#ifndef COLLDETECTH
#define COLLDETECTH

#include <stdio.h>
#include <stdlib.h>
#include <sysexits.h>
#include <math.h>
#include <malloc.h>

#define STRLEN	20		/* max length for strings */
#define ORDER 	512		/* 2^M where M is the order of an object's matrix */
#define M		9		/* M the order of an object's SEADS matrix */
#define ETA		0.00001	/* floating point error tolerance */

#define	MAX(A, B) ((A) > (B) ? (A) : (B))
#define MIN(A, B) ((A) < (B) ? (A) : (B))
#define SQR(a) ((a) * (a))

typedef double Real;	/* specify precision here - float or double */
typedef enum {False, True} Boolean;
typedef enum {Cpoint, Cline, Carea} ContactType;
typedef enum {Polygonal} ObjectType;	/* in future may support other types */
typedef enum {Intersection, Contact, Nothing} Status;
typedef unsigned long Ulong;
typedef Boolean (*ChangeTrans)(Real, void *);	/* pointer to function that */
												/* is used to update */
												/* Transforms */

typedef struct {		/* collision interest matrix definition */
	Ulong numObjs;
	Ulong rowStep;
	int bitsPerLong;
	Ulong *matrix;
} CollIntMat;

typedef struct {
	Real i, j, k;
	} Tupple;

typedef struct {
	int total;
	Tupple *v;
	} TuppleArray;

typedef struct {
	Tupple dir;
	Tupple origin;
	} Ray;

typedef struct pnode {
	int *vertices;		/* array of indices into vertex list of object */
	int *vertNorms;		/* array of indices into vertex normal list of object */
	int numVertices;	/* number of vertices */
	Real d;				/* ax + by + cz = d */
	Tupple normal;		/* nominal normal of plane containing polygon */
	int i1, i2;			/* ray intersect stuff */
	} PolyNode;

typedef struct {
	int total;
	PolyNode *p;
	} PolyNodeArray;

									/* Have used the name from ARTS paper */
typedef struct {					/* for lack of a better name */
	int dimi, dimj, dimk;			/* the dimensions of the SEADS matrix */
	Tupple voxSizes;				/* the side lengths of a voxel */
	struct {
		int total;					/* number of polygons */
		int *a;						/* array of polygon numbers */
		} matrix[ORDER];			/* the 3D matrix */
	} SEADS;

typedef struct {			/* transforms are 4 x 4 matrices, the last row */
	Real m[3][4];			/* is implicit [ 0 0 0 1 ] */
	} Transform;

typedef struct onode {
	char name[STRLEN];		/* name of object (optional) */
	ObjectType type;		/* type of object */
	unsigned long id;		/* unique id of object */
	Boolean valid;			/* some objects need to be ignored */
	TuppleArray va;			/* array of vertices */
	TuppleArray vn;			/* array of vertex normals */
	PolyNodeArray polys;	/* array of polygons */
	Tupple min, max;		/* minimum and maximum co-ords of object */
	Tupple gmin, gmax;		/* bounding box in global frame, changes with t */
	SEADS *seads;			/* pointer to the object's SEADS */
	Transform *loc2glob; 	/* matrix to transform from local frame to global */
	Transform *glob2loc;	/* matrix to transform from global to local frame */
	ChangeTrans ctrans;		/* pointer to function that is used to find the
							 * loc2glob transform at a given time */
	void *info;				/* pointer to info that gets passed to ctrans */
	struct onode *next;		/* pointer to next ObjNode */
	} ObjNode;

typedef struct {
	ObjNode *objects;	/* list of objects */
	CollIntMat *cim;	/* collision interest matrix */
	void *ptr;			/* unused pointer */
	} ObjDB;

typedef struct cnode {
	unsigned long objs[2];		/* IDs of the two objects involved */
	int polys[2];				/* polygons (1 from each object) involved */
	Status statusType;			/* Intersection or Contact */
	ContactType type;			/* Point, Line, or Area */
	union {
		Tupple point;			/* Value of point/line/area */
		Tupple line[2];
		TuppleArray area;
		} data;
	struct cnode *next;
	} ConNode;

ConNode *collisionDetect(ObjDB, Status *, Real *);

#endif