Kivy label show Khmer error

[onsunsl]

Software Versions

• Python: 3.6.6
• OS: Windows 10
• Kivy: 1.11.1
• Kivy installation method: pip install kivy

Expected behavior

I want to show Khmer text like this សួស្តី, but the kivy show effect is like this:

I think SDL2 has a problem with Khmer rendering. The KhmerOSBattambang-Regular.ttf font file i have verified in PyQt
that it can be show Khmer language normally.

Code and Logs and screenshots

from kivy.uix.label import Label
from kivy.app import App


class KhmerApp(App):
    def build(self):
        label = Label(text="សួស្តី")
        label.font_name = "./KhmerOSBattambang-Regular.ttf"
        label.font_size = 40
        return label


if __name__ == '__main__':
    KhmerApp().run()

[Julian-O]

Confirming that I ran this code on Windows 11, Kivy 2.2.1 using a copy of the font I downloaded from khmer-fonts.com, and got the wrongly-displayed text.

Furthermore, I copied the text into the previewer on that site, and confirmed that the font is capable of showing it.

[misl6]

Well ...

I've just tested the following on macOS (and maybe @Julian-O can confirm that on Windows):

• Downloaded a copy of the font from khmer-fonts.com: I'm able to replicate the issue
• Downloaded a copy of the font from https://github.com/python-pillow/Pillow/blob/main/Tests/fonts/KhmerOSBattambang-Regular.ttf, the issue disappears.

Is that a font issue that needs to be investigated on freetype?

[misl6]

By looking at file infos, dates and releases are pretty different between the two versions, but I'm not able to find a release note for the font file.

[Julian-O]

Interesting. On Windows...

• khmer-fonts: Problem replicated
• Pillow: Problem disappears
• Google Fonts: Problem replicated
• Straight from Danh Hong's (the typographer's) GitHub: Problem replicated

Is Khmer OS Battambang the same font (albeit different versions) as the ones called Battambang on Google? Well EagleFonts seems to think so, listing Danh Hong as the author.

[misl6]

Downloaded a copy from Google Fonts. Problem replicated also on macOS.

However, by providing the correct script name it actually works. (with all the 3 fonts files)

from kivy.uix.label import Label
from kivy.app import App


class KhmerApp(App):
    def build(self):
        label = Label(text="សួស្តី")
        label.font_name = "./Battambang-Regular.ttf"
        label.font_script_name = "Khmr"
        label.font_size = 300
        return label


if __name__ == '__main__':
    KhmerApp().run()

If you @Julian-O can confirm the same, I guess we can close the issue as fixed. (font_script_name landed in 2.2.0 - https://kivy.org/doc/stable/api-kivy.uix.label.html#kivy.uix.label.Label.font_script_name)

[Julian-O]

Confirm it works on Windows when label.font_script_name = "Khmr" is set.

That's a new concept for me.

Closing as solved, but I am thinking about working it into the FAQ.

(Oh, and a big thanks to the @onsunsl. Your test code and clear explanation made this possible to debug and test despite not being able to read a word of Khmer. សូមអរគុណ)