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