rom/graphics/setrgb32cm.c

   1 /*
   2     Copyright © 1995-2012, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Graphics function SetRGB32CM()
   6     Lang: english
   7 */
   8 #include <graphics/view.h>
   9 #include "graphics_intern.h"
  10
  11 /*****************************************************************************
  12
  13     NAME */
  14 #include <proto/graphics.h>
  15
  16         AROS_LH5(void, SetRGB32CM,
  17
  18 /*  SYNOPSIS */
  19         AROS_LHA(struct ColorMap *, cm, A0),
  20         AROS_LHA(ULONG            , n , D0),
  21         AROS_LHA(ULONG            , r , D1),
  22         AROS_LHA(ULONG            , g , D2),
  23         AROS_LHA(ULONG            , b , D3),
  24
  25 /*  LOCATION */
  26         struct GfxBase *, GfxBase, 166, Graphics)
  27
  28 /*  FUNCTION
  29         Set one color in the ColorMap.
  30
  31     INPUTS
  32         cm - ColorMap structure obtained via GetColorMap()
  33         n  - the number of the color register to set
  34         r  - red level   (32 bit left justified fraction)
  35         g  - green level (32 bit left justified fraction)
  36         b  - blue level  (32 bit left justified fraction)
  37
  38     RESULT
  39         Store the (r,g,b) triplet at index n in the ColorMap structure.
  40         The changes will not be immediately displayed. Use this function
  41         before linking the ColorMap to a ViewPort. Do not access the entries
  42         in the ColorTable yourself, as the ColorTable format is subject to
  43         change.
  44
  45     NOTES
  46
  47     EXAMPLE
  48
  49     BUGS
  50
  51     SEE ALSO
  52         GetColorMap(), SetRGB32(), GetRGB32(), SetRGB4CM(), graphics/view.h
  53
  54     INTERNALS
  55         This function depends on the ColorMap->ColorTable structure
  56
  57     HISTORY
  58
  59 *****************************************************************************/
  60 {
  61     AROS_LIBFUNC_INIT
  62
  63     if (NULL != cm && n < cm->Count)
  64     {
  65         /* Preserve the highest nibble. Needed for interoperability
  66            with m68k graphics.library. Exact purpose is currently
  67            unknown - sonic */
  68         UWORD a = cm->ColorTable[n];
  69
  70         cm->ColorTable[n] = (a & 0xF000) |
  71             ((r >> 20) & 0x0f00) |
  72             ((g >> 24) & 0x00f0) |
  73             ((b >> 28) & 0x000f);
  74
  75         if (cm->Type > COLORMAP_TYPE_V1_2)
  76             cm->LowColorBits[n] = ((r >> 16) & 0x0f00) |
  77                 ((g >> 20) & 0x00f0) |
  78                 ((b >> 24) & 0x000f);
  79     }
  80
  81     AROS_LIBFUNC_EXIT
  82
  83 } /* SetRGB32CM */