From dc130514389588b626cd477c57b6be919950f11b Mon Sep 17 00:00:00 2001
From: Mugen87 <michael.herzog@human-interactive.org>
Date: Tue, 5 Sep 2023 13:18:58 +0200
Subject: [PATCH] LDrawLoader: Use WeakMap instead of `userData` for indexing
 materials.

---
 examples/jsm/loaders/LDrawLoader.js | 32 ++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 12 deletions(-)

diff --git a/examples/jsm/loaders/LDrawLoader.js b/examples/jsm/loaders/LDrawLoader.js
index 0aa121c3fffc42..487c4eb5173463 100644
--- a/examples/jsm/loaders/LDrawLoader.js
+++ b/examples/jsm/loaders/LDrawLoader.js
@@ -45,6 +45,9 @@ const COLOR_SPACE_LDRAW = SRGBColorSpace;
 const _tempVec0 = new Vector3();
 const _tempVec1 = new Vector3();
 
+const _edgeMaterialCache = new WeakMap();
+const _conditionalEdgeMaterialCache = new WeakMap();
+
 class LDrawConditionalLineMaterial extends ShaderMaterial {
 
 	constructor( parameters ) {
@@ -1759,11 +1762,13 @@ function createObject( elements, elementSize, isConditionalSegments = false, tot
 
 					if ( isConditionalSegments ) {
 
-						materials.push( material.userData.edgeMaterial.userData.conditionalEdgeMaterial );
+						const edgeMaterial = _edgeMaterialCache.get( material );
+
+						materials.push( _conditionalEdgeMaterialCache.get( edgeMaterial ) );
 
 					} else {
 
-						materials.push( material.userData.edgeMaterial );
+						materials.push( _edgeMaterialCache.get( material ) );
 
 					}
 
@@ -1906,8 +1911,9 @@ class LDrawLoader extends Loader {
 		this.missingColorMaterial = new MeshStandardMaterial( { name: Loader.DEFAULT_MATERIAL_NAME, color: 0xFF00FF, roughness: 0.3, metalness: 0 } );
 		this.missingEdgeColorMaterial = new LineBasicMaterial( { name: Loader.DEFAULT_MATERIAL_NAME, color: 0xFF00FF } );
 		this.missingConditionalEdgeColorMaterial = new LDrawConditionalLineMaterial( { name: Loader.DEFAULT_MATERIAL_NAME, fog: true, color: 0xFF00FF } );
-		this.missingColorMaterial.userData.edgeMaterial = this.missingEdgeColorMaterial;
-		this.missingEdgeColorMaterial.userData.conditionalEdgeMaterial = this.missingConditionalEdgeColorMaterial;
+
+		_edgeMaterialCache.set( this.missingColorMaterial, this.missingEdgeColorMaterial );
+		_conditionalEdgeMaterialCache.set( this.missingEdgeColorMaterial, this.missingConditionalEdgeColorMaterial );
 
 	}
 
@@ -2126,11 +2132,11 @@ class LDrawLoader extends Loader {
 
 			if ( c.isLineSegments ) {
 
-				material = material.userData.edgeMaterial;
+				material = _edgeMaterialCache.get( material );
 
 				if ( c.isConditionalLine ) {
 
-					material = material.userData.conditionalEdgeMaterial;
+					material = _conditionalEdgeMaterialCache.get( material );
 
 				}
 
@@ -2151,7 +2157,7 @@ class LDrawLoader extends Loader {
 	getMainEdgeMaterial() {
 
 		const mat = this.getMaterial( MAIN_EDGE_COLOUR_CODE );
-		return mat ? mat.userData.edgeMaterial : null;
+		return mat ? _edgeMaterialCache.get( mat ) : null;
 
 	}
 
@@ -2236,7 +2242,7 @@ class LDrawLoader extends Loader {
 							}
 
 							// Get the edge material for this triangle material
-							edgeMaterial = edgeMaterial.userData.edgeMaterial;
+							edgeMaterial = _edgeMaterialCache.get( edgeMaterial );
 
 						}
 
@@ -2380,7 +2386,7 @@ class LDrawLoader extends Loader {
 			edgeMaterial.name = name + ' - Edge';
 
 			// This is the material used for conditional edges
-			edgeMaterial.userData.conditionalEdgeMaterial = new LDrawConditionalLineMaterial( {
+			const conditionalEdgeMaterial = new LDrawConditionalLineMaterial( {
 
 				fog: true,
 				transparent: isTransparent,
@@ -2389,15 +2395,17 @@ class LDrawLoader extends Loader {
 				opacity: alpha,
 
 			} );
-			edgeMaterial.userData.conditionalEdgeMaterial.userData.code = code;
-			edgeMaterial.userData.conditionalEdgeMaterial.name = name + ' - Conditional Edge';
+			conditionalEdgeMaterial.userData.code = code;
+			conditionalEdgeMaterial.name = name + ' - Conditional Edge';
+
+			_conditionalEdgeMaterialCache.set( edgeMaterial, conditionalEdgeMaterial );
 
 		}
 
 		material.userData.code = code;
 		material.name = name;
 
-		material.userData.edgeMaterial = edgeMaterial;
+		_edgeMaterialCache.set( material, edgeMaterial );
 
 		this.addMaterial( material );