class Fl_Double_Window : public Fl_Window
Provides a double-buffered window. If possible this will use the X
double buffering extension (Xdbe). If not, it will draw the window
data into an off-screen pixmap, and then using XCopyArea to put it in
the on-screen window.
To make sure that Xdbe is being used, you should use
Fl::visual(FL_DOUBLE)
before calling show() on any
window. This will select a visual that is double buffered, if one
exists.
Fl_Double_Window::Fl_Double_Window(int W, int H, const char *l=0);
Fl_Double_Window::Fl_Double_Window(int X, int Y, int W, int H, const char *l);
Exactly the same constructors as for Fl_Window.
ulong Fl_Double_Window::pixmap() const;
Under X you can get the xid of the offscreen pixmap or back buffer.
This value is zero until the first time flush() is called.