Update Image Processing

[okyanusoz]

Fixes #433

See here for more details: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#crossorigin

[greggman]

This issue is covered here: https://webglfundamentals.org/webgl/lessons/webgl-cors-permission.html

It's intentionally omitted here because otherwise I have explain everything in that article. Just setting crossDomain is not enough. The fact that it worked for you with picsum.photos is just luck that the picsum.photos site's server happens to set the right headers to give permission to use the image. Most sites do not

[okyanusoz]

Maybe we could link to that article though, what do you think? Or should we close this? It'd be easier to find.

[greggman]

I'm not sure what's best. I started to add a link to the article, the comment appears in 5 places, but I think maybe it's better just to remove the original comment instead (which I did) 6e7f809

There reason being, there are all kinds of side issues like this and if every place one of those side issues comes up you needed a link or an explanation it would get really hard to read. For example just this one issue in particular, effectively if I put the comment with a link to that article then for consistency, every single time a texture is mentioned I need the link to the article, all 57 times.