157 lines
3.7 KiB
JavaScript
157 lines
3.7 KiB
JavaScript
export const uniContext = (canvasId, context) => {
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let ctx = uni.createCanvasContext(canvasId, context)
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if (!ctx.uniDrawImage) {
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ctx.uniDrawImage = ctx.drawImage
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ctx.drawImage = (image, ...agrs) => {
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ctx.uniDrawImage(image.src, ...agrs)
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}
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}
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if (!ctx.getImageData) {
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ctx.getImageData = (x, y, width, height) => {
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return new Promise((resolve, reject) => {
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// #ifdef MP || VUE2
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if (context.proxy) context = context.proxy
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// #endif
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uni.canvasGetImageData({
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canvasId,
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x,
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y,
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width,
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height,
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success(res) {
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resolve(res)
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},
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fail(error) {
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reject(error)
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}
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}, context)
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})
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}
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}
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return ctx
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}
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class Image {
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constructor() {
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this.currentSrc = null
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this.naturalHeight = 0
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this.naturalWidth = 0
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this.width = 0
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this.height = 0
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this.tagName = 'IMG'
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}
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set src(src) {
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this.currentSrc = src
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uni.getImageInfo({
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src,
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success: (res) => {
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this.naturalWidth = this.width = res.width
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this.naturalHeight = this.height = res.height
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this.onload()
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},
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fail: () => {
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this.onerror()
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}
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})
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}
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get src() {
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return this.currentSrc
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}
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}
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export const createImage = () => {
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return new Image()
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}
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export function useCurrentPage() {
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const pages = getCurrentPages();
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return pages[pages.length - 1];
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}
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export const toDataURL = (canvasId, context, options = {}) => {
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// #ifdef MP-QQ
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// context = context.$scope
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// #endif
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// #ifdef MP-ALIPAY
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context = ''
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// #endif
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return new Promise((resolve, reject) => {
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let {canvas, width, height, destWidth = 0, destHeight = 0, x = 0, y = 0, useCanvas2d} = options
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const {pixelRatio} =uni.getSystemInfoSync()
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// #ifdef MP-ALIPAY
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if(!destWidth || !destHeight) {
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destWidth = width * pixelRatio;
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destHeight = height * pixelRatio;
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width = destWidth;
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height = destHeight;
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x = x * pixelRatio
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y = y * pixelRatio
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}
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// #endif
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const params = {
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...options,
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canvasId,
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id: canvasId,
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// #ifdef MP-ALIPAY
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x,
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y,
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width,
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height,
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destWidth,
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destHeight,
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// #endif
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canvas,
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success: (res) => {
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resolve(res.tempFilePath)
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},
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fail: (err) => {
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reject(err)
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}
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}
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// 抖音小程序canvas 2d不支持canvasToTempFilePath
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if(canvas && canvas.toDataURL){
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let next = true
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const devtools = uni.getSystemInfoSync().platform == 'devtools'
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// #ifdef MP-TOUTIAO
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next = uni.getSystemInfoSync().platform != 'devtools'
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if(!next){
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console.warn('[lime-signature] 抖音开发工具不支持bbox')
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}
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// #endif
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if((x || y) && next){
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const offCanvas = uni.createOffscreenCanvas({type: '2d'});
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const ctx = offCanvas.getContext("2d");
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const destWidth = Math.floor(width*pixelRatio)
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const destHeight = Math.floor(height*pixelRatio)
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offCanvas.width = destWidth // canvas.width;
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offCanvas.height = destHeight // canvas.height;
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// ctx.scale(pixelRatio, pixelRatio)
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// ctx.drawImage(canvas, Math.floor(x*pixelRatio), Math.floor(y*pixelRatio), destWidth, destHeight, 0,0, destWidth, destHeight);
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// 抖音不能在drawImage使用canvas
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const image = canvas.createImage()
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image.onload = ()=>{
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ctx.drawImage(image, Math.floor(x*pixelRatio), Math.floor(y*pixelRatio), destWidth, destHeight, 0,0, destWidth, destHeight)
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const tempFilePath = offCanvas.toDataURL();
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resolve(tempFilePath)
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if(params.success){
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params.success({tempFilePath})
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}
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}
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image.src = canvas.toDataURL()
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} else {
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const tempFilePath = canvas.toDataURL()
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resolve(tempFilePath)
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if(params.success){
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params.success({tempFilePath})
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}
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}
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} else
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if(canvas && canvas.toTempFilePath) {
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canvas.toTempFilePath(params)
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} else {
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uni.canvasToTempFilePath(params, context)
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}
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})
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} |