font cache!

Cargo.lock

@@ -548,7 +548,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0793f5137567643cf65ea42043a538804ff0fbf288649e2141442b602d81f9bc"
 dependencies = [
  "hashbrown 0.13.2",
- "rayon",
  "ttf-parser 0.15.2",
 ]
 
@@ -774,7 +773,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "43a3c133739dddd0d2990f9a4bdf8eb4b21ef50e4851ca85ab661199821d510e"
 dependencies = [
  "ahash",
- "rayon",
 ]
 
 [[package]]
@@ -1048,7 +1046,6 @@ dependencies = [
  "kubi-logging",
  "log",
  "nohash-hasher",
- "rayon",
  "rect_packer",
  "winit",
 ]

kubi-ui/Cargo.toml

@@ -10,9 +10,8 @@ nohash-hasher = "0.2"
 glam = "0.24"
 glium = { git = "https://github.com/glium/glium", rev = "968fc92378caf", optional = true }
 fontdue = "0.7"
-rect_packer = { version = "0.2.1", optional = true }
+rect_packer = "0.2"
 log = "0.4"
-rayon = { version = "1.8", optional = true }
 
 [dev-dependencies]
 kubi-logging = { path = "../kubi-logging" }
@@ -20,8 +19,8 @@ glium = { git = "https://github.com/glium/glium", rev = "968fc92378caf" }
 winit = "0.29"
 
 [features]
-default = ["builtin_elements", "builtin_font", "backend_glium", "parallel"]
+default = ["builtin_elements", "builtin_font", "backend_glium"]
 backend_glium = ["dep:glium"]
 builtin_font = []
 builtin_elements = []
-parallel = ["dep:rayon", "fontdue/parallel"]
+#parallel = ["dep:rayon", "fontdue/parallel"]

kubi-ui/src/lib.rs

@@ -43,7 +43,7 @@ impl KubiUi {
       draw_commands: UiDrawCommands::default(),
       draw_plan: UiDrawPlan::default(),
       draw_plan_modified: false,
-      font_renderer: TextRenderer::new(),
+      font_renderer: TextRenderer::default(),
     }
   }
 

kubi-ui/src/text.rs

@@ -1,59 +1,87 @@
+use std::sync::Arc;
 use fontdue::{Font, Metrics};
+use glam::{IVec2, UVec2, uvec2, ivec2};
 use hashbrown::HashMap;
-use nohash_hasher::BuildNoHashHasher;
-
-#[cfg(feature = "parallel")]
-use rayon::prelude::*;
+use rect_packer::DensePacker;
 
 #[cfg(feature = "builtin_font")]
 const BIN_FONT: &[u8] = include_bytes!("../assets/font/ProggyTiny.ttf");
 
-// pub struct Glyph {
-//   pub metrics: Metrics,
-//   pub data: Box<[u8]>
-// }
+#[derive(Clone, Copy, PartialEq, Eq, Hash)]
+pub struct FontHandle(pub(crate) usize);
 
-// pub struct FontData {
-//   font: Font,
-//   cache: HashMap<(u8, char), Glyph, BuildNoHashHasher<u8>>
-// }
+#[derive(PartialEq, Eq, Hash)]
+struct GlyphCacheKey {
+  font_index: usize,
+  character: char,
+  size: u8,
+}
 
-// impl FontData {
-//   pub fn new() -> Self {
-//     FontData {
-//       font: Font::from_bytes(BIN_FONT, fontdue::FontSettings::default()).unwrap(),
-//       cache: HashMap::default()
-//     }
-//   }
-
-//   fn prebake(&mut self, size: u8) {
-//     self.cache = (33..=126).par_bridge().map(|c| {
-//       let (metrics, data) = self.font.rasterize(
-//         char::from(c),
-//         c as f32,
-//       );
-//       Glyph { metrics, data: data.into_boxed_slice() }
-//     }).collect();
-//   }
-// }
+struct GlyphCacheEntry {
+  pub data: Vec<u8>,
+  pub metrics: Metrics,
+  pub texture_position: IVec2,
+  pub texture_size: UVec2,
+}
 
 pub struct TextRenderer {
-  font_stack: Vec<Font>,
-  cache: ()
+  fonts: Vec<Font>,
+  glyph_cache: HashMap<GlyphCacheKey, Arc<GlyphCacheEntry>>,
+  packer: DensePacker,
+  font_texture: Vec<u8>,
+  font_texture_size: UVec2,
 }
 
 impl TextRenderer {
-  pub fn new() -> Self {
-    let font = Font::from_bytes(BIN_FONT, fontdue::FontSettings::default()).unwrap();
-    TextRenderer {
-      font_stack: vec![font],
-      cache: ()
+  pub fn new(size: UVec2) -> Self {
+    let mut renderer = TextRenderer {
+      fonts: Vec::new(),
+      glyph_cache: HashMap::new(),
+      packer: DensePacker::new(size.x as i32, size.y as i32),
+      font_texture: vec![0; (size.x * size.y) as usize],
+      font_texture_size: size,
+    };
+    #[cfg(feature = "builtin_font")]
+    {
+      let font = Font::from_bytes(BIN_FONT, fontdue::FontSettings::default()).unwrap();
+      renderer.add_font(font);
     }
+    renderer
+  }
+
+  /// Add a (fontdue) font to the renderer.
+  pub fn add_font(&mut self, font: Font) -> FontHandle {
+    self.fonts.push(font);
+    FontHandle(self.fonts.len() - 1)
+  }
+
+  /// Either looks up the glyph in the cache or renders it and adds it to the cache.
+  pub fn glyph(&mut self, font: FontHandle, character: char, size: u8) -> Arc<GlyphCacheEntry> {
+    let key = GlyphCacheKey {
+      font_index: font.0,
+      character,
+      size,
+    };
+    if let Some(entry) = self.glyph_cache.get(&key) {
+      return Arc::clone(entry);
+    }
+    let font = &self.fonts[key.font_index];
+    let (metrics, bitmap) = font.rasterize(character, size as f32);
+    let texture_position = self.packer.pack(metrics.width as i32, metrics.height as i32, false).unwrap();
+    let texture_size = uvec2(metrics.width as u32, metrics.height as u32);
+    let entry = Arc::new(GlyphCacheEntry {
+      data: bitmap,
+      metrics,
+      texture_position: ivec2(texture_position.x, texture_position.y),
+      texture_size,
+    });
+    self.glyph_cache.insert_unique_unchecked(key, Arc::clone(&entry));
+    entry
   }
 }
 
 impl Default for TextRenderer {
   fn default() -> Self {
-    Self::new()
+    Self::new(uvec2(2048, 2048))
   }
 }