Merge pull request #140 from gkjohnson/set-type

Add support for changing the attribute buffer type for TypedBackedArray

src/core/TypeBackedArray.js

@@ -1,35 +1,70 @@
 import { areSharedArrayBuffersSupported } from './utils.js';
 
+function ceilToFourByteStride( byteLength ) {
+
+	byteLength = ~ ~ byteLength;
+	return byteLength + 4 - byteLength % 4;
+
+}
+
 // Make a new array wrapper class that more easily affords expansion when reaching it's max capacity
 export class TypeBackedArray {
 
 	constructor( type, initialSize = 500 ) {
 
-		const bufferType = areSharedArrayBuffersSupported() ? SharedArrayBuffer : ArrayBuffer;
 
 		this.expansionFactor = 1.5;
 		this.type = type;
-		this.array = new type( new bufferType( initialSize * type.BYTES_PER_ELEMENT ) );
 		this.length = 0;
+		this.array = null;
+
+		this.setSize( initialSize );
 
 	}
 
-	expand( size = null ) {
+	setType( type ) {
 
-		const { type, array, expansionFactor } = this;
+		if ( this.length !== 0 ) {
 
-		if ( size === null ) {
+			throw new Error( 'TypeBackedArray: Cannot change the type while there is used data in the buffer.' );
+
+		}
+
+		const buffer = this.array.buffer;
+		this.array = new type( buffer );
+		this.type = type;
+
+	}
 
-			size = ~ ~ ( array.length * expansionFactor );
+	setSize( size ) {
+
+		if ( this.array && size === this.array.length ) {
+
+			return;
+
+		}
+
+		// ceil to the nearest 4 bytes so we can replace the array with any type using the same buffer
+		const type = this.type;
+		const bufferType = areSharedArrayBuffersSupported() ? SharedArrayBuffer : ArrayBuffer;
+		const newArray = new type( new bufferType( ceilToFourByteStride( size * type.BYTES_PER_ELEMENT ) ) );
+		if ( this.array ) {
+
+			newArray.set( this.array, 0 );
 
 		}
 
-		const newArray = new type( size );
-		newArray.set( array, 0 );
 		this.array = newArray;
 
 	}
 
+	expand() {
+
+		const { array, expansionFactor } = this;
+		this.setSize( array.length * expansionFactor );
+
+	}
+
 	push( ...args ) {
 
 		let { array, length } = this;

src/core/TypedAttributeData.js

@@ -88,7 +88,17 @@ export class TypedAttributeData {
 
 			if ( referenceAttr.type !== type ) {
 
-				throw new Error( `TypedAttributeData: Array ${ name } already initialized with a different type.` );
+				for ( let i = 0, l = groupAttributes.length; i < l; i ++ ) {
+
+					groupAttributes[ i ][ name ].setType( type );
+
+				}
+
+				// } else {
+
+				// 	throw new Error( `TypedAttributeData: Array ${ name } already initialized with a different type.` );
+
+				// }
 
 			}
 

tests/BVH.Evaluator.test.js

@@ -0,0 +1,30 @@
+import { Brush, Evaluator, SUBTRACTION } from '../src';
+import { SphereGeometry, BufferAttribute } from 'three';
+
+describe( 'Evaluator', () => {
+
+	it( 'it not fail if multiple operations with different buffer types.', () => {
+
+		const geo1 = new SphereGeometry();
+		const geo2 = new SphereGeometry();
+		geo2.setAttribute(
+			'uv',
+			new BufferAttribute( new Uint8Array( geo2.attributes.uv.array.length ), 2, true ),
+		);
+
+		const brush1A = new Brush( geo1 );
+		const brush1B = new Brush( geo1 );
+
+		const brush2A = new Brush( geo2 );
+		const brush2B = new Brush( geo2 );
+
+		const evaluator = new Evaluator();
+		const result1 = evaluator.evaluate( brush1A, brush1B, SUBTRACTION );
+		const result2 = evaluator.evaluate( brush2A, brush2B, SUBTRACTION );
+
+		expect( result1.geometry.attributes.uv.array.constructor ).toBe( Float32Array );
+		expect( result2.geometry.attributes.uv.array.constructor ).toBe( Uint8Array );
+
+	} );
+
+} );

tests/Utils.TypeBackedArray.test.js

@@ -0,0 +1,5 @@
+describe( 'TypeBackedArray', () => {
+
+	it.todo( 'make tests' );
+
+} );

tests/Utils.TypedAttributeData.test.js

@@ -0,0 +1,5 @@
+describe( 'TypedAttributeData', () => {
+
+	it.todo( 'make tests' );
+
+} );