rom/graphics/scrollregion.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Graphics function ScrollRegion()
   6     Lang: english
   7 */
   8 #include "graphics_intern.h"
   9 #include <graphics/regions.h>
  10 #include "intregions.h"
  11 #include "gfxfuncsupport.h"
  12
  13 /*****************************************************************************
  14
  15     NAME */
  16 #include <proto/graphics.h>
  17
  18         AROS_LH4(BOOL, ScrollRegion,
  19
  20 /*  SYNOPSIS */
  21         AROS_LHA(struct Region *,    region, A0),
  22         AROS_LHA(struct Rectangle *, rect,   A1),
  23         AROS_LHA(WORD,               dx,     D0),
  24         AROS_LHA(WORD,               dy,     D1),
  25
  26 /*  LOCATION */
  27         struct GfxBase *, GfxBase, 191, Graphics)
  28
  29 /*  FUNCTION
  30         Scroll the rectangles in the region by the amount of pixels specified, within the
  31         specified rectangle.
  32
  33     INPUTS
  34         region - pointer to a region structure
  35         rect   - pointer to the rectangle within which the scrolling has to happen.
  36                  If NULL, the region's bounds are used instead.
  37         dx, dy - the amount of pixels by which to scroll the region. Negative values mean
  38                  respectively left and up, positive values mean right and down.
  39     RESULT
  40         TRUE if the operation succeeded, FALSE otherwise.
  41
  42     NOTES
  43        This function doesn't exist in AmigaOS
  44
  45     EXAMPLE
  46
  47     BUGS
  48
  49     SEE ALSO
  50         NewRegion()
  51
  52     INTERNALS
  53
  54     HISTORY
  55
  56 *****************************************************************************/
  57 {
  58     AROS_LIBFUNC_INIT
  59
  60     BOOL res = FALSE;
  61
  62     if (!rect)
  63     {
  64         TranslateRect(Bounds(region), dx, dy);
  65
  66         res = TRUE;
  67     }
  68     else
  69     {
  70         struct Region *cutRegion;
  71
  72         cutRegion = AndRectRegionND(region, rect);
  73         if (cutRegion)
  74         {
  75             struct Region *newRegion;
  76
  77             TranslateRect(Bounds(cutRegion), dx, dy);
  78
  79             AndRectRegion(cutRegion, rect);
  80
  81             newRegion = ClearRectRegionND(region, rect);
  82             if (newRegion)
  83             {
  84                 if (OrRegionRegion(cutRegion, newRegion))
  85                 {
  86                     _SwapRegions(region, newRegion);
  87
  88                     res = TRUE;
  89                 }
  90
  91                 DisposeRegion(newRegion);
  92             }
  93
  94             DisposeRegion(cutRegion);
  95         }
  96     }
  97
  98     return res;
  99
 100     AROS_LIBFUNC_EXIT
 101 }