31 lines
1.2 KiB
JavaScript
31 lines
1.2 KiB
JavaScript
import '../_thirdparty/regenerator-runtime/runtime.js'
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import { decode as decodeBlurHash } from 'blurhash'
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import registerPromiseWorker from 'promise-worker/register'
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import { BLURHASH_RESOLUTION as RESOLUTION } from '../_static/blurhash'
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import { isChrome } from '../_utils/userAgent/isChrome'
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// Disabled in Chrome because convertToBlob() is slow
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// https://github.com/nolanlawson/pinafore/issues/1396
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const OFFSCREEN_CANVAS = !isChrome() && typeof OffscreenCanvas === 'function'
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? new OffscreenCanvas(RESOLUTION, RESOLUTION) : null
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const OFFSCREEN_CANVAS_CONTEXT_2D = OFFSCREEN_CANVAS
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? OFFSCREEN_CANVAS.getContext('2d') : null
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registerPromiseWorker(async (encoded) => {
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const pixels = decodeBlurHash(encoded, RESOLUTION, RESOLUTION)
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if (!pixels) {
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throw new Error('decode did not return any pixels')
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}
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const imageData = new ImageData(pixels, RESOLUTION, RESOLUTION)
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if (OFFSCREEN_CANVAS) {
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OFFSCREEN_CANVAS_CONTEXT_2D.putImageData(imageData, 0, 0)
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const blob = await OFFSCREEN_CANVAS.convertToBlob()
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const decoded = URL.createObjectURL(blob)
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return { decoded, imageData: null }
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} else {
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return { imageData, decoded: null }
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}
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})
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