js-watermark

JavaScript 图片文字水印、图片图片水印生成工具,生成 base64 编码图片。

Este script não deve ser instalado diretamente. Este script é uma biblioteca de outros scripts para incluir com o diretório meta // @require https://update.greasyfork.org/scripts/452322/1470429/js-watermark.js

// @ts-nocheck
/**
 * @js-watermark.js
 * @author WhiteSev
 * @Created: 22-09-26
 * @repository: https://github.com/WhiteSevs/js-watermark
 * @forked by:https://github.com/gisonyeung/js-watermark
 * @description JavaScript 图片文字水印、图片图片水印生成工具,生成 base64 编码图片。
 */

(function (global, factory) {
	/**
	 * 不使用define
	 * typeof define === "function" && define.amd
	 * define(factory)
	 */
	if (typeof exports === "object" && typeof module !== "undefined") {
		/* 适用于NodeJs或typeScript */
		module.exports = factory();
	} else {
		global = typeof globalThis !== "undefined" ? globalThis : global || self;
		/* 适用于浏览器中,且this对象是window,如果this是其它,那么会在其它对象下注册对象 */
		global.Watermark = factory(global.Watermark);
	}
})(typeof window !== "undefined" ? window : this, function (AnotherWatermark) {
	"use strict";
	/**
	 * @class
	 */
	let Watermark = function () {};
	/**
	 * @author zhangxinxu(.com)
	 * @licence MIT
	 * @description http://www.zhangxinxu.com/wordpress/?p=7362
	 */
	/* api扩展-设置字符间距 */
	CanvasRenderingContext2D.prototype.letterSpacingText = function (
		text,
		x,
		y,
		letterSpacing
	) {
		var context = this;
		var canvas = context.canvas;

		if (!letterSpacing && canvas) {
			letterSpacing = parseFloat(window.getComputedStyle(canvas).letterSpacing);
		}
		if (!letterSpacing) {
			return this.fillText(text, x, y);
		}

		var arrText = text.split("");
		var align = context.textAlign || "left";

		/* 这里仅考虑水平排列 */
		var originWidth = context.measureText(text).width;
		/* 应用letterSpacing占据宽度 */
		var actualWidth = originWidth + letterSpacing * (arrText.length - 1);
		/* 根据水平对齐方式确定第一个字符的坐标	 */
		if (align == "center") {
			x = x - actualWidth / 2;
		} else if (align == "right") {
			x = x - actualWidth;
		}

		/* 临时修改为文本左对齐	 */
		context.textAlign = "left";
		/* 开始逐字绘制	 */
		arrText.forEach(function (letter) {
			var letterWidth = context.measureText(letter).width;
			context.fillText(letter, x, y);
			/* 确定下一个字符的横坐标	 */
			x = x + letterWidth + letterSpacing;
		});
		/* 对齐方式还原	 */
		context.textAlign = align;
	};

	/* api扩展-自动换行 */
	CanvasRenderingContext2D.prototype.wrapText = function (
		text,
		x,
		y,
		maxWidth,
		lineHeight,
		stroke
	) {
		if (
			typeof text != "string" ||
			typeof x != "number" ||
			typeof y != "number"
		) {
			return;
		}

		var context = this;
		var canvas = context.canvas;

		if (typeof maxWidth == "undefined") {
			maxWidth = (canvas && canvas.width) || 300;
		}
		if (typeof lineHeight == "undefined") {
			lineHeight =
				(canvas && parseInt(window.getComputedStyle(canvas).lineHeight)) ||
				parseInt(window.getComputedStyle(document.body).lineHeight);
		}

		/* 字符分隔为数组	 */
		var arrText = text.split("");
		var line = "";

		for (var n = 0; n < arrText.length; n++) {
			var testLine = line + arrText[n];
			var metrics = context.measureText(testLine);
			var testWidth = metrics.width;
			if (testWidth > maxWidth && n > 0) {
				if (stroke) {
					context.strokeText(line, x, y, canvas.width);
				} else {
					context.fillText(line, x, y);
				}
				line = arrText[n];
				y += lineHeight;
			} else {
				line = testLine;
			}
		}
		if (stroke) {
			context.strokeText(line, x, y, canvas.width);
		} else {
			context.fillText(line, x, y);
		}
	};

	/* api扩展-垂直排列 */
	CanvasRenderingContext2D.prototype.fillTextVertical = function (text, x, y) {
		var context = this;
		var canvas = context.canvas;

		var arrText = text.split("");
		var arrWidth = arrText.map(function (letter) {
			return context.measureText(letter).width;
		});

		var align = context.textAlign;
		var baseline = context.textBaseline;

		if (align == "left") {
			x = x + Math.max.apply(null, arrWidth) / 2;
		} else if (align == "right") {
			x = x - Math.max.apply(null, arrWidth) / 2;
		}
		if (
			baseline == "bottom" ||
			baseline == "alphabetic" ||
			baseline == "ideographic"
		) {
			y = y - arrWidth[0] / 2;
		} else if (baseline == "top" || baseline == "hanging") {
			y = y + arrWidth[0] / 2;
		}

		context.textAlign = "center";
		context.textBaseline = "middle";

		/* 开始逐字绘制 */
		arrText.forEach(function (letter, index) {
			/* 确定下一个字符的纵坐标位置 */
			var letterWidth = arrWidth[index];
			/* 是否需要旋转判断 */
			var code = letter.charCodeAt(0);
			if (code <= 256) {
				context.translate(x, y);
				/* 英文字符,旋转90° */
				context.rotate((90 * Math.PI) / 180);
				context.translate(-x, -y);
			} else if (index > 0 && text.charCodeAt(index - 1) < 256) {
				/* y修正 */
				y = y + arrWidth[index - 1] / 2;
			}
			context.fillText(letter, x, y);
			/* 旋转坐标系还原成初始态 */
			context.setTransform(1, 0, 0, 1, 0, 0);
			/* 确定下一个字符的纵坐标位置 */
			var letterWidth = arrWidth[index];
			y = y + letterWidth;
		});
		/* 水平垂直对齐方式还原 */
		context.textAlign = align;
		context.textBaseline = baseline;
	};

	/**
	 * 加载File对象
	 *
	 * @param {File} file
	 * @async
   * @returns {Promise<ProgressEvent<FileReader>>}
	 */
	function loadFile(file) {
		let fileReader = new FileReader();
		return new Promise((resolve) => {
			fileReader.onloadend = async function (event) {
				resolve(event);
			};
			fileReader.readAsDataURL(file);
		});
	}

	/**
	 * 加载Image对象
	 *
	 * @param {string} src
	 * @async
	 * @returns {Promise<HTMLImageElement>}
	 */
	function loadImage(src) {
		let image = new Image();

		return new Promise((resolve) => {
			image.onload = () => {
				resolve(image);
			};
			image.src = src;
		});
	}
	/**
	 * 检查坐标是否重复
	 * @param {any[]} arrayData
	 * @param {number} x
	 * @param {number} y
	 * @returns {boolean}
	 */
	function checkInArrayByPos(arrayData, x, y) {
		let flag = false;
		Array.from(arrayData).forEach((item) => {
			if (item["x"] == x && item["y"] == y) {
				flag = true;
				return;
			}
		});
		return flag;
	}
	/**
	 * 获取文字占据的宽度,高度
	 * @param {string} char
	 * @param {any} style
	 * @returns {{height:Number,width:Number}}
	 */
	function getCharSizeByCanvas(char, style = {}) {
		let textCanvas = document.createElement("canvas");
		textCanvas.style.positon = "ablsolute";
		let textCTX = textCanvas.getContext("2d");
		let { fontSize = 14, fontFamily = "Microsoft Yahei" } = style;
		document.body.appendChild(textCanvas);
		textCTX.font = `${fontSize}px ${fontFamily}`;
		document.body.removeChild(textCanvas);
		let text = textCTX.measureText(char); /* TextMetrics object */
		textCTX.fillText(char, 50, 50);
		let result = {
			height: parseInt(fontSize),
			width: parseInt(text.width),
		};
		return result;
	}
	/**
	 * 获取随机值
	 * @param {any[]} arr
	 */
	function getRandValue(arr) {
		if (arr instanceof Array) {
			return arr[Math.floor(Math.random() * arr.length)];
		} else {
			return arr;
		}
	}
	/**
	 * 通过 file 对象载入图片文件-异步
	 * @async
	 * @param {File} file
	 * @returns {Promise<boolean>}
	 */
	Watermark.prototype.setFile = function (file) {
		let that = this;
		return new Promise(async (resolve) => {
			try {
				var fileReader = await loadFile(file);
				await that.setImage(fileReader.target.result);
				resolve(true);
			} catch (error) {
				resolve(false);
			}
		});
	};
	/**
	 * 通过 base64 载入图片文件-异步
	 * @param {string} src
	 * @async
	 * @returns {Promise<boolean>}
	 */
	Watermark.prototype.setImage = function (src) {
		this.dataUrl = src;
		let that = this;
		return new Promise(async (res) => {
			var image = await loadImage(src);
			that.sizes = {
				width: image.width,
				height: image.height,
			};

			var canvas = document.createElement("canvas");

			canvas.width = that.sizes.width;
			canvas.height = that.sizes.height;
			var ctx = canvas.getContext("2d");

			ctx.drawImage(image, 0, 0);
			image = null;
			that.canvas = canvas;
			res(true);
		});
	};

	/**
	 * 获取是否存在图片对象
	 * @returns {boolean}
	 */
	Watermark.prototype.hasImage = function () {
		return !!this.dataUrl;
	};

	/**
	 * 获取当前图片尺寸
	 * @returns {number}
	 */
	Watermark.prototype.getSize = function () {
		return this.sizes;
	};

	/**
	 * 清空水印
	 */
	Watermark.prototype.clearMark = function () {
		let that = this;
		if (typeof that.canvas === "undefined") {
			return;
		}

		function _clearMark_() {
			var ctx = that.canvas.getContext("2d");
			/* 清空画布 */
			ctx.clearRect(0, 0, that.canvas.width, that.canvas.height);
			var w = that.canvas.width;
			var h = that.canvas.height;
			that.canvas.width = w;
			that.canvas.height = h;
			/* 清除path路径 */
			ctx.beginPath();
			/* 重绘 */
			var image = new Image();
			image.src = that.dataUrl;
			ctx.drawImage(image, 0, 0);
			image = null;
		}
		_clearMark_();
	};

	/**
	 * 添加文字水印(全屏)
	 * @param {object} opts
	 */
	Watermark.prototype.addText = function (opts) {
		var options = {
			text: ["Call By waterMark.addText"],
			fontSize: "6vw",
			fontFamily: "Microsoft Yahei",
			color: "#000000",
			textAlign: "center",
			/* 描边 */
			stroke: false,
			globalAlpha: 0.7,
			/* -360 ~ 360 */
			rotateAngle: 50,
			/* 必须大于0 */
			maxWidth: 100,
			/* 必须大于0 */
			xMoveDistance: 30,
			/* 必须大于0 */
			yMoveDistance: 30,
		};
		for (let key in options) {
			if (typeof opts[key] !== "undefined") {
				options[key] = opts[key];
			}
		}
		options.maxWidth = parseInt(options.maxWidth) > 0 ? options.maxWidth : 1;
		options.xMoveDistance =
			parseInt(options.xMoveDistance) > 0 ? options.xMoveDistance : 1;
		options.yMoveDistance =
			parseInt(options.yMoveDistance) > 0 ? options.yMoveDistance : 1;
		var ctx = this.canvas.getContext("2d");

		var fontSize = options.fontSize;
		fontSize = fontSize.toString();
		/* 转换 vw */
		if (~fontSize.indexOf("vw")) {
			fontSize = ((this.sizes.width / 100) * parseInt(fontSize)).toFixed(0);
		}
		fontSize = parseInt(fontSize);

		/* 绘制水印 */
		ctx.font = fontSize + "px " + options.fontFamily;
		ctx.fillStyle = options.color;
		ctx.textAlign = options.textAlign;
		ctx.globalAlpha = options.globalAlpha; /* 透明度 */

		let canvasWidth = this.sizes.width,
			/* 画布宽高 */
			canvasHeight = this.sizes.height;
		let rotateAngle = (options.rotateAngle * Math.PI) / 180;
		let xMoveDistance = options.xMoveDistance; /* 水平移动距离 */
		let yMoveDistance = options.yMoveDistance; /* 垂直移动距离 */
		let maxWidth = options.maxWidth; /* 文字最大宽度 */
		let lineHeight = fontSize; /* 文字占据高度 */
		let pos = [];
		for (var i = canvasWidth / 2; i < canvasWidth; i += xMoveDistance) {
			/* 右侧铺满 */
			for (var j = canvasHeight / 2; j < canvasHeight; j += yMoveDistance) {
				/* 右下 */
				if (!checkInArrayByPos(pos, i, j)) {
					pos = pos.concat({
						x: i,
						y: j,
					});
					ctx.setTransform(1, 0, 0, 1, 0, 0);
					ctx.translate(i, j);
					ctx.rotate(rotateAngle);
					ctx.wrapText(
						getRandValue(options.text),
						0,
						0,
						maxWidth,
						lineHeight,
						options.stroke
					);
				}
			}
			for (var k = canvasHeight / 2; k > 0; k -= yMoveDistance) {
				/* 右上 */
				if (!checkInArrayByPos(pos, i, k)) {
					pos = pos.concat({
						x: i,
						y: k,
					});
					ctx.setTransform(1, 0, 0, 1, 0, 0);
					ctx.translate(i, k);
					ctx.rotate(rotateAngle);
					ctx.wrapText(
						getRandValue(options.text),
						0,
						0,
						maxWidth,
						lineHeight,
						options.stroke
					);
				}
			}
		}

		for (var i = canvasWidth / 2; i > 0; i -= xMoveDistance) {
			/* 左侧铺满 */
			for (var j = canvasHeight / 2; j < canvasHeight; j += yMoveDistance) {
				/* 左下 */
				if (!checkInArrayByPos(pos, i, j)) {
					pos = pos.concat({
						x: i,
						y: j,
					});
					ctx.setTransform(1, 0, 0, 1, 0, 0);
					ctx.translate(i, j);
					ctx.rotate(rotateAngle);
					ctx.wrapText(
						getRandValue(options.text),
						0,
						0,
						maxWidth,
						lineHeight,
						options.stroke
					);
				}
			}
			for (var k = canvasHeight / 2; k > 0; k -= yMoveDistance) {
				/* 左上 */
				if (!checkInArrayByPos(pos, i, k)) {
					pos = pos.concat({
						x: i,
						y: k,
					});
					ctx.setTransform(1, 0, 0, 1, 0, 0);
					ctx.translate(i, k);
					ctx.rotate(rotateAngle);
					ctx.wrapText(
						getRandValue(options.text),
						0,
						0,
						maxWidth,
						lineHeight,
						options.stroke
					);
				}
			}
		}
	};

	/**
	 * 添加像素文字水印(单个)
	 * @param {object} opts
	 */
	Watermark.prototype.addPixelText = function (opts) {
		var options = {
			text: "像素文字水印",
			/* 像素文字 */
			big: {
				fontSize: 150,
				fontFamily: "微软雅黑",
				textAlign: "center",
				rotateAngle: 0,
				/* 描边 */
				stroke: false,
			},
			/* 绘制像素的文字 */
			small: {
				fontSize: 10,
				fontFamily: "微软雅黑",
				color: "#000",
				textAlign: "center",
				globalAlpha: 0.7,
			},
		};
		for (let key in options) {
			if (typeof opts[key] !== "undefined") {
				options[key] = opts[key];
			}
		}
		var ctx = this.canvas.getContext("2d");
		var tmpCanvas = document.createElement("canvas");
		var tmpctx = tmpCanvas.getContext("2d");
		tmpCanvas.width = this.sizes.width;
		tmpCanvas.height = this.sizes.height;
		tmpctx.font = options.big.fontSize + "px " + options.big.fontFamily;
		tmpctx.textAlign = options.big.textAlign;
		tmpctx.textBaseline = "middle";
		tmpctx.translate(tmpCanvas.width / 2, tmpCanvas.height / 2);
		tmpctx.rotate((options.big.rotateAngle * Math.PI) / 180);
		tmpctx.translate(-tmpCanvas.width / 2, -tmpCanvas.height / 2);
		if (options.big.stroke) {
			tmpctx.strokeText(
				options.text,
				tmpCanvas.width / 2,
				tmpCanvas.height / 2,
				tmpCanvas.width
			);
		} else {
			tmpctx.fillText(options.text, tmpCanvas.width / 2, tmpCanvas.height / 2);
		}

		var textArray = options.text.split("");
		var textPixleInfo = tmpctx.getImageData(
			0,
			0,
			tmpCanvas.width,
			tmpCanvas.height
		);
		var pixelArray = [];
		for (var i = 0; i < tmpCanvas.height; i += options.small.fontSize) {
			for (var j = 0; j < tmpCanvas.width; j += options.small.fontSize) {
				var index = j + i * tmpCanvas.width;
				var a = textPixleInfo.data[index * 4 + 3];
				if (a > 128) {
					//存入数组
					pixelArray.push({
						text: getRandValue(textArray),
						x: j,
						y: i,
					});
				}
			}
		}

		ctx.font = options.small.fontSize + "px " + options.small.fontFamily;
		ctx.fillStyle = options.small.color;
		ctx.textAlign = options.small.textAlign;
		ctx.textBaseline = "middle";
		ctx.globalAlpha = options.small.globalAlpha;
		pixelArray.forEach((item) => {
			ctx.fillText(item.text, item.x, item.y);
		});
	};

	/**
	 * 添加图片水印(全屏)
	 * @param {object} opts
	 * @returns
	 */
	Watermark.prototype.addImage = function (opts) {
		if (opts.imageArray == null) {
			alert("参数缺少imageArray");
			return false;
		}
		if (opts.imageArray.length === 0) {
			alert("参数imageArray不能为空");
			return false;
		}
		let options = {
			imageArray: [],
			/* 里面为水印Image对象 */
			width: 50,
			/* 必须大于0 */
			height: 50,
			/* 必须大于0 */
			globalAlpha: 0.5,
			rotateAngle: 0,
			xMoveDistance: 70,
			/* 必须大于0 */
			yMoveDistance: 70,
			/* 必须大于0 */
		};
		for (let key in options) {
			if (typeof opts[key] !== "undefined") {
				options[key] = opts[key];
			}
		}
		options.width = parseInt(options.width) > 0 ? options.width : 1;
		options.height = parseInt(options.height) > 0 ? options.height : 1;
		options.xMoveDistance =
			parseInt(options.xMoveDistance) > 0 ? options.xMoveDistance : 1;
		options.yMoveDistance =
			parseInt(options.yMoveDistance) > 0 ? options.yMoveDistance : 1;
		let ctx = this.canvas.getContext("2d");

		let waterImageCanvasArray = [];
		let waterImageCanvasDiagonal = parseInt(
			Math.sqrt(options.width * options.width + options.height * options.height)
		); /* 水印对角线 */

		let canvasWidth = this.sizes.width,
			/* 画布宽高 */
			canvasHeight = this.sizes.height;
		let rotateAngle = (options.rotateAngle * Math.PI) / 180; /* 旋转角度 */
		let xMoveDistance = options.xMoveDistance; /* 水平移动距离 */
		let yMoveDistance = options.yMoveDistance; /* 垂直移动距离 */

		let centerDrawLeftPosX =
			canvasWidth / 2 -
			waterImageCanvasDiagonal / 2; /* 中心的绘制水印的左上角坐标x */
		let centerDrawLeftPosY =
			canvasHeight / 2 -
			waterImageCanvasDiagonal / 2; /* 绘制水印的左上角坐标y */
		let waterDrawPosX =
			(waterImageCanvasDiagonal - options.width) / 2; /* 水印里图片坐标x */
		let waterDrawPosY =
			(waterImageCanvasDiagonal - options.height) / 2; /* 水印里图片坐标y */

		Array.from(options.imageArray).forEach((item) => {
			/* 先把水印绘制好 */
			var waterImageCanvas = document.createElement("canvas");
			var waterctx = waterImageCanvas.getContext("2d");

			waterImageCanvas.width = waterImageCanvasDiagonal;
			waterImageCanvas.height = waterImageCanvasDiagonal;
			waterctx.globalAlpha = options.globalAlpha; /* 透明度 */
			waterctx.translate(
				waterImageCanvasDiagonal / 2,
				waterImageCanvasDiagonal / 2
			);
			waterctx.rotate(rotateAngle);
			waterctx.translate(
				-waterImageCanvasDiagonal / 2,
				-waterImageCanvasDiagonal / 2
			);
			waterctx.drawImage(
				item,
				waterDrawPosX,
				waterDrawPosY,
				options.width,
				options.height
			);

			waterImageCanvasArray = waterImageCanvasArray.concat(waterImageCanvas);
		});

		function randomArrayData(array_data) {
			/* 随机项 */
			return array_data[Math.floor(Math.random() * array_data.length)];
		}
		ctx.setTransform(1, 0, 0, 1, 0, 0);
		let pos = [];
		for (let i = centerDrawLeftPosX; i < canvasWidth; i += xMoveDistance) {
			/* 右侧铺满 */
			for (let j = centerDrawLeftPosY; j < canvasHeight; j += yMoveDistance) {
				/* 右下 */
				if (!checkInArrayByPos(pos, i, j)) {
					pos = pos.concat({
						x: i,
						y: j,
					});
					ctx.drawImage(
						randomArrayData(waterImageCanvasArray),
						i,
						j
					); /* 绘制水印 */
				}
			}
			for (
				let k = centerDrawLeftPosY;
				k > -Math.abs(waterImageCanvasDiagonal);
				k -= yMoveDistance
			) {
				/* 右上 */
				if (!checkInArrayByPos(pos, i, k)) {
					pos = pos.concat({
						x: i,
						y: k,
					});
					ctx.drawImage(randomArrayData(waterImageCanvasArray), i, k);
				}
			}
		}
		for (
			let i = centerDrawLeftPosX;
			i > -Math.abs(waterImageCanvasDiagonal);
			i -= xMoveDistance
		) {
			/* 左侧铺满 */
			for (let j = centerDrawLeftPosY; j < canvasHeight; j += yMoveDistance) {
				/* 左下 */
				if (!checkInArrayByPos(pos, i, j)) {
					pos = pos.concat({
						x: i,
						y: j,
					});
					ctx.drawImage(randomArrayData(waterImageCanvasArray), i, j);
				}
			}
			for (
				let k = centerDrawLeftPosY;
				k > -Math.abs(waterImageCanvasDiagonal);
				k -= yMoveDistance
			) {
				/* 左上 */
				if (!checkInArrayByPos(pos, i, k)) {
					pos = pos.concat({
						x: i,
						y: k,
					});
					ctx.drawImage(randomArrayData(waterImageCanvasArray), i, k);
				}
			}
		}
	};

	/**
	 * 获得原图
	 * @returns {?string}
	 */
	Watermark.prototype.getPreview = function () {
		return this.dataUrl;
	};

	/**
	 * 绘制图片
	 * @param {string} type png|jpeg
	 * @returns
	 */
	Watermark.prototype.render = function (type) {
		type = type === "png" ? "png" : "jpeg";
		return this.canvas.toDataURL("image/" + type);
	};

	/**
	 * 绘制图片Blob Url-异步
	 * @async
	 */
	Watermark.prototype.renderBlob = function () {
		let that = this;
		return new Promise((res) => {
			that.canvas.toBlob(function (blob) {
				res(window.URL.createObjectURL(blob));
			});
		});
	};

	/**
	 * 释放控制权
	 * @returns {Watermark}
	 */
	Watermark.prototype.noConflict = function () {
		if (window.Watermark) {
			delete window.Watermark;
		}
		if (AnotherWatermark) {
			window.Watermark = AnotherWatermark;
		}
		return Watermark;
	};
	return Watermark;
});