Why does my canvas go blank after converting to image?

Question

I am trying to convert the canvas element on this page to a png using the following snippet (e.g. enter in JavaScript console):

(function conver         


        

Answer 1

Here's some things to try. I don't know whether either of these should be necessary to make this work, but they might make a difference.

• Add preserveDrawingBuffer: true to the getContext attributes.
• Try doing this with a later tutorial which does animation; i.e. draws on the canvas repeatedly rather than just once.