Merge gdImageColorMatch from php-libgd

1 files changed, 60 insertions, 0 deletions

diff --git a/src/gd_color_match.c b/src/gd_color_match.c
new file mode 100644
index 0000000..551c844
--- /dev/null
+++ b/src/gd_color_match.c
@@ -0,0 +1,60 @@
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include "gd.h"
+#include "gdhelpers.h"
+
+/* bring the palette colors in im2 to be closer to im1
+ *
+ */
+BGD_DECLARE(int) gdImageColorMatch (gdImagePtr im1, gdImagePtr im2)
+{
+	unsigned long *buf; /* stores our calculations */
+	unsigned long *bp; /* buf ptr */
+	int color, rgb;
+	int x,y;
+	int count;
+
+	if (!im1->trueColor) {
+		return -1; /* im1 must be True Color */
+	}
+	if (im2->trueColor) {
+		return -2; /* im2 must be indexed */
+	}
+	if ((im1->sx != im2->sx) || (im1->sy != im2->sy)) {
+		return -3; /* the images are meant to be the same dimensions */
+	}
+	if (im2->colorsTotal < 1) {
+		return -4; /* At least 1 color must be allocated */
+	}
+
+	buf = (unsigned long *)gdMalloc(sizeof(unsigned long) * 5 * im2->colorsTotal);
+	memset (buf, 0, sizeof(unsigned long) * 5 * im2->colorsTotal );
+
+	for (x=0; x < im1->sx; x++) {
+		for( y=0; y<im1->sy; y++ ) {
+			color = im2->pixels[y][x];
+			rgb = im1->tpixels[y][x];
+			bp = buf + (color * 5);
+			(*(bp++))++;
+			*(bp++) += gdTrueColorGetRed(rgb);
+			*(bp++) += gdTrueColorGetGreen(rgb);
+			*(bp++) += gdTrueColorGetBlue(rgb);
+			*(bp++) += gdTrueColorGetAlpha(rgb);
+		}
+	}
+	bp = buf;
+	for (color=0; color < im2->colorsTotal; color++) {
+		count = *(bp++);
+		if( count > 0 ) {
+			im2->red[color]		= *(bp++) / count;
+			im2->green[color]	= *(bp++) / count;
+			im2->blue[color]	= *(bp++) / count;
+			im2->alpha[color]	= *(bp++) / count;
+		} else {
+			bp += 4;
+		}
+	}
+	gdFree(buf);
+	return 0;
+}