rom/graphics/clearrectregionnd.c

   1 /*
   2     Copyright © 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Graphics function AndRectRegion()
   6     Lang: english
   7 */
   8
   9 #include <graphics/regions.h>
  10 #include <proto/exec.h>
  11 #include <clib/macros.h>
  12
  13 #include "graphics_intern.h"
  14 #include "intregions.h"
  15
  16 /*****************************************************************************
  17
  18     NAME */
  19 #include <proto/graphics.h>
  20
  21         AROS_LH2(struct Region *, ClearRectRegionND,
  22
  23 /*  SYNOPSIS */
  24         AROS_LHA(struct Region    *, Reg, A0),
  25         AROS_LHA(struct Rectangle *, Rect, A1),
  26
  27 /*  LOCATION */
  28         struct GfxBase *, GfxBase, 192, Graphics)
  29
  30 /*  FUNCTION
  31         Clear the given Rectangle from the given Region
  32
  33     INPUTS
  34         region - pointer to Region structure
  35         rectangle - pointer to Rectangle structure
  36
  37     RESULT
  38         The resulting region or NULL in case there's no enough free memory
  39
  40     NOTES
  41
  42     BUGS
  43
  44     SEE ALSO
  45         AndRegionRegion(), OrRectRegion(), XorRectRegion(), ClearRectRegion()
  46         NewRegion()
  47
  48     INTERNALS
  49
  50     HISTORY
  51         27-11-96    digulla automatically created from
  52                             graphics_lib.fd and clib/graphics_protos.h
  53         16-01-97    mreckt  initial version
  54
  55 *****************************************************************************/
  56 {
  57     AROS_LIBFUNC_INIT
  58
  59     struct Region *Res = NewRegion();
  60
  61     if (!Res)
  62         return NULL;
  63
  64     if (!Reg->RegionRectangle        ||
  65         IS_RECT_EVIL(Rect)           ||
  66         !overlap(*Rect, Reg->bounds))
  67     {
  68         /* Nothing to clear. Make a plain copy. */
  69         if (!_CopyRegionRectangles(Reg, Res, GfxBase))
  70         {
  71             DisposeRegion(Res);
  72             Res = NULL;
  73         }
  74     }
  75
  76     else if (Rect->MinX > MinX(Reg) || Rect->MinY > MinY(Reg) ||
  77              Rect->MaxX < MaxX(Reg) || Rect->MaxY < MaxY(Reg))
  78     {
  79         /* Partial overlapping detected. Do the complete algorithm. */
  80         struct RegionRectangle rr;
  81
  82         rr.bounds = *Rect;
  83         rr.Next   = NULL;
  84         rr.Prev   = NULL;
  85
  86         if
  87         (
  88             _DoOperationBandBand
  89             (
  90                 _ClearBandBand,
  91                 0,
  92                 MinX(Reg),
  93                 0,
  94                 MinY(Reg),
  95                 &rr,
  96                 Reg->RegionRectangle,
  97                 &Res->RegionRectangle,
  98                 &Res->bounds,
  99                 GfxBase
 100             )
 101         )
 102         {
 103             _TranslateRegionRectangles(Res->RegionRectangle, -MinX(Res), -MinY(Res));
 104         }
 105         else
 106         {
 107             DisposeRegion(Res);
 108             Res = NULL;
 109         }
 110     }
 111     /* If neither of two cases above were true, we've removed everything (Rect completely covers Reg). Return empty Res. */
 112
 113     return Res;
 114
 115     AROS_LIBFUNC_EXIT
 116 } /* AndRectRegion */
 117
 118
 119
 120