Lag after too many lines drawn

[ghost]

Drawing is not longer smooth after too many lines have been made (not even that many).

Rather than looping each stroke and drawing them every frame, it could make more sense to only draw the last line but don't clear the canvas, so you still have the full drawing visible. Also redraw all lines on undo / redo.

[ghost]

I can no longer reproduce this issue after refreshing the page with the sketchpad.