schrift-rs/README.md

schrift-rs

libschrift is a lightweight TrueType rendering library implemented in C, and this crate wraps the libschrift library into safe Rust. The result is a font loading and glyph rendering crate with no runtime dependencies other than the C and Rust standard libraries.

The following example code renders a single glyph into a PGM file:

use schrift_rs::*;
let font = Font::load_from_file(
    concat!(
        env!("CARGO_MANIFEST_DIR"),
        "/libschrift/resources/FiraGO-Regular.ttf")).unwrap();
let sch = Schrift::build(font)
    .with_scale(10.0)
    .flag_y_downwards()
    .build();
let aglyph = sch
    .glyph_lookup('a')
    .expect("couldn't look up lowercase 'a'");

let mut pxdata = vec![0u8; 256];

sch.render(aglyph, pxdata.as_mut_slice(), 16, 16).expect("couldn't render lowercase 'a'");

let mut pgm = String::new();
pgm.push_str("P2\n16 16\n255\n");
for y in 0..16 {
    for x in 0..16 {
        pgm.push_str(format!(" {}", pxdata[x + (y * 16)]).as_str());
    }
    pgm.push_str("\n");
}
std::fs::write(concat!(env!("OUT_DIR"), "render_test.pgm"), pgm).unwrap();