/* $Id: clip.h,v 1.2 2002-07-17 21:55:19 bradleyb Exp $ */ /* THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX SOFTWARE CORPORATION ("PARALLAX"). PARALLAX, IN DISTRIBUTING THE CODE TO END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS IN USING, DISPLAYING, AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE FREE PURPOSES. IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES. THE END-USER UNDERSTANDS AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE. COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION. ALL RIGHTS RESERVED. */ /* * * Macros used for clipping * * Old Log: * * Revision 1.3 1993/10/15 16:22:28 john * *** empty log message *** * * Revision 1.2 1993/09/29 16:14:31 john * made work with fix point * * Revision 1.1 1993/09/08 11:40:53 john * Initial revision * * */ /*#define MIN(a,b) (((a) < (b)) ? (a) : (b)) #define MAX(a,b) (((a) > (b)) ? (a) : (b)) */ #define IABS(x) (((x) < 0) ? -(x) : (x)) #define EXCHG(a,b) do { \ int __temp__ = (a); \ (a) = (b); \ (b) = __temp__; \ } while(0) // sort two values #define SORT2(a,b) do { \ if((a) > (b)) EXCHG(a,b); \ } while(0) # define SCALE(var,arg,num,den) \ ((var) = ((arg) * (num)) / (den)) # define USCALE(var,arg,num,den) \ ((var) = ((unsigned)(arg) * (unsigned)(num)) / (unsigned)(den)) # define FSCALE(var,arg,num,den) ((var) = fixmuldiv((arg),(num),(den))) #define CLIPDOT(xx,yy,WHEN_OUTSIDE,WHEN_CLIPPED) { \ if((xx > XMAX) || (xx < XMIN)) { WHEN_OUTSIDE; } \ if((yy > YMAX) || (yy < YMIN)) { WHEN_OUTSIDE; } \ } #define CLIPHLINE(x1,x2,yy,WHEN_OUTSIDE,WHEN_CLIPPED) { \ if(x1 > x2) EXCHG(x1,x2); \ if((x1 > XMAX) || (x2 < XMIN)) { WHEN_OUTSIDE; } \ if((yy > YMAX) || (yy < YMIN)) { WHEN_OUTSIDE; } \ if(x1 < XMIN) { x1 = XMIN; WHEN_CLIPPED; } \ if(x2 > XMAX) { x2 = XMAX; WHEN_CLIPPED; } \ } #define CLIPVLINE(xx,y1,y2,WHEN_OUTSIDE,WHEN_CLIPPED) { \ if(y1 > y2) EXCHG(y1,y2); \ if((xx > XMAX) || (xx < XMIN)) { WHEN_OUTSIDE; } \ if((y1 > YMAX) || (y2 < YMIN)) { WHEN_OUTSIDE; } \ if(y1 < YMIN) { y1 = YMIN; WHEN_CLIPPED; } \ if(y2 > YMAX) { y2 = YMAX; WHEN_CLIPPED; } \ } #define CLIPBOX(x1,y1,x2,y2,WHEN_OUTSIDE,WHEN_CLIPPED) { \ if(x1 > x2) EXCHG(x1,x2); \ if(y1 > y2) EXCHG(y1,y2); \ if((x1 > XMAX) || (x2 < 0)) { WHEN_OUTSIDE; } \ if((y1 > YMAX) || (y2 < 0)) { WHEN_OUTSIDE; } \ if(x1 < 0) { x1 = 0; WHEN_CLIPPED; } \ if(y1 < 0) { y1 = 0; WHEN_CLIPPED; } \ if(x2 > XMAX) { x2 = XMAX; WHEN_CLIPPED; } \ if(y2 > YMAX) { y2 = YMAX; WHEN_CLIPPED; } \ } #define CLIPLINE(x1,y1,x2,y2,XMIN,YMIN,XMAX,YMAX,WHEN_OUTSIDE,WHEN_CLIPPED,MY_SCALE) do { \ register int temp; \ if(y1 > y2) \ { EXCHG(y1,y2); EXCHG(x1,x2); } \ if((y2 < YMIN) || (y1 > YMAX)) \ { WHEN_OUTSIDE; } \ if(x1 < x2) { \ if((x2 < XMIN) || (x1 > XMAX)) { \ WHEN_OUTSIDE; \ } \ if(x1 < XMIN) { \ MY_SCALE(temp,(y2 - y1),(XMIN - x1),(x2 - x1)); \ if((y1 += temp) > YMAX) { WHEN_OUTSIDE; } \ x1 = XMIN; \ WHEN_CLIPPED; \ } \ if(x2 > XMAX) { \ MY_SCALE(temp,(y2 - y1),(x2 - XMAX),(x2 - x1)); \ if((y2 -= temp) < YMIN) { WHEN_OUTSIDE; } \ x2 = XMAX; \ WHEN_CLIPPED; \ } \ if(y1 < YMIN) { \ MY_SCALE(temp,(x2 - x1),(YMIN - y1),(y2 - y1)); \ x1 += temp; \ y1 = YMIN; \ WHEN_CLIPPED; \ } \ if(y2 > YMAX) { \ MY_SCALE(temp,(x2 - x1),(y2 - YMAX),(y2 - y1)); \ x2 -= temp; \ y2 = YMAX; \ WHEN_CLIPPED; \ } \ } \ else { \ if((x1 < XMIN) || (x2 > XMAX)) { \ WHEN_OUTSIDE; \ } \ if(x1 > XMAX) { \ MY_SCALE(temp,(y2 - y1),(x1 - XMAX),(x1 - x2)); \ if((y1 += temp) > YMAX) { WHEN_OUTSIDE; } \ x1 = XMAX; \ WHEN_CLIPPED; \ } \ if(x2 < XMIN) { \ MY_SCALE(temp,(y2 - y1),(XMIN - x2),(x1 - x2)); \ if((y2 -= temp) < YMIN) { WHEN_OUTSIDE; } \ x2 = XMIN; \ WHEN_CLIPPED; \ } \ if(y1 < YMIN) { \ MY_SCALE(temp,(x1 - x2),(YMIN - y1),(y2 - y1)); \ x1 -= temp; \ y1 = YMIN; \ WHEN_CLIPPED; \ } \ if(y2 > YMAX) { \ MY_SCALE(temp,(x1 - x2),(y2 - YMAX),(y2 - y1)); \ x2 += temp; \ y2 = YMAX; \ WHEN_CLIPPED; \ } \ } \ } while(0)