Bug 238943

Created attachment 456938 [details] Flash thing 1 at 45s mark Hi, everyone. At Felt we are creating a tool to build maps. This involves having a background with tiled canvases where the basemap is rendered and some SVGs on top of them. We've been having some issues with the rendering on Safari itself: - We weren't able to render large paths: https://bugs.webkit.org/show_bug.cgi?id=231157 This was solved in STP 139 - Problems with the Garbage collection of canvases: https://bugs.webkit.org/show_bug.cgi?id=195325 Which we solved with the solution exposed in the first post What we are finding now is that in STP 142, the whole browser starts doing really weird flashes when we zoom in/out in a map with lots of elements. I can provide a map to reproduce what we are seeing: https://felt.com/map/Untitled-Map-aMPeGQj2ThqwJf43XpyQCB Zooming in/out quickly will get to a point were the whole browser screen. including the navbar starts flashing like crazy. I have also recorded a video, which can be accessed here https://drive.google.com/file/d/1WheqbvMu1nriGjvLijHHxmEFp44cbQ4l/view?usp=sharing Looking at that video, around 45 seconds in, you'll see the browser starts lagging even though I'm constantly scrolling up/down with the trackpad as I was doing before. Later, at the 1 minute mark, you'll see the first occurrence of that flashing thing and later, at 1:16 you'll see an even worse flashing thing.