Dynamic scale factor updates (#817)

* wip: dynamic scale factor updates

* refactor font options

* update font opts

* refacor scale factor updates

* cargo fmt

src/renderer/fonts/caching_shaper.rs

@@ -12,8 +12,6 @@ use unicode_segmentation::UnicodeSegmentation;
 use super::font_loader::*;
 use super::font_options::*;
 
-const DEFAULT_FONT_SIZE: f32 = 14.0;
-
 #[derive(new, Clone, Hash, PartialEq, Eq, Debug)]
 struct ShapeKey {
     pub cells: Vec<String>,
@@ -22,7 +20,7 @@ struct ShapeKey {
 }
 
 pub struct CachingShaper {
-    pub options: Option<FontOptions>,
+    options: FontOptions,
     font_loader: FontLoader,
     blob_cache: LruCache<ShapeKey, Vec<TextBlob>>,
     shape_context: ShapeContext,
@@ -30,11 +28,12 @@ pub struct CachingShaper {
 }
 
 impl CachingShaper {
-    pub fn new(device_scale_factor: f32) -> CachingShaper {
-        let scale_factor = points_to_pixels(device_scale_factor);
+    pub fn new(scale_factor: f32) -> CachingShaper {
+        let options = FontOptions::default();
+        let font_size = options.size * scale_factor;
         CachingShaper {
-            options: None,
-            font_loader: FontLoader::new(DEFAULT_FONT_SIZE * scale_factor),
+            options,
+            font_loader: FontLoader::new(font_size),
             blob_cache: LruCache::new(10000),
             shape_context: ShapeContext::new(),
             scale_factor,
@@ -42,21 +41,8 @@ impl CachingShaper {
     }
 
     fn current_font_pair(&mut self) -> Arc<FontPair> {
-        let default_key = FontKey {
-            italic: false,
-            bold: false,
-            font_selection: FontSelection::Default,
-        };
-
-        let font_key = self
-            .options
-            .as_ref()
-            .map(|options| FontKey {
-                italic: options.italic,
-                bold: options.bold,
-                font_selection: options.fallback_list.first().unwrap().clone().into(),
-            })
-            .unwrap_or_else(|| default_key.clone());
+        let default_key = FontKey::default();
+        let font_key = FontKey::from(&self.options);
 
         if let Some(font_pair) = self.font_loader.get_or_load(&font_key) {
             return font_pair;
@@ -68,26 +54,28 @@ impl CachingShaper {
     }
 
     pub fn current_size(&self) -> f32 {
-        self.options
-            .as_ref()
-            .map(|options| options.size)
-            .unwrap_or(DEFAULT_FONT_SIZE)
-            * self.scale_factor
+        self.options.size * self.scale_factor
     }
 
-    pub fn update_font(&mut self, guifont_setting: &str) -> bool {
-        let new_options = FontOptions::parse(guifont_setting, DEFAULT_FONT_SIZE);
+    pub fn update_scale_factor(&mut self, scale_factor: f32) {
+        trace!("scale_factor changed: {:.2}", scale_factor);
+        self.scale_factor = scale_factor;
+        self.reset_font_loader();
+    }
 
-        if new_options != self.options && new_options.is_some() {
-            self.font_loader =
-                FontLoader::new(new_options.as_ref().unwrap().size * self.scale_factor);
-            self.blob_cache.clear();
-            self.options = new_options;
+    pub fn update_font(&mut self, guifont_setting: &str) {
+        trace!("Updating font: {}", guifont_setting);
 
-            true
-        } else {
-            false
+        self.options = FontOptions::parse(guifont_setting);
+        self.reset_font_loader();
     }
+
+    fn reset_font_loader(&mut self) {
+        let font_size = self.options.size * self.scale_factor;
+        trace!("Using font_size: {:.2}px", font_size);
+
+        self.font_loader = FontLoader::new(font_size);
+        self.blob_cache.clear();
     }
 
     fn metrics(&mut self) -> Metrics {
@@ -156,34 +144,17 @@ impl CachingShaper {
             // Create font fallback list
             let mut font_fallback_keys = Vec::new();
 
-            // Add guifont fallback list
-            if let Some(options) = &self.options {
-                font_fallback_keys.extend(options.fallback_list.iter().map(|font_name| FontKey {
-                    italic: options.italic || italic,
-                    bold: options.bold || bold,
+            // Add parsed fonts from guifont
+            font_fallback_keys.extend(self.options.font_list.iter().map(|font_name| FontKey {
+                italic: self.options.italic || italic,
+                bold: self.options.bold || bold,
                 font_selection: font_name.into(),
             }));
 
             // Add default font
             font_fallback_keys.push(FontKey {
-                    italic: options.italic || italic,
-                    bold: options.bold || bold,
-                    font_selection: FontSelection::Default,
-                });
-
-                // Add skia fallback
-                font_fallback_keys.push(FontKey {
-                    italic: options.italic || italic,
-                    bold: options.bold || bold,
-                    font_selection: cluster.chars()[0].ch.into(),
-                });
-            } else {
-                // No confgured option. Default to not italic and not bold versions
-
-                // Add default font
-                font_fallback_keys.push(FontKey {
-                    italic,
-                    bold,
+                italic: self.options.italic || italic,
+                bold: self.options.bold || bold,
                 font_selection: FontSelection::Default,
             });
 
@@ -193,7 +164,6 @@ impl CachingShaper {
                 bold,
                 font_selection: cluster.chars()[0].ch.into(),
             });
-            }
 
             // Add last resort
             font_fallback_keys.push(FontKey {
@@ -312,25 +282,3 @@ impl CachingShaper {
         self.blob_cache.get(&key).unwrap()
     }
 }
-
-fn points_to_pixels(value: f32) -> f32 {
-    // Fonts in neovim are using points, not pixels.
-    //
-    // Skia docs is incorrectly stating it uses points, but uses pixels:
-    // https://api.skia.org/classSkFont.html#a7e28a156a517d01bc608c14c761346bf
-    // https://github.com/mono/SkiaSharp/issues/1147#issuecomment-587421201
-    //
-    // So, we need to convert points to pixels.
-    //
-    // In reality, this depends on DPI/PPI of monitor, but here we only care about converting
-    // from points to pixels, so this is standard constant values.
-    let pixels_per_inch = 96.0;
-    let points_per_inch = 72.0;
-    // On macos points == pixels
-    #[cfg(target_os = "macos")]
-    let points_per_inch = 96.0;
-
-    let pixels_per_point = pixels_per_inch / points_per_inch;
-
-    value * pixels_per_point
-}

src/renderer/fonts/font_loader.rs

@@ -3,6 +3,7 @@ use std::sync::Arc;
 use lru::LruCache;
 use skia_safe::{font::Edging, Data, Font, FontHinting, FontMgr, FontStyle, Typeface};
 
+use super::font_options::FontOptions;
 use super::swash_font::SwashFont;
 
 #[derive(RustEmbed)]
@@ -54,6 +55,26 @@ pub struct FontKey {
     pub font_selection: FontSelection,
 }
 
+impl Default for FontKey {
+    fn default() -> Self {
+        FontKey {
+            italic: false,
+            bold: false,
+            font_selection: FontSelection::Default,
+        }
+    }
+}
+
+impl From<&FontOptions> for FontKey {
+    fn from(options: &FontOptions) -> FontKey {
+        FontKey {
+            italic: options.italic,
+            bold: options.bold,
+            font_selection: options.primary_font(),
+        }
+    }
+}
+
 #[derive(Debug, Hash, PartialEq, Eq, Clone)]
 pub enum FontSelection {
     Name(String),

src/renderer/fonts/font_options.rs

@@ -1,30 +1,33 @@
+use super::font_loader::FontSelection;
+
+const DEFAULT_FONT_SIZE: f32 = 14.0;
+
 #[derive(Clone, Debug)]
 pub struct FontOptions {
-    guifont_setting: Option<String>,
-    pub fallback_list: Vec<String>,
+    pub font_list: Vec<String>,
     pub size: f32,
     pub bold: bool,
     pub italic: bool,
 }
 
 impl FontOptions {
-    pub fn parse(guifont_setting: &str, default_size: f32) -> Option<FontOptions> {
-        let mut fallback_list = None;
-        let mut size = default_size;
+    pub fn parse(guifont_setting: &str) -> FontOptions {
+        let mut font_list = Vec::new();
+        let mut size = DEFAULT_FONT_SIZE;
         let mut bold = false;
         let mut italic = false;
 
         let mut parts = guifont_setting.split(':').filter(|part| !part.is_empty());
 
         if let Some(parts) = parts.next() {
-            let parsed_fallback_list: Vec<String> = parts
+            let parsed_font_list: Vec<String> = parts
                 .split(',')
                 .filter(|fallback| !fallback.is_empty())
                 .map(|fallback| fallback.to_string())
                 .collect();
 
-            if !parsed_fallback_list.is_empty() {
-                fallback_list = Some(parsed_fallback_list);
+            if !parsed_font_list.is_empty() {
+                font_list = parsed_font_list;
             }
         }
 
@@ -40,25 +43,60 @@ impl FontOptions {
             }
         }
 
-        fallback_list.map(|fallback_list| FontOptions {
-            guifont_setting: Some(guifont_setting.to_string()),
-            fallback_list,
+        FontOptions {
+            font_list,
             bold,
             italic,
-            size,
-        })
+            size: points_to_pixels(size),
         }
     }
 
-impl PartialEq for FontOptions {
-    fn eq(&self, other: &Self) -> bool {
-        if self.guifont_setting.is_some() && self.guifont_setting == other.guifont_setting {
-            return true;
+    pub fn primary_font(&self) -> FontSelection {
+        self.font_list
+            .first()
+            .map(|f| FontSelection::from(f))
+            .unwrap_or(FontSelection::Default)
+    }
 }
 
-        self.fallback_list == other.fallback_list
+impl Default for FontOptions {
+    fn default() -> Self {
+        FontOptions {
+            font_list: Vec::new(),
+            bold: false,
+            italic: false,
+            size: points_to_pixels(DEFAULT_FONT_SIZE),
+        }
+    }
+}
+
+impl PartialEq for FontOptions {
+    fn eq(&self, other: &Self) -> bool {
+        self.font_list == other.font_list
             && (self.size - other.size).abs() < std::f32::EPSILON
             && self.bold == other.bold
             && self.italic == other.italic
     }
 }
+
+fn points_to_pixels(value: f32) -> f32 {
+    // Fonts in neovim are using points, not pixels.
+    //
+    // Skia docs is incorrectly stating it uses points, but uses pixels:
+    // https://api.skia.org/classSkFont.html#a7e28a156a517d01bc608c14c761346bf
+    // https://github.com/mono/SkiaSharp/issues/1147#issuecomment-587421201
+    //
+    // So, we need to convert points to pixels.
+    //
+    // In reality, this depends on DPI/PPI of monitor, but here we only care about converting
+    // from points to pixels, so this is standard constant values.
+    let pixels_per_inch = 96.0;
+    let points_per_inch = 72.0;
+    // On macos points == pixels
+    #[cfg(target_os = "macos")]
+    let points_per_inch = 96.0;
+
+    let pixels_per_point = pixels_per_inch / points_per_inch;
+
+    value * pixels_per_point
+}

src/renderer/mod.rs

@@ -2,7 +2,7 @@ use std::collections::HashMap;
 use std::sync::mpsc::Receiver;
 use std::sync::Arc;
 
-use log::error;
+use log::{error, trace};
 use skia_safe::{colors, dash_path_effect, BlendMode, Canvas, Color, Paint, Rect};
 
 pub mod animation_utils;
@@ -87,12 +87,25 @@ impl Renderer {
         }
     }
 
+    pub fn handle_scale_factor_update(&mut self, scale_factor: f64) {
+        self.shaper.update_scale_factor(scale_factor as f32);
+        self.update_font_dimensions();
+    }
+
     fn update_font(&mut self, guifont_setting: &str) {
-        if self.shaper.update_font(guifont_setting) {
+        self.shaper.update_font(guifont_setting);
+        self.update_font_dimensions();
+    }
+
+    fn update_font_dimensions(&mut self) {
         let (font_width, font_height) = self.shaper.font_base_dimensions();
         self.font_width = font_width;
         self.font_height = font_height;
-        }
+        trace!(
+            "Updating font dimensions: {}x{}",
+            self.font_height,
+            self.font_width,
+        );
     }
 
     fn compute_text_region(&self, grid_pos: (u64, u64), cell_width: u64) -> Rect {

src/window/window_wrapper/mod.rs

@@ -19,6 +19,7 @@ use glutin::{
     window::{self, Fullscreen, Icon},
     ContextBuilder, GlProfile, WindowedContext,
 };
+use log::trace;
 
 #[cfg(target_os = "linux")]
 use glutin::platform::unix::WindowBuilderExtUnix;
@@ -128,6 +129,12 @@ impl GlutinWindowWrapper {
             } => {
                 self.handle_quit(running);
             }
+            Event::WindowEvent {
+                event: WindowEvent::ScaleFactorChanged { scale_factor, .. },
+                ..
+            } => {
+                self.handle_scale_factor_update(scale_factor);
+            }
             Event::WindowEvent {
                 event: WindowEvent::DroppedFile(path),
                 ..
@@ -159,6 +166,7 @@ impl GlutinWindowWrapper {
         let previous_size = self.saved_inner_size;
 
         if previous_size != current_size {
+            trace!("Updating grid size: {:#?}", current_size);
             self.saved_inner_size = current_size;
             handle_new_grid_size(current_size, &self.renderer, &self.ui_command_sender);
             self.skia_renderer.resize(&self.windowed_context);
@@ -181,6 +189,10 @@ impl GlutinWindowWrapper {
             self.windowed_context.swap_buffers().unwrap();
         }
     }
+
+    fn handle_scale_factor_update(&mut self, scale_factor: f64) {
+        self.renderer.handle_scale_factor_update(scale_factor);
+    }
 }
 
 pub fn start_loop(