skia-python m130 is out (Re: freetype/harfbuzz-based multi-line paragraph layout in skia

[Hin-Tak Leung]

skia-python m130 is out. New to this new release is the binding to upstream's multi-line multilingual skparagraph module, for multi-line text layout. During the final testing stage, it is found that it doesn't work on windows; recent reports of other skia-derivatives (rust-skia, skia java, and upstream skia c discussions) seems to indicate that, for windows users, they need to copy icudtl.dat from somewhere else to the search/load path for skparagraph functionality to work. If some windows python users could give this a try and report, that would be useful. Linux and Mac users, enjoy the new functionality.

More details below, and at the release notes at https://github.com/kyamagu/skia-python/ .

On Wednesday 14 August 2024 at 20:05:35 BST, Hin-Tak Leung <htl10@users.sourceforge.net> wrote:

There was a recent enquiry about the availability of skia's skparagraph functionality in skia-python, so I did some digging and added that to the next skia-python release. (m129/130 in about two months' time, when skia m130 get forked by google).

For those who doesn't know what it is (that includes me two weeks ago...), skia's skparagraph offers multi-line text layout, with a variety of alignment options (left/right, centered, justified), and decorations (underline/strikethrough). I guess that functionality is probably somewhat equivalent to pango's role. Skia's skparagraph is based on freetype/harfbuzz so can mostly "do the right thing" with the middle-eastern languages on line-breaks, etc. Have a try with Arabic / Hebrew etc if you feel like it. I did.

This is mostly a RFC / request for testers etc. The main info and source code is at https://github.com/kyamagu/skia-python/pull/258 , and example program at https://github.com/HinTak/skia-python-examples/blob/main/shape_text.py . Prebuilt python wheels is at https://github.com/kyamagu/skia-python/actions/runs/10355210169 for the three major platforms, linux, windows, mac os x.

The quickest way for people to try it out is simply download one of the relevant wheels, install it, and play with the example. (edit it with your own text for rendering, setting various options, then run "shape_text.py chosen-font.ttf output.png").

Note that most of the problems with documentations, and additional functions, neither https://github.com/kyamagu/skia-python/ nor https://github.com/HinTak/skia-python-examples/ is the correct place: see https://issues.skia.org/358587937 and https://issues.skia.org/307357528 - we basically replicate upstream's API / documentations, so it needs to be in Google's skia repo first.

Thanks for reading so far.