rom/graphics/initmasks.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Graphics function InitMasks()
   6     Lang: english
   7 */
   8 #include <graphics/gels.h>
   9 #include <graphics/rastport.h>
  10 #include "graphics_intern.h"
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <proto/graphics.h>
  16
  17         AROS_LH1(void, InitMasks,
  18
  19 /*  SYNOPSIS */
  20         AROS_LHA(struct VSprite *, vs, A0),
  21
  22 /*  LOCATION */
  23         struct GfxBase *, GfxBase, 21, Graphics)
  24
  25 /*  FUNCTION
  26         Creates the standard BorderLine and CollMask masks of the VSprite.
  27         VSprites and Bobs are treated accordingly.
  28
  29     INPUTS
  30         vs = pointer to VSprite structure
  31
  32     RESULT
  33
  34     NOTES
  35
  36     EXAMPLE
  37
  38     BUGS
  39
  40     SEE ALSO
  41         InitGels() InitGMasks() graphics/gels.h
  42
  43     INTERNALS
  44
  45     HISTORY
  46
  47 *****************************************************************************/
  48 {
  49   AROS_LIBFUNC_INIT
  50   AROS_LIBBASE_EXT_DECL(struct GfxBase *,GfxBase)
  51
  52   long depth, WordsPerPlane, WordsPerLine, count;
  53   /* is this a Bob or a VSprite? */
  54   if (0 != (vs -> Flags & VSPRITE))
  55   {
  56     /* assumption: vs -> Widtht = 16 (or 32 on a better chipset??)*/
  57     WordsPerLine = vs -> Width >> 4; /* Width:16 */
  58     depth = 2; /* standard */
  59   }
  60   else
  61   {
  62     WordsPerLine = vs -> Width;
  63     depth = vs -> Depth;
  64   }
  65   WordsPerPlane = (vs -> Height) * WordsPerLine;
  66
  67
  68   /* create the standard collision mask by or'ing all bitplanes */
  69   for (count = 0; count < WordsPerPlane; count++)
  70   {
  71     WORD * PlaneData = vs -> ImageData;
  72     WORD Data = PlaneData[count];
  73     long z;
  74     for (z = 1; z < depth; z++)
  75         Data |= PlaneData[count + z*WordsPerPlane];
  76     (vs -> CollMask)[count] = Data;
  77   }
  78
  79   /* create the standard BorderLine from the collision mask by or'ing all
  80      lines */
  81   for (count = 0 ; count < WordsPerLine; count++)
  82   {
  83         WORD * CollMask = vs -> CollMask;
  84         WORD Data = CollMask[count];
  85         long z;
  86         for (z = 1; z < vs-> Height; z++)
  87           Data |= CollMask[count + z*WordsPerLine];
  88         (vs -> BorderLine)[count] = Data;
  89   }
  90
  91   AROS_LIBFUNC_EXIT
  92 } /* InitMasks */