rom/graphics/readpixel.c

   1 /*
   2     Copyright © 1995-2007, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Graphics function ReadPixel()
   6     Lang: english
   7 */
   8
   9 #include <graphics/rastport.h>
  10 #include <graphics/clip.h>
  11 #include <proto/graphics.h>
  12
  13 #include "graphics_intern.h"
  14 #include "gfxfuncsupport.h"
  15
  16 #include <aros/debug.h>
  17
  18 struct prlut8_render_data
  19 {
  20     ULONG pen;
  21     HIDDT_PixelLUT *pixlut;
  22 };
  23
  24 static LONG pix_read_lut8(APTR prlr_data, OOP_Object *bm, OOP_Object *gc,
  25                           LONG x, LONG y, struct GfxBase *GfxBase);
  26
  27 /*****************************************************************************
  28
  29     NAME */
  30
  31         AROS_LH3(LONG, ReadPixel,
  32
  33 /*  SYNOPSIS */
  34         AROS_LHA(struct RastPort *, rp, A1),
  35         AROS_LHA(LONG             , x, D0),
  36         AROS_LHA(LONG             , y, D1),
  37
  38 /*  LOCATION */
  39         struct GfxBase *, GfxBase, 53, Graphics)
  40
  41 /*  FUNCTION
  42         Read the pen number of the given x,y coordinate.
  43
  44     INPUTS
  45         rp  - RastPort
  46         x,y - Coordinate
  47
  48     RESULT
  49
  50     NOTES
  51
  52     EXAMPLE
  53
  54     BUGS
  55
  56     SEE ALSO
  57
  58     INTERNALS
  59         This function takes layers into account. Some pixel that is
  60         being read is not found on the display-bitmap but in some
  61         clipped rectangle (cliprect) in a layer structure.
  62         There is no support of anything else than bitplanes now.
  63         (No chunky pixels)
  64         This function resembles very much the function WritePixel()!!
  65
  66     HISTORY
  67         29-10-95    digulla automatically created from
  68                             graphics_lib.fd and clib/graphics_protos.h
  69
  70 *****************************************************************************/
  71 {
  72    AROS_LIBFUNC_INIT
  73
  74     struct prlut8_render_data prlrd;
  75     LONG                       ret;
  76
  77     HIDDT_PixelLUT pixlut = { AROS_PALETTE_SIZE, HIDD_BM_PIXTAB(rp->BitMap) };
  78
  79     FIX_GFXCOORD(x);
  80     FIX_GFXCOORD(y);
  81
  82     if(!OBTAIN_DRIVERDATA(rp, GfxBase))
  83         return ((ULONG)-1);
  84
  85     if (IS_HIDD_BM(rp->BitMap))
  86         prlrd.pixlut = &pixlut;
  87     else
  88         prlrd.pixlut = NULL;
  89
  90     prlrd.pen = -1;
  91
  92     ret = do_pixel_func(rp, x, y, pix_read_lut8, &prlrd, FALSE, GfxBase);
  93
  94     RELEASE_DRIVERDATA(rp, GfxBase);
  95
  96     if (-1 == ret || -1 == (LONG)prlrd.pen)
  97     {
  98         D(bug("ReadPixel(), COULD NOT GET PEN. TRYING TO READ FROM SimpleRefresh cliprect ??"));
  99         return (ULONG)-1;
 100     }
 101
 102     return prlrd.pen;
 103
 104     AROS_LIBFUNC_EXIT
 105
 106 } /* ReadPixel */
 107
 108 static LONG pix_read_lut8(APTR prlr_data, OOP_Object *bm, OOP_Object *gc,
 109                           LONG x, LONG y, struct GfxBase *GfxBase)
 110 {
 111     struct prlut8_render_data *prlrd;
 112
 113     prlrd = (struct prlut8_render_data *)prlr_data;
 114
 115     if (NULL != prlrd->pixlut)
 116     {
 117         HIDD_BM_GetImageLUT(bm, (UBYTE *)&prlrd->pen, 1, x, y, 1, 1, prlrd->pixlut);
 118     }
 119     else
 120     {
 121         prlrd->pen = HIDD_BM_GetPixel(bm, x, y);
 122     }
 123
 124     return 0;
 125 }
 126