Reset the overlay context for each draw request and use global font cache (#3231)

Author: TrueDoctor

editor/src/messages/portfolio/document/overlays/overlays_message_handler.rs

@@ -15,8 +15,6 @@ pub struct OverlaysMessageHandler {
 	canvas: Option<web_sys::HtmlCanvasElement>,
 	#[cfg(target_family = "wasm")]
 	context: Option<web_sys::CanvasRenderingContext2d>,
-	#[cfg(all(not(target_family = "wasm"), not(test)))]
-	context: Option<super::utility_types::OverlayContext>,
 }
 
 #[message_handler_data]
@@ -82,11 +80,7 @@ impl MessageHandler<OverlaysMessage, OverlaysMessageContext<'_>> for OverlaysMes
 
 				let size = ipp.viewport_bounds.size();
 
-				if self.context.is_none() {
-					self.context = Some(OverlayContext::new(size, device_pixel_ratio, visibility_settings));
-				}
-
-				let overlay_context = self.context.as_mut().unwrap();
+				let overlay_context = OverlayContext::new(size, device_pixel_ratio, visibility_settings);
 
 				if visibility_settings.all() {
 					responses.add(DocumentMessage::GridOverlays { context: overlay_context.clone() });
@@ -95,7 +89,7 @@ impl MessageHandler<OverlaysMessage, OverlaysMessageContext<'_>> for OverlaysMes
 						responses.add(provider(overlay_context.clone()));
 					}
 				}
-				responses.add(FrontendMessage::RenderOverlays { context: overlay_context.clone() });
+				responses.add(FrontendMessage::RenderOverlays { context: overlay_context });
 			}
 			#[cfg(all(not(target_family = "wasm"), test))]
 			OverlaysMessage::Draw => {

editor/src/messages/portfolio/document/overlays/utility_types_vello.rs

@@ -20,10 +20,22 @@ use graphene_std::vector::{PointId, SegmentId, Vector};
 use kurbo::{self, BezPath, ParamCurve};
 use kurbo::{Affine, PathSeg};
 use std::collections::HashMap;
-use std::sync::{Arc, Mutex, MutexGuard};
+use std::sync::{Arc, LazyLock, Mutex, MutexGuard};
 use vello::Scene;
 use vello::peniko;
 
+// Global lazy initialized font cache and text context
+static GLOBAL_FONT_CACHE: LazyLock<FontCache> = LazyLock::new(|| {
+	let mut font_cache = FontCache::default();
+	// Initialize with the hardcoded font used by overlay text
+	const FONT_DATA: &[u8] = include_bytes!("source-sans-pro-regular.ttf");
+	let font = Font::new("Source Sans Pro".to_string(), "Regular".to_string());
+	font_cache.insert(font, String::new(), FONT_DATA.to_vec());
+	font_cache
+});
+
+static GLOBAL_TEXT_CONTEXT: LazyLock<Mutex<TextContext>> = LazyLock::new(|| Mutex::new(TextContext::default()));
+
 pub type OverlayProvider = fn(OverlayContext) -> Message;
 
 pub fn empty_provider() -> OverlayProvider {
@@ -412,8 +424,6 @@ pub(super) struct OverlayContextInternal {
 	size: DVec2,
 	device_pixel_ratio: f64,
 	visibility_settings: OverlaysVisibilitySettings,
-	font_cache: FontCache,
-	thread_text: TextContext,
 }
 
 impl Default for OverlayContextInternal {
@@ -424,19 +434,11 @@ impl Default for OverlayContextInternal {
 
 impl OverlayContextInternal {
 	pub(super) fn new(size: DVec2, device_pixel_ratio: f64, visibility_settings: OverlaysVisibilitySettings) -> Self {
-		let mut font_cache = FontCache::default();
-		// Initialize with the hardcoded font used by overlay text
-		const FONT_DATA: &[u8] = include_bytes!("source-sans-pro-regular.ttf");
-		let font = Font::new("Source Sans Pro".to_string(), "Regular".to_string());
-		font_cache.insert(font, String::new(), FONT_DATA.to_vec());
-
 		Self {
 			scene: Scene::new(),
 			size,
 			device_pixel_ratio,
 			visibility_settings,
-			font_cache,
-			thread_text: TextContext::default(),
 		}
 	}
 
@@ -1031,7 +1033,8 @@ impl OverlayContextInternal {
 		// TODO: Grab this from the node_modules folder (either with `include_bytes!` or ideally at runtime) instead of checking the font file into the repo.
 		// TODO: And maybe use the WOFF2 version (if it's supported) for its smaller, compressed file size.
 		let font = Font::new("Source Sans Pro".to_string(), "Regular".to_string());
-		let bounds = self.thread_text.bounding_box(text, &font, &self.font_cache, typesetting, false);
+		let mut text_context = GLOBAL_TEXT_CONTEXT.lock().expect("Failed to lock global text context");
+		let bounds = text_context.bounding_box(text, &font, &GLOBAL_FONT_CACHE, typesetting, false);
 		bounds.x
 	}
 
@@ -1056,14 +1059,15 @@ impl OverlayContextInternal {
 		let font = Font::new("Source Sans Pro".to_string(), "Regular".to_string());
 
 		// Get text dimensions directly from layout
-		let text_size = self.thread_text.bounding_box(text, &font, &self.font_cache, typesetting, false);
+		let mut text_context = GLOBAL_TEXT_CONTEXT.lock().expect("Failed to lock global text context");
+		let text_size = text_context.bounding_box(text, &font, &GLOBAL_FONT_CACHE, typesetting, false);
 		let text_width = text_size.x;
 		let text_height = text_size.y;
 		// Create a rect from the size (assuming text starts at origin)
 		let text_bounds = kurbo::Rect::new(0.0, 0.0, text_width, text_height);
 
 		// Convert text to vector paths for rendering
-		let text_table = self.thread_text.to_path(text, &font, &self.font_cache, typesetting, false);
+		let text_table = text_context.to_path(text, &font, &GLOBAL_FONT_CACHE, typesetting, false);
 
 		// Calculate position based on pivot
 		let mut position = DVec2::ZERO;