[sapwood] add a cairo_surface_t for the mask

[Sven Herzberg <herzi src gnome org>]

commit fd55b2841c8ffc9bd737c1eefd387d1d51cc6480
Author: Sven Herzberg <herzi gnome-de org>
Date:   Fri Aug 13 12:03:57 2010 +0200

    add a cairo_surface_t for the mask
    
    * engine/sapwood-pixmap.c: in order to slowly migrate from the GdkBitmap
      for the temporary mask towards a cairo_surface_t

 engine/sapwood-pixmap.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/engine/sapwood-pixmap.c b/engine/sapwood-pixmap.c
index 3b1db39..92c6467 100644
--- a/engine/sapwood-pixmap.c
+++ b/engine/sapwood-pixmap.c
@@ -471,6 +471,7 @@ sapwood_pixmap_render_rects (SapwoodPixmap* self,
                              gint           n_rect,
                              SapwoodRect   *rect)
 {
+  cairo_surface_t* mask_surface = NULL;
   cairo_surface_t* tmp;
   gboolean         need_tmp_mask = FALSE;
   GdkPixmap      * tmp_mask = NULL;
@@ -519,6 +520,8 @@ sapwood_pixmap_render_rects (SapwoodPixmap* self,
       mask_cr = gdk_cairo_create (tmp_mask);
       cairo_set_operator (mask_cr, CAIRO_OPERATOR_CLEAR);
       cairo_paint (mask_cr);
+
+      mask_surface = cairo_surface_reference (cairo_get_target (mask_cr));
     }
 
   tmp_cr = cairo_create (tmp);
@@ -573,6 +576,10 @@ sapwood_pixmap_render_rects (SapwoodPixmap* self,
 
   /* clean up */
   cairo_destroy (cr);
+  if (mask_surface)
+    {
+      cairo_surface_destroy (mask_surface);
+    }
   if (mask_cr)
     cairo_destroy (mask_cr);
   if (tmp_mask)