protected:
MonoColorModel& cm_;
virtual void update();
virtual void disable() { method_ = &WindowDitherer::dither_null; }
virtual void disable() { method_ = &MonoWindowRenderer::dither_null; }
MonoMethod method_;
void dither(const u_char* frm, u_int off, u_int x,
u_int width, u_int height) const;