Set willReadFrequently attribute of HTML canvas - Githubissues

donkirkby / live-py-plugin

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Set willReadFrequently attribute of HTML canvas #503

Closed donkirkby closed 1 year ago

donkirkby commented 1 year ago

What I did

Refresh the Matplotlib intro tutorial with Ctrl+F5 and the console window open.

What happened

Saw a warning in the console:

Canvas2D: Multiple readback operations using getImageData are faster with the willReadFrequently attribute set to true. See: https://html.spec.whatwg.org/multipage/canvas.html#concept-canvas-will-read-frequently

donkirkby commented 1 year ago

Timing of Romania tutorial after I made matplotlib optional:

localhost after F5
- Total 5.57 +/- 0.42s 19.8MB data transferred

Timing of Matplotlib intro:

localhost after F5
- Total 9.97 +/- 0.16s 41.2MB data transferred

Timing of Romania tutorial after I made willReadFrequently true:

localhost after F5
- Total 5.38 +/- 0.03s 19.8MB data transferred

Timing of Matplotlib intro:

localhost after F5
- Total 10.14 +/- 0.10s 41.2MB data transferred

So there's no significant change to the timing, but the warning went away. I guess I'll keep the change.