Merge branch 'master' into webgl2

src/common/CircularList.ts

@@ -154,24 +154,22 @@ export class CircularList<T> extends EventEmitter implements ICircularList<T> {
       this._length -= deleteCount;
     }
 
-    if (items && items.length) {
-      // Add items
-      for (let i = this._length - 1; i >= start; i--) {
-        this._array[this._getCyclicIndex(i + items.length)] = this._array[this._getCyclicIndex(i)];
-      }
-      for (let i = 0; i < items.length; i++) {
-        this._array[this._getCyclicIndex(start + i)] = items[i];
-      }
+    // Add items
+    for (let i = this._length - 1; i >= start; i--) {
+      this._array[this._getCyclicIndex(i + items.length)] = this._array[this._getCyclicIndex(i)];
+    }
+    for (let i = 0; i < items.length; i++) {
+      this._array[this._getCyclicIndex(start + i)] = items[i];
+    }
 
-      // Adjust length as needed
-      if (this._length + items.length > this._maxLength) {
-        const countToTrim = (this._length + items.length) - this._maxLength;
-        this._startIndex += countToTrim;
-        this._length = this._maxLength;
-        this.emitMayRemoveListeners('trim', countToTrim);
-      } else {
-        this._length += items.length;
-      }
+    // Adjust length as needed
+    if (this._length + items.length > this._maxLength) {
+      const countToTrim = (this._length + items.length) - this._maxLength;
+      this._startIndex += countToTrim;
+      this._length = this._maxLength;
+      this.emitMayRemoveListeners('trim', countToTrim);
+    } else {
+      this._length += items.length;
     }
   }
 

src/common/TypedArrayUtils.test.ts

@@ -3,21 +3,20 @@
  * @license MIT
  */
 import { assert } from 'chai';
-import { fillFallback, sliceFallback } from './TypedArrayUtils';
+import { fillFallback, sliceFallback, concat } from './TypedArrayUtils';
 
 type TypedArray = Uint8Array | Uint16Array | Uint32Array | Uint8ClampedArray
   | Int8Array | Int16Array | Int32Array
   | Float32Array | Float64Array;
 
-describe('polyfill conformance tests', function(): void {
-
-  function deepEquals(a: TypedArray, b: TypedArray): void {
-    assert.equal(a.length, b.length);
-    for (let i = 0; i < a.length; ++i) {
-      assert.equal(a[i], b[i]);
-    }
+function deepEquals(a: TypedArray, b: TypedArray): void {
+  assert.equal(a.length, b.length);
+  for (let i = 0; i < a.length; ++i) {
+    assert.equal(a[i], b[i]);
   }
+}
 
+describe('polyfill conformance tests', function(): void {
   describe('TypedArray.fill', function(): void {
     it('should work with all typed array types', function(): void {
       const u81 = new Uint8Array(5);
@@ -190,3 +189,12 @@ describe('polyfill conformance tests', function(): void {
     });
   });
 });
+
+describe('typed array convenience functions', () => {
+  it('concat', () => {
+    const a = new Uint8Array([1, 2, 3, 4, 5]);
+    const b = new Uint8Array([6, 7, 8, 9, 0]);
+    const merged = concat(a, b);
+    deepEquals(merged, new Uint8Array([1, 2, 3, 4, 5, 6, 7, 8, 9, 0]));
+  });
+});

src/common/TypedArrayUtils.ts

@@ -3,15 +3,15 @@
  * @license MIT
  */
 
+export type TypedArray = Uint8Array | Uint16Array | Uint32Array | Uint8ClampedArray
+  | Int8Array | Int16Array | Int32Array
+  | Float32Array | Float64Array;
+
+
 /**
  * polyfill for TypedArray.fill
  * This is needed to support .fill in all safari versions and IE 11.
  */
-
-type TypedArray = Uint8Array | Uint16Array | Uint32Array | Uint8ClampedArray
-  | Int8Array | Int16Array | Int32Array
-  | Float32Array | Float64Array;
-
 export function fill<T extends TypedArray>(array: T, value: number, start?: number, end?: number): T {
   // all modern engines that support .fill
   if (array.fill) {
@@ -65,3 +65,14 @@ export function sliceFallback<T extends TypedArray>(array: T, start: number = 0,
   }
   return result;
 }
+
+/**
+ * Concat two typed arrays `a` and `b`.
+ * Returns a new typed array.
+ */
+export function concat<T extends TypedArray>(a: T, b: T): T {
+  const result = new (a.constructor as any)(a.length + b.length);
+  result.set(a);
+  result.set(b, a.length);
+  return result;
+}