Use std::borrow::Cow for the font data.
This saves some memory usage and copies in the common case.
It also fixes a weird 10x performance regression in the web demo.
@@ -44,6 +44,17 @@ pub enum FontFamily {
VariableWidth,
}
+/// The data of a `.ttf` or `.otf` file.
+pub type FontData = std::borrow::Cow<'static, [u8]>;
+
+fn rusttype_font_from_font_data(name: &str, data: &FontData) -> rusttype::Font<'static> {
+ match data {
+ std::borrow::Cow::Borrowed(bytes) => rusttype::Font::try_from_bytes(bytes),
+ std::borrow::Cow::Owned(bytes) => rusttype::Font::try_from_vec(bytes.clone()),
+ }
+ .unwrap_or_else(|| panic!("Error parsing {:?} TTF/OTF font file", name))
+}
+
/// This is how you tell Egui which fonts and font sizes to use.
#[derive(Clone, Debug, PartialEq)]
pub struct FontDefinitions {
@@ -55,7 +66,7 @@ pub struct FontDefinitions {
///
/// Egui has built-in-default for these,
/// but you can override them if you like.
- pub font_data: BTreeMap<String, Vec<u8>>,
+ pub font_data: BTreeMap<String, FontData>,
/// Which fonts (names) to use for each `FontFamily`.
///
@@ -78,26 +89,26 @@ impl Default for FontDefinitions {
impl FontDefinitions {
/// Default values for the fonts
pub fn default_with_pixels_per_point(pixels_per_point: f32) -> Self {
- let mut font_data: BTreeMap<String, Vec<u8>> = BTreeMap::new();
+ let mut font_data: BTreeMap<String, FontData> = BTreeMap::new();
// Use size 13 for this. NOTHING ELSE:
font_data.insert(
"ProggyClean".to_owned(),
- include_bytes!("../../fonts/ProggyClean.ttf").to_vec(),
+ std::borrow::Cow::Borrowed(include_bytes!("../../fonts/ProggyClean.ttf")),
);
font_data.insert(
"Ubuntu-Light".to_owned(),
- include_bytes!("../../fonts/Ubuntu-Light.ttf").to_vec(),
+ std::borrow::Cow::Borrowed(include_bytes!("../../fonts/Ubuntu-Light.ttf")),
);
// Few, but good looking. Use as first priority:
font_data.insert(
"NotoEmoji-Regular".to_owned(),
- include_bytes!("../../fonts/NotoEmoji-Regular.ttf").to_vec(),
+ std::borrow::Cow::Borrowed(include_bytes!("../../fonts/NotoEmoji-Regular.ttf")),
);
// Bigger emojis, and more. <http://jslegers.github.io/emoji-icon-font/>:
font_data.insert(
"emoji-icon-font".to_owned(),
- include_bytes!("../../fonts/emoji-icon-font.ttf").to_vec(),
+ std::borrow::Cow::Borrowed(include_bytes!("../../fonts/emoji-icon-font.ttf")),
);
// TODO: figure out a way to make the WASM smaller despite including fonts. Zip them?
@@ -254,10 +265,7 @@ impl FontImplCache {
.map(|(name, font_data)| {
(
name.clone(),
- Arc::new(
- rusttype::Font::try_from_vec(font_data.clone())
- .expect("Error parsing TTF/OTF font file"),
- ),
+ Arc::new(rusttype_font_from_font_data(name, font_data)),
)
})
.collect();
