mirror of https://github.com/GNOME/gimp.git
103 lines
2.6 KiB
C
103 lines
2.6 KiB
C
/* The GIMP -- an image manipulation program
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* Copyright (C) 1995 Spencer Kimball and Peter Mattis
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#include "appenv.h"
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#include "drawable.h"
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#include "desaturate.h"
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#include "paint_funcs.h"
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#include "gimage.h"
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#include "libgimp/gimpintl.h"
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void
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image_desaturate (GimpImage *gimage)
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{
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GimpDrawable *drawable;
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drawable = gimage_active_drawable (gimage);
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if (! drawable_color (drawable))
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{
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g_message (_("Desaturate operates only on RGB color drawables."));
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return;
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}
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desaturate (drawable);
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}
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/* Desaturater */
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void
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desaturate (GimpDrawable *drawable)
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{
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PixelRegion srcPR, destPR;
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unsigned char *src, *s;
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unsigned char *dest, *d;
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int h, j;
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int lightness, min, max;
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int has_alpha;
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void *pr;
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int x1, y1, x2, y2;
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if (!drawable)
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return;
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has_alpha = drawable_has_alpha (drawable);
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drawable_mask_bounds (drawable, &x1, &y1, &x2, &y2);
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pixel_region_init (&srcPR, drawable_data (drawable), x1, y1, (x2 - x1), (y2 - y1), FALSE);
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pixel_region_init (&destPR, drawable_shadow (drawable), x1, y1, (x2 - x1), (y2 - y1), TRUE);
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for (pr = pixel_regions_register (2, &srcPR, &destPR); pr != NULL; pr = pixel_regions_process (pr))
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{
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src = srcPR.data;
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dest = destPR.data;
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h = srcPR.h;
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while (h--)
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{
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s = src;
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d = dest;
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for (j = 0; j < srcPR.w; j++)
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{
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max = MAX (s[RED_PIX], s[GREEN_PIX]);
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max = MAX (max, s[BLUE_PIX]);
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min = MIN (s[RED_PIX], s[GREEN_PIX]);
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min = MIN (min, s[BLUE_PIX]);
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lightness = (max + min) / 2;
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d[RED_PIX] = lightness;
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d[GREEN_PIX] = lightness;
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d[BLUE_PIX] = lightness;
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if (has_alpha)
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d[ALPHA_PIX] = s[ALPHA_PIX];
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d += destPR.bytes;
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s += srcPR.bytes;
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}
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src += srcPR.rowstride;
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dest += destPR.rowstride;
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}
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}
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drawable_merge_shadow (drawable, TRUE);
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drawable_update (drawable, x1, y1, (x2 - x1), (y2 - y1));
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}
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