处理谷歌地图marker旋转

/* * 功能：使用canvas旋转图标，并生成路径 * 参数：options（Object） * 用途：处理谷歌地图marker旋转 * */ const setRotation = (options) => {   return new Promise((resolve, reject) => {     let w = options.width || 40     let h = options.height || 40     let canvas = document.createElement('canvas')     canvas.width = w     canvas.height = h     let ctx = canvas.getContext('2d')     let angle = options.deg ? options.deg * Math.PI / 180 : 0     let centerX = w / 2     let centerY = h / 2     let dataURL = ''     let img = new Image()     img.src = options.url     img.onload = function() {       ctx.clearRect(0, 0, w, h)       ctx.save()       ctx.translate(centerX, centerY)       ctx.rotate(angle)       ctx.translate(-centerX, -centerY)       ctx.drawImage(img, centerX/2, 0)       ctx.restore()       dataURL = canvas.toDataURL('image/png')       resolve({         size: options.size,         origin: options.origin,         url: dataURL       })     }   }) }

来源：博客园

作者：kiscon

链接：https://www.cnblogs.com/kiscon/p/11423561.html