rom/graphics/clearregionregionnd.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Graphics function AndRegionRegion()
   6     Lang: english
   7 */
   8 #include "graphics_intern.h"
   9 #include <graphics/regions.h>
  10 #include "intregions.h"
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <proto/graphics.h>
  16
  17         AROS_LH2(struct Region *, ClearRegionRegionND,
  18
  19 /*  SYNOPSIS */
  20         AROS_LHA(struct Region *, R1, A0),
  21         AROS_LHA(struct Region *, R2, A1),
  22
  23 /*  LOCATION */
  24         struct GfxBase *, GfxBase, 141, Graphics)
  25
  26 /*  FUNCTION
  27         Clear the given Region region1 from the given Region region2.
  28
  29     INPUTS
  30         region1 - pointer to a region structure
  31         region2 - pointer to a region structure
  32
  33     RESULT
  34         The resulting region or NULL in case there's no enough free memory
  35
  36     NOTES
  37
  38     EXAMPLE
  39
  40     BUGS
  41
  42     SEE ALSO
  43         XorRegionRegion(), OrRegionRegion()
  44
  45     INTERNALS
  46
  47     HISTORY
  48
  49 *****************************************************************************/
  50 {
  51     AROS_LIBFUNC_INIT
  52
  53     struct Region *R3;
  54
  55     if
  56     (
  57         !R1->RegionRectangle            ||
  58         !R2->RegionRectangle            ||
  59         !overlap(R1->bounds, R2->bounds)
  60     )
  61     {
  62         return CopyRegion(R2);
  63     }
  64
  65     R3 = NewRegion();
  66
  67     if (R3)
  68     {
  69         if
  70         (
  71             _DoOperationBandBand
  72             (
  73                 _ClearBandBand,
  74                 MinX(R1),
  75                 MinX(R2),
  76                 MinY(R1),
  77                 MinY(R2),
  78                 R1->RegionRectangle,
  79                 R2->RegionRectangle,
  80                 &R3->RegionRectangle,
  81                 &R3->bounds,
  82                 GfxBase
  83             )
  84         )
  85         {
  86             _TranslateRegionRectangles(R3->RegionRectangle, -MinX(R3), -MinY(R3));
  87         }
  88         else
  89         {
  90             DisposeRegion(R3);
  91             R3 = NULL;
  92         }
  93     }
  94
  95     return R3;
  96
  97     AROS_LIBFUNC_EXIT
  98 }