Truncating fractional height in pixels about cairosvg

[liZe]

Yes, the size is currently truncated.

It seems obvious that rounding would be a perfect idea … but it’s not 😄.

If your SVG’s size is 10.5px, with a 10.5px white square for the background, you want to get a white PNG, and not semi-transparent pixels on the right and the bottom. So, unfortunately, rounding the surface size is not perfect in all cases.

What if we add a scale factor of 11/10.5 before rendering? That would avoid the transparent pixels (if floating point arithmetic gods love you), but we would lose pixel alignment and get blurry rendering even for horizontal and vertical lines. So, even rounding + scaling is not perfect.

So… I’m not sure about what to do here.

Even my image viewer is "broken" with this SVG file 😢

Half pixels are devil.

[judge2005]

I think it would be easiest(?) to just provide options that allow the user to define what behavior they want, i.e. specify the rounding and/or specify a border to grow the rendering surface. That way the user has some tools to manage the conversion and you don't break the existing functionality.

[liZe]

Let’s round values. It’s not perfect, but nobody will ever complain. 😄

[liZe]

Let’s round values. It’s not perfect, but nobody will ever complain. 😄

Except tests, of course…