatch();
	static Mesh* GenerateSegmentedQuads(unsigned int numSegments);
	void GenerateNormals();
	static Mesh *GenerateLine(const Vector3 &begin, const Vector3 &finish);

	GLuint	type;	//Primitive type for this mesh (GL_TRIANGLES...etc)

protected:
	//Buffers all VBO data into graphics memory. Required before drawing!
	void	BufferData();

	//VAO for this mesh
	GLuint	arrayObject;
	//VBOs for this mesh
	GLuint	bufferObject[MAX_BUFFER];
	//Number of vertices for this mesh
	GLuint	numVertices;

	//Number of indices for this mesh
	GLuint			numIndices;

	//Pointer to vertex position attribute data (badly named...?)
	Vector3*		vertices;
	//Pointer to vertex colour attribute data
	Vector4*		colours;
	//Pointer to vertex texture coordinate attribute data
	Vector2*		textureCoords;
	//Pointer to vertex normals attribute data
	Vector3*		normals;
	//Pointer to vertex tangents attribute data
	Vector3*		tangents;
	//Pointer to vertex indices attribute data
	unsigned int*	indices;


	GLuint normalBuffer; // VBO name for for normals buffer
};