Canvas drawing speed

01 Jun 2018

@mathisonian and I were wondering if we could speed up canvas drawing by using an offscreen canvas. Tested with . Observations:

In Chrome/Mac, offscreen was fast and regular was slow. In Firefox/Mac, they were both medium. In Safari/Mac they were both fast, or offscreen was slower (depending on how many draw calls I made).
Setting globalAlpha was faster than setting a new fillStyle for each point.

Test 1: regular drawing with arc():

Test 2: offscreen canvas drawing:

Use View Source to see the source code. It’s on the html page.