first commit

public/sdk/three/jsm/renderers/common/Attributes.js

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+import DataMap from './DataMap.js';
+import { AttributeType } from './Constants.js';
+import { DynamicDrawUsage } from 'three';
+
+class Attributes extends DataMap {
+
+	constructor( backend ) {
+
+		super();
+
+		this.backend = backend;
+
+	}
+
+	delete( attribute ) {
+
+		const attributeData = super.delete( attribute );
+
+		if ( attributeData !== undefined ) {
+
+			this.backend.destroyAttribute( attribute );
+
+		}
+
+	}
+
+	update( attribute, type ) {
+
+		const data = this.get( attribute );
+
+		if ( data.version === undefined ) {
+
+			if ( type === AttributeType.VERTEX ) {
+
+				this.backend.createAttribute( attribute );
+
+			} else if ( type === AttributeType.INDEX ) {
+
+				this.backend.createIndexAttribute( attribute );
+
+			} else if ( type === AttributeType.STORAGE ) {
+
+				this.backend.createStorageAttribute( attribute );
+
+			}
+
+			data.version = this._getBufferAttribute( attribute ).version;
+
+		} else {
+
+			const bufferAttribute = this._getBufferAttribute( attribute );
+
+			if ( data.version < bufferAttribute.version || bufferAttribute.usage === DynamicDrawUsage ) {
+
+				this.backend.updateAttribute( attribute );
+
+				data.version = bufferAttribute.version;
+
+			}
+
+		}
+
+	}
+
+	_getBufferAttribute( attribute ) {
+
+		if ( attribute.isInterleavedBufferAttribute ) attribute = attribute.data;
+
+		return attribute;
+
+	}
+
+}
+
+export default Attributes;