42 lines
863 B
TypeScript
42 lines
863 B
TypeScript
import {decode} from 'blurhash'
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export async function getBlobFromBlurHash(blurHash: string): Promise<Blob | null> {
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if (blurHash === '') {
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return null
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}
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const pixels = decode(blurHash, 32, 32)
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const canvas = document.createElement('canvas')
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canvas.width = 32
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canvas.height = 32
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const ctx = canvas.getContext('2d')
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if (ctx === null) {
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return null
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}
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const imageData = ctx.createImageData(32, 32)
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imageData.data.set(pixels)
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ctx.putImageData(imageData, 0, 0)
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return new Promise<Blob>((resolve, reject) => {
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canvas.toBlob(b => {
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if (b === null) {
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reject(b)
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return
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}
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resolve(b)
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})
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})
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}
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export async function getBlurHash(blurHashString: string) {
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if (!blurHashString) {
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return
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}
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const blurHashBlob = await getBlobFromBlurHash(blurHashString)
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if (!blurHashBlob) {
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return
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}
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return URL.createObjectURL(blurHashBlob)
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} |