CustomWidget: add missing SetViewportOrgEx call

The viewport origin should be adjusted for a partial update, specifically when updateBounds Rectangle is not at the origin.
lxn · Dec 5, 2015 · 43a7f4c · 43a7f4c
1 parent c31f26c
commit 43a7f4c
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/customwidget.go b/customwidget.go
@@ -177,6 +177,9 @@ func (cw *CustomWidget) bufferedPaint(canvas *Canvas, updateBounds Rectangle) er
 	}
 	defer win.SelectObject(buffered.hdc, oldbmp)
 
+	win.SetViewportOrgEx(buffered.hdc, -int32(updateBounds.X), -int32(updateBounds.Y), nil)
+	win.SetBrushOrgEx(buffered.hdc, -int32(updateBounds.X), -int32(updateBounds.Y), nil)
+
 	err := cw.paint(&buffered, updateBounds)
 
 	if !win.BitBlt(canvas.hdc,