Funny how few canvas libs use stacking of interaction layers. Obviously the slowest part is redrawing quickly for a drag/hover operation. Only one charting exam

Funny how few canvas libs use stacking of interaction layers. Obviously the slowest part is redrawing quickly for a drag/hover operation. Only one charting example that I know of (CytoscapeWeb) drops the interaction elements to an otherwise empty canvas for the interaction to minimize the redraws needed, and then brings them back when done. Most just seem to render everything, all the time, in the same canvas element and pray that browsers keep getting more optimized. Funny.