rom/graphics/readpixel.c

   1 /*
   2     Copyright © 1995-2011, 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                           WORD x, WORD 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(WORD             , x, D0),
  36         AROS_LHA(WORD             , 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 (IS_HIDD_BM(rp->BitMap))
  83         prlrd.pixlut = &pixlut;
  84     else
  85         prlrd.pixlut = NULL;
  86
  87     prlrd.pen = -1;
  88
  89     ret = do_pixel_func(rp, x, y, pix_read_lut8, &prlrd, FALSE, GfxBase);
  90
  91     if (-1 == ret || -1 == (LONG)prlrd.pen)
  92     {
  93         D(bug("ReadPixel(), COULD NOT GET PEN. TRYING TO READ FROM SimpleRefresh cliprect ??"));
  94         return (ULONG)-1;
  95     }
  96
  97     return prlrd.pen;
  98
  99     AROS_LIBFUNC_EXIT
 100
 101 } /* ReadPixel */
 102
 103 static LONG pix_read_lut8(APTR prlr_data, OOP_Object *bm, OOP_Object *gc,
 104                           WORD x, WORD y, struct GfxBase *GfxBase)
 105 {
 106     struct prlut8_render_data *prlrd;
 107     UBYTE pen;
 108
 109     prlrd = (struct prlut8_render_data *)prlr_data;
 110
 111     if (NULL != prlrd->pixlut)
 112     {
 113         HIDD_BM_GetImageLUT(bm, &pen, 1, x, y, 1, 1, prlrd->pixlut);
 114     }
 115     else
 116     {
 117         pen = HIDD_BM_GetPixel(bm, x, y);
 118     }
 119
 120     prlrd->pen = pen;
 121
 122     return 0;
 123 }
 124