image.c for the Openbox window manager
Copyright (c) 2006 Mikael Magnusson
- Copyright (c) 2003 Ben Jansens
+ Copyright (c) 2003-2007 Dana Jansens
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
gulong dstX, dstY, srcX, srcY;
gulong srcX1, srcX2, srcY1, srcY2;
gulong ratioX, ratioY;
-
+
ratioX = (srcW << FRACTION) / dstW;
ratioY = (srcH << FRACTION) / dstH;
-
+
srcY2 = 0;
for (dstY = 0; dstY < dstH; dstY++) {
srcY1 = srcY2;
srcY2 += ratioY;
-
+
srcX2 = 0;
for (dstX = 0; dstX < dstW; dstX++) {
gulong red = 0, green = 0, blue = 0, alpha = 0;
gulong portionX, portionY, portionXY, sumXY = 0;
RrPixel32 pixel;
-
+
srcX1 = srcX2;
srcX2 += ratioX;
-
+
for (srcY = srcY1; srcY < srcY2; srcY += (1UL << FRACTION)) {
if (srcY == srcY1) {
srcY = FLOOR(srcY);
portionY = srcY2 - srcY;
else
portionY = (1UL << FRACTION);
-
+
for (srcX = srcX1; srcX < srcX2; srcX += (1UL << FRACTION)) {
if (srcX == srcX1) {
srcX = FLOOR(srcX);
portionX = srcX2 - srcX;
else
portionX = (1UL << FRACTION);
-
+
portionXY = (portionX * portionY) >> FRACTION;
sumXY += portionXY;
-
+
pixel = *(src + (srcY >> FRACTION) * srcW
+ (srcX >> FRACTION));
red += ((pixel >> RrDefaultRedOffset) & 0xFF)
* portionXY;
}
}
-
+
g_assert(sumXY != 0);
red /= sumXY;
green /= sumXY;
blue /= sumXY;
alpha /= sumXY;
-
+
*dst++ = (red << RrDefaultRedOffset) |
(green << RrDefaultGreenOffset) |
(blue << RrDefaultBlueOffset) |
source = rgba->data;
}
- /* copy source -> dest, and apply the alpha channel */
+ /* copy source -> dest, and apply the alpha channel.
+
+ center the image if it is smaller than the area */
col = 0;
num_pixels = dw * dh;
- dest = target + area->x + target_w * area->y;
+ dest = target + area->x + (area->width - dw) / 2 +
+ (target_w * (area->y + (area->height - dh) / 2));
while (num_pixels-- > 0) {
guchar alpha, r, g, b, bgr, bgg, bgb;
- alpha = *source >> RrDefaultAlphaOffset;
+ /* apply the rgba's opacity as well */
+ alpha = ((*source >> RrDefaultAlphaOffset) * rgba->alpha) >> 8;
r = *source >> RrDefaultRedOffset;
g = *source >> RrDefaultGreenOffset;
b = *source >> RrDefaultBlueOffset;