upgrade fluid && add snowflake

2024-12-27 14:25:16 +08:00
parent 470dcf001c
commit c65fb9718e
4 changed files with 224 additions and 31 deletions
@@ -0,0 +1,127 @@
+/* 控制下雪 */
+function snowFall(snow) {
+    /* 可配置属性 */
+    snow = snow || {};
+    this.maxFlake = snow.maxFlake || 150;   /* 最多片数 */
+    this.flakeSize = snow.flakeSize || 10;  /* 雪花形状 */
+    this.fallSpeed = snow.fallSpeed || 1;   /* 坠落速度 */
+}
+/* 兼容写法 */
+requestAnimationFrame = window.requestAnimationFrame ||
+    window.mozRequestAnimationFrame ||
+    window.webkitRequestAnimationFrame ||
+    window.msRequestAnimationFrame ||
+    window.oRequestAnimationFrame ||
+    function(callback) { setTimeout(callback, 1000 / 60); };
+ 
+cancelAnimationFrame = window.cancelAnimationFrame ||
+    window.mozCancelAnimationFrame ||
+    window.webkitCancelAnimationFrame ||
+    window.msCancelAnimationFrame ||
+    window.oCancelAnimationFrame;
+/* 开始下雪 */
+snowFall.prototype.start = function(){
+    /* 创建画布 */
+    snowCanvas.apply(this);
+    /* 创建雪花形状 */
+    createFlakes.apply(this);
+    /* 画雪 */
+    drawSnow.apply(this)
+}
+/* 创建画布 */
+function snowCanvas() {
+    /* 添加Dom结点 */
+    var snowcanvas = document.createElement("canvas");
+    snowcanvas.id = "snowfall";
+    snowcanvas.width = document.body.offsetWidth;
+    snowcanvas.height = window.innerHeight;
+    snowcanvas.setAttribute("style", "position:fixed; top: 0; left: 0; z-index: 9999; pointer-events: none;");
+    document.getElementsByTagName("body")[0].appendChild(snowcanvas);
+    this.canvas = snowcanvas;
+    this.ctx = snowcanvas.getContext("2d");
+    /* 窗口大小改变的处理 */
+    window.onresize = function() {
+        // snowcanvas.width = document.body.offsetWidth;
+        /* snowcanvas.height = window.innerHeight */
+    }
+}
+/* 雪运动对象 */
+function flakeMove(canvasWidth, canvasHeight, flakeSize, fallSpeed) {
+    this.x = Math.floor(Math.random() * canvasWidth);   /* x坐标 */
+    this.y = Math.floor(Math.random() * canvasHeight);  /* y坐标 */
+    this.size = Math.random() * flakeSize + 2;          /* 形状 */
+    this.maxSize = flakeSize;                           /* 最大形状 */
+    this.speed = Math.random() * 1 + fallSpeed;         /* 坠落速度 */
+    this.fallSpeed = fallSpeed;                         /* 坠落速度 */
+    this.velY = this.speed;                             /* Y方向速度 */
+    this.velX = 0;                                      /* X方向速度 */
+    this.stepSize = Math.random() / 30;                 /* 步长 */
+    this.step = 0                                       /* 步数 */
+}
+flakeMove.prototype.update = function() {
+    var x = this.x,
+        y = this.y;
+    /* 左右摆动(余弦) */
+    this.velX *= 0.98;
+    if (this.velY <= this.speed) {
+        this.velY = this.speed
+    }
+    this.velX += Math.cos(this.step += .05) * this.stepSize;
+ 
+    this.y += this.velY;
+    this.x += this.velX;
+    /* 飞出边界的处理 */
+    if (this.x >= canvas.width || this.x <= 0 || this.y >= canvas.height || this.y <= 0) {
+        this.reset(canvas.width, canvas.height)
+    }
+};
+/* 飞出边界-放置最顶端继续坠落 */
+flakeMove.prototype.reset = function(width, height) {
+    this.x = Math.floor(Math.random() * width);
+    this.y = 0;
+    this.size = Math.random() * this.maxSize + 2;
+    this.speed = Math.random() * 1 + this.fallSpeed;
+    this.velY = this.speed;
+    this.velX = 0;
+};
+// 渲染雪花-随机形状（此处可修改雪花颜色！！！）
+flakeMove.prototype.render = function(ctx) {
+    var snowFlake = ctx.createRadialGradient(this.x, this.y, 0, this.x, this.y, this.size);
+    snowFlake.addColorStop(0, "rgba(255, 255, 255, 0.9)");  /* 此处是雪花颜色，默认是白色 */
+    snowFlake.addColorStop(.5, "rgba(255, 255, 255, 0.5)"); /* 若要改为其他颜色，请自行查 */
+    snowFlake.addColorStop(1, "rgba(255, 255, 255, 0)");    /* 找16进制的RGB 颜色代码。 */
+    ctx.save();
+    ctx.fillStyle = snowFlake;
+    ctx.beginPath();
+    ctx.arc(this.x, this.y, this.size, 0, Math.PI * 2);
+    ctx.fill();
+    ctx.restore();
+};
+/* 创建雪花-定义形状 */
+function createFlakes() {
+    var maxFlake = this.maxFlake,
+        flakes = this.flakes = [],
+        canvas = this.canvas;
+    for (var i = 0; i < maxFlake; i++) {
+        flakes.push(new flakeMove(canvas.width, canvas.height, this.flakeSize, this.fallSpeed))
+    }
+}
+/* 画雪 */
+function drawSnow() {
+    var maxFlake = this.maxFlake,
+        flakes = this.flakes;
+    ctx = this.ctx, canvas = this.canvas, that = this;
+    /* 清空雪花 */
+    ctx.clearRect(0, 0, canvas.width, canvas.height);
+    for (var e = 0; e < maxFlake; e++) {
+        flakes[e].update();
+        flakes[e].render(ctx);
+    }
+    /*  一帧一帧的画 */
+    this.loop = requestAnimationFrame(function() {
+        drawSnow.apply(that);
+    });
+}
+/* 调用及控制方法 */
+var snow = new snowFall({maxFlake:200});
+snow.start();