Better algorithm for font choosing

[ilya-fedin]

No description provided.

[ghost]

Why it's Microsoft Yahei instead of Microsoft Yahei UI just like other fonts?

[ilya-fedin]

I took a list of fonts from FontMod readme

[Coxxs]

AFAIK, every Windows system has Microsoft YaHei, Microsoft JhengHei UI, and Yu Gothic UI font. We should change the font priority based on the system region.

For example, for Traditional Chinese, Microsoft JhengHei UI should be prioritized, and for Japanese, Yu Gothic UI should be prioritized. Microsoft YaHei is designed just for Simplified Chinese.

[ilya-fedin]

We should change the font priority based on the system region.

Qt doesn't prioritize them in any locale. I.e. if these substitutions will be only for japanese/chinese/korean locale, users with english locale will get the old fonts from winxp, as it was before substiutions.

[Coxxs]

The issue here is system with Japanese / Tradition Chinese language will use Microsoft YaHei (not Yu Gothic UI or Microsoft JhengHei UI).

[ysc3839]

@ilya-fedin

Qt doesn't prioritize them in any locale.

No, Qt has 5 lists and it's selected based on GetUserDefaultLangID:
https://github.com/qt/qtbase/blob/44e8c90ad4ae5a3d08651a61ac9f0937fb49d26b/src/platformsupport/fontdatabases/windows/qwindowsfontdatabasebase.cpp#L895-L986

The best solution is to use system "MessageFont", it's implemented but disabled for Qt 5:
https://github.com/qt/qtbase/blob/44e8c90ad4ae5a3d08651a61ac9f0937fb49d26b/src/platformsupport/fontdatabases/windows/qwindowsfontdatabasebase.cpp#L761-L784

[ilya-fedin]

No, Qt has 5 lists and it's selected based on GetUserDefaultLangID:

According to your list, it is old winxp fonts, as I said:

    "MS UI Gothic",
    "Gulim",
    "SimSun",
    "PMingLiU",

[ilya-fedin]

btw @ysc3839 thank you for the link, now we can patch Qt instead of substituions, I sent it to @john-preston

[Coxxs]

What Qt 5 does is not perfect, but it's right. Use Simplified Chinese font for Japanese is not right.

Telegram 2.0.1 (Japanese System):

Telegram 2.1 (Japanese System):

You can see the wrong glyph displayed in Telegram 2.1 (Japanese System).

I'm not familiar with Qt, but I guess @ysc3839 means you can use Qt 6's method (call WinApi SystemParametersInfo, https://github.com/qt/qtbase/blob/44e8c90ad4ae5a3d08651a61ac9f0937fb49d26b/src/platformsupport/fontdatabases/windows/qwindowsfontdatabasebase.cpp#L767) to get default GUI font, and set it as the fallback font.

[ilya-fedin]

call WinApi SystemParametersInfo

based on GetUserDefaultLangID

🤔