1 files changed, 61 insertions, 0 deletions
diff --git a/Imaging/libImaging/Offset.c b/Imaging/libImaging/Offset.c
new file mode 100644
index 0000000..7e5ac14
--- /dev/null
+++ b/Imaging/libImaging/Offset.c
@@ -0,0 +1,61 @@
+/*
+ * The Python Imaging Library
+ * $Id: Offset.c 2134 2004-10-06 08:55:20Z fredrik $
+ *
+ * offset an image in x and y directions
+ *
+ * history:
+ * 96-07-22 fl:	Created
+ * 98-11-01 cgw@pgt.com: Fixed negative-array index bug
+ *
+ * Copyright (c) Fredrik Lundh 1996.
+ * Copyright (c) Secret Labs AB 1997.
+ *
+ * See the README file for information on usage and redistribution.
+ */
+
+
+#include "Imaging.h"
+
+
+Imaging
+ImagingOffset(Imaging im, int xoffset, int yoffset)
+{
+    int x, y;
+    Imaging imOut;
+
+    if (!im)
+	return (Imaging) ImagingError_ModeError();
+
+    imOut = ImagingNew(im->mode, im->xsize, im->ysize);
+    if (!imOut)
+	return NULL;
+
+    ImagingCopyInfo(imOut, im);
+
+    /* make offsets positive to avoid negative coordinates */
+    xoffset %= im->xsize;
+    xoffset = im->xsize - xoffset;
+    if (xoffset < 0)
+	xoffset += im->xsize;
+
+    yoffset %= im->ysize;
+    yoffset = im->ysize - yoffset;
+    if (yoffset < 0)
+	yoffset += im->ysize;
+
+#define	OFFSET(image)\
+    for (y = 0; y < im->ysize; y++)\
+	for (x = 0; x < im->xsize; x++) {\
+	    int yi = (y + yoffset) % im->ysize;\
+	    int xi = (x + xoffset) % im->xsize;\
+	    imOut->image[y][x] = im->image[yi][xi];\
+	}
+
+    if (im->image8)
+	OFFSET(image8)
+    else
+	OFFSET(image32)
+
+    return imOut;
+}