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 is subject to change.
  43
  44     NOTES
  45
  46     EXAMPLE
  47
  48     BUGS
  49
  50     SEE ALSO
  51         GetColorMap(), SetRGB32(), GetRGB32(), SetRGB4CM(), graphics/view.h
  52
  53     INTERNALS
  54         This function depends on the ColorMap->ColorTable structure
  55
  56     HISTORY
  57
  58 *****************************************************************************/
  59 {
  60     AROS_LIBFUNC_INIT
  61
  62     if (NULL != cm && n < cm->Count)
  63     {
  64         /* Preserve the highest nibble. Needed for interoperability
  65            with m68k graphics.library. Exact purpose is currently
  66            unknown - sonic */
  67         UWORD a = cm->ColorTable[n];
  68
  69         cm->ColorTable[n] = (a & 0xF000) |
  70             ((r >> 20) & 0x0f00) |
  71             ((g >> 24) & 0x00f0) |
  72             ((b >> 28) & 0x000f);
  73
  74         if (cm->Type > COLORMAP_TYPE_V1_2)
  75             cm->LowColorBits[n] = ((r >> 16) & 0x0f00) |
  76                 ((g >> 20) & 0x00f0) |
  77                 ((b >> 24) & 0x000f);
  78     }
  79
  80     AROS_LIBFUNC_EXIT
  81
  82 } /* SetRGB32CM */