// 动静尺寸
const dynamicDateSize = function (size) {//return (document.body.offsetWidth / 375) * size;
return (getClientW() / 375) * size
}
export function addWaterBack(text) {
const width = window.screen.width || document.body.offsetWidth;
const height = window.screen.height || document.body.clientHeight;
let selector = document.querySelector("body");
let section = document.createElement("section");
const styleStr = `
position: fixed;
width: 100%;
height: 100%;
left: 0;
top: 0;
pointer-events: none;
z-index: 199999999;`;
section.setAttribute('style', styleStr);
section.style.background = `url(${_canvasToimg(width, height, text)})`;
//section.classList.add("warter-back");
selector.appendChild(section);
//selector.style.background = `url(${_canvasToimg(width, height, text)})`;
}
function _canvasToimg(width, height, text) {
const width2 = width / 2;
const height3 = height / 5;
// 单个水印
let sCanvas = document.createElement("canvas"); // 创立 canvas 标签
sCanvas.width = width2; // 设置画布大小
sCanvas.height = height3;
let ctx = sCanvas.getContext("2d");
ctx.fillStyle = "rgba(35,24,21,0.1)";
const fontSize = Math.min(Number(CommonJs.dynamicDateSize(12)).toFixed(0) || 12, 24);
ctx.font = `${fontSize}px Arial`;
ctx.rotate((-25 * Math.PI) / 180);
ctx.fillText(text, 0, height3 / 1.5);
ctx.rotate((25 * Math.PI) / 180);
// 大的 canvas
let bCanvas = document.createElement("canvas");
bCanvas.width = width;
bCanvas.height = height;
let ctx1 = bCanvas.getContext("2d");
ctx1.clearRect(0, 0, width, height);
let pat = ctx1.createPattern(sCanvas, "repeat"); // 在指定的方向上反复指定的元素
ctx1.fillStyle = pat;
ctx1.fillRect(0, 0, width, width);
return sCanvas.toDataURL("image/png");
}