691ff10066
- Identified build/unmapped-glyph-names.json as the primary config file - Documented DifferencesOverlay struct in encoding.rs as the Rust config structure - Described the build-time generation process via build.rs - Listed all files involved in the config pipeline Closes bf-10vsm
75 lines
2.3 KiB
Markdown
75 lines
2.3 KiB
Markdown
# bf-10vsm: Generator Config Structure Location
|
|
|
|
## Summary
|
|
|
|
Found the generator config structure for unmapped glyph names handling.
|
|
|
|
## Config Structure Location
|
|
|
|
**Primary config file:** `/home/coding/pdftract/build/unmapped-glyph-names.json`
|
|
|
|
**Rust config struct:** `crates/pdftract-core/src/font/encoding.rs` - `DifferencesOverlay` struct
|
|
|
|
## Current Fields and Types
|
|
|
|
### JSON Config Format (`unmapped-glyph-names.json`)
|
|
|
|
```json
|
|
{
|
|
"unmapped_glyph_names": [
|
|
".notdef",
|
|
".null",
|
|
"g000",
|
|
"g001",
|
|
// ... more glyph names
|
|
],
|
|
"description": "...",
|
|
"version": "1.0"
|
|
}
|
|
```
|
|
|
|
**Fields:**
|
|
- `unmapped_glyph_names` - Array of strings (glyph names to skip during CMAP entry creation)
|
|
- `description` - String (optional documentation)
|
|
- `version` - String (format version identifier)
|
|
|
|
### Rust Struct (`DifferencesOverlay` in `encoding.rs`)
|
|
|
|
```rust
|
|
pub struct DifferencesOverlay {
|
|
entries: Vec<(u8, Arc<str>)>,
|
|
unmapped_glyph_names: std::collections::HashSet<String>,
|
|
}
|
|
```
|
|
|
|
**Fields:**
|
|
- `entries` - Sparse list of (code, glyph_name) overrides
|
|
- `unmapped_glyph_names` - HashSet of glyph names to skip during CMAP entry creation
|
|
|
|
## Build Process
|
|
|
|
The config is processed at **build time** by `crates/pdftract-core/build.rs`:
|
|
|
|
1. Reads `build/unmapped-glyph-names.json`
|
|
2. Calls `generate_unmapped_glyph_names()` function (lines 946-1050)
|
|
3. Emits `unmapped_glyph_names.rs` in OUT_DIR with a `UNMAPPED_GLYPH_NAMES` static HashSet
|
|
4. This is auto-included by `crates/pdftract-core/src/font/unmapped.rs` via `include!()`
|
|
|
|
## Usage
|
|
|
|
The config is used in `DifferencesOverlay::parse()` (encoding.rs:190-241) to skip unmapped glyph names when creating CMAP entries. This prevents glyphs like `.notdef` from appearing in text extraction output.
|
|
|
|
## Files Involved
|
|
|
|
- Config: `build/unmapped-glyph-names.json`
|
|
- Build script: `crates/pdftract-core/build.rs` (lines 946-1050)
|
|
- Rust struct: `crates/pdftract-core/src/font/encoding.rs` (lines 128-297)
|
|
- Auto-generated: `target/*/build/*/out/unmapped_glyph_names.rs`
|
|
- Module: `crates/pdftract-core/src/font/unmapped.rs`
|
|
|
|
## Verification
|
|
|
|
- ✅ JSON file exists and is valid
|
|
- ✅ Build script reads and processes the file
|
|
- ✅ Generated code is included in the font::unmapped module
|
|
- ✅ DifferencesOverlay uses the generated UNMAPPED_GLYPH_NAMES set
|