libs/Rectangles.c

   1 /* -*-c-*- */
   2 /* This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License as published by
   4  * the Free Software Foundation; either version 2 of the License, or
   5  * (at your option) any later version.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  *
  12  * You should have received a copy of the GNU General Public License
  13  * along with this program; if not, write to the Free Software
  14  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  15  */
  16
  17 /* ---------------------------- included header files ---------------------- */
  18
  19 #include "config.h"
  20
  21 #include <X11/Xlib.h>
  22
  23 #include "Rectangles.h"
  24
  25 /* ---------------------------- local definitions -------------------------- */
  26
  27 /* ---------------------------- local macros ------------------------------- */
  28
  29 /* ---------------------------- imports ------------------------------------ */
  30
  31 /* ---------------------------- included code files ------------------------ */
  32
  33 /* ---------------------------- local types -------------------------------- */
  34
  35 /* ---------------------------- forward declarations ----------------------- */
  36
  37 /* ---------------------------- local variables ---------------------------- */
  38
  39 /* ---------------------------- interface functions ------------------------ */
  40
  41 Bool frect_get_intersection(
  42         int x1, int y1, int w1, int h1, int x2, int y2, int w2, int h2,
  43         XRectangle *r)
  44 {
  45         if (x1 + w1 > x2 && x1 < x2 + w2 &&
  46             y1 + h1 > y2 && y1 < y2 + h2)
  47         {
  48                 if (r)
  49                 {
  50                         r->x = max(x1,x2);
  51                         r->y = max(y1,y2);
  52                         r->width = min(x1+w1,x2+w2) - max(x1,x2);
  53                         r->height =min(y1+h1,y2+h2) - max(y1,y2);
  54                 }
  55                 return True;
  56         }
  57         return False;
  58 }
  59
  60
  61 Bool frect_get_seg_intersection(
  62         int x1, int w1, int x2, int w2, int *x, int *w)
  63 {
  64         if (x1 + w1 > x2 && x1 < x2 + w2)
  65         {
  66                 if (x)
  67                 {
  68                         *x = max(x1,x2);
  69                 }
  70                 if (w)
  71                 {
  72                         *w = min(x1+w1,x2+w2) - max(x1,x2);
  73                 }
  74                 return True;
  75         }
  76         return False;
  77 }
  78
  79 Bool frect_get_rect_intersection(
  80         XRectangle a, XRectangle b, XRectangle *r)
  81 {
  82         return frect_get_intersection(
  83                 a.x, a.y, a.width, a.height, b.x, b.y, b.width, b.height, r);
  84 }