Function getInterleavedArray

packages/core/src/io/reader.ts:583–634

* Returns the contents of an interleaved accessor, as a typed array. * @internal

(accessorDef: GLTF.IAccessor, context: ReaderContext)

 * @internal
 */
function getInterleavedArray(accessorDef: GLTF.IAccessor, context: ReaderContext): TypedArray {
	const jsonDoc = context.jsonDoc;
	const bufferView = context.bufferViews[accessorDef.bufferView!];
	const bufferViewDef = jsonDoc.json.bufferViews![accessorDef.bufferView!];

	const TypedArray = ComponentTypeToTypedArray[accessorDef.componentType];
	const elementSize = Accessor.getElementSize(accessorDef.type);
	const componentSize = TypedArray.BYTES_PER_ELEMENT;
	const accessorByteOffset = accessorDef.byteOffset || 0;

	const array = new TypedArray(accessorDef.count * elementSize);
	const view = new DataView(bufferView.buffer, bufferView.byteOffset, bufferView.byteLength);
	const byteStride = bufferViewDef.byteStride!;

	for (let i = 0; i < accessorDef.count; i++) {
		for (let j = 0; j < elementSize; j++) {
			const byteOffset = accessorByteOffset + i * byteStride + j * componentSize;
			let value: number;
			switch (accessorDef.componentType) {
				case Accessor.ComponentType.FLOAT:
					value = view.getFloat32(byteOffset, true);
					break;
				case Accessor.ComponentType.UNSIGNED_INT:
					value = view.getUint32(byteOffset, true);
					break;
				case Accessor.ComponentType.UNSIGNED_SHORT:
					value = view.getUint16(byteOffset, true);
					break;
				case Accessor.ComponentType.UNSIGNED_BYTE:
					value = view.getUint8(byteOffset);
					break;
				case Accessor.ComponentType.SHORT:
					value = view.getInt16(byteOffset, true);
					break;
				case Accessor.ComponentType.BYTE:
					value = view.getInt8(byteOffset);
					break;
				case Accessor.ComponentType.FLOAT16: // KHR_accessor_float16
					value = view.getFloat16(byteOffset, true);
					break;
				case Accessor.ComponentType.FLOAT64: // KHR_accessor_float64
					value = view.getFloat64(byteOffset, true);
					break;
				default:
					throw new Error(`Unexpected componentType "${accessorDef.componentType}".`);
			}
			array[i * elementSize + j] = value;
		}
	}

	return array;
}

/**
 * Returns the contents of an accessor, as a typed array.