68 lines
1.5 KiB
JavaScript
68 lines
1.5 KiB
JavaScript
/*
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* Caching pixels for a few ms before sending them
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* in bursts per chunk
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*/
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import socketEvents from '../socket/socketEvents';
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class PixelCache {
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PXL_CACHE;
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constructor() {
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this.PXL_CACHE = new Map();
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this.flushCache = this.flushCache.bind(this);
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}
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/*
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* append pixel to cache
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* @param canvasId canvas id
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* @param i Chunk coordinates
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* @param j Chunk coordinates
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* @param offset Offset of pixel within chunk
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* @param color color index of pixel
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*/
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async append(
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canvasId,
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color,
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i,
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j,
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offset,
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) {
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const { PXL_CACHE } = this;
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const chunkCanvasId = (canvasId << 16) | (i << 8) | j;
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const pxls = PXL_CACHE.get(chunkCanvasId);
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const newpxl = Buffer.allocUnsafe(4);
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newpxl.writeUInt8(offset >>> 16, 0);
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newpxl.writeUInt16BE(offset & 0x00FFFF, 1);
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newpxl.writeUInt8(color, 3);
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if (typeof pxls === 'undefined') {
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PXL_CACHE.set(chunkCanvasId, newpxl);
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} else {
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PXL_CACHE.set(
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chunkCanvasId,
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Buffer.concat([pxls, newpxl]),
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);
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}
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}
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async flushCache() {
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const { PXL_CACHE: cache } = this;
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this.PXL_CACHE = new Map();
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cache.forEach((pxls, chunkCanvasId) => {
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const canvasId = (chunkCanvasId & 0xFF0000) >> 16;
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const chunkId = chunkCanvasId & 0x00FFFF;
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socketEvents.broadcastPixels(canvasId, chunkId, pxls);
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});
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}
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}
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const pixelCache = new PixelCache();
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// send pixels from cache to websockets every 50ms
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setInterval(pixelCache.flushCache, 50);
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export default pixelCache;
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