Mongolian T + FVS3 displaying incorrect with Oyun Qagan Tig

[KrasnayaPloshchad]

The sequence ᠊ᡨ᠊ᡨ᠋᠊ᡨ᠌᠊ᡨ᠍᠊ looks incorrect when using Oyun Qagan Tig font (from here) in HarfBuzz based environment.

This is displayed via Uniscribe (tested on LO for Windows, BabelPad and Notepad)

This is displayed via HarfBuzz (tested on both Chrome and Firefox)

In this case Mongolian T + FVS3 looks the same as T + FVS2

[behdad]

Does it reproduce with hb-view?

[behdad]

Redirect to a PNG file using --output-file or '>'

[KrasnayaPloshchad]

I have tried to output a PNG file, but it always produce a file with mojibake text looks like '????????'. So what should I do? I have no idea.

[KrasnayaPloshchad]

I have tested via Command Prompt, and when I open the properties window, I found only GBK code page (936 (ANSI/OEM - 简体中文 GBK)) available.

[KrasnayaPloshchad]

I have reproduced it via cmder just now, but it still generating mojibake picture, and there is no suitable charset.

[khaledhosny]

Here is what I get with hb-view:

[behdad]

Ok, I'm on it. I've found the root cause: we allow matching to skip over FVSes. That's not desirable. Let me see what's the best fix.

On a side note: I have a hard time believing that this font really needs 150 GSUB lookups...

[khaledhosny]

The lookups seems to be fragmented for no clear reason, for example there are 5 isol lookups all are ligature substitutions that could have been combined together.

[behdad]

The lookups seems to be fragmented for no clear reason, for example there are 5 isol lookups all are ligature substitutions that could have been combined together.

Yeah, seems to be just for the heck of making debugging harder :). At least --debug came handy.

[KrasnayaPloshchad]

@khaledhosny Thank you very much.