rom/graphics/scrollregion.c

   1 /*
   2     Copyright © 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Graphics function ScrollRegion()
   6     Lang: english
   7 */
   8
   9 #include "graphics_intern.h"
  10 #include <graphics/regions.h>
  11 #include "intregions.h"
  12 #include "gfxfuncsupport.h"
  13
  14 /*****************************************************************************
  15
  16     NAME */
  17 #include <proto/graphics.h>
  18
  19         AROS_LH4(BOOL, ScrollRegion,
  20
  21 /*  SYNOPSIS */
  22         AROS_LHA(struct Region *,    region, A0),
  23         AROS_LHA(struct Rectangle *, rect,   A1),
  24         AROS_LHA(WORD,               dx,     D0),
  25         AROS_LHA(WORD,               dy,     D1),
  26
  27 /*  LOCATION */
  28         struct GfxBase *, GfxBase, 185, Graphics)
  29
  30 /*  FUNCTION
  31         Scroll the rectangles in the region by the amount of pixels specified, within the
  32         specified rectangle.
  33
  34     INPUTS
  35         region - pointer to a region structure
  36         rect   - pointer to the rectangle within which the scrolling has to happen.
  37                  If NULL, the region's bounds are used instead.
  38         dx, dy - the amount of pixels by which to scroll the region. Negative values mean
  39                  respectively left and up, positive values mean right and down.
  40     RESULT
  41         TRUE if the operation succeeded, FALSE otherwise.
  42
  43     NOTES
  44        This function doesn't exist in AmigaOS
  45
  46     EXAMPLE
  47
  48     BUGS
  49
  50     SEE ALSO
  51         NewRegion()
  52
  53     INTERNALS
  54
  55     HISTORY
  56
  57 *****************************************************************************/
  58 {
  59     AROS_LIBFUNC_INIT
  60
  61     BOOL res = FALSE;
  62
  63     if (!rect)
  64     {
  65         TranslateRect(Bounds(region), dx, dy);
  66
  67         res = TRUE;
  68     }
  69     else
  70     {
  71         struct Region *cutRegion;
  72
  73         cutRegion = AndRectRegionND(region, rect);
  74         if (cutRegion)
  75         {
  76             struct Region *newRegion;
  77
  78             TranslateRect(Bounds(cutRegion), dx, dy);
  79
  80             AndRectRegion(cutRegion, rect);
  81
  82             newRegion = ClearRectRegionND(region, rect);
  83             if (newRegion)
  84             {
  85                 if (OrRegionRegion(cutRegion, newRegion))
  86                 {
  87                     _SwapRegions(region, newRegion);
  88
  89                     res = TRUE;
  90                 }
  91
  92                 DisposeRegion(newRegion);
  93             }
  94
  95             DisposeRegion(cutRegion);
  96         }
  97     }
  98
  99     return res;
 100
 101     AROS_LIBFUNC_EXIT
 102 }