/* 
 * GraphicsGems.h  
 * Version 1.0 - Andrew Glassner
 * from "Graphics Gems", Academic Press, 1990
 */

#ifndef GG_H
#define GG_H

/*********************/
/* 2d geometry types */
/*********************/

typedef struct Point2Struct {   /* 2d point */
        double x, y;
        } Point2;
typedef Point2 Vector2;

typedef struct IntPoint2Struct {        /* 2d integer point */
        int x, y;
        } IntPoint2;

typedef struct Matrix3Struct {  /* 3-by-3 matrix */
        double element[3][3];
        } Matrix3;

typedef struct Box2dStruct {            /* 2d box */
        Point2 min, max;
        } Box2;
        

/*********************/
/* 3d geometry types */
/*********************/

typedef struct Point3Struct {   /* 3d point */
        double x, y, z;
        } Point3;
typedef Point3 Vector3;

typedef struct IntPoint3Struct {        /* 3d integer point */
        int x, y, z;
        } IntPoint3;


typedef struct Matrix4Struct {  /* 4-by-4 matrix */
        double element[4][4];
        } Matrix4;

typedef struct Box3dStruct {            /* 3d box */
        Point3 min, max;
        } Box3;



/***********************/
/* one-argument macros */
/***********************/

/* absolute value of a */
#define ABS(a)          (((a)<0) ? -(a) : (a))

/* round a to nearest int */
#define ROUND(a)        ((a)>0 ? (int)((a)+0.5) : -(int)(0.5-(a)))

/* take sign of a, either -1, 0, or 1 */
#define ZSGN(a)         (((a)<0) ? -1 : (a)>0 ? 1 : 0)  

/* take binary sign of a, either -1, or 1 if >= 0 */
#define SGN(a)          (((a)<0) ? -1 : 1)

/* shout if something that should be true isn't */
#define ASSERT(x) \
if (!(x)) fprintf(stderr," Assert failed: x\n");

/* square a */
#define SQR(a)          ((a)*(a))       


/***********************/
/* two-argument macros */
/***********************/

/* find minimum of a and b */
#define MIN(a,b)        (((a)<(b))?(a):(b))     

/* find maximum of a and b */
#define MAX(a,b)        (((a)>(b))?(a):(b))     

/* swap a and b (see Gem by Wyvill) */
#define SWAP(a,b)       { a^=b; b^=a; a^=b; }

/* linear interpolation from l (when a=0) to h (when a=1)*/
/* (equal to (a*h)+((1-a)*l) */
#define LERP(a,l,h)     ((l)+(((h)-(l))*(a)))

/* clamp the input to the specified range */
#define CLAMP(v,l,h)    ((v)<(l) ? (l) : (v) > (h) ? (h) : v)


/****************************/
/* memory allocation macros */
/****************************/

/* create a new instance of a structure (see Gem by Hultquist) */
#define NEWSTRUCT(x)    (struct x *)(malloc((unsigned)sizeof(struct x)))

/* create a new instance of a type */
#define NEWTYPE(x)      (x *)(malloc((unsigned)sizeof(x)))


/********************/
/* useful constants */
/********************/

#ifndef PI
#define PI              3.141592        /* the venerable pi */
#endif
#define PITIMES2        6.283185        /* 2 * pi */
#define PIOVER2         1.570796        /* pi / 2 */
#define E               2.718282        /* the venerable e */
#define SQRT2           1.414214        /* sqrt(2) */
#define SQRT3           1.732051        /* sqrt(3) */
#define GOLDEN          1.618034        /* the golden ratio */
#define DTOR            0.017453        /* convert degrees to radians */
#define RTOD            57.29578        /* convert radians to degrees */


/************/
/* booleans */
/************/

#define ON              1
#define OFF             0
typedef int boolean;                    /* boolean data type */
typedef boolean flag;                   /* flag data type */



/*extern double V2SquaredLength(Vector2 *a), V2Length();
extern double V2Dot(Vector2 *a, Vector2 *b), V2DistanceBetween2Points(); 
extern Vector2 *V2Negate(), *V2Normalize(), *V2Scale(), *V2Add(), *V2Sub(Vector2 *a, Vector2 *b, Vector2 *c);
extern Vector2 *V2Lerp(), *V2Combine(), *V2Mul(), *V2MakePerpendicular();
extern Vector2 *V2New(), *V2Duplicate();
extern Point2 *V2MulPointByMatrix();
extern Matrix3 *V2MatMul();

extern double V3SquaredLength(), V3Length();
extern double V3Dot(), V3DistanceBetween2Points();
extern Vector3 *V3Normalize(), *V3Scale(), *V3Add(), *V3Sub();
extern Vector3 *V3Lerp(), *V3Combine(), *V3Mul(), *V3Cross();
extern Vector3 *V3New(), *V3Duplicate();
extern Point3 *V3MulPointByMatrix();
extern Matrix4 *V3MatMul();

extern double RegulaFalsi(), NewtonRaphson(), findroot();*/

#endif
