69 lines
1.8 KiB
TypeScript
69 lines
1.8 KiB
TypeScript
/*
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* https://github.com/morethanwords/tweb
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* Copyright (C) 2019-2021 Eduard Kuzmenko
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* https://github.com/morethanwords/tweb/blob/master/LICENSE
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*/
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import _DEBUG from '../config/debug';
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import fastBlur from '../vendor/fastBlur';
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import pushHeavyTask from './heavyQueue';
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const RADIUS = 2;
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const ITERATIONS = 2;
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const DEBUG = _DEBUG && true;
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function processBlur(dataUri: string, radius: number, iterations: number) {
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return new Promise<string>((resolve) => {
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const img = new Image();
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const perf = performance.now();
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if(DEBUG) {
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console.log('[blur] start');
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}
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img.onload = () => {
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const canvas = document.createElement('canvas');
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canvas.width = img.width;
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canvas.height = img.height;
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const ctx = canvas.getContext('2d')!;
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ctx.drawImage(img, 0, 0);
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fastBlur(ctx, 0, 0, canvas.width, canvas.height, radius, iterations);
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//resolve(canvas.toDataURL());
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canvas.toBlob(blob => {
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resolve(URL.createObjectURL(blob));
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if(DEBUG) {
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console.log(`[blur] end, radius: ${radius}, iterations: ${iterations}, time: ${performance.now() - perf}`);
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}
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});
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};
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img.src = dataUri;
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});
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}
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const blurPromises: {[dataUri: string]: Promise<string>} = {};
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export default function blur(dataUri: string, radius: number = RADIUS, iterations: number = ITERATIONS) {
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if(!dataUri) {
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console.error('no dataUri for blur', dataUri);
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return Promise.resolve(dataUri);
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}
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if(blurPromises[dataUri]) return blurPromises[dataUri];
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return blurPromises[dataUri] = new Promise<string>((resolve) => {
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//return resolve(dataUri);
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pushHeavyTask({
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items: [[dataUri, radius, iterations]],
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context: null,
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process: processBlur
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}).then(results => {
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resolve(results[0]);
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});
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});
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}
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