The only way to fix geometry calculations for border-image in Safari was to disable hidpi/retina painting, since it seems Webkit does not respect DPR when calculating the effective image slice for -webkit-canvas-derived border images. The polyfill injects image-rendering:optimizeSpeed to make things look a little less blurry than the default value in Safari.
Note: there is a separate PR to css-houdini-lines to fix the color issue, it wasn't a bug in the polyfill.
The only way to fix geometry calculations for border-image in Safari was to disable hidpi/retina painting, since it seems Webkit does not respect DPR when calculating the effective image slice for
-webkit-canvas-derived border images. The polyfill injectsimage-rendering:optimizeSpeedto make things look a little less blurry than the default value in Safari.Note: there is a separate PR to
css-houdini-linesto fix the color issue, it wasn't a bug in the polyfill.