initial commit

src/font.rs

@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: MIT OR Apache-2.0
+// SPDX-FileCopyrightText: Copyright (c) 2025 Markus Zehnder
+
+use ab_glyph::{FontArc, FontRef, FontVec};
+use anyhow::{Context, anyhow};
+use log::warn;
+use once_cell::sync::Lazy;
+use std::collections::HashMap;
+use std::fs;
+use std::path::PathBuf;
+
+static DEFAULT_TTF_FONT: Lazy<FontArc> = Lazy::new(|| {
+    FontArc::new(
+        FontRef::try_from_slice(include_bytes!("../fonts/DejaVuSans.ttf"))
+            .expect("Failed to load default font"),
+    )
+});
+
+pub struct FontHandler {
+    ttf_path: PathBuf,
+    ttf_cache: HashMap<String, FontArc>,
+}
+
+impl FontHandler {
+    pub fn new(ttf_path: impl Into<PathBuf>) -> Self {
+        Self {
+            ttf_path: ttf_path.into(),
+            ttf_cache: Default::default(),
+        }
+    }
+
+    pub fn default_font() -> FontArc {
+        DEFAULT_TTF_FONT.clone()
+    }
+
+    pub fn get_ttf_font_or_default(&mut self, name: &str) -> FontArc {
+        self.get_ttf_font(name).unwrap_or_else(|e| {
+            warn!("Failed to load font: {e}. Using default");
+            FontHandler::default_font()
+        })
+    }
+
+    pub fn get_ttf_font(&mut self, name: &str) -> anyhow::Result<FontArc> {
+        if let Some(font) = self.ttf_cache.get(name) {
+            return Ok(font.clone());
+        }
+        let mut path = self.ttf_path.join(name);
+        path.set_extension("ttf");
+
+        if !path.exists() {
+            return Err(anyhow!("{name}.ttf not found"));
+        }
+
+        let data = fs::read(path).with_context(|| format!("Error reading font {name}.ttf"))?;
+        let font = FontArc::new(
+            FontVec::try_from_vec(data)
+                .with_context(|| format!("Error parsing font {name}.ttf"))?,
+        );
+
+        self.ttf_cache.insert(name.to_string(), font.clone());
+
+        Ok(font)
+    }
+}