From 0d5091555c96150ef34509ab2f13013abfeb2a9d Mon Sep 17 00:00:00 2001
From: Ryan Di <ryan.weihao.di@gmail.com>
Date: Thu, 27 Feb 2025 19:09:22 +1100
Subject: [PATCH] simplify path threshold adaptive to zoom

---
 packages/excalidraw/lasso/index.ts  | 1 +
 packages/excalidraw/lasso/worker.ts | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/packages/excalidraw/lasso/index.ts b/packages/excalidraw/lasso/index.ts
index 24fc33f53..c5fffe14a 100644
--- a/packages/excalidraw/lasso/index.ts
+++ b/packages/excalidraw/lasso/index.ts
@@ -168,6 +168,7 @@ export class LassoTrail extends AnimatedTrail {
         elementsSegments: this.elementsSegments,
         intersectedElements: this.intersectedElements,
         enclosedElements: this.enclosedElements,
+        simplifyDistance: 5 / this.app.state.zoom.value,
       };
 
       this.worker?.postMessage(message);
diff --git a/packages/excalidraw/lasso/worker.ts b/packages/excalidraw/lasso/worker.ts
index d9a9f7196..aa1379c90 100644
--- a/packages/excalidraw/lasso/worker.ts
+++ b/packages/excalidraw/lasso/worker.ts
@@ -79,6 +79,7 @@ export type LassoWorkerInput = {
   elementsSegments: ElementsSegments;
   intersectedElements: Set<ExcalidrawElement["id"]>;
   enclosedElements: Set<ExcalidrawElement["id"]>;
+  simplifyDistance: number;
 };
 
 export type LassoWorkerOutput = {
@@ -92,9 +93,10 @@ export const updateSelection = (input: LassoWorkerInput): LassoWorkerOutput => {
     elementsSegments,
     intersectedElements,
     enclosedElements,
+    simplifyDistance,
   } = input;
   // simplify the path to reduce the number of points
-  const path = simplify(lassoPath, 2) as GlobalPoint[];
+  let path = simplify(lassoPath, simplifyDistance) as GlobalPoint[];
   // close the path to form a polygon for enclosure check
   const closedPath = polygonFromPoints(path);
   // as the path might not enclose a shape anymore, clear before checking