Documentation
Docs/en/reference/font-format/index.md
Generated Font Format Reference
Generated reference. Do not edit directly. Update
BuildTools/FontFormatInterface.json, then runpython BuildTools/docs_font_format.py --write.
| Index | Formats | FOFNT | BMFont | Binding | Layout | Rendering | Validation | Canonical JSON | Guide |
This reference describes Engine-owned font descriptors, client binding, text layout, rendering, scaling, and validation. Project font selection and typography policy remain outside this contract.
Contract status
| Field | Value |
|---|---|
| Stability | experimental |
| Support policy | The two runtime descriptor formats and client layout behavior are supported but still experimental; embedding projects own font choice, glyph coverage, typography, GUI slots, and visual acceptance. |
| Source manifest | BuildTools/FontFormatInterface.json |
| Contract digest | 76258828339a7603add4ae984ecf8d557484940d4d92fdadd8e0d950135ec3bc |
| Runtime descriptors | .fofnt, .fnt |
| FOFNT maximum version | 2 |
| BMFont binary version | 3 |
| Client atlas | IfaceSprites |
| Reference | Entries | Purpose |
|---|---|---|
| Formats | 3 | Descriptor roles and supported resource suffixes. |
| FOFNT | 13 | Text descriptor keys and glyph metrics. |
| BMFont | 9 | Accepted binary-v3 blocks and metric transformations. |
| Binding | 8 | Raw-copy, slot, atlas, scale, and startup behavior. |
| Layout | 9 | TextFormat, wrapping, alignment, measurement, and glyph fallback. |
| Rendering | 7 | Texture preparation, borders, effects, color tags, and cache. |
| Validation | 8 | Failure modes and executable validation gates. |
Boundary
Included:
- .fofnt text descriptors and their glyph metrics
- binary BMFont v3 .fnt descriptors accepted by the client
- raw-copy delivery and separately baked font images
- Game.BindFont dispatch, font slots, atlas placement, and startup fallback
- bind-time downscaling, grayscale conversion, border generation, and effects
- TextFormat flags, wrapping, alignment, measurement, inline colors, and caching
- source-backed diagnostics and validation routing
Excluded:
- embedding-project font names, slot catalogs, GUI assignments, and typography policy
- font licensing, redistribution rights, and language-specific glyph acceptance
- BMFont text or XML descriptors, which the runtime does not parse
- .bmfc authoring-tool configuration semantics
- vector font or runtime TTF/OTF rasterization, which the client does not provide
- project-local localization packs and authored display strings