rom/graphics/scrollraster.c

   1 /*
   2     Copyright © 1995-2007, 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
  71     ULONG old_drmd = GetDrMd(rp);
  72     LONG width, height, absdx, absdy;
  73
  74     FIX_GFXCOORD(xMin);
  75     FIX_GFXCOORD(yMin);
  76     FIX_GFXCOORD(xMax);
  77     FIX_GFXCOORD(yMax);
  78
  79     if ((xMin > xMax) || (yMin > yMax)) return;
  80
  81     /*
  82        This function will simply call ScrollRaster() and fill the empty
  83        space with calls to RectFill
  84      */
  85
  86     /*
  87        adjust xMax and yMax in case the lower right corner would be outside
  88        the rastport
  89     */
  90     /* Is it a window's rastport ? */
  91     if (NULL != rp->Layer)
  92     {
  93         struct Layer * L = rp->Layer;
  94
  95         if (xMax > (L->bounds.MaxX - L->bounds.MinX) )
  96             xMax = (L->bounds.MaxX - L->bounds.MinX) ;
  97
  98         if (yMax > (L->bounds.MaxY - L->bounds.MinY) )
  99             yMax = (L->bounds.MaxY - L->bounds.MinY) ;
 100
 101     }
 102     else
 103     {
 104         /* this one belongs to a screen */
 105         struct BitMap * bm = rp->BitMap;
 106         ULONG width  = GetBitMapAttr(bm, BMA_WIDTH);
 107         ULONG height = GetBitMapAttr(bm, BMA_HEIGHT);
 108         if ((ULONG)xMax >= width )
 109             xMax = width - 1;
 110         if ((ULONG)yMax >= height)
 111             yMax = height - 1;
 112     }
 113
 114     absdx = (dx >= 0) ? dx : -dx;
 115     absdy = (dy >= 0) ? dy : -dy;
 116
 117     width  = xMax - xMin + 1;
 118     height = yMax - yMin + 1;
 119
 120     if ((width < 1) || (height < 1)) return;
 121
 122     if ((absdx >= width) || (absdy >= height))
 123     {
 124         SetDrMd(rp, old_drmd ^ INVERSVID);
 125         RectFill(rp, xMin, yMin, xMax, yMax);
 126         SetDrMd(rp, old_drmd);
 127
 128         return;
 129     }
 130
 131     if (!MoveRaster(rp, dx, dy, xMin, yMin, xMax, yMax, TRUE, GfxBase))
 132          return;
 133
 134     /*
 135        The raster is scrolled and I fill the empty area with the
 136        RectFill()
 137      */
 138
 139     SetDrMd(rp, old_drmd ^ INVERSVID);
 140
 141     /* was it scrolled left or right? */
 142     if (0 != dx)
 143     {
 144         if (dx > 0)
 145         {
 146             /* scrolled towards left, clearing on the right */
 147             RectFill (rp,
 148                       xMax - dx + 1,
 149                       yMin,
 150                       xMax,
 151                       yMax);
 152         }
 153         else
 154         {
 155             /* scrolled towards right, clearing on the left */
 156             RectFill (rp,
 157                       xMin,
 158                       yMin,
 159                       xMin - dx - 1,  /* a scroll by -1 should only erase a row of width 1 */
 160                       yMax);
 161         }
 162     }
 163
 164     if (0 != dy)
 165     {
 166         if (dy > 0)
 167         {
 168             /* scrolled up, clearing on the bottom */
 169             RectFill (rp,
 170                       xMin,
 171                       yMax - dy + 1,
 172                       xMax,
 173                       yMax);
 174         }
 175         else
 176         {
 177             /* scrolled down, clearing on the top */
 178             RectFill (rp,
 179                       xMin,
 180                       yMin,
 181                       xMax,
 182                       yMin - dy - 1);
 183         }
 184     }
 185
 186     SetDrMd(rp, old_drmd);
 187
 188     AROS_LIBFUNC_EXIT
 189 } /* ScrollRaster */