pango-view: nondeterminism with --serialize-to option (windows)
I have setup a small github project https://github.com/a3emdot/pangoviewdemo/actions/runs/6198780368/job/16829899735
which uses the VCPKG project from Microsoft for building pango on Windows.
Additionally I have added a test batch file which repeatedly uses the built pango-view tool for rendering small images of text.
There are 4 subdirectories 'build/pangoview/{0,1,2,3}' for 4 runs.
If one searches within the output of the build step 'Run test' for the pattern 'different'. Line 2921 shows that sometimes the output .json file has a different content.
My expectation would have been that the runs produces always the same files for the same used font family and font size.
The test batch file uses the 'Cascadia Code' font, because it is already installed on the windows image used.
Other fonts like 'roboto' may show a more pronounced behavior. Originally we intended to use fc-match and pango-view as 'poor-man's' validation tools for installed fonts.
We use the fontconfig pango backend for rendering on Windows, which is essential for us, because we would like to have a similar workflow as within Linux. It looks like the chance for having the fontconfig pango backend on both Windows and Linux increases the probability for near binary identical text renderings, if the same font files are used.
Kind Regards Andre