1 /* -*- indent-tabs-mode: nil; tab-width: 4; c-basic-offset: 4; -*-
3 image.c for the Openbox window manager
4 Copyright (c) 2006 Mikael Magnusson
5 Copyright (c) 2003-2007 Dana Jansens
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 See the COPYING file for a copy of the GNU General Public License.
27 #define FLOOR(i) ((i) & (~0UL << FRACTION))
28 #define AVERAGE(a, b) (((((a) ^ (b)) & 0xfefefefeL) >> 1) + ((a) & (b)))
30 static void ImageCopyResampled(RrPixel32 *dst, RrPixel32 *src,
31 gulong dstW, gulong dstH,
32 gulong srcW, gulong srcH)
34 gulong dstX, dstY, srcX, srcY;
35 gulong srcX1, srcX2, srcY1, srcY2;
36 gulong ratioX, ratioY;
38 ratioX = (srcW << FRACTION) / dstW;
39 ratioY = (srcH << FRACTION) / dstH;
42 for (dstY = 0; dstY < dstH; dstY++) {
47 for (dstX = 0; dstX < dstW; dstX++) {
48 gulong red = 0, green = 0, blue = 0, alpha = 0;
49 gulong portionX, portionY, portionXY, sumXY = 0;
55 for (srcY = srcY1; srcY < srcY2; srcY += (1UL << FRACTION)) {
58 portionY = (1UL << FRACTION) - (srcY1 - srcY);
59 if (portionY > srcY2 - srcY1)
60 portionY = srcY2 - srcY1;
62 else if (srcY == FLOOR(srcY2))
63 portionY = srcY2 - srcY;
65 portionY = (1UL << FRACTION);
67 for (srcX = srcX1; srcX < srcX2; srcX += (1UL << FRACTION)) {
70 portionX = (1UL << FRACTION) - (srcX1 - srcX);
71 if (portionX > srcX2 - srcX1)
72 portionX = srcX2 - srcX1;
74 else if (srcX == FLOOR(srcX2))
75 portionX = srcX2 - srcX;
77 portionX = (1UL << FRACTION);
79 portionXY = (portionX * portionY) >> FRACTION;
82 pixel = *(src + (srcY >> FRACTION) * srcW
83 + (srcX >> FRACTION));
84 red += ((pixel >> RrDefaultRedOffset) & 0xFF)
86 green += ((pixel >> RrDefaultGreenOffset) & 0xFF)
88 blue += ((pixel >> RrDefaultBlueOffset) & 0xFF)
90 alpha += ((pixel >> RrDefaultAlphaOffset) & 0xFF)
101 *dst++ = (red << RrDefaultRedOffset) |
102 (green << RrDefaultGreenOffset) |
103 (blue << RrDefaultBlueOffset) |
104 (alpha << RrDefaultAlphaOffset);
109 void RrImageDraw(RrPixel32 *target, RrTextureRGBA *rgba,
110 gint target_w, gint target_h,
116 gint col, num_pixels;
123 dh = (gint)(dw * ((gdouble)sh / sw));
124 if (dh > area->height) {
126 dw = (gint)(dh * ((gdouble)sw / sh));
130 return; /* XXX sanity check */
132 if (sw != dw || sh != dh) {
133 /*if (!(rgba->cache && dw == rgba->cwidth && dh == rgba->cheight))*/ {
135 rgba->cache = g_new(RrPixel32, dw * dh);
136 ImageCopyResampled(rgba->cache, rgba->data, dw, dh, sw, sh);
140 source = rgba->cache;
145 /* copy source -> dest, and apply the alpha channel.
147 center the image if it is smaller than the area */
149 num_pixels = dw * dh;
150 dest = target + area->x + (area->width - dw) / 2 +
151 (target_w * (area->y + (area->height - dh) / 2));
152 while (num_pixels-- > 0) {
153 guchar alpha, r, g, b, bgr, bgg, bgb;
155 /* apply the rgba's opacity as well */
156 alpha = ((*source >> RrDefaultAlphaOffset) * rgba->alpha) >> 8;
157 r = *source >> RrDefaultRedOffset;
158 g = *source >> RrDefaultGreenOffset;
159 b = *source >> RrDefaultBlueOffset;
161 /* background color */
162 bgr = *dest >> RrDefaultRedOffset;
163 bgg = *dest >> RrDefaultGreenOffset;
164 bgb = *dest >> RrDefaultBlueOffset;
166 r = bgr + (((r - bgr) * alpha) >> 8);
167 g = bgg + (((g - bgg) * alpha) >> 8);
168 b = bgb + (((b - bgb) * alpha) >> 8);
170 *dest = ((r << RrDefaultRedOffset) |
171 (g << RrDefaultGreenOffset) |
172 (b << RrDefaultBlueOffset));
179 dest += target_w - dw;