89 lines
1.9 KiB
JavaScript
89 lines
1.9 KiB
JavaScript
/* global XMLHttpRequest, Image */
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let imgCache = {}
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function GET (url, istext) {
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return new Promise((resolve, reject) => {
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var xmlHttp = new XMLHttpRequest()
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xmlHttp.onreadystatechange = function () {
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if (xmlHttp.readyState === 4 && xmlHttp.status === 200) {
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resolve(xmlHttp.responseText)
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} else if (xmlHttp.readyState === 4 && xmlHttp.status >= 400) {
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let err = new Error(xmlHttp.status)
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err.request = xmlHttp
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reject(err)
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}
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}
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xmlHttp.open('GET', url, true)
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istext && (xmlHttp.responseType = 'text')
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xmlHttp.send(null)
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})
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}
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function smartGET (data) {
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if (typeof data === 'string') {
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data = {
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url: data,
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type: 'text'
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}
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}
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if (!data.type) data.type = 'text'
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let istext = (data.type !== 'image' && data.type !== 'file')
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let url = data.url
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if (!url) throw new Error('URL is required!')
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if (data.type === 'json') {
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return new Promise((resolve, reject) => {
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GET(url).then((dtext) => {
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try {
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let jsonp = JSON.parse(dtext)
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return resolve(jsonp)
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} catch (e) {
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reject(e)
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}
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}, reject)
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})
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}
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return GET(data.url, istext)
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}
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function loadImage (url) {
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url = '/assets/textures/' + url
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// Ensure we don't load a texture multiple times
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if (imgCache[url]) return imgCache[url]
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return new Promise((resolve, reject) => {
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let img = new Image()
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img.onload = function () {
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imgCache[url] = img
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resolve(img)
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}
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img.onerror = function (e) {
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reject(e)
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}
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img.src = url
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})
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}
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function imageToSampler (img) {
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let canvas = document.createElement('canvas')
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let ctx = canvas.getContext('2d')
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canvas.width = img.width
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canvas.height = img.height
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ctx.drawImage(img, 0, 0, img.width, img.height)
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return function (x, y) {
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return ctx.getImageData(x, y, 1, 1).data
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}
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}
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export default { GET: smartGET, imageToSampler, loadImage }
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