rom/graphics/scrollraster.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$        $Log
   4
   5     Desc: Graphics function ScrollRaster()
   6     Lang: english
   7 */
   8 #include "graphics_intern.h"
   9 #include <graphics/rastport.h>
  10 #include "gfxfuncsupport.h"
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <graphics/rastport.h>
  16 #include <proto/graphics.h>
  17
  18         AROS_LH7(void, ScrollRaster,
  19
  20 /*  SYNOPSIS */
  21         AROS_LHA(struct RastPort *, rp, A1),
  22         AROS_LHA(LONG             , dx, D0),
  23         AROS_LHA(LONG             , dy, D1),
  24         AROS_LHA(LONG             , xMin, D2),
  25         AROS_LHA(LONG             , yMin, D3),
  26         AROS_LHA(LONG             , xMax, D4),
  27         AROS_LHA(LONG             , yMax, D5),
  28
  29 /*  LOCATION */
  30         struct GfxBase *, GfxBase, 66, Graphics)
  31
  32 /*  FUNCTION
  33       Scroll the contents of a rastport (dx,dy) towards (0,0).
  34       The empty spaces is filled by a call to RectFill().
  35       Only the pixel in the rectangle (xMin,yMin)-(xMax,yMax)
  36       will be affected. The lower right corner (xMax, yMax) is
  37       automatically adjusted to the lower right corner in case
  38       it would be outside.
  39       After this operation the Flags bit of the layer associated
  40       with this rastport, if there is any layer, should be tested
  41       for simple layers in case there has any damage been created.
  42
  43
  44     INPUTS
  45       rp    - pointer to rastport
  46       dx,dy - distance to move in x and y direction. Positive values go
  47               towards (0,0)
  48       xMin,yMin - upper left  hand corner of the affected rectangle
  49       xMax,yMax - lower right hand corner of the affected rectangle
  50
  51     RESULT
  52
  53     NOTES
  54
  55     EXAMPLE
  56
  57     BUGS
  58
  59     SEE ALSO
  60
  61     INTERNALS
  62
  63     HISTORY
  64         29-10-95    digulla automatically created from
  65                             graphics_lib.fd and clib/graphics_protos.h
  66
  67 *****************************************************************************/
  68 {
  69     AROS_LIBFUNC_INIT
  70     AROS_LIBBASE_EXT_DECL(struct GfxBase *,GfxBase)
  71
  72     ULONG old_drmd = GetDrMd(rp);
  73     LONG width, height, absdx, absdy;
  74
  75     FIX_GFXCOORD(xMin);
  76     FIX_GFXCOORD(yMin);
  77     FIX_GFXCOORD(xMax);
  78     FIX_GFXCOORD(yMax);
  79
  80     if ((xMin > xMax) || (yMin > yMax)) return;
  81
  82     /*
  83        This function will simply call ScrollRaster() and fill the empty
  84        space with calls to RectFill
  85      */
  86
  87     /*
  88        adjust xMax and yMax in case the lower right corner would be outside
  89        the rastport
  90     */
  91     /* Is it a window's rastport ? */
  92     if (NULL != rp->Layer)
  93     {
  94         struct Layer * L = rp->Layer;
  95
  96         if (xMax > (L->bounds.MaxX - L->bounds.MinX) )
  97             xMax = (L->bounds.MaxX - L->bounds.MinX) ;
  98
  99         if (yMax > (L->bounds.MaxY - L->bounds.MinY) )
 100             yMax = (L->bounds.MaxY - L->bounds.MinY) ;
 101
 102     }
 103     else
 104     {
 105         /* this one belongs to a screen */
 106         struct BitMap * bm = rp->BitMap;
 107         ULONG width  = GetBitMapAttr(bm, BMA_WIDTH);
 108         ULONG height = GetBitMapAttr(bm, BMA_HEIGHT);
 109         if ((ULONG)xMax >= width )
 110             xMax = width - 1;
 111         if ((ULONG)yMax >= height)
 112             yMax = height - 1;
 113     }
 114
 115     absdx = (dx >= 0) ? dx : -dx;
 116     absdy = (dy >= 0) ? dy : -dy;
 117
 118     width  = xMax - xMin + 1;
 119     height = yMax - yMin + 1;
 120
 121     if ((width < 1) || (height < 1)) return;
 122
 123     if ((absdx >= width) || (absdy >= height))
 124     {
 125         SetDrMd(rp, old_drmd ^ INVERSVID);
 126         RectFill(rp, xMin, yMin, xMax, yMax);
 127         SetDrMd(rp, old_drmd);
 128
 129         return;
 130     }
 131
 132     if (FALSE == MoveRaster(rp, dx, dy, xMin, yMin, xMax, yMax, TRUE, GfxBase))
 133          return;
 134
 135     /*
 136        The raster is scrolled and I fill the empty area with the
 137        RectFill()
 138      */
 139
 140     SetDrMd(rp, old_drmd ^ INVERSVID);
 141
 142     /* was it scrolled left or right? */
 143     if (0 != dx)
 144     {
 145         if (dx > 0)
 146         {
 147             /* scrolled towards left, clearing on the right */
 148             RectFill (rp,
 149                       xMax - dx + 1,
 150                       yMin,
 151                       xMax,
 152                       yMax);
 153         }
 154         else
 155         {
 156             /* scrolled towards right, clearing on the left */
 157             RectFill (rp,
 158                       xMin,
 159                       yMin,
 160                       xMin - dx - 1,  /* a scroll by -1 should only erase a row of width 1 */
 161                       yMax);
 162         }
 163     }
 164
 165     if (0 != dy)
 166     {
 167         if (dy > 0)
 168         {
 169             /* scrolled up, clearing on the bottom */
 170             RectFill (rp,
 171                       xMin,
 172                       yMax - dy + 1,
 173                       xMax,
 174                       yMax);
 175         }
 176         else
 177         {
 178             /* scrolled down, clearing on the top */
 179             RectFill (rp,
 180                       xMin,
 181                       yMin,
 182                       xMax,
 183                       yMin - dy - 1);
 184         }
 185     }
 186
 187     SetDrMd(rp, old_drmd);
 188
 189     AROS_LIBFUNC_EXIT
 190 } /* ScrollRaster */