compiler/alib/andrectrect.c

   1 /*
   2     Copyright © 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Graphics function AndRectRect()
   6     Lang: english
   7 */
   8
   9 #include <graphics/gfx.h>
  10 #include <clib/macros.h>
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <proto/alib.h>
  16
  17         BOOL AndRectRect(
  18
  19 /*  SYNOPSIS */
  20         struct Rectangle *rect1,
  21         struct Rectangle *rect2,
  22         struct Rectangle *intersect)
  23
  24 /*  FUNCTION
  25         Calculate the intersection rectangle between the
  26         given Rectangle rect1 and the given Rectangle rect2
  27         leaving the result in intersect (if intersect != NULL).
  28
  29     INPUTS
  30         rect1 - pointer to 1st Rectangle
  31         rect2 - pointer to 2nd Rectangle
  32         intersect - pointer to rectangle which will hold result.
  33
  34     RESULT
  35         TRUE if rect1 and rect2 do intersect. In this case intersect
  36         will contain the intersection rectangle.
  37
  38         FALSE if rect1 and rect2 do not overlap. "intersect" will
  39         then be left unchanged.
  40
  41     NOTES
  42
  43     EXAMPLE
  44
  45     BUGS
  46
  47     SEE ALSO
  48
  49     INTERNALS
  50
  51     HISTORY
  52         15-12-2000  stegerg implemented
  53
  54 *****************************************************************************/
  55 {
  56     WORD MinX = MAX(rect1->MinX, rect2->MinX);
  57     WORD MinY = MAX(rect1->MinY, rect2->MinY);
  58     WORD MaxX = MIN(rect1->MaxX, rect2->MaxX);
  59     WORD MaxY = MIN(rect1->MaxY, rect2->MaxY);
  60
  61     if ((MinX > MaxX) || (MinY > MaxY))
  62         return FALSE;
  63     else
  64     {
  65         if (intersect) {
  66             intersect->MinX = MinX;
  67             intersect->MinY = MinY;
  68             intersect->MaxX = MaxX;
  69             intersect->MaxY = MaxY;
  70         }
  71
  72         return TRUE;
  73     }
  74 } /* AndRectRect */