rom/graphics/getrgb4.c

   1 /*
   2     Copyright © 1995-2012, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Graphics function GetRGB4()
   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_LH2(ULONG, GetRGB4,
  17
  18 /*  SYNOPSIS */
  19         AROS_LHA(struct ColorMap *, colormap, A0),
  20         AROS_LHA(LONG             , entry   , D0),
  21
  22 /*  LOCATION */
  23         struct GfxBase *, GfxBase, 97, Graphics)
  24
  25 /*  FUNCTION
  26         Read a value from the ColorMap. Use this function, as the colormap
  27         is subject to change.
  28
  29     INPUTS
  30         colormap - pointer to ColorMap structure
  31         entry    - index into colormap
  32
  33     RESULT
  34         -1      : if no valid entry. (index too high)
  35         other   : UWORD RGB value, 4 bits per electron gun, right justified
  36
  37     NOTES
  38
  39     EXAMPLE
  40
  41     BUGS
  42
  43     SEE ALSO
  44         GetColorMap(), FreeColorMap(), SetRGB4(), LoadRGB4(), graphics/view.h
  45
  46     INTERNALS
  47         This function depends on the structure of ColorMap->ColorTable.
  48
  49     HISTORY
  50
  51 *****************************************************************************/
  52 {
  53     AROS_LIBFUNC_INIT
  54
  55     UWORD * CT;
  56
  57     /* anything invalid?  */
  58     if ( (NULL == colormap) || (entry >= colormap->Count) )
  59         return -1L;
  60
  61     /* All we're currently doing is read the entry and return it. */
  62     CT = colormap->ColorTable;
  63     return CT[entry];
  64
  65     AROS_LIBFUNC_EXIT
  66
  67 } /* GetRGB4 */