fix(core): applyProps assign geometry directly instead of copying

Author: nartc

apps/examples/src/app/soba/lod/scene.ts

@@ -1,4 +1,4 @@
-import { ChangeDetectionStrategy, Component, CUSTOM_ELEMENTS_SCHEMA, input } from '@angular/core';
+import { ChangeDetectionStrategy, Component, computed, CUSTOM_ELEMENTS_SCHEMA, input } from '@angular/core';
 import { NgtEuler, NgtVector3 } from 'angular-three';
 import { NgtsOrbitControls } from 'angular-three-soba/controls';
 import { injectGLTF } from 'angular-three-soba/loaders';
@@ -54,7 +54,7 @@ export class LODBust {
 @Component({
 	selector: 'app-lod-scene-graph',
 	template: `
-		@for (p of positions; track $index) {
+		@for (p of positions(); track $index) {
 			<app-bust [position]="p.position" [rotation]="p.rotation" />
 		}
 
@@ -74,7 +74,11 @@ export class LODBust {
 })
 export class SceneGraph {
 	protected Math = Math;
-	protected positions = positions;
 
 	asRenderTexture = input(false);
+	protected positions = computed(() => {
+		const asRenderTexture = this.asRenderTexture();
+		if (!asRenderTexture) return positions;
+		return positions.slice(250);
+	});
 }

libs/core/src/lib/utils/apply-props.ts

@@ -35,6 +35,21 @@ const colorMaps = ['map', 'emissiveMap', 'sheenColorMap', 'specularColorMap', 'e
 
 type ClassConstructor = { new (): void };
 
+const MEMOIZED_PROTOTYPES = new Map();
+
+function getMemoizedPrototype(root: any) {
+	let ctor = MEMOIZED_PROTOTYPES.get(root.constructor);
+	try {
+		if (!ctor) {
+			ctor = new root.constructor();
+			MEMOIZED_PROTOTYPES.set(root.constructor, ctor);
+		}
+	} catch (e) {
+		// ...
+	}
+	return ctor;
+}
+
 // This function applies a set of changes to the instance
 export function applyProps<T extends NgtAnyRecord>(instance: NgtInstanceState<T>['object'], props: NgtAnyRecord) {
 	// if props is empty
@@ -77,7 +92,21 @@ export function applyProps<T extends NgtAnyRecord>(instance: NgtInstanceState<T>
 			(value as ClassConstructor | undefined)?.constructor &&
 			(targetProp as ClassConstructor).constructor === (value as ClassConstructor).constructor
 		) {
-			targetProp.copy(value);
+			// If both are geometries, we should assign the value directly instead of copying
+			if (
+				is.three<THREE.BufferGeometry>(targetProp, 'isBufferGeometry') &&
+				is.three<THREE.BufferGeometry>(value, 'isBufferGeometry')
+			) {
+				Object.assign(currentInstance, { [key]: value });
+			} else {
+				// fetch the default state of the target
+				const ctor = getMemoizedPrototype(currentInstance);
+				// The target key was originally null or undefined, which indicates that the object which
+				// is now present was externally set by the user, we should therefore assign the value directly
+				if (ctor !== undefined && ctor[key] == null) Object.assign(currentInstance, { [key]: value });
+				// Otherwise copy is correct
+				else targetProp.copy(value);
+			}
 		}
 		// Layers have no copy function, we must therefore copy the mask property
 		else if (targetProp instanceof THREE.Layers && value instanceof THREE.Layers) {