- add image flip API support

pierrejoye · pierrejoye · commit 246de922e616 · 2013-02-27T10:37:48.000+01:00
diff --git a/ext/gd/libgd/gd_transform.c b/ext/gd/libgd/gd_transform.c
@@ -0,0 +1,73 @@
+#include "gd.h"
+
+void gdImageFlipVertical(gdImagePtr im)
+{
+	register int x, y;
+
+	if (im->trueColor) {
+		for (y = 0; y < im->sy / 2; y++) {
+			int *row_dst = im->tpixels[y];
+			int *row_src = im->tpixels[im->sy - 1 - y];
+			for (x = 0; x < im->sx; x++) {
+				register int p;
+				p = row_dst[x];
+				row_dst[x] = im->tpixels[im->sy - 1 - y][x];
+				row_src[x] = p;
+			}
+		}
+	} else {
+		unsigned char p;
+		for (y = 0; y < im->sy / 2; y++) {
+			for (x = 0; x < im->sx; x++) {
+				p = im->pixels[y][x];
+				im->pixels[y][x] =	im->pixels[im->sy - 1 - y][x];
+				im->pixels[im->sy - 1 - y][x] = p;
+			}
+		}
+	}
+	return;
+}
+
+void gdImageFlipHorizontal(gdImagePtr im)
+{
+
+	int x, y;
+
+	if (im->trueColor) {
+   		int *px1, *px2, tmp;
+
+		for (y = 0; y < im->sy; y++) {
+			px1 = im->tpixels[y];
+			px2 = im->tpixels[y] + im->sx - 1;
+			for (x = 0; x < (im->sx >> 1); x++) {
+				tmp = *px1;
+				*px1 = *px2;
+				*px2 = tmp;
+				px1++;
+				px2--;
+			}
+		}
+	} else {
+		unsigned char *px1, *px2, tmp;
+
+		for (y = 0; y < im->sy; y++) {
+			px1 = im->pixels[y];
+			px2 = im->pixels[y] + im->sx - 1;
+			for (x = 0; x < (im->sx >> 1); x++) {
+				tmp = *px1;
+				*px1 = *px2;
+				*px2 = tmp;
+				px1++;
+				px2--;
+			}
+		}
+	}
+}
+
+void gdImageFlipBoth(gdImagePtr im)
+{
+	gdImageFlipVertical(im);
+	gdImageFlipHorizontal(im);
+}
+
+
