Remove pixels_per_point from FontDefinitions

CHANGELOG.md

@@ -12,6 +12,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Changed 🔧
 
 * Renamed `FontFamily::VariableWidth` to `FontFamily::Proportional`.
+* Remove `pixels_per_point` from `FontDefinitions`.
 
 ### Fixed 🐛
 

egui/src/context.rs

@@ -543,14 +543,20 @@ impl Context {
         self.input = std::mem::take(&mut self.input).begin_frame(new_raw_input);
         self.frame_state.lock().begin_frame(&self.input);
 
-        let mut font_definitions = self.options.lock().font_definitions.clone();
+        let font_definitions = self.options.lock().font_definitions.clone();
-        font_definitions.pixels_per_point = self.input.pixels_per_point();
+        let pixels_per_point = self.input.pixels_per_point();
         let same_as_current = match &self.fonts {
             None => false,
-            Some(fonts) => *fonts.definitions() == font_definitions,
+            Some(fonts) => {
+                *fonts.definitions() == font_definitions
+                    && (fonts.pixels_per_point() - pixels_per_point).abs() < 1e-3
+            }
         };
         if !same_as_current {
-            self.fonts = Some(Arc::new(Fonts::from_definitions(font_definitions)));
+            self.fonts = Some(Arc::new(Fonts::from_definitions(
+                pixels_per_point,
+                font_definitions,
+            )));
         }
 
         // Ensure we register the background area so panels and background ui can catch clicks:

egui/src/introspection.rs

@@ -62,7 +62,7 @@ impl paint::FontDefinitions {
             );
         }
         if ui.button("Reset fonts").clicked {
-            *self = paint::FontDefinitions::default_with_pixels_per_point(self.pixels_per_point);
+            *self = Default::default();
         }
     }
 }

egui/src/paint/fonts.rs

@@ -81,9 +81,6 @@ fn rusttype_font_from_font_data(name: &str, data: &FontData) -> rusttype::Font<'
 /// ```
 #[derive(Clone, Debug, PartialEq)]
 pub struct FontDefinitions {
-    /// The dpi scale factor. Needed to get pixel perfect fonts.
-    pub pixels_per_point: f32, // TODO: remove from here
-
     /// List of font names and their definitions.
     /// The definition must be the contents of either a `.ttf` or `.otf` font file.
     ///
@@ -105,13 +102,6 @@ pub struct FontDefinitions {
 
 impl Default for FontDefinitions {
     fn default() -> Self {
-        Self::default_with_pixels_per_point(f32::NAN) // must be set later
-    }
-}
-
-impl FontDefinitions {
-    /// Default values for the fonts
-    pub fn default_with_pixels_per_point(pixels_per_point: f32) -> Self {
         #[allow(unused)]
         let mut font_data: BTreeMap<String, FontData> = BTreeMap::new();
 
@@ -175,7 +165,6 @@ impl FontDefinitions {
         family_and_size.insert(TextStyle::Monospace, (FontFamily::Monospace, 13.0)); // 13 for `ProggyClean`
 
         Self {
-            pixels_per_point,
             font_data,
             fonts_for_family,
             family_and_size,
@@ -183,9 +172,12 @@ impl FontDefinitions {
     }
 }
 
-/// Note: the `default()` fonts are invalid (missing `pixels_per_point`).
+/// The collection of fonts used by Egui.
+///
+/// Note: `Fonts::default()` is invalid (missing `pixels_per_point`).
 #[derive(Default)]
 pub struct Fonts {
+    pixels_per_point: f32,
     definitions: FontDefinitions,
     fonts: BTreeMap<TextStyle, Font>,
     atlas: Arc<Mutex<TextureAtlas>>,
@@ -195,22 +187,7 @@ pub struct Fonts {
 }
 
 impl Fonts {
-    pub fn from_definitions(definitions: FontDefinitions) -> Fonts {
+    pub fn from_definitions(pixels_per_point: f32, definitions: FontDefinitions) -> Self {
-        let mut fonts = Self::default();
-        fonts.set_definitions(definitions);
-        fonts
-    }
-
-    pub fn definitions(&self) -> &FontDefinitions {
-        &self.definitions
-    }
-
-    pub fn set_definitions(&mut self, definitions: FontDefinitions) {
-        if self.definitions == definitions {
-            return;
-        }
-        self.definitions = definitions;
-
         // We want an atlas big enough to be able to include all the Emojis in the `TextStyle::Heading`,
         // so we can show the Emoji picker demo window.
         let mut atlas = TextureAtlas::new(2048, 64);
@@ -224,14 +201,13 @@ impl Fonts {
 
         let atlas = Arc::new(Mutex::new(atlas));
 
-        let mut font_impl_cache = FontImplCache::new(atlas.clone(), &self.definitions);
+        let mut font_impl_cache = FontImplCache::new(atlas.clone(), pixels_per_point, &definitions);
 
-        self.fonts = self
+        let fonts = definitions
-            .definitions
             .family_and_size
             .iter()
             .map(|(&text_style, &(family, scale_in_points))| {
-                let fonts = &self.definitions.fonts_for_family.get(&family);
+                let fonts = &definitions.fonts_for_family.get(&family);
                 let fonts = fonts.unwrap_or_else(|| {
                     panic!("FontFamily::{:?} is not bound to any fonts", family)
                 });
@@ -254,10 +230,24 @@ impl Fonts {
             texture.version = hasher.finish();
         }
 
-        self.buffered_texture = Default::default(); //atlas.lock().texture().clone();
+        Self {
-        self.atlas = atlas;
+            pixels_per_point,
+            definitions,
+            fonts,
+            atlas,
+            buffered_texture: Default::default(), //atlas.lock().texture().clone();
+        }
     }
 
+    pub fn pixels_per_point(&self) -> f32 {
+        self.pixels_per_point
+    }
+
+    pub fn definitions(&self) -> &FontDefinitions {
+        &self.definitions
+    }
+
+    /// Call each frame to get the latest available font texture data.
     pub fn texture(&self) -> Arc<Texture> {
         let atlas = self.atlas.lock();
         let mut buffered_texture = self.buffered_texture.lock();
@@ -290,7 +280,11 @@ struct FontImplCache {
 }
 
 impl FontImplCache {
-    pub fn new(atlas: Arc<Mutex<TextureAtlas>>, definitions: &super::FontDefinitions) -> Self {
+    pub fn new(
+        atlas: Arc<Mutex<TextureAtlas>>,
+        pixels_per_point: f32,
+        definitions: &super::FontDefinitions,
+    ) -> Self {
         let rusttype_fonts = definitions
             .font_data
             .iter()
@@ -304,7 +298,7 @@ impl FontImplCache {
 
         Self {
             atlas,
-            pixels_per_point: definitions.pixels_per_point,
+            pixels_per_point,
             rusttype_fonts,
             cache: Default::default(),
         }

egui/src/paint/galley.rs

@@ -657,9 +657,7 @@ fn test_text_layout() {
     use crate::paint::*;
 
     let pixels_per_point = 1.0;
-    let fonts = Fonts::from_definitions(FontDefinitions::default_with_pixels_per_point(
+    let fonts = Fonts::from_definitions(pixels_per_point, FontDefinitions::default());
-        pixels_per_point,
-    ));
     let font = &fonts[TextStyle::Monospace];
 
     let galley = font.layout_multiline("".to_owned(), 1024.0);

egui/src/paint/texture_atlas.rs

@@ -1,3 +1,4 @@
+// TODO: `TextureData` or similar?
 /// An 8-bit texture containing font data.
 #[derive(Clone, Default)]
 pub struct Texture {