2d/clip.h

   1 /*
   2 THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
   3 SOFTWARE CORPORATION ("PARALLAX").  PARALLAX, IN DISTRIBUTING THE CODE TO
   4 END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
   5 ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
   6 IN USING, DISPLAYING,  AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
   7 SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
   8 FREE PURPOSES.  IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
   9 CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES.  THE END-USER UNDERSTANDS
  10 AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
  11 COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
  12 */
  13 /*
  14  * $Source: /cvs/cvsroot/d2x/2d/clip.h,v $
  15  * $Revision: 1.1.1.1 $
  16  * $Author: bradleyb $
  17  * $Date: 2001-01-19 03:29:57 $
  18  *
  19  * Macros used for clipping
  20  *
  21  * $Log: not supported by cvs2svn $
  22  * Revision 1.1.1.1  1999/06/14 21:57:39  donut
  23  * Import of d1x 1.37 source.
  24  *
  25  * Revision 1.3  1993/10/15  16:22:28  john
  26  * *** empty log message ***
  27  *
  28  * Revision 1.2  1993/09/29  16:14:31  john
  29  * made work with fix point
  30  *
  31  * Revision 1.1  1993/09/08  11:40:53  john
  32  * Initial revision
  33  *
  34  *
  35  */
  36
  37
  38 /*#define MIN(a,b)        (((a) < (b)) ? (a) : (b))
  39 #define MAX(a,b)        (((a) > (b)) ? (a) : (b))
  40 */
  41 #define IABS(x)         (((x) < 0) ?  -(x) : (x))
  42
  43 #define EXCHG(a,b) do {                                                 \
  44     int __temp__ = (a);                                                 \
  45     (a) = (b);                                                          \
  46     (b) = __temp__;                                                     \
  47 } while(0)
  48
  49 // sort two values
  50 #define SORT2(a,b) do {                                                 \
  51     if((a) > (b)) EXCHG(a,b);                                           \
  52 } while(0)
  53
  54 # define SCALE(var,arg,num,den)                                         \
  55     ((var) = ((arg) * (num)) / (den))
  56
  57 # define USCALE(var,arg,num,den)                                        \
  58         ((var) = ((unsigned)(arg) * (unsigned)(num)) / (unsigned)(den))
  59
  60 # define FSCALE(var,arg,num,den) ((var) = fixmuldiv((arg),(num),(den)))
  61
  62 #define CLIPDOT(xx,yy,WHEN_OUTSIDE,WHEN_CLIPPED) {                      \
  63     if((xx > XMAX) || (xx < XMIN)) { WHEN_OUTSIDE; }                    \
  64     if((yy > YMAX) || (yy < YMIN)) { WHEN_OUTSIDE; }                    \
  65 }
  66
  67 #define CLIPHLINE(x1,x2,yy,WHEN_OUTSIDE,WHEN_CLIPPED) {                 \
  68     if(x1 > x2) EXCHG(x1,x2);                                           \
  69     if((x1 > XMAX) || (x2 < XMIN)) { WHEN_OUTSIDE; }                    \
  70     if((yy > YMAX) || (yy < YMIN)) { WHEN_OUTSIDE; }                    \
  71     if(x1 < XMIN) { x1 = XMIN; WHEN_CLIPPED; }                          \
  72     if(x2 > XMAX) { x2 = XMAX; WHEN_CLIPPED; }                          \
  73 }
  74
  75 #define CLIPVLINE(xx,y1,y2,WHEN_OUTSIDE,WHEN_CLIPPED) {                 \
  76     if(y1 > y2) EXCHG(y1,y2);                                           \
  77     if((xx > XMAX) || (xx < XMIN)) { WHEN_OUTSIDE; }                    \
  78     if((y1 > YMAX) || (y2 < YMIN)) { WHEN_OUTSIDE; }                    \
  79     if(y1 < YMIN) { y1 = YMIN; WHEN_CLIPPED; }                          \
  80     if(y2 > YMAX) { y2 = YMAX; WHEN_CLIPPED; }                          \
  81 }
  82
  83 #define CLIPBOX(x1,y1,x2,y2,WHEN_OUTSIDE,WHEN_CLIPPED) {                \
  84     if(x1 > x2) EXCHG(x1,x2);                                           \
  85     if(y1 > y2) EXCHG(y1,y2);                                           \
  86     if((x1 > XMAX) || (x2 < 0)) { WHEN_OUTSIDE; }                       \
  87     if((y1 > YMAX) || (y2 < 0)) { WHEN_OUTSIDE; }                       \
  88     if(x1 < 0) { x1 = 0; WHEN_CLIPPED; }                                \
  89     if(y1 < 0) { y1 = 0; WHEN_CLIPPED; }                                \
  90     if(x2 > XMAX) { x2 = XMAX; WHEN_CLIPPED; }                          \
  91     if(y2 > YMAX) { y2 = YMAX; WHEN_CLIPPED; }                          \
  92 }
  93
  94 #define CLIPLINE(x1,y1,x2,y2,XMIN,YMIN,XMAX,YMAX,WHEN_OUTSIDE,WHEN_CLIPPED,MY_SCALE) do {       \
  95     register int temp;                                                  \
  96     if(y1 > y2)                                                         \
  97         { EXCHG(y1,y2); EXCHG(x1,x2); }                                 \
  98     if((y2 < YMIN) || (y1 > YMAX))                                      \
  99         { WHEN_OUTSIDE; }                                               \
 100     if(x1 < x2) {                                                       \
 101         if((x2 < XMIN) || (x1 > XMAX)) {                                \
 102             WHEN_OUTSIDE;                                               \
 103         }                                                               \
 104         if(x1 < XMIN) {                                                 \
 105                         MY_SCALE(temp,(y2 - y1),(XMIN - x1),(x2 - x1)); \
 106             if((y1 += temp) > YMAX) { WHEN_OUTSIDE; }                   \
 107             x1 = XMIN;                                                  \
 108             WHEN_CLIPPED;                                               \
 109         }                                                               \
 110         if(x2 > XMAX) {                                                 \
 111                         MY_SCALE(temp,(y2 - y1),(x2 - XMAX),(x2 - x1)); \
 112             if((y2 -= temp) < YMIN) { WHEN_OUTSIDE; }                   \
 113             x2 = XMAX;                                                  \
 114             WHEN_CLIPPED;                                               \
 115         }                                                               \
 116         if(y1 < YMIN) {                                                 \
 117                         MY_SCALE(temp,(x2 - x1),(YMIN - y1),(y2 - y1)); \
 118             x1 += temp;                                                 \
 119             y1 = YMIN;                                                  \
 120             WHEN_CLIPPED;                                               \
 121         }                                                               \
 122         if(y2 > YMAX) {                                                 \
 123                         MY_SCALE(temp,(x2 - x1),(y2 - YMAX),(y2 - y1)); \
 124             x2 -= temp;                                                 \
 125             y2 = YMAX;                                                  \
 126             WHEN_CLIPPED;                                               \
 127         }                                                               \
 128     }                                                                   \
 129     else {                                                              \
 130         if((x1 < XMIN) || (x2 > XMAX)) {                                \
 131             WHEN_OUTSIDE;                                               \
 132         }                                                               \
 133         if(x1 > XMAX) {                                                 \
 134                         MY_SCALE(temp,(y2 - y1),(x1 - XMAX),(x1 - x2)); \
 135             if((y1 += temp) > YMAX) { WHEN_OUTSIDE; }                   \
 136             x1 = XMAX;                                                  \
 137             WHEN_CLIPPED;                                               \
 138         }                                                               \
 139         if(x2 < XMIN) {                                                 \
 140                         MY_SCALE(temp,(y2 - y1),(XMIN - x2),(x1 - x2)); \
 141             if((y2 -= temp) < YMIN) { WHEN_OUTSIDE; }                   \
 142             x2 = XMIN;                                                  \
 143             WHEN_CLIPPED;                                               \
 144         }                                                               \
 145         if(y1 < YMIN) {                                                 \
 146                         MY_SCALE(temp,(x1 - x2),(YMIN - y1),(y2 - y1)); \
 147             x1 -= temp;                                                 \
 148             y1 = YMIN;                                                  \
 149             WHEN_CLIPPED;                                               \
 150         }                                                               \
 151         if(y2 > YMAX) {                                                 \
 152                         MY_SCALE(temp,(x1 - x2),(y2 - YMAX),(y2 - y1)); \
 153             x2 += temp;                                                 \
 154             y2 = YMAX;                                                  \
 155             WHEN_CLIPPED;                                               \
 156         }                                                               \
 157     }                                                                   \
 158 } while(0)