Category : C Source Code
Archive   : GRAFGEM1.ZIP
Filename : LINE.H

 
Output of file : LINE.H contained in archive : GRAFGEM1.ZIP


/*
Two-Dimensional Clipping: A Vector Based Approach
by Hans Spoelder and Fons Ullings
from "Graphics Gems", Academic Press, 1990
*/


/*
* file line.h
* contains major definitions for the clipping routines
*
*/
#define NFAC 10 /* discrete measure */

#define SCALE (1 << NFAC) /* 1024 points/cm */
#define TO_INT(X) ((int)((X)*SCALE))
#define TO_FLT(X) (((float)(X))/SCALE)

#define COINCIDE 1 /* what do the lines do */
#define PARALLEL 2
#define CROSS 3
#define NO_CROSS 4

#define STD 0 /* crossing types */
#define DELAY 1

#define CLIP_NORMAL 1

typedef struct { /* holds a point */
long _x; /* holds x coordinate */
long _y; /* holds y coordinate */
} POINT;

typedef struct { /* holds a cross point */
POINT _p; /* holds the solution */
short _type; /* more information */
} CLIST;

struct segment { /* holds a segment */
POINT _from; /* start coordinates */
POINT _to; /* stop coordinates */
struct segment *_next;
struct segment *_prev;
};


#define SEGMENT struct segment

struct contour { /* holds a contour */
short _no; /* contour counter */
short _status; /* holds information */
short _cnt; /* number of elements */
SEGMENT *_s; /* the segments */
struct contour *_next; /* linked list */
long _minx; /* coordinates of box */
long _miny;
long _maxx;
long _maxy;
};

#define CONTOUR struct contour

#define ACTIVE 01 /* polygon attributes */
#define NORMAL 02

#define SET_ON(p) ((p)->_status |= ACTIVE)
#define SET_NORMAL(p) ((p)->_status |= NORMAL)

#define SET_OFF(p) ((p)->_status &= ~ACTIVE)
#define SET_INVERSE(p) ((p)->_status &= ~NORMAL)

#define IS_ON(p) ((p)->_status & ACTIVE)
#define IS_NORMAL(p) ((p)->_status & NORMAL)

extern CONTOUR *CL;

CONTOUR *get_contour_ptr();

extern short C_COUNT;