playcanvas/build/playcanvas/src/platform/graphics/index-buffer.js

PlayCanvas WebGL game engine

import { BUFFER_STATIC, typedArrayIndexFormatsByteSize, INDEXFORMAT_UINT32, INDEXFORMAT_UINT16 } from './constants.js';

let id = 0;
class IndexBuffer {
		constructor(graphicsDevice, format, numIndices, usage = BUFFER_STATIC, initialData, options){
				this.device = graphicsDevice;
				this.format = format;
				this.numIndices = numIndices;
				this.usage = usage;
				this.id = id++;
				this.impl = graphicsDevice.createIndexBufferImpl(this, options);
				const bytesPerIndex = typedArrayIndexFormatsByteSize[format];
				this.bytesPerIndex = bytesPerIndex;
				this.numBytes = this.numIndices * bytesPerIndex;
				if (initialData) {
						this.setData(initialData);
				} else {
						this.storage = new ArrayBuffer(this.numBytes);
				}
				this.adjustVramSizeTracking(graphicsDevice._vram, this.numBytes);
				this.device.buffers.push(this);
		}
		destroy() {
				const device = this.device;
				const idx = device.buffers.indexOf(this);
				if (idx !== -1) {
						device.buffers.splice(idx, 1);
				}
				if (this.device.indexBuffer === this) {
						this.device.indexBuffer = null;
				}
				if (this.impl.initialized) {
						this.impl.destroy(device);
						this.adjustVramSizeTracking(device._vram, -this.storage.byteLength);
				}
		}
		adjustVramSizeTracking(vram, size) {
				vram.ib += size;
		}
		loseContext() {
				this.impl.loseContext();
		}
		getFormat() {
				return this.format;
		}
		getNumIndices() {
				return this.numIndices;
		}
		lock() {
				return this.storage;
		}
		unlock() {
				this.impl.unlock(this);
		}
		setData(data) {
				if (data.byteLength !== this.numBytes) {
						return false;
				}
				this.storage = data;
				this.unlock();
				return true;
		}
		_lockTypedArray() {
				const lock = this.lock();
				const indices = this.format === INDEXFORMAT_UINT32 ? new Uint32Array(lock) : this.format === INDEXFORMAT_UINT16 ? new Uint16Array(lock) : new Uint8Array(lock);
				return indices;
		}
		writeData(data, count) {
				const indices = this._lockTypedArray();
				if (data.length > count) {
						if (ArrayBuffer.isView(data)) {
								data = data.subarray(0, count);
								indices.set(data);
						} else {
								for(let i = 0; i < count; i++){
										indices[i] = data[i];
								}
						}
				} else {
						indices.set(data);
				}
				this.unlock();
		}
		readData(data) {
				const indices = this._lockTypedArray();
				const count = this.numIndices;
				if (ArrayBuffer.isView(data)) {
						data.set(indices);
				} else {
						data.length = 0;
						for(let i = 0; i < count; i++){
								data[i] = indices[i];
						}
				}
				return count;
		}
}

export { IndexBuffer };