Fix drawing beyond drawing area viewport (bug #762307).

Fixes Bug #762307.  Clip the drawing area's bin_window to a
viewport determined by the widget's physical window size and
current scroll adjustments.

diff --git a/src/view.c b/src/view.c
index b7eff714f190926ab26282d245a3ffab8de8e583..69590b89e128378b0b95256e9e54eb1fe916a62e 100644 (file)
--- a/src/view.c
+++ b/src/view.c
@@ -563,6 +563,17 @@ draw_cb (glView         *view,
         bin_window = gtk_layout_get_bin_window (GTK_LAYOUT (view->canvas));
         bin_cr = gdk_cairo_create (bin_window);
 
+        /* Figure out viewport and clip to this region. */
+        GtkAdjustment *hadj = gtk_scrollable_get_hadjustment (GTK_SCROLLABLE (view->canvas));
+        GtkAdjustment *vadj = gtk_scrollable_get_vadjustment (GTK_SCROLLABLE (view->canvas));
+        GdkWindow *window   = gtk_widget_get_window (GTK_WIDGET (view->canvas));
+        gdouble window_x0   = gtk_adjustment_get_value (hadj);
+        gdouble window_y0   = gtk_adjustment_get_value (vadj);
+        gdouble window_w    = gdk_window_get_width (window);
+        gdouble window_h    = gdk_window_get_height (window);
+        cairo_rectangle (bin_cr, window_x0, window_y0, window_w, window_h);
+        cairo_clip (bin_cr);
+
        draw_layers (view, bin_cr);
 
         cairo_destroy (bin_cr);