/*! 
    \file md2Model.h
    \brief Definition of an MD2 Model, a model format invented by ID Software.
	
	We are deeply thankfull for all the wunderfull things id software made for us gamers!

	The md2 file format is structured in a very simple way: it contains animations which are made out of
	frames (so called keyframes). Each frame is a complete draweable model in a specific position.
	A frame is a collection of vertex and its compagnions (normals, texture coordinates).
	
	A typical model has about 200 frames, the maximum frame count is fixed by MD2_MAX_FRAMES to currently 
	512 frames. The maximal vetices count is set to 2048 verteces, not enough?
	You just have to change the MD2_MAX_* values if it doesn't fit your purposes...

	Surface Culling is fully implemented in md2 models: quake2 uses front face culling.
*/

#ifndef _MD2MODEL_H
#define _MD2MODEL_H

#include "abstract_model.h"
#include "base_object.h"
#include "stdincl.h"


//! These are the needed defines for the max values when loading .MD2 files
#define MD2_MAX_TRIANGLES		4096
#define MD2_MAX_VERTICES		2048
#define MD2_MAX_TEXCOORDS		2048
#define MD2_MAX_FRAMES			512
#define MD2_MAX_SKINS			32
#define MD2_MAX_FRAMESIZE		(MD2_MAX_VERTICES * 4 + 128)

//! This stores the speed of the animation between each key frame - currently conflicting with the animation framework
#define kAnimationSpeed			5.0f

//! This holds the header information that is read in at the beginning of the file: id software definition
struct tMd2Header
{ 
   int ident;			        //!< This is used to identify the file
   int version;			        //!< The version number of the file (Must be 8)
    
   int skinWidth;			//!< The skin width in pixels
   int skinHeight;			//!< The skin height in pixels
   int frameSize;			//!< The size in bytes the frames are
   
   int numSkins;		        //!< The number of skins associated with the model
   int numVertices;			//!< The number of vertices (constant for each frame)
   int numTexCoords;			//!< The number of texture coordinates
   int numTriangles;			//!< The number of faces (polygons)
   int numGlCommands;			//!< The number of gl commands
   int numFrames;			//!< The number of animation frames
   
   int offsetSkins;			//!< The offset in the file for the skin data
   int offsetTexCoords;			//!< The offset in the file for the texture data
   int offsetTriangles;			//!< The offset in the file for the face data
   int offsetFrames;			//!< The offset in the file for the frames data
   int offsetGlCommands;		//!< The offset in the file for the gl commands data
   int offsetEnd;			//!< The end of the file offset
};


//! This is used to store the vertices that are read in for the current frame directly from the file (compressed)
struct tMd2AliasTriangle
{
   byte vertex[3];
   byte lightNormalIndex;
};

//! This stores the normals and vertices for the frames (uncompressed)
struct tMd2Triangle
{
   float vertex[3];
   float normal[3];
};

//! This stores the indices into the vertex and texture coordinate arrays
struct tMd2Face
{
   short vertexIndices[3];
   short textureIndices[3];
};

//! This stores UV coordinates
struct tMd2TexCoord
{
   short u, v;
};

//! This stores the animation scale, translation and name information for a frame, plus verts
struct tMd2AliasFrame
{
   float scale[3];
   float translate[3];
   char name[16];
   tMd2AliasTriangle aliasVertices[1];
};

//! This stores the frames vertices after they have been transformed
struct tMd2Frame
{
   char strName[16];
   tMd2Triangle *pVertices;
};

//! This stores a skin name
typedef char tMd2Skin[64];

//! This is a MD2 Model class
class MD2Model : public AbstractModel {

public:
  MD2Model();
  virtual ~MD2Model();
  
  bool loadModel(const char* filename);
  bool loadSkin(const char* filename);
  
  void drawModel(float time);
  void drawFrame(int frame);
  
  void draw(t3DModel *pModel);
  
  void setAnim(int type);
  void scaleModel(float s);

  void tick(float dtS);
  
private:
  void animate(/*float time*/ t3DModel *pModel);
  void processLightning();
  void interpolate(CVector3* vertlist);
  void renderFrame();
  float getCurrentTime(t3DModel *pModel, int nextFrame);

  float dtS;
};

//! A class that handles all of the loading code
class MD2Loader : public BaseObject {

public:
  MD2Loader();
  virtual ~MD2Loader();
  
  bool importMD2(t3DModel *pModel, char *fileName, char *texture);

private:
  void readMD2Data();
  void parseAnimations(t3DModel *pModel);
  void convertDataStructures(t3DModel *pModel);
  void computeNormals(t3DModel *pModel);
  void cleanUp();
  
  FILE *pFile;	
  tMd2Header header;			      //!< The header data
  tMd2Skin *pSkins;			      //!< The skin data
  tMd2TexCoord *pTexCoords;		      //!< The texture coordinates
  tMd2Face *pTriangles;			      //!< Face index information
  tMd2Frame *pFrames;			      //!< The frames of animation (vertices)
};


#endif /* _MD2MODEL_H */