1 files changed, 52 insertions, 0 deletions
diff --git a/src/libdraw/ml-unload.c b/src/libdraw/ml-unload.c
new file mode 100644
index 00000000..23a8b290
--- /dev/null
+++ b/src/libdraw/ml-unload.c
@@ -0,0 +1,52 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <memdraw.h>
+#include <memlayer.h>
+
+int
+memunload(Memimage *src, Rectangle r, uchar *data, int n)
+{
+	Memimage *tmp;
+	Memlayer *dl;
+	Rectangle lr;
+	int dx;
+
+    Top:
+	dl = src->layer;
+	if(dl == nil)
+		return unloadmemimage(src, r, data, n);
+
+	/*
+ 	 * Convert to screen coordinates.
+	 */
+	lr = r;
+	r.min.x += dl->delta.x;
+	r.min.y += dl->delta.y;
+	r.max.x += dl->delta.x;
+	r.max.y += dl->delta.y;
+	dx = dl->delta.x&(7/src->depth);
+	if(dl->clear && dx==0){
+		src = dl->screen->image;
+		goto Top;
+	}
+
+	/*
+	 * src is an obscured layer or data is unaligned
+	 */
+	if(dl->save && dx==0){
+		if(dl->refreshfn != nil)
+			return -1;	/* can't unload window if it's not Refbackup */
+		if(n > 0)
+			memlhide(src, r);
+		n = unloadmemimage(dl->save, lr, data, n);
+		return n;
+	}
+	tmp = allocmemimage(lr, src->chan);
+	if(tmp == nil)
+		return -1;
+	memdraw(tmp, lr, src, lr.min, nil, lr.min, S);
+	n = unloadmemimage(tmp, lr, data, n);
+	freememimage(tmp);
+	return n;
+}