Html编写发射粒子爱心

时间:2024-11-01 07:08:33

 

<!DOCTYPE html>
<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    
    <title>????</title>
    <style>
        canvas {
            position: absolute;
            left: 0;
            top: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(0, 0, 0, .2);
        }
    </style>
</head>
<body>

<canvas id="heart" width="1920" height="947"></canvas>
<script>
    window.requestAnimationFrame =
        window.__requestAnimationFrame ||
        window.requestAnimationFrame ||
        window.webkitRequestAnimationFrame ||
        window.mozRequestAnimationFrame ||
        window.oRequestAnimationFrame ||
        window.msRequestAnimationFrame ||
        (function () {
            return function (callback, element) {
                var lastTime = element.__lastTime;
                if (lastTime === undefined) {
                    lastTime = 0;
                }
                var currTime = Date.now();
                var timeToCall = Math.max(1, 33 - (currTime - lastTime));
                window.setTimeout(callback, timeToCall);
                element.__lastTime = currTime + timeToCall;
            };
        })();
    window.isDevice = (/android|webos|iphone|ipad|ipod|blackberry|iemobile|opera mini/i.test(((navigator.userAgent || navigator.vendor || window.opera)).toLowerCase()));
    var loaded = false;
    var init = function () {
        if (loaded) return;
        loaded = true;
        var mobile = window.isDevice;
        var koef = mobile ? 0.5 : 1;
        var canvas = document.getElementById('heart');
        var ctx = canvas.getContext('2d');
        var width = canvas.width = koef * innerWidth;
        var height = canvas.height = koef * innerHeight;
        var rand = Math.random;
        ctx.fillStyle = "rgba(0,0,0,1)";
        ctx.fillRect(0, 0, width, height);

        var heartPosition = function (rad) {
            //return [Math.sin(rad), Math.cos(rad)];
            return [Math.pow(Math.sin(rad), 3), -(15 * Math.cos(rad) - 5 * Math.cos(2 * rad) - 2 * Math.cos(3 * rad) - Math.cos(4 * rad))];
        };
        var scaleAndTranslate = function (pos, sx, sy, dx, dy) {
            return [dx + pos[0] * sx, dy + pos[1] * sy];
        };

        window.addEventListener('resize', function () {
            width = canvas.width = koef * innerWidth;
            height = canvas.height = koef * innerHeight;
            ctx.fillStyle = "rgba(0,0,0,1)";
            ctx.fillRect(0, 0, width, height);
        });

        var traceCount = mobile ? 20 : 50;
        var pointsOrigin = [];
        var i;
        var dr = mobile ? 0.3 : 0.1;
        for (i = 0; i < Math.PI * 2; i += dr) pointsOrigin.push(scaleAndTranslate(heartPosition(i), 210, 13, 0, 0));
        for (i = 0; i < Math.PI * 2; i += dr) pointsOrigin.push(scaleAndTranslate(heartPosition(i), 150, 9, 0, 0));
        for (i = 0; i < Math.PI * 2; i += dr) pointsOrigin.push(scaleAndTranslate(heartPosition(i), 90, 5, 0, 0));
        var heartPointsCount = pointsOrigin.length;

        var targetPoints = [];
        var pulse = function (kx, ky) {
            for (i = 0; i < pointsOrigin.length; i++) {
                targetPoints[i] = [];
                targetPoints[i][0] = kx * pointsOrigin[i][0] + width / 2;
                targetPoints[i][1] = ky * pointsOrigin[i][1] + height / 2;
            }
        };

        var e = [];
        for (i = 0; i < heartPointsCount; i++) {
            var x = rand() * width;
            var y = rand() * height;
            e[i] = {
                vx: 0,
                vy: 0,
                R: 2,
                speed: rand() + 5,
                q: ~~(rand() * heartPointsCount),
                D: 2 * (i % 2) - 1,
                force: 0.2 * rand() + 0.7,
                f: "hsla(0," + ~~(40 * rand() + 60) + "%," + ~~(60 * rand() + 20) + "%,.3)",
                trace: []
            };
            for (var k = 0; k < traceCount; k++) e[i].trace[k] = {x: x, y: y};
        }

        var config = {
            traceK: 0.4,
            timeDelta: 0.01
        };

        var time = 0;
        var loop = function () {
            var n = -Math.cos(time);
            pulse((1 + n) * .5, (1 + n) * .5);
            time += ((Math.sin(time)) < 0 ? 9 : (n > 0.8) ? .2 : 1) * config.timeDelta;
            ctx.fillStyle = "rgba(0,0,0,.1)";
            ctx.fillRect(0, 0, width, height);
            for (i = e.length; i--;) {
                var u = e[i];
                var q = targetPoints[u.q];
                var dx = u.trace[0].x - q[0];
                var dy = u.trace[0].y - q[1];
                var length = Math.sqrt(dx * dx + dy * dy);
                if (10 > length) {
                    if (0.95 < rand()) {
                        u.q = ~~(rand() * heartPointsCount);
                    } else {
                        if (0.99 < rand()) {
                            u.D *= -1;
                        }
                        u.q += u.D;
                        u.q %= heartPointsCount;
                        if (0 > u.q) {
                            u.q += heartPointsCount;
                        }
                    }
                }
                u.vx += -dx / length * u.speed;
                u.vy += -dy / length * u.speed;
                u.trace[0].x += u.vx;
                u.trace[0].y += u.vy;
                u.vx *= u.force;
                u.vy *= u.force;
                for (k = 0; k < u.trace.length - 1;) {
                    var T = u.trace[k];
                    var N = u.trace[++k];
                    N.x -= config.traceK * (N.x - T.x);
                    N.y -= config.traceK * (N.y - T.y);
                }
                ctx.fillStyle = u.f;
                for (k = 0; k < u.trace.length; k++) {
                    ctx.fillRect(u.trace[k].x, u.trace[k].y, 1, 1);
                }
            }
            ctx.fillStyle = "rgba(255,255,255,1)";
            for (i = u.trace.length + 13; i--;) ctx.fillRect(targetPoints[i][0], targetPoints[i][1], 2, 2);

            window.requestAnimationFrame(loop, canvas);
        };
        loop();
    };

    var s = document.readyState;
    if (s === 'complete' || s === 'loaded' || s === 'interactive') init();
    else document.addEventListener('DOMContentLoaded', init, false);
</script>

</body></html>