egui/eframe/examples/custom_font.rs

use eframe::{egui, epi};

struct MyApp {
    text: String,
}

impl Default for MyApp {
    fn default() -> Self {
        Self {
            text: "Edit this text field if you want".to_owned(),
        }
    }
}

impl epi::App for MyApp {
    fn name(&self) -> &str {
        "egui example: custom font"
    }

    fn setup(
        &mut self,
        ctx: &egui::Context,
        _frame: &epi::Frame,
        _storage: Option<&dyn epi::Storage>,
        _gl: &std::rc::Rc<epi::glow::Context>,
    ) {
        // Start with the default fonts (we will be adding to them rather than replacing them).
        let mut fonts = egui::FontDefinitions::default();

        // Install my own font (maybe supporting non-latin characters).
        // .ttf and .otf files supported.
        fonts.font_data.insert(
            "my_font".to_owned(),
            egui::FontData::from_static(include_bytes!("../../epaint/fonts/Hack-Regular.ttf")),
        );

        // Put my font first (highest priority) for proportional text:
        fonts
            .families
            .entry(egui::FontFamily::Proportional)
            .or_default()
            .insert(0, "my_font".to_owned());

        // Put my font as last fallback for monospace:
        fonts
            .families
            .entry(egui::FontFamily::Monospace)
            .or_default()
            .push("my_font".to_owned());

        // Tell egui to use these fonts:
        ctx.set_fonts(fonts);
    }

    fn update(&mut self, ctx: &egui::Context, _frame: &epi::Frame) {
        egui::CentralPanel::default().show(ctx, |ui| {
            ui.heading("egui using custom fonts");
            ui.text_edit_multiline(&mut self.text);
        });
    }
}

fn main() {
    let options = eframe::NativeOptions::default();
    eframe::run_native(Box::new(MyApp::default()), options);
}