Integral graph flashes when first used

[KatieWoe]

Test device Samsung Operating System Win 11 Browser Chrome Problem description For https://github.com/phetsims/qa/issues/924 On the Advanced screen, the first time you switch from the derivative graph to the integral graph the integral graph flashes noticeably. This doesn't happen again after the first time, even after using the reset all button. You need to Refresh the page. Steps to reproduce

1. Refresh the sim if you've been using it
2. Go to the advanced screen
3. Switch to the integral graph

Visuals

https://user-images.githubusercontent.com/41024075/228621383-13069797-4842-4365-9f0b-464311244262.MOV

Troubleshooting information:

!!!!! DO NOT EDIT !!!!! Name: ‪Calculus Grapher‬ URL: https://phet-dev.colorado.edu/html/calculus-grapher/1.0.0-rc.1/phet/calculus-grapher_all_phet.html Version: 1.0.0-rc.1 2023-03-28 17:54:45 UTC Features missing: applicationcache, applicationcache, touch Flags: pixelRatioScaling User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/111.0.0.0 Safari/537.36 Language: en-US Window: 1536x656 Pixel Ratio: 1.25/1 WebGL: WebGL 1.0 (OpenGL ES 2.0 Chromium) GLSL: WebGL GLSL ES 1.0 (OpenGL ES GLSL ES 1.0 Chromium) Vendor: WebKit (WebKit WebGL) Vertex: attribs: 16 varying: 31 uniform: 4096 Texture: size: 8192 imageUnits: 32 (vertex: 32, combined: 64) Max viewport: 8192x8192 OES_texture_float: true Dependencies JSON: {}

[veillette]

I am able to reproduce the visual artefact on Win 10, with chrome 111.0.5563.147 and edge 111.0.1661.54. However, I am unable to reproduce it on Win 10, with firefox 111.0.1.

[KatieWoe]

I do see this on Win 11 Firefox

[veillette]

I stand corrected. I observed it on Win10 firefox as well. You can only see it the first time you switch from the derivative graph to the integral graph.

[veillette]

I should note that the artefact is also present on the fourth screen with the second derivative graph.

[pixelzoom]

Reproduced on macOS 13.2.1 + Chrome 111.0.5563.146.

[pixelzoom]

Fixed in the commit below. @veillette and @KatieWoe could you please check in master on your test platforms? Report back to me, and assign me the issue for cherry-picking.

[veillette]

Yes the commit addresses the issue on master (tested on Win 10, Chrome and Win 10, Edge). The lazylink explains why it occurred only once. Good finding @KatieWoe.

[veillette]

Reassigning to @pixelzoom for cherry-picking.

[pixelzoom]

Cherry-pick applied, ready for verification in the next RC test.

[pixelzoom]

To verify in the next RC:

1. Start the PhET brand sim.
2. Go to the Advanced screen.
3. Press the radio button labeled with the integral symbol.
4. At the end of the animation, verify that the integral (top) graph does not flash as it fades in.
5. Go to the Lab screen.
6. Press the radio button labeled f''(x).
7. At the end of the animation, verify that the second derivative (bottom) graph does not flash as it fades in.

Since the flashing only occurs on the first animation, reload the sim if you need to re-test.

[Nancy-Salpepi]

This looks fixed to me in rc.2!