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CreateJS / EaselJS

The Easel Javascript library provides a full, hierarchical display list, a core interaction model, and helper classes to make working with the HTML5 Canvas element much easier.
http://createjs.com/
MIT License
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Multiple readback operations using getImageData are faster with the willReadFrequently attribute set to true #1078

Open danzen opened 1 year ago

danzen commented 1 year ago

Some people are getting this warning in Chrome:

Multiple readback operations using getImageData are faster with the willReadFrequently attribute set to true

We have looked briefly into it. Does anyone see a problem setting this to true as default for non-stageGL contexts?

We are probably going to try it for our ZIM CreateJS unless someone suggests otherwise. Will have to re-read the specs on it...

Cheers.

danzen commented 1 year ago

Just trying to look through what uses getImageData() and it seems it is in CreateJS hitTest which is used in handlePointerDown, testMouseOver, masking and filters (some of these might be _ methods). I think maybe if mouseover is true for CreateJS we may as well automatically set willReadFrequently:true on the getContext2D. I am just not sure of any drawbacks to setting the flag to true. Anyone know?

danzen commented 1 year ago

Okay - we have explored this and come up with a potential solution. If anyone would like to try this test version of CreateJS with a flag - we have had a couple of us try it and it removes the warning and seems to work as well as without the flag. We did find that if we put the flag in a other calls to getContext() that it would run more slowly. https://zimjs.com/cdn/1.3.4/createjs_doc_flag.js We will wait to see if we get some more test results before we update here.

danzen commented 1 year ago

We had a couple people over in the ZIM forums test and so far so good. We will adjust our version of CreateJS and run with it for a while. If all looks good we will do a patch here. Cheers. Still, any feedback welcome.

danzen commented 1 year ago

We have now been running https://zimjs.org/cdn/1.3.4/createjs.js or https://zimjs.org/cdn/1.3.4/createjs_doc.js for a week and all seems good and the chrome message is gone. Will be looking to adjust the GitHub here in a few days unless anyone has any comments otherwise.

ArshadSiddiqui commented 1 year ago

Hey @danzen Happy to see you addressed this issue. I got the warning for the "cacheCanvas" canvas of DisplayObject as I frequently call context.getImageData() on cacheCanvas. I think it would make more sense if we have the option of setting flag through function parameter. For example when I call container.cache() I can set the flag through "options" parameter: container.cache(x, y, width, height, scale, { willReadFrequently: true });

danzen commented 1 year ago

Sorry - sort of lost the thread here. I think the message is coming up internally a lot... and our solution seems to be running along just fine. So will have another look at it in a bit and do the pullrequest here.