From 0199c82e9830736748532d35ef21f6f1b73a6961 Mon Sep 17 00:00:00 2001
From: dwelle <5153846+dwelle@users.noreply.github.com>
Date: Fri, 27 Jun 2025 14:18:48 +0200
Subject: [PATCH] differentiate between constant/variable stroke type

---
 .../components/FreedrawDebugSliders.tsx       |  8 +--
 packages/element/src/freedraw.ts              | 70 ++++++++++++++-----
 packages/excalidraw/components/App.tsx        |  8 ++-
 3 files changed, 64 insertions(+), 22 deletions(-)

diff --git a/excalidraw-app/components/FreedrawDebugSliders.tsx b/excalidraw-app/components/FreedrawDebugSliders.tsx
index bf8b66b111..2666a6f99a 100644
--- a/excalidraw-app/components/FreedrawDebugSliders.tsx
+++ b/excalidraw-app/components/FreedrawDebugSliders.tsx
@@ -3,10 +3,10 @@ import { useState, useEffect } from "react";
 
 export const FreedrawDebugSliders = () => {
   const [streamline, setStreamline] = useState<number>(
-    DRAWING_CONFIGS.default.streamline,
+    DRAWING_CONFIGS.default.variable.streamline,
   );
   const [simplify, setSimplify] = useState<number>(
-    DRAWING_CONFIGS.default.simplify,
+    DRAWING_CONFIGS.default.variable.simplify,
   );
 
   useEffect(() => {
@@ -14,7 +14,7 @@ export const FreedrawDebugSliders = () => {
       window.h = {} as any;
     }
     if (!window.h.debugFreedraw) {
-      window.h.debugFreedraw = DRAWING_CONFIGS.default;
+      window.h.debugFreedraw = DRAWING_CONFIGS.default.variable;
     }
 
     setStreamline(window.h.debugFreedraw.streamline);
@@ -39,7 +39,7 @@ export const FreedrawDebugSliders = () => {
     <div
       style={{
         position: "absolute",
-        bottom: "10px",
+        bottom: "70px",
         left: "50%",
         transform: "translateX(-50%)",
         zIndex: 9999,
diff --git a/packages/element/src/freedraw.ts b/packages/element/src/freedraw.ts
index bc91490baf..af071e130d 100644
--- a/packages/element/src/freedraw.ts
+++ b/packages/element/src/freedraw.ts
@@ -8,34 +8,70 @@ import type { StrokeOptions } from "perfect-freehand";
 
 import type { ExcalidrawFreeDrawElement, PointerType } from "./types";
 
+type FreedrawStrokeType = "constant" | "variable";
+
+export const getElementStrokeType = (
+  element: ExcalidrawFreeDrawElement,
+): FreedrawStrokeType => {
+  return element.drawingConfigs?.fixedStrokeWidth ? "constant" : "variable";
+};
+
 export const DRAWING_CONFIGS: Record<
   PointerType | "default",
-  { streamline: number; simplify: number }
+  Record<FreedrawStrokeType, { streamline: number; simplify: number }>
 > = {
   default: {
-    streamline: 0.35,
-    simplify: 0.1,
+    constant: {
+      streamline: 0.35,
+      simplify: 0.1,
+    },
+    variable: {
+      streamline: 0.35,
+      simplify: 0.1,
+    },
   },
   mouse: {
-    streamline: 0.6,
-    simplify: 0.1,
+    constant: {
+      streamline: 0.6,
+      simplify: 0.1,
+    },
+    variable: {
+      streamline: 0.6,
+      simplify: 0.1,
+    },
   },
   pen: {
-    // for optimal performance, we use a lower streamline and simplify
-    streamline: 0.2,
-    simplify: 0.1,
+    constant: {
+      // for optimal performance, we use a lower streamline and simplify
+      streamline: 0.2,
+      simplify: 0.1,
+    },
+    variable: {
+      // for optimal performance, we use a lower streamline and simplify
+      streamline: 0.2,
+      simplify: 0.1,
+    },
   },
   touch: {
-    streamline: 0.65,
-    simplify: 0.1,
+    constant: {
+      streamline: 0.65,
+      simplify: 0.1,
+    },
+    variable: {
+      streamline: 0.65,
+      simplify: 0.1,
+    },
   },
 } as const;
 
-export const getFreedrawConfig = (eventType: string | null | undefined) => {
-  return (
+export const getFreedrawConfig = (
+  eventType: string | null | undefined,
+  strokeType: FreedrawStrokeType,
+): { streamline: number; simplify: number } => {
+  const inputConfig =
     DRAWING_CONFIGS[(eventType as PointerType | null) || "default"] ||
-    DRAWING_CONFIGS.default
-  );
+    DRAWING_CONFIGS.default;
+  return inputConfig[strokeType];
 };
 
 /**
@@ -105,9 +141,11 @@ export const getFreedrawStroke = (element: ExcalidrawFreeDrawElement) => {
   }
 
   const streamline =
-    element.drawingConfigs?.streamline ?? DRAWING_CONFIGS.default.streamline;
+    element.drawingConfigs?.streamline ??
+    getFreedrawConfig("default", getElementStrokeType(element)).streamline;
   const simplify =
-    element.drawingConfigs?.simplify ?? DRAWING_CONFIGS.default.simplify;
+    element.drawingConfigs?.simplify ??
+    getFreedrawConfig("default", getElementStrokeType(element)).simplify;
 
   const laser = new LaserPointer({
     size: element.strokeWidth,
diff --git a/packages/excalidraw/components/App.tsx b/packages/excalidraw/components/App.tsx
index 405eb045ee..91964e40ae 100644
--- a/packages/excalidraw/components/App.tsx
+++ b/packages/excalidraw/components/App.tsx
@@ -7476,7 +7476,10 @@ class App extends React.Component<AppProps, AppState> {
 
     const simulatePressure = event.pressure === 0.5 || event.pressure === 0;
 
-    const freedrawConfig = getFreedrawConfig(event.pointerType);
+    const freedrawConfig = getFreedrawConfig(
+      event.pointerType,
+      this.state.currentItemFixedStrokeWidth ? "constant" : "variable",
+    );
 
     const element = newFreeDrawElement({
       type: elementType,
@@ -11159,7 +11162,8 @@ export const createTestHook = () => {
     window.h = window.h || ({} as Window["h"]);
 
     // Initialize debug freedraw parameters
-    window.h.debugFreedraw = window.h.debugFreedraw || DRAWING_CONFIGS.default;
+    window.h.debugFreedraw =
+      window.h.debugFreedraw || DRAWING_CONFIGS.default.variable;
 
     Object.defineProperties(window.h, {
       elements: {