Render on a temporary surface when needed

Some platforms draw directly to the screen, which means that updates
will flicker if we draw multiple layers. Prevent this by first
composing the update on a hidden surface.

1 files changed, 3 insertions, 0 deletions

diff --git a/vncviewer/Viewport.h b/vncviewer/Viewport.h
index ac1ec338..0967fcbb 100644
--- a/vncviewer/Viewport.h
+++ b/vncviewer/Viewport.h
@@ -29,6 +29,7 @@ class Fl_RGB_Image;
 
 class CConn;
 class PlatformPixelBuffer;
+class Surface;
 
 class Viewport : public Fl_Widget {
 public:
@@ -46,6 +47,8 @@ public:
   void setCursor(int width, int height, const rfb::Point& hotspot,
                  void* data, void* mask);
 
+  void draw(Surface* dst);
+
   // Fl_Widget callback methods
 
   void draw();