<template>
<div class="s-canvas">
<canvas id="s-canvas" :width="contentWidth" :height="contentHeight"></canvas>
</div>
</template>
<script>
export default {
name: "SIdentify",
props: {
identifyCode: {
type: String,
default: "1234"
},
fontSizeMin: {
type: Number,
default: 16
},
fontSizeMax: {
type: Number,
default: 40
},
backgroundColorMin: {
type: Number,
default: 180
},
backgroundColorMax: {
type: Number,
default: 240
},
colorMin: {
type: Number,
default: 50
},
colorMax: {
type: Number,
default: 160
},
lineColorMin: {
type: Number,
default: 40
},
lineColorMax: {
type: Number,
default: 180
},
dotColorMin: {
type: Number,
default: 0
},
dotColorMax: {
type: Number,
default: 255
},
contentWidth: {
type: Number,
default: 112
},
contentHeight: {
type: Number,
default: 38
}
},
methods: {
// 生成一个随机数
randomNum(min, max) {
return Math.floor(Math.random() * (max - min) + min);
},
// 生成一个随机的颜色
randomColor(min, max) {
let r = this.randomNum(min, max);
let g = this.randomNum(min, max);
let b = this.randomNum(min, max);
return "rgb(" + r + "," + g + "," + b + ")";
},
drawPic() {
let canvas = document.getElementById("s-canvas");
let ctx = canvas.getContext("2d");
ctx.textBaseline = "bottom";
// 绘制背景
ctx.fillStyle = this.randomColor(
this.backgroundColorMin,
this.backgroundColorMax
);
ctx.fillRect(0, 0, this.contentWidth, this.contentHeight);
// 绘制文字
for (let i = 0; i < this.identifyCode.length; i++) {
this.drawText(ctx, this.identifyCode[i], i);
}
this.drawLine(ctx);
this.drawDot(ctx);
},
drawText(ctx, txt, i) {
ctx.fillStyle = this.randomColor(this.colorMin, this.colorMax);
ctx.font =
this.randomNum(this.fontSizeMin, this.fontSizeMax) + "px SimHei";
let x = (i + 1) * (this.contentWidth / (this.identifyCode.length + 1));
let y = this.randomNum(this.fontSizeMax, this.contentHeight - 5);
var deg = this.randomNum(-45, 45);
// 修改坐标原点和旋转角度
ctx.translate(x, y);
ctx.rotate((deg * Math.PI) / 180);
ctx.fillText(txt, 0, 0);
// 恢复坐标原点和旋转角度
ctx.rotate((-deg * Math.PI) / 180);
ctx.translate(-x, -y);
},
drawLine(ctx) {
// 绘制干扰线
for (let i = 0; i < 8; i++) {
ctx.strokeStyle = this.randomColor(
this.lineColorMin,
this.lineColorMax
);
ctx.beginPath();
ctx.moveTo(
this.randomNum(0, this.contentWidth),
this.randomNum(0, this.contentHeight)
);
ctx.lineTo(
this.randomNum(0, this.contentWidth),
this.randomNum(0, this.contentHeight)
);
ctx.stroke();
}
},
drawDot(ctx) {
// 绘制干扰点
for (let i = 0; i < 100; i++) {
ctx.fillStyle = this.randomColor(0, 255);
ctx.beginPath();
ctx.arc(
this.randomNum(0, this.contentWidth),
this.randomNum(0, this.contentHeight),
1,
0,
2 * Math.PI
);
ctx.fill();
}
}
},
watch: {
identifyCode() {
this.drawPic();
}
},
mounted() {
this.drawPic();
}
};
</script>
