表白必备小心心 biubiubiu~

野性酷女 2022-12-01 11:55 172阅读 0赞

**效果图**

![在这里插入图片描述][20200826204146384.gif_pic_center]

<!DOCTYPE html>
    <html lang="en">
    
    <head>
        <meta charset="UTF-8">
        <title>小心心</title>
        <style>
            body {
                background: #000800;
            }
            
            canvas {
                margin: 0 auto;
                display: block;
            }
        </style>
    </head>
    
    <body>
        <canvas></canvas>
        <div style="text-align:center;margin:50px 0; font:normal 14px/24px 'MicroSoft YaHei';color:#ffffff">
        </div>
    
    </body>
    <script>
        let canvas = document.querySelector('canvas'),
            speedSelect = document.querySelector('#speed'),
            width = 300,
            height = 300,
            ctx = canvas.getContext('2d'),
            pSystemSize = 1000,
            deform = {
                a: 100,
                s: 0.4,
                min: -200,
                max: 200,
                dir: 1
            }; // a=4 is natural if not animated;
    
        const mcos = Math.cos,
            msin = Math.sin,
            mpow = Math.pow,
            PI180 = Math.PI / 180,
            tau = Math.PI * 2;
    
        canvas.width = width;
        canvas.height = height;
        ctx.lineWidth = 1;
    
        const ParticleSystem = function(num) {
            this.scalar = 8;
            this.numParticles = num;
            this.allParticles = [];
            this.x = width * .5;
            this.y = height * .5;
            this.generate();
        }
        ParticleSystem.prototype.generate = function() {
            for (let i = 0; i < this.numParticles; i++) {
                let vo = {};
                vo.degrees = (360 / this.numParticles) * i * PI180;
                vo.parent = this;
                vo.x = width / 2;
                vo.y = height / 2;
                vo.vx = 0;
                vo.vy = 0;
                this.allParticles.push(new Particle(vo));
            }
        }
        ParticleSystem.prototype.update = function() {
            for (let i = 0; i < this.allParticles.length; i++) {
                this.allParticles[i].update();
            }
        }
    
        const Particle = function(vo) {
            this.degrees = vo.degrees;
            this.parent = vo.parent;
            this.x = vo.x;
            this.y = vo.y;
            this.vx = 0;
            this.vy = 0;
            this.colour = 'hsl(' + (Math.round((this.degrees * (180 / Math.PI)))) + ',100%,50%)';
        }
        Particle.prototype.update = function() {
            // http://mathworld.wolfram.com/HeartCurve.html
            this.vx = 16 * mpow(msin(this.degrees), 3) * deform.dir;
            this.vy = ((13 * mcos(this.degrees)) -
                (6 * mcos(2 * this.degrees)) - // 5
                (2 * mcos(3 * this.degrees)) -
                (mcos(deform.a * this.degrees))) * -1;
    
            // update position
            this.x = this.vx * this.parent.scalar + this.parent.x;
            this.y = this.vy * this.parent.scalar + this.parent.y;
        }
    
        function update() {
            if (deform.dir === 1) {
                if (deform.a > deform.min) {
                    deform.a -= deform.s;
                } else {
                    flipDirection();
                }
            } else {
                if (deform.a < deform.max) {
                    deform.a += deform.s;
                } else {
                    flipDirection();
                }
            }
            system.update();
        }
    
        function flipDirection() {
            deform.dir *= -1;
        }
    
        function draw() {
            ctx.clearRect(0, 0, width, height);
            ctx.save();
            for (let i = 0; i < system.numParticles; i++) {
                let p = system.allParticles[i];
                ctx.fillStyle = p.colour;
                ctx.beginPath();
                ctx.arc(p.x, p.y, 1, 0, tau, false);
                ctx.fill();
            }
            ctx.restore();
        }
    
        function animate() {
            update();
            draw();
            requestAnimationFrame(animate);
        }
        let system = new ParticleSystem(pSystemSize);
        animate();
    </script>
    
    </html>

[20200826204146384.gif_pic_center]: /images/20221123/f714709393df445ca8cdf15a94a4c502.png