christoph-heinrich
commented
2 years ago Don't merge this... it might make things work for everyone, but it doesn't really solve the underlying problem. I have definitely had thumbnails work no problem with odd sizes before, which means odd numbers are not inherently the problem. But then I add or subtract an odd number from one dimension and it doesn't work anymore. Add or subtract an even number? No problem.
And it's not like there isn't an output file. it does write a file and even updates it. We just can't see it for some reason.
Apparently scaling filters don't like odd resolutions, but always choosing even numbers leads to black borders. The solution is to generate thumbnails with a different resolution then they are being rendered in.
The idea is that we can cut off thing from the bottom when rendering, but we can't cut off things from the right side, so use the highest width we are allowed to, and then use the appropriate height for that width + whatever is needed to fill up to
% 2 == 0. That might result in a black border at the bottom of the generated image, but we can simply cut that off when displaying it, resulting in no visible black borders while still adhering to the "no odd numbers" rule.Currently it's using resolutions for generating that are
% 2 == 0, but according to @Natural-Harmonia-Gropius it might be necessary to increase it to% 4 == 0. We'll see if it causes problems for anyone.