I'm trying to create a minimap/preview function for my canvas network graph. The basic idea is like this : https://jsfiddle.net/neo_6053/2378smfg/1/

But the problem is that any updates in the main canvas will not be reflected in the small canvas. Even if I add redrawing on graph change, it cannot handle zoom properly. Example if I zoomed in, when I try to copy/clone the canvas, I can only copy the current visible area and thus I cannot refresh the minimap canvas with the newly drawn main canvas. https://jsfiddle.net/neo_6053/2378smfg/2/

 else {
    drawRadar();
    drawMinimapImage();
 }

Is there a way to copy off-screen area of canvas? Does canvas actually render elements outside of the canvas boundary? I googled abit and I think it doesn't, correct me If I'm wrong. Does HTML5 Canvas render off-screen by default?