rom/graphics/readpixel.c

   1 /*
   2     Copyright © 1995-2001, 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
  43     INPUTS
  44
  45     RESULT
  46
  47     NOTES
  48
  49     EXAMPLE
  50
  51     BUGS
  52
  53     SEE ALSO
  54
  55     INTERNALS
  56         This function takes layers into account. Some pixel that is
  57         being read is not found on the display-bitmap but in some
  58         clipped rectangle (cliprect) in a layer structure.
  59         There is no support of anything else than bitplanes now.
  60         (No chunky pixels)
  61         This function resembles very much the function WritePixel()!!
  62
  63     HISTORY
  64         29-10-95    digulla automatically created from
  65                             graphics_lib.fd and clib/graphics_protos.h
  66
  67 *****************************************************************************/
  68 {
  69    AROS_LIBFUNC_INIT
  70    AROS_LIBBASE_EXT_DECL(struct GfxBase *,GfxBase)
  71
  72     struct prlut8_render_data prlrd;
  73     LONG                       ret;
  74
  75     HIDDT_PixelLUT pixlut = { AROS_PALETTE_SIZE, HIDD_BM_PIXTAB(rp->BitMap) };
  76
  77     FIX_GFXCOORD(x);
  78     FIX_GFXCOORD(y);
  79
  80     if(!OBTAIN_DRIVERDATA(rp, GfxBase))
  81         return ((ULONG)-1L);
  82
  83     if (IS_HIDD_BM(rp->BitMap))
  84         prlrd.pixlut = &pixlut;
  85     else
  86         prlrd.pixlut = NULL;
  87
  88     prlrd.pen = -1;
  89
  90     ret = do_pixel_func(rp, x, y, pix_read_lut8, &prlrd, GfxBase);
  91
  92     RELEASE_DRIVERDATA(rp, GfxBase);
  93
  94     if (-1 == ret || -1 == (LONG)prlrd.pen)
  95     {
  96         D(bug("ReadPixel(), COULD NOT GET PEN. TRYING TO READ FROM SimpleRefresh cliprect ??"));
  97         return (ULONG)-1;
  98     }
  99
 100     return prlrd.pen;
 101
 102     AROS_LIBFUNC_EXIT
 103
 104 } /* ReadPixel */
 105
 106 static LONG pix_read_lut8(APTR prlr_data, OOP_Object *bm, OOP_Object *gc,
 107                           LONG x, LONG y, struct GfxBase *GfxBase)
 108 {
 109     struct prlut8_render_data *prlrd;
 110
 111     prlrd = (struct prlut8_render_data *)prlr_data;
 112
 113     if (NULL != prlrd->pixlut)
 114     {
 115         HIDD_BM_GetImageLUT(bm, (UBYTE *)&prlrd->pen, 1, x, y, 1, 1, prlrd->pixlut);
 116     }
 117     else
 118     {
 119         prlrd->pen = HIDD_BM_GetPixel(bm, x, y);
 120     }
 121
 122     return 0;
 123 }
 124