/* * GraphicsGems.h * Version 1.0 - Andrew Glassner * from "Graphics Gems", Academic Press, 1990 */ #ifndef GG_H #define GG_H 1 /*********************/ /* 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 */ /********************/ #define PI 3.141592 /* the venerable pi */ #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 TRUE 1 #define FALSE 0 #define ON 1 #define OFF 0 typedef int boolean; /* boolean data type */ typedef boolean flag; /* flag data type */ extern double V2SquaredLength(), V2Length(); extern double V2Dot(), V2DistanceBetween2Points(); extern Vector2 *V2Negate(), *V2Normalize(), *V2Scale(), *V2Add(), *V2Sub(); 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