80593 2012-03-08 07:01:55 -0800 Unnecessary discard of image buffer with idempotent canvas size change 2022-07-18 14:15:25 -0700 1 1 1 Unclassified WebKit Canvas 528+ (Nightly build) All Unspecified RESOLVED DUPLICATE 80871 P2 Normal --- 1 tomhudson tomhudson bfulgham oldest_to_newest 573807 0 tomhudson 2012-03-08 07:01:55 -0800 canvas.width = canvas.width has become an accepted shorthand for clearing the canvas. WebCore::HTMLCanvasElement::parseAttribute() calls reset() every time the width or height is set from JavaScript. That calls setSurfaceSize(), which forcibly throws away the WebCore::ImageBuffer, even when the width or height isn't actually changing. Most of the calls in reset() check to make sure that size() != oldSize; if we could extend that to being *all* the calls, we ought to be able to avoid destroying and recreating the ImageBuffer, which has a measurable performance impact on Chromium and may be thrashing textures in the driver for hardware-accelerated canvas rendering. 1884860 1 bfulgham 2022-07-18 14:15:25 -0700 It looks like this suggestion was done in Bug 80871. *** This bug has been marked as a duplicate of bug 80871 ***