Home > Article > Web Front-end > How to use CSS3 to create switching effects for irregular images
How to use CSS3 to create switching effects for irregular images

php中世界最好的语言Original: 2017-11-25 10:24:192338browse
I bring you a source code of how to use CSS3 to create switching effects for irregular images. Friends in need can use it.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>TweenMax不规则图片切换特效</title>
<link rel="stylesheet" type="text/css" href="css/style.css" />
</head>
<body>
<div id="container"> </div>
<script src=&#39;js/delaunay.js&#39;></script>
<script src=&#39;js/TweenMax.js&#39;></script>
<script>
 
const TWO_PI = Math.PI * 2;
 
var images = [],
    imageIndex = 0;
 
var image,
    imageWidth = 768,
    imageHeight = 485;
 
var vertices = [],
    indices = [],
    prevfrag = [],
    fragments = [];
 
var margin = 50;
 
var container = document.getElementById(&#39;container&#39;);
 
var clickPosition = [imageWidth * 0.5, imageHeight * 0.5];
 
window.onload = function() {
    TweenMax.set(container, {perspective:500});
 
    // images from http://www.hdwallpapers.in
    var urls = [
            &#39;images/1.jpg&#39;,
            &#39;images/2.jpg&#39;,
            &#39;images/3.jpg&#39;,
            &#39;images/4.jpg&#39;
        ],
        image,
        loaded = 0;
    // very quick and dirty hack to load and display the first image asap
    images[0] = image = new Image();
        image.onload = function() {
            if (++loaded === 1) {
               
                for (var i = 1; i < 4; i++) {
                    images[i] = image = new Image();
 
                    image.src = urls[i];
                }
                placeImage();
            }
        };
        image.src = urls[0];
};
 
function placeImage(transitionIn) {
    image = images[imageIndex];
 
    if (++imageIndex === images.length) imageIndex = 0;
 
    var num = Math.random();
    if(num < .25) {
      image.direction = "left";
    } else if(num < .5) {
      image.direction = "top";
    } else if(num < .75) {
      image.direction = "bottom";
    } else {
      image.direction = "right";
    }
 
    container.appendChild(image);
    image.style.opacity = 0;
 
    if (transitionIn !== false) {
        triangulateIn();
    }
}
 
function triangulateIn(event) {
    var box = image.getBoundingClientRect(),
        top = box.top,
        left = box.left;
 
    if(image.direction == "left") {
      clickPosition[0] = 0;
      clickPosition[1] = imageHeight / 2;
    } else if(image.direction == "top") {
      clickPosition[0] = imageWidth / 2;
      clickPosition[1] = 0;
    } else if(image.direction == "bottom") {
      clickPosition[0] = imageWidth / 2;
      clickPosition[1] = imageHeight;
    } else if(image.direction == "right") {
      clickPosition[0] = imageWidth;
      clickPosition[1] = imageHeight / 2;
    }
   
 
    triangulate();
    build();
}
 
function triangulate() {
    for(var i = 0; i < 40; i++) {     
      x = -margin + Math.random() * (imageWidth + margin * 2);
      y = -margin + Math.random() * (imageHeight + margin * 2);
      vertices.push([x, y]);
    }
    vertices.push([0,0]);
    vertices.push([imageWidth,0]);
    vertices.push([imageWidth, imageHeight]);
    vertices.push([0, imageHeight]);
 
    vertices.forEach(function(v) {
        v[0] = clamp(v[0], 0, imageWidth);
        v[1] = clamp(v[1], 0, imageHeight);
    });
 
    indices = Delaunay.triangulate(vertices);
}
 
function build() {
    var p0, p1, p2,
        fragment;
 
    var tl0 = new TimelineMax({onComplete:buildCompleteHandler});
 
    for (var i = 0; i < indices.length; i += 3) {
        p0 = vertices[indices[i + 0]];
        p1 = vertices[indices[i + 1]];
        p2 = vertices[indices[i + 2]];
 
        fragment = new Fragment(p0, p1, p2);
 
        var dx = fragment.centroid[0] - clickPosition[0],
            dy = fragment.centroid[1] - clickPosition[1],
            d = Math.sqrt(dx * dx + dy * dy),
            rx = 30 * sign(dy),
            ry = 90 * -sign(dx),
            delay = d * 0.003 * randomRange(0.9, 1.1);
        fragment.canvas.style.zIndex = Math.floor(d).toString();
 
        var tl1 = new TimelineMax();
 
        if(image.direction == "left") {
          rx = Math.abs(rx);
          ry = 0;         
        } else if(image.direction == "top") {
          rx = 0;
          ry = Math.abs(ry);
        } else if(image.direction == "bottom") {
          rx = 0;
          ry = - Math.abs(ry);
        } else if(image.direction == "right") {
          rx = - Math.abs(rx);
          ry = 0;
        }
       
        tl1.from(fragment.canvas, 1, {
              z:-50,
              rotationX:rx,
              rotationY:ry,
              scaleX:0,
              scaleY:0,
              ease:Cubic.easeIn
         });
        tl1.from(fragment.canvas, 0.4,{alpha:0}, 0.6);
     
        tl0.insert(tl1, delay);
 
        fragments.push(fragment);
        container.appendChild(fragment.canvas);
    }
}
 
function buildCompleteHandler() {
    // add pooling?
    image.style.opacity = 1;
    image.addEventListener(&#39;transitionend&#39;, function catchTrans() {
      fragments.forEach(function(f) {
          container.removeChild(f.canvas);
      });
 
      fragments.length = 0;
      vertices.length = 0;
      indices.length = 0;
 
      placeImage();
      this.removeEventListener(&#39;transitionend&#39;,catchTrans,false);
    }, false);
   
}
 
//////////////
// MATH UTILS
//////////////
 
function randomRange(min, max) {
    return min + (max - min) * Math.random();
}
 
function clamp(x, min, max) {
    return x < min ? min : (x > max ? max : x);
}
 
function sign(x) {
    return x < 0 ? -1 : 1;
}
 
//////////////
// FRAGMENT
//////////////
 
Fragment = function(v0, v1, v2) {
    this.v0 = v0;
    this.v1 = v1;
    this.v2 = v2;
 
    this.computeBoundingBox();
    this.computeCentroid();
    this.createCanvas();
    this.clip();
};
Fragment.prototype = {
    computeBoundingBox:function() {
        var xMin = Math.min(this.v0[0], this.v1[0], this.v2[0]),
            xMax = Math.max(this.v0[0], this.v1[0], this.v2[0]),
            yMin = Math.min(this.v0[1], this.v1[1], this.v2[1]),
            yMax = Math.max(this.v0[1], this.v1[1], this.v2[1]);
 
         this.box = {
            x:Math.round(xMin),
            y:Math.round(yMin),
            w:Math.round(xMax - xMin),
            h:Math.round(yMax - yMin)
        };
 
    },
    computeCentroid:function() {
        var x = (this.v0[0] + this.v1[0] + this.v2[0]) / 3,
            y = (this.v0[1] + this.v1[1] + this.v2[1]) / 3;
 
        this.centroid = [x, y];
    },
    createCanvas:function() {
        this.canvas = document.createElement(&#39;canvas&#39;);
        this.canvas.width = this.box.w;
        this.canvas.height = this.box.h;
        this.canvas.style.width = this.box.w + &#39;px&#39;;
        this.canvas.style.height = this.box.h + &#39;px&#39;;
        this.canvas.style.left = this.box.x + &#39;px&#39;;
        this.canvas.style.top = this.box.y + &#39;px&#39;;
        this.ctx = this.canvas.getContext(&#39;2d&#39;);
    },
    clip:function() {
        this.ctx.save();
        this.ctx.translate(-this.box.x, -this.box.y);
        this.ctx.beginPath();
        this.ctx.moveTo(this.v0[0], this.v0[1]);
        this.ctx.lineTo(this.v1[0], this.v1[1]);
        this.ctx.lineTo(this.v2[0], this.v2[1]);
        this.ctx.closePath();
        this.ctx.clip();
        this.ctx.drawImage(image, 0, 0);
        this.ctx.restore();
    }
};//@ sourceURL=pen.js
</script>
 
<div style="text-align:center;margin:10px 0; font:normal 14px/24px &#39;MicroSoft YaHei&#39;;">
</div>
</body>
</html>
That’s it for the codes for producing the switching special effects of irregular pictures. For more exciting information, please pay attention to other related articles on the PHP Chinese website!
How to use CSS3 to create switching effects for irregular images

Related articles
