Add an eframe example of how to install a custom font

eframe/examples/custom_font.rs

@@ -0,0 +1,65 @@
+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::CtxRef,
+        _frame: &epi::Frame,
+        _storage: Option<&dyn epi::Storage>,
+    ) {
+        // 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
+            .fonts_for_family
+            .entry(egui::FontFamily::Proportional)
+            .or_default()
+            .insert(0, "my_font".to_owned());
+
+        // Put my font as last fallback for monospace:
+        fonts
+            .fonts_for_family
+            .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::CtxRef, _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);
+}