添加图片修改

This commit is contained in:
lyc 2024-11-14 16:58:27 +08:00
parent d553d6b8a8
commit 863092b21b
3 changed files with 101 additions and 106 deletions

View File

@ -1,6 +1,6 @@
{ {
"name": "whiteboard_lyc", "name": "whiteboard_lyc",
"version": "0.1.3", "version": "0.1.7",
"description": "一个简单的在线白板", "description": "一个简单的在线白板",
"authors": [ "authors": [
{ {

View File

@ -50,14 +50,13 @@ export default class Export {
} }
// 导出为图片 // 导出为图片
async exportImage({ exportImage({
type = 'image/png', type = 'image/png',
renderBg = true, renderBg = true,
useBlob = false, useBlob = false,
paddingX = 10, paddingX = 10,
paddingY = 10, paddingY = 10,
onlySelected, onlySelected
backgroundColor
} = {}) { } = {}) {
// 计算所有元素的外包围框 // 计算所有元素的外包围框
let { minx, maxx, miny, maxy } = getMultiElementRectInfo( let { minx, maxx, miny, maxy } = getMultiElementRectInfo(
@ -65,11 +64,6 @@ export default class Export {
) )
let width = maxx - minx + paddingX * 2 let width = maxx - minx + paddingX * 2
let height = maxy - miny + paddingY * 2 let height = maxy - miny + paddingY * 2
if(!width && !height){
width = this.app.width
height = this.app.height
backgroundColor = '#ffffff'
}
// 创建导出canvas // 创建导出canvas
let { canvas, ctx } = createCanvas(width, height, { let { canvas, ctx } = createCanvas(width, height, {
noStyle: true, noStyle: true,
@ -79,12 +73,12 @@ export default class Export {
this.saveAppState() this.saveAppState()
this.changeAppState(minx - paddingX, miny - paddingY, ctx) this.changeAppState(minx - paddingX, miny - paddingY, ctx)
// 绘制背景颜色 // 绘制背景颜色
if (renderBg && backgroundColor ? backgroundColor : this.app.state.backgroundColor) { if (renderBg && this.app.state.backgroundColor) {
this.app.background.canvasAddBackgroundColor( this.app.background.canvasAddBackgroundColor(
ctx, ctx,
width, width,
height, height,
backgroundColor this.app.state.backgroundColor
) )
} }
// 绘制元素到导出canvas // 绘制元素到导出canvas
@ -102,94 +96,89 @@ export default class Export {
}, type) }, type)
}) })
} else { } else {
return canvas.toDataURL(type)
return await this.compressImg(canvas.toDataURL(type), 1, 0.2,type)
} }
} }
/** /**
* 压缩base64图片的函数 * 压缩base64图片的函数
* *
* @param {string} base64 - 图片的base64编码 * @param {string} base64 - 图片的base64编码
* @param {number} multiple - 缩放比例 * @param {number} multiple - 缩放比例
* @param {number} quality - 输出图片的质量0.0到1.0之间 * @param {number} quality - 输出图片的质量0.0到1.0之间
* @param {string} format - 输出图片的格式默认为"image/webp" 可选参数 image/pngimage/jpegimage/webp * @param {string} format - 输出图片的格式默认为"image/webp" 可选参数 image/pngimage/jpegimage/webp
* @param {number} min - 压缩后图片的最小KB大小 * @param {number} min - 压缩后图片的最小KB大小
* @param {number} max - 压缩后图片的最大KB大小 * @param {number} max - 压缩后图片的最大KB大小
* @returns {Promise<string>} - 返回压缩后的图片的base64编码 * @returns {Promise<string>} - 返回压缩后的图片的base64编码
*/ */
compressImg(base64, multiple, quality, format = 'image/webp', min, max) {
return new Promise((resolve, reject) => {
try {
// 如果base64为空则直接返回
if (!base64) {
return
}
// 创建一个新的Image对象
let newImage = new Image()
// 设置Image对象的src为传入的base64编码
newImage.src = base64
// 设置crossOrigin属性为'Anonymous',用于处理跨域图片
newImage.setAttribute('crossOrigin', 'Anonymous')
compressImg(base64, multiple, quality, format = "image/webp", min, max) { // 定义图片的宽度、高度和缩放比例
return new Promise((resolve, reject) => { let imgWidth, imgHeight, proportion
try {
// 如果base64为空则直接返回
if (!base64) {
return;
}
// 创建一个新的Image对象
let newImage = new Image();
// 设置Image对象的src为传入的base64编码
newImage.src = base64;
// 设置crossOrigin属性为'Anonymous',用于处理跨域图片
newImage.setAttribute('crossOrigin', 'Anonymous');
// 定义图片的宽度、高度和缩放比例 // 当图片加载完成后执行的操作
let imgWidth, imgHeight, proportion; newImage.onload = function () {
// 计算缩放后的宽度
proportion = this.width * multiple
// 记录原始宽度和高度
imgWidth = this.width
imgHeight = this.height
// 当图片加载完成后执行的操作 // 创建一个canvas元素
newImage.onload = function() { let canvas = document.createElement('canvas')
// 计算缩放后的宽度 // 获取canvas的2D渲染上下文
proportion = this.width * multiple; let ctx = canvas.getContext('2d')
// 记录原始宽度和高度
imgWidth = this.width;
imgHeight = this.height;
// 创建一个canvas元素 // 设置canvas的宽高按照等比例缩放
let canvas = document.createElement('canvas'); // 等比例缩小放大
// 获取canvas的2D渲染上下文 canvas.width = proportion
let ctx = canvas.getContext('2d'); canvas.height = proportion * (imgHeight / imgWidth)
// 设置canvas的宽高按照等比例缩放 // 清除canvas上的内容
// 等比例缩小放大 ctx.clearRect(0, 0, canvas.width, canvas.height)
canvas.width = proportion;
canvas.height = proportion * (imgHeight / imgWidth);
// 清除canvas上的内容 // 在canvas上绘制缩放后的图片
ctx.clearRect(0, 0, canvas.width, canvas.height); ctx.drawImage(this, 0, 0, canvas.width, canvas.height)
// 在canvas上绘制缩放后的图片 // 将canvas转换为base64编码的图片
ctx.drawImage(this, 0, 0, canvas.width, canvas.height); let smallBase64 = canvas.toDataURL(format, quality)
// 将canvas转换为base64编码的图片
let smallBase64 = canvas.toDataURL(format, quality);
// 如果设置了最小KB大小并且压缩后的图片大小小于最小KB大小则增加质量并重新压缩
if (min && smallBase64.length / 1024 < min) {
while (smallBase64.length / 1024 < min) {
quality += 0.01;
smallBase64 = canvas.toDataURL(format, quality);
}
}
// 如果设置了最大KB大小并且压缩后的图片大小大于最大KB大小则减小质量并重新压缩
else if (max && smallBase64.length / 1024 > max) {
while (smallBase64.length / 1024 > max) {
quality -= 0.01;
smallBase64 = canvas.toDataURL(format, quality);
}
}
// 将压缩后的图片的base64编码作为Promise的解决值返回
resolve(smallBase64);
};
} catch (error) {
reject(error)
throw new Error(error);
}
});
}
// 如果设置了最小KB大小并且压缩后的图片大小小于最小KB大小则增加质量并重新压缩
if (min && smallBase64.length / 1024 < min) {
while (smallBase64.length / 1024 < min) {
quality += 0.01
smallBase64 = canvas.toDataURL(format, quality)
}
}
// 如果设置了最大KB大小并且压缩后的图片大小大于最大KB大小则减小质量并重新压缩
else if (max && smallBase64.length / 1024 > max) {
while (smallBase64.length / 1024 > max) {
quality -= 0.01
smallBase64 = canvas.toDataURL(format, quality)
}
}
// 将压缩后的图片的base64编码作为Promise的解决值返回
resolve(smallBase64)
}
} catch (error) {
reject(error)
throw new Error(error)
}
})
}
// 保存app类当前状态数据 // 保存app类当前状态数据
saveAppState() { saveAppState() {

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@ -71,17 +71,23 @@ export default class ImageEdit extends EventEmitter {
img.onload = () => { img.onload = () => {
let width = img.width let width = img.width
let height = img.height let height = img.height
// 图片过大,缩小宽高
let ratio = img.width / img.height let appWidth = this.app.width
if (img.width > this.maxWidth || img.height > this.maxHeight) { let appHeight = this.app.height
if (ratio > this.maxRatio) { if(width > appWidth && height > appHeight){
width = this.maxWidth let ratio = (appWidth / width) - 0.2
height = this.maxWidth / ratio console.log(ratio)
} else { this.app.setZoom(ratio)
height = this.maxHeight
width = this.maxHeight * ratio
}
} }
if(height > appHeight && width <= appWidth){
let ratio = (appHeight / height)
this.app.setZoom(ratio)
}
if(width >= appWidth && height <= appHeight){
let ratio = (appWidth / width) - 0.2
this.app.setZoom(ratio)
}
let ratio = img.width / img.height
resolve({ resolve({
imageObj: img, imageObj: img,
size: { size: {