workbench/libs/cgfx/readrgbpixel.c

   1 /*
   2     Copyright © 1995-2017, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc:
   6     Lang: english
   7 */
   8
   9 #include <hidd/gfx.h>
  10 #include <aros/debug.h>
  11
  12 #include "cybergraphics_intern.h"
  13
  14 struct render_data
  15 {
  16     HIDDT_Pixel pixel;
  17 };
  18
  19 static LONG PixelHook(struct render_data *data, OOP_Object *bm, OOP_Object *gc,
  20     LONG x, LONG y, struct GfxBase *GfxBase);
  21
  22 /*****************************************************************************
  23
  24     NAME */
  25 #include <proto/cybergraphics.h>
  26
  27         AROS_LH3(ULONG, ReadRGBPixel,
  28
  29 /*  SYNOPSIS */
  30         AROS_LHA(struct RastPort *, rp  , A1),
  31         AROS_LHA(UWORD            , x   , D0),
  32         AROS_LHA(UWORD            , y   , D1),
  33
  34 /*  LOCATION */
  35         struct Library *, CyberGfxBase, 18, Cybergraphics)
  36
  37 /*  FUNCTION
  38         Reads a particular pixel's color value from a RastPort.
  39
  40     INPUTS
  41         rp - the RastPort to read from.
  42         x, y - the coordinates of the pixel to read.
  43
  44     RESULT
  45         color - the pixel's color value in 32-bit ARGB format: 1 byte
  46             per component, in the order alpha, red, green, blue.
  47
  48     NOTES
  49
  50     EXAMPLE
  51
  52     BUGS
  53
  54     SEE ALSO
  55
  56     INTERNALS
  57
  58 *****************************************************************************/
  59 {
  60     AROS_LIBFUNC_INIT
  61
  62     struct render_data data;
  63     HIDDT_Color col;
  64     HIDDT_Pixel pix;
  65     LONG ret;
  66
  67     /* This is cybergraphx. We only work wih HIDD bitmaps */
  68     if (!IS_HIDD_BM(rp->BitMap))
  69     {
  70         D(bug("!!!!! Trying to use CGFX call on non-hidd bitmap "
  71             "in ReadRGBPixel()!!!\n"));
  72         return (ULONG)-1;
  73     }
  74
  75     /* Get the HIDD pixel val */
  76     ret = DoPixelFunc(rp, x, y, PixelHook, &data, FALSE);
  77
  78     if (-1 == ret)
  79         return (ULONG)-1;
  80
  81     HIDD_BM_UnmapPixel(HIDD_BM_OBJ(rp->BitMap), data.pixel, &col);
  82
  83     /* HIDDT_ColComp are 16 Bit */
  84
  85     pix = ((col.alpha & 0xFF00) << 16)
  86         | ((col.red & 0xFF00) << 8)
  87         | (col.green & 0xFF00)
  88         | ((col.blue & 0xFF00) >> 8);
  89
  90     return pix;
  91
  92     AROS_LIBFUNC_EXIT
  93 } /* ReadRGBPixel */
  94
  95 static LONG PixelHook(struct render_data *data, OOP_Object *bm, OOP_Object *gc,
  96     LONG x, LONG y, struct GfxBase *GfxBase)
  97 {
  98     data->pixel = HIDD_BM_GetPixel(bm, x, y);
  99     return 0;
 100 }
 101