PNG export lines color does not match screen color about city-roads HOT 5 CLOSED

Tried now on latest Chrome, MacOS 10.15.2 and it worked fine.

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interesting one! What's your alpha channel for the background color when you export in Firefox?

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Good point: lines had a default 0.8 alpha color set while background had 1.
I did manually change the lines alpha to 1 and the downloaded PNG is now matching the one on the screen.

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Please check now. I've updated a blending function, and colors in Firefox seem to be correct now during save: https://anvaka.github.io/city-roads/

I have also created this playground to reproduce the error:
https://jsbin.com/debuzoziyo/edit?js,output

Changing

context.blendFunc(context.SRC_ALPHA, context.ONE_MINUS_SRC_ALPHA);

To

context.blendFunc(context.ONE, context.ONE_MINUS_SRC_ALPHA);

fixes the issue. I'm still learning WebGL, and I hope I'm not missing something else. Please let me know if I do!

EDIT: Updated formulas after playing with https://www.andersriggelsen.dk/glblendfunc.php

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Closing. Please let me know if you find any other issue

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