CSS-网页底部小鱼游动特效
约 953 字大约 3 分钟
2025-01-17
CSS-网页底部小鱼游动特效
<template>
<div class="fish-demo-container" id="fish-demo">
<div class="container">
<div id="jsi-flying-fish-container" class="container"></div>
<canvas id="fish"></canvas>
</div>
</div>
</template>
<script>
const RENDERER = {
POINT_INTERVAL: 5,
FISH_COUNT: 3,
MAX_INTERVAL_COUNT: 50,
INIT_HEIGHT_RATE: 0.5,
THRESHOLD: 50,
init: function () {
this.setParameters();
this.reconstructMethods();
this.setup();
this.bindEvent();
this.render();
},
setParameters: function () {
this.$window = window;
this.$document = document.getElementById("fish-demo");
this.$container = document.getElementById("jsi-flying-fish-container");
this.$canvas = document.getElementById("fish");
// this.$container.appendChild(this.$canvas)
this.context = this.$canvas.getContext("2d");
this.points = [];
this.fishes = [];
this.watchIds = [];
},
createSurfacePoints: function () {
var count = Math.round(this.width / this.POINT_INTERVAL);
this.pointInterval = this.width / (count - 1);
this.points.push(new SURFACE_POINT(this, 0));
for (var i = 1; i < count; i++) {
var point = new SURFACE_POINT(this, i * this.pointInterval),
previous = this.points[i - 1];
point.setPreviousPoint(previous);
previous.setNextPoint(point);
this.points.push(point);
}
},
reconstructMethods: function () {
this.watchWindowSize = this.watchWindowSize.bind(this);
this.jdugeToStopResize = this.jdugeToStopResize.bind(this);
this.startEpicenter = this.startEpicenter.bind(this);
this.moveEpicenter = this.moveEpicenter.bind(this);
this.reverseVertical = this.reverseVertical.bind(this);
this.render = this.render.bind(this);
},
setup: function () {
this.points.length = 0;
this.fishes.length = 0;
this.watchIds.length = 0;
this.intervalCount = this.MAX_INTERVAL_COUNT;
this.width = this.$container.offsetWidth;
this.height = this.$container.offsetHeight;
this.fishCount =
(((this.FISH_COUNT * this.width) / 500) * this.height) / 500;
this.$canvas.width = this.width;
this.$canvas.height = this.height;
this.reverse = false;
this.fishes.push(new FISH(this));
this.createSurfacePoints();
},
watchWindowSize: function () {
this.clearTimer();
this.tmpWidth = this.$window.width;
this.tmpHeight = this.$window.height;
this.watchIds.push(setTimeout(this.jdugeToStopResize, this.WATCH_INTERVAL));
},
clearTimer: function () {
while (this.watchIds.length > 0) {
clearTimeout(this.watchIds.pop());
}
},
jdugeToStopResize: function () {
var width = this.$window.width(),
height = this.$window.height(),
stopped = width == this.tmpWidth && height == this.tmpHeight;
this.tmpWidth = width;
this.tmpHeight = height;
if (stopped) {
this.setup();
}
},
bindEvent: function () {
this.$window.onresize = this.watchWindowSize;
this.$container.onclick = this.reverseVertical;
this.$container.onmouseenter = this.startEpicenter;
this.$container.addEventListener("onmousemove", this.moveEpicenter);
},
getAxis: function (event) {
var offset = this.getOffset(this.$container);
return {
x: event.clientX - offset.left + this.$document.scrollLeft,
y: event.clientY - offset.top + this.$document.scrollTop,
};
},
getOffset: function (Node, offset) {
if (!offset) {
offset = {};
offset.top = 0;
offset.left = 0;
}
if (Node == document.body) {
//当该节点为body节点时,结束递归
return offset;
}
offset.top += Node.offsetTop;
offset.left += Node.offsetLeft;
return this.getOffset(Node.parentNode, offset); //向上累加offset里的值
},
startEpicenter: function (event) {
this.axis = this.getAxis(event);
},
moveEpicenter: function (event) {
var axis = this.getAxis(event);
if (!this.axis) {
this.axis = axis;
}
this.generateEpicenter(axis.x, axis.y, axis.y - this.axis.y);
this.axis = axis;
},
generateEpicenter: function (x, y, velocity) {
if (
y < this.height / 2 - this.THRESHOLD ||
y > this.height / 2 + this.THRESHOLD
) {
return;
}
var index = Math.round(x / this.pointInterval);
if (index < 0 || index >= this.points.length) {
return;
}
this.points[index].interfere(y, velocity);
},
reverseVertical: function () {
this.reverse = !this.reverse;
for (var i = 0, count = this.fishes.length; i < count; i++) {
this.fishes[i].reverseVertical();
}
},
controlStatus: function () {
for (var i = 0, count = this.points.length; i < count; i++) {
this.points[i].updateSelf();
}
for (var i = 0, count = this.points.length; i < count; i++) {
this.points[i].updateNeighbors();
}
if (this.fishes.length < this.fishCount) {
if (--this.intervalCount == 0) {
this.intervalCount = this.MAX_INTERVAL_COUNT;
this.fishes.push(new FISH(this));
}
}
},
render: function () {
requestAnimationFrame(this.render);
this.controlStatus();
this.context.clearRect(0, 0, this.width, this.height);
this.context.fillStyle = "hsl(184, 95.00%, 47.50%)";
for (var i = 0, count = this.fishes.length; i < count; i++) {
this.fishes[i].render(this.context);
}
this.context.save();
this.context.globalCompositeOperation = "xor";
this.context.beginPath();
this.context.moveTo(0, this.reverse ? 0 : this.height);
for (var i = 0, count = this.points.length; i < count; i++) {
this.points[i].render(this.context);
}
this.context.lineTo(this.width, this.reverse ? 0 : this.height);
this.context.closePath();
this.context.fill();
this.context.restore();
},
};
var SURFACE_POINT = function (renderer, x) {
this.renderer = renderer;
this.x = x;
this.init();
};
SURFACE_POINT.prototype = {
SPRING_CONSTANT: 0.03,
SPRING_FRICTION: 0.9,
WAVE_SPREAD: 0.3,
ACCELARATION_RATE: 0.01,
init: function () {
this.initHeight = this.renderer.height * this.renderer.INIT_HEIGHT_RATE;
this.height = this.initHeight;
this.fy = 0;
this.force = { previous: 0, next: 0 };
},
setPreviousPoint: function (previous) {
this.previous = previous;
},
setNextPoint: function (next) {
this.next = next;
},
interfere: function (y, velocity) {
this.fy =
this.renderer.height *
this.ACCELARATION_RATE *
(this.renderer.height - this.height - y >= 0 ? -1 : 1) *
Math.abs(velocity);
},
updateSelf: function () {
this.fy += this.SPRING_CONSTANT * (this.initHeight - this.height);
this.fy *= this.SPRING_FRICTION;
this.height += this.fy;
},
updateNeighbors: function () {
if (this.previous) {
this.force.previous =
this.WAVE_SPREAD * (this.height - this.previous.height);
}
if (this.next) {
this.force.next = this.WAVE_SPREAD * (this.height - this.next.height);
}
},
render: function (context) {
if (this.previous) {
this.previous.height += this.force.previous;
this.previous.fy += this.force.previous;
}
if (this.next) {
this.next.height += this.force.next;
this.next.fy += this.force.next;
}
context.lineTo(this.x, this.renderer.height - this.height);
},
};
var FISH = function (renderer) {
this.renderer = renderer;
this.init();
};
FISH.prototype = {
GRAVITY: 0.4,
init: function () {
this.direction = Math.random() < 0.5;
this.x = this.direction
? this.renderer.width + this.renderer.THRESHOLD
: -this.renderer.THRESHOLD;
this.previousY = this.y;
this.vx = this.getRandomValue(4, 10) * (this.direction ? -1 : 1);
if (this.renderer.reverse) {
this.y = this.getRandomValue(
(this.renderer.height * 1) / 10,
(this.renderer.height * 4) / 10,
);
this.vy = this.getRandomValue(2, 5);
this.ay = this.getRandomValue(0.05, 0.2);
} else {
this.y = this.getRandomValue(
(this.renderer.height * 6) / 10,
(this.renderer.height * 9) / 10,
);
this.vy = this.getRandomValue(-5, -2);
this.ay = this.getRandomValue(-0.2, -0.05);
}
this.isOut = false;
this.theta = 0;
this.phi = 0;
},
getRandomValue: function (min, max) {
return min + (max - min) * Math.random();
},
reverseVertical: function () {
this.isOut = !this.isOut;
this.ay *= -1;
},
controlStatus: function (context) {
this.previousY = this.y;
this.x += this.vx;
this.y += this.vy;
this.vy += this.ay;
if (this.renderer.reverse) {
if (this.y > this.renderer.height * this.renderer.INIT_HEIGHT_RATE) {
this.vy -= this.GRAVITY;
this.isOut = true;
} else {
if (this.isOut) {
this.ay = this.getRandomValue(0.05, 0.2);
}
this.isOut = false;
}
} else {
if (this.y < this.renderer.height * this.renderer.INIT_HEIGHT_RATE) {
this.vy += this.GRAVITY;
this.isOut = true;
} else {
if (this.isOut) {
this.ay = this.getRandomValue(-0.2, -0.05);
}
this.isOut = false;
}
}
if (!this.isOut) {
this.theta += Math.PI / 20;
this.theta %= Math.PI * 2;
this.phi += Math.PI / 30;
this.phi %= Math.PI * 2;
}
this.renderer.generateEpicenter(
this.x + (this.direction ? -1 : 1) * this.renderer.THRESHOLD,
this.y,
this.y - this.previousY,
);
if (
(this.vx > 0 && this.x > this.renderer.width + this.renderer.THRESHOLD) ||
(this.vx < 0 && this.x < -this.renderer.THRESHOLD)
) {
this.init();
}
},
render: function (context) {
context.save();
context.translate(this.x, this.y);
context.rotate(Math.PI + Math.atan2(this.vy, this.vx));
context.scale(1, this.direction ? 1 : -1);
context.beginPath();
context.moveTo(-30, 0);
context.bezierCurveTo(-20, 15, 15, 10, 40, 0);
context.bezierCurveTo(15, -10, -20, -15, -30, 0);
context.fill();
context.save();
context.translate(40, 0);
context.scale(0.9 + 0.2 * Math.sin(this.theta), 1);
context.beginPath();
context.moveTo(0, 0);
context.quadraticCurveTo(5, 10, 20, 8);
context.quadraticCurveTo(12, 5, 10, 0);
context.quadraticCurveTo(12, -5, 20, -8);
context.quadraticCurveTo(5, -10, 0, 0);
context.fill();
context.restore();
context.save();
context.translate(-3, 0);
context.rotate(
(Math.PI / 3 + (Math.PI / 10) * Math.sin(this.phi)) *
(this.renderer.reverse ? -1 : 1),
);
context.beginPath();
if (this.renderer.reverse) {
context.moveTo(5, 0);
context.bezierCurveTo(10, 10, 10, 30, 0, 40);
context.bezierCurveTo(-12, 25, -8, 10, 0, 0);
} else {
context.moveTo(-5, 0);
context.bezierCurveTo(-10, -10, -10, -30, 0, -40);
context.bezierCurveTo(12, -25, 8, -10, 0, 0);
}
context.closePath();
context.fill();
context.restore();
context.restore();
this.controlStatus(context);
},
};
export default {
data() {
return {};
},
mounted() {
this.$nextTick(() => {
RENDERER.init();
});
},
methods: {},
};
</script>
<style scoped>
.fish-demo-container {
position: relative;
width: 100%;
height: 100%;
padding: 50px 0;
}
.container {
width: 100%;
height: 200px;
position: absolute;
z-index: -1;
opacity: 0.37;
bottom: 0;
left: 0;
}
</style>