[Bug 59252] New: FL STUDIO piano roll - generate chord progressions: DirectWrite Font Fallback Not Working for Unicode Music Symbols

[WineHQ Bugzilla]

http://bugs.winehq.org/show_bug.cgi?id=59252

            Bug ID: 59252
           Summary: FL STUDIO piano roll - generate chord progressions:
                    DirectWrite Font Fallback Not Working for Unicode
                    Music Symbols
           Product: Wine
           Version: 11.0
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: dwrite
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Created attachment 80169
  --> http://bugs.winehq.org/attachment.cgi?id=80169
fl studio piano roll - generate chord progressions

# Wine Bug Report: DirectWrite Font Fallback Not Working for Unicode Music
Symbols

## Summary

DirectWrite font fallback (FontLink) does not work for Unicode music symbols
(U+266D ♭, U+266E ♮, U+266F ♯) in FL Studio 2025. These symbols render as empty
rectangles (tofu) instead of the correct glyphs, even though Segoe UI Symbol
font is installed and FontLink is configured.

## Environment

- **Wine Version:** wine-11.0
- **OS:** Ubuntu 24.04.3 LTS (Noble Numbat)
- **Architecture:** 64-bit (WINEARCH=win64, wow64 mode)
- **Application:** FL Studio 2025 (FL64.exe)

## Steps to Reproduce

1. Install FL Studio 2025 under Wine
2. Install Segoe UI Symbol font (`seguisym.ttf`) to
`~/.wine/drive_c/windows/Fonts/`
3. Register font in registry under
`HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Fonts`
4. Configure FontLink for fonts used by FL Studio (Open Sans, Roboto Condensed,
Ubuntu Condensed, etc.)
5. Open FL Studio → Piano Roll → Tools → Generate Chord Progression
6. Observe chord names with accidentals (e.g., C#m, Bbm, F#m)

## Expected Behavior

Chord names should display with proper music symbols:
- C♯m (C sharp minor)
- B♭m (B flat minor)
- F♯m (F sharp minor)

This works correctly on native Windows.

## Actual Behavior

Chord names display with empty rectangles (tofu boxes) instead of ♯ and ♭
symbols:
- C□m
- G□m
- F□m

## Analysis

FL Studio uses DirectWrite for text rendering (confirmed via
`WINEDEBUG=+dwrite`). The application uses condensed fonts (Open Sans
Condensed, Roboto Condensed, Ubuntu Condensed) that do not contain the Unicode
music symbols (U+266D, U+266E, U+266F).

Under Windows, DirectWrite's font fallback mechanism (FontLink) automatically
substitutes missing glyphs from Segoe UI Symbol. Under Wine, this fallback does
not occur.

### Verified Configuration

FontLink registry entries were added:
```
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows
NT\CurrentVersion\FontLink\SystemLink
"Open Sans Condensed"="SEGUISYM.TTF,Segoe UI Symbol"
"Roboto Condensed"="SEGUISYM.TTF,Segoe UI Symbol"
"Ubuntu Condensed"="SEGUISYM.TTF,Segoe UI Symbol"
```

Segoe UI Symbol font is correctly loaded by Wine (confirmed via
`WINEDEBUG=+font`):
```
trace:font:unix_face_create parsed font names family_name L"Segoe UI Symbol"
trace:font:insert_face_in_family_list Adding face L"Segoe UI Symbol" in family
L"Segoe UI Symbol"
```

### Workarounds Attempted (All Failed)

1. ✗ Installing Segoe UI Symbol to Wine fonts folder
2. ✗ Registering font in Windows registry
3. ✗ Configuring FontLink for all relevant fonts
4. ✗ Patching FL Studio fonts with fontforge to include music symbols (breaks
QuickFontCache)
5. ✗ Font substitution via `HKEY_CURRENT_USER\Software\Wine\Fonts\Replacements`
6. ✗ Setting Windows version to Windows 11
7. ✗ Enabling DirectWrite GdiInterop

## Technical Details

### Relevant Wine Debug Output

```
WINEDEBUG=+dwrite wine FL64.exe 2>&1 | grep glyph
0380:trace:dwrite:dwritefontface_GetGlyphIndices ...
0380:trace:dwrite:dwritefontface_GetDesignGlyphMetrics ...
```

Wine's DirectWrite receives glyph requests but does not perform fallback to
FontLink fonts for missing glyphs.

### Unicode Code Points

- U+266D: MUSIC FLAT SIGN (♭)
- U+266E: MUSIC NATURAL SIGN (♮)  
- U+266F: MUSIC SHARP SIGN (♯)

### FL Studio Font Configuration

FL Studio bundles its own FreeType DLL (`freetype_x64.dll`) and QuickFontCache
system. However, the actual text rendering goes through Windows DirectWrite
API, which Wine should handle.

## Suggested Component

`dlls/dwrite` - DirectWrite font fallback / FontLink implementation

## Related Wine Bugs

**Bug #53739** - "Text does not show in QQ UI and Enterprise WeChat UI"
https://bugs.winehq.org/show_bug.cgi?id=53739

This bug describes the same root cause - DirectWrite font fallback not working
correctly. 

The problematic commit was identified as:
- `dwrite: Remove old system fallback logic.`
- Commit ID: `26e717c5653d2c6fcb29846e7d22aa97e37048e1`

Problematic code in `dlls/dwrite/analyzer.c`:
```c
data = fallback->data.count == ~0u ? &system_fallback : &fallback->data;
```

The `system_fallback` does not correctly provide fallback fonts for missing
glyphs.

## References

- Wine Bugzilla: Related to Bug #53739
- FL Studio runs under Wine:
https://appdb.winehq.org/objectManager.php?sClass=application&iId=178

## Attachments

Screenshot showing the issue is available in the project folder.

-- 
Do not reply to this email, post in Bugzilla using the
above URL to reply.
You are receiving this mail because:
You are watching all bug changes.