Crate rust_fontconfig 

rust-fontconfig

Pure-Rust rewrite of the Linux fontconfig library (no system dependencies) - using allsorts as a font parser to support .woff, .woff2, .ttc, .otf and .ttf

NOTE: Also works on Windows, macOS and WASM - without external dependencies!

Usage

Basic Font Query

use rust_fontconfig::{FcFontCache, FcPattern};

fn main() {
    // Build the font cache
    let cache = FcFontCache::build();

    // Query a font by name
    let results = cache.query(
        &FcPattern {
            name: Some(String::from("Arial")),
            ..Default::default()
        },
        &mut Vec::new() // Trace messages container
    );

    if let Some(font_match) = results {
        println!("Font match ID: {:?}", font_match.id);
        println!("Font unicode ranges: {:?}", font_match.unicode_ranges);
    } else {
        println!("No matching font found");
    }
}

Resolve Font Chain and Query for Text

use rust_fontconfig::{FcFontCache, FcWeight, PatternMatch};

fn main() {
    let cache = FcFontCache::build();

    // Build font fallback chain (without text parameter)
    let font_chain = cache.resolve_font_chain(
        &["Arial".to_string(), "sans-serif".to_string()],
        FcWeight::Normal,
        PatternMatch::DontCare,
        PatternMatch::DontCare,
        &mut Vec::new(),
    );

    // Query which fonts to use for specific text
    let text = "Hello 你好 Здравствуйте";
    let font_runs = font_chain.query_for_text(&cache, text);

    println!("Text split into {} font runs:", font_runs.len());
    for run in font_runs {
        println!("  '{}' -> font {:?}", run.text, run.font_id);
    }
}

Modules

config

OS-specific font configuration: directories, common families, and font file constants.

utils

Structs

CssFallbackGroup

A group of fonts that are fallbacks for a single CSS font-family name

FcFont

In-memory font data

FcFontCache

Font cache, initialized at startup

FcFontMetadata

Font metadata from the OS/2 table

FcFontPath

Path to a font file

FcFontRenderConfig

Per-font rendering configuration from system font config (Linux fonts.conf).

FcPattern

Font pattern for matching

FontFallbackChain

Resolved font fallback chain for a CSS font-family stack This represents the complete chain of fonts to use for rendering text

FontId

UUID to identify a font (collections are broken up into separate fonts)

FontMatch

Font match result with UUID

FontMatchNoFallback

Font match result with UUID (without fallback)

NamedFont

A named font to be added to the font cache from memory. This is the primary way to supply custom fonts to the application.

ResolvedFontRun

A run of text that uses the same font Returned by FontFallbackChain::query_for_text()

TraceMsg

Trace message for debugging font matching

UnicodeRange

Unicode range representation for font matching

Enums

FcHintStyle

Hinting style for font rendering.

FcLcdFilter

LCD filter mode for subpixel rendering.

FcRgba

Subpixel rendering order.

FcStretch

CSS font-stretch values

FcWeight

Font weight values as defined in CSS specification

FontBytes

A handle to font bytes returned by FcFontCache::get_font_bytes.

FontSource

Font source enum to represent either disk or memory fonts

MatchReason

Reason for font matching failure or success

OperatingSystem

Operating system type for generic font family resolution

PatternMatch

Whether a field is required to match (yes / no / don’t care)

TraceLevel

Log levels for trace messages

Constants

DEFAULT_UNICODE_FALLBACK_SCRIPTS

The default set of Unicode-block fallback scripts that FcFontCache::resolve_font_chain pulls in when no explicit scripts_hint is supplied.

Functions

expand_font_families

Expand a CSS font-family stack with generic families resolved to OS-specific fonts Prioritizes fonts based on Unicode range coverage Example: [“Arial”, “sans-serif”] on macOS with CJK ranges -> [“Arial”, “PingFang SC”, “Hiragino Sans”, …]

has_arabic_ranges

Check if any range covers the Arabic block

has_cjk_ranges

Check if any range covers CJK Unified Ideographs, Hiragana, Katakana, or Hangul

has_cyrillic_ranges

Check if any range covers the Cyrillic block

has_hebrew_ranges

Check if any range covers the Hebrew block

has_thai_ranges

Check if any range covers the Thai block