也许你见过HTML5图片破碎动画特效，实现的原理也挺简单的。但是你应该没有见过视频也可以破碎重组，这个HTML5动画就是利用Canvas的相关特性，实现了点击鼠标让视频破碎重组的效果。在视频区域点击鼠标，即可让该区域的视频破碎，让后经过一段时间后，破碎的区域又可以重组还原，视觉效果非常棒。这篇HTML5教程将教你如何制作。

HTML代码

<div style="display:none">

<video id="sourcevid" autoplay="true" loop="true">

<source src="BigBuckBunny_640x360.mp4" type="video/mp4"/>

<source src="BigBuckBunny_640x360.ogv" type="video/ogg"/>

</video>

<canvas id="sourcecopy" width="640" height="360"></canvas></div><div><center>

<div style="z-index:1;position:relative;text-align:center;font-size:16px;font-weight:bold;width:1000px;top:60px;">Click video to blow it up!</div>

<canvas id="output" width="1000" height="600" onmousedown="dropBomb(event, this)" style="border: 0 none">        </canvas></center></div>

JavaScript代码

var video;var copy;var copycanvas;var draw;

var TILE_WIDTH = 32;var TILE_HEIGHT = 24;var TILE_CENTER_WIDTH = 16;var TILE_CENTER_HEIGHT = 12;var SOURCERECT = {x:0, y:0, width:0, height:0};var PAINTRECT = {x:0, y:0, width:1000, height:600};

function init(){

video = document.getElementById('sourcevid');

copycanvas = document.getElementById('sourcecopy');

copy = copycanvas.getContext('2d');

var outputcanvas = document.getElementById('output');

draw = outputcanvas.getContext('2d');

setInterval("processFrame()", 33);

}function createTiles(){

var offsetX = TILE_CENTER_WIDTH+(PAINTRECT.width-SOURCERECT.width)/2;

var offsetY = TILE_CENTER_HEIGHT+(PAINTRECT.height-SOURCERECT.height)/2;

var y=0;

while(y < SOURCERECT.height){

var x=0;

while(x < SOURCERECT.width){

var tile = new Tile();

tile.videoX = x;

tile.videoY = y;

tile.originX = offsetX+x;

tile.originY = offsetY+y;

tile.currentX = tile.originX;

tile.currentY = tile.originY;

tiles.push(tile);

x+=TILE_WIDTH;

}

y+=TILE_HEIGHT;

}

}

var RAD = Math.PI/180;var randomJump = false;var tiles = [];var debug = false;function processFrame(){

if(!isNaN(video.duration)){

if(SOURCERECT.width == 0){

SOURCERECT = {x:0,y:0,width:video.videoWidth,height:video.videoHeight};

createTiles();

}

//this is to keep my sanity while developing

if(randomJump){

randomJump = false;

video.currentTime = Math.random()*video.duration;

}

//loop

if(video.currentTime == video.duration){

video.currentTime = 0;

}

}

var debugStr = "";

//copy tiles

copy.drawImage(video, 0, 0);

draw.clearRect(PAINTRECT.x, PAINTRECT.y,PAINTRECT.width,PAINTRECT.height);

for(var i=0; i<tiles.length; i++){

var tile = tiles[i];

if(tile.force > 0.0001){

//expand

tile.moveX *= tile.force;

tile.moveY *= tile.force;

tile.moveRotation *= tile.force;

tile.currentX += tile.moveX;

tile.currentY += tile.moveY;

tile.rotation += tile.moveRotation;

tile.rotation %= 360;

tile.force *= 0.9;

if(tile.currentX <= 0 || tile.currentX >= PAINTRECT.width){

tile.moveX *= -1;

}

if(tile.currentY <= 0 || tile.currentY >= PAINTRECT.height){

tile.moveY *= -1;

}

}else if(tile.rotation != 0 || tile.currentX != tile.originX || tile.currentY != tile.originY){

//contract

var diffx = (tile.originX-tile.currentX)*0.2;

var diffy = (tile.originY-tile.currentY)*0.2;

var diffRot = (0-tile.rotation)*0.2;

if(Math.abs(diffx) < 0.5){

tile.currentX = tile.originX;

}else{

tile.currentX += diffx;

}

if(Math.abs(diffy) < 0.5){

tile.currentY = tile.originY;

}else{

tile.currentY += diffy;

}

if(Math.abs(diffRot) < 0.5){

tile.rotation = 0;

}else{

tile.rotation += diffRot;

}

}else{

tile.force = 0;

}

draw.save();

draw.translate(tile.currentX, tile.currentY);

draw.rotate(tile.rotation*RAD);

draw.drawImage(copycanvas, tile.videoX, tile.videoY, TILE_WIDTH, TILE_HEIGHT, -TILE_CENTER_WIDTH, -TILE_CENTER_HEIGHT, TILE_WIDTH, TILE_HEIGHT);

draw.restore();

}

if(debug){

debug = false;

document.getElementById('trace').innerHTML = debugStr;

}

}

function explode(x, y){

for(var i=0; i<tiles.length; i++){

var tile = tiles[i];

var xdiff = tile.currentX-x;

var ydiff = tile.currentY-y;

var dist = Math.sqrt(xdiff*xdiff + ydiff*ydiff);

var randRange = 220+(Math.random()*30);

var range = randRange-dist;

var force = 3*(range/randRange);

if(force > tile.force){

tile.force = force;

var radians = Math.atan2(ydiff, xdiff);

tile.moveX = Math.cos(radians);

tile.moveY = Math.sin(radians);

tile.moveRotation = 0.5-Math.random();

}

}

tiles.sort(zindexSort);

processFrame();

}function zindexSort(a, b){

return (a.force-b.force);

}

function dropBomb(evt, obj){

var posx = 0;

var posy = 0;

var e = evt || window.event;

if (e.pageX || e.pageY){

posx = e.pageX;

posy = e.pageY;

}else if (e.clientX || e.clientY) {

posx = e.clientX + document.body.scrollLeft + document.documentElement.scrollLeft;

posy = e.clientY + document.body.scrollTop + document.documentElement.scrollTop;

}

var canvasX = posx-obj.offsetLeft;

var canvasY = posy-obj.offsetTop;

explode(canvasX, canvasY);

}

function Tile(){

this.originX = 0;

this.originY = 0;

this.currentX = 0;

this.currentY = 0;

this.rotation = 0;

this.force = 0;

this.z = 0;

this.moveX= 0;

this.moveY= 0;

this.moveRotation = 0;

this.videoX = 0;

this.videoY = 0;

}

/*

getPixel

return pixel object {r,g,b,a}

*/function getPixel(imageData, x, y){

var data = imageData.data;

var pos = (x + y * imageData.width) * 4;

return {r:data[pos], g:data[pos+1], b:data[pos+2], a:data[pos+3]}

}/*

setPixel

set pixel object {r,g,b,a}

*/function setPixel(imageData, x, y, pixel){

var data = imageData.data;

var pos = (x + y * imageData.width) * 4;

data[pos] = pixel.r;

data[pos+1] = pixel.g;

data[pos+2] = pixel.b;

data[pos+3] = pixel.a;

}/*

copyPixel

faster then using getPixel/setPixel combo

*/function copyPixel(sImageData, sx, sy, dImageData, dx, dy){

var spos = (sx + sy * sImageData.width) * 4;

var dpos = (dx + dy * dImageData.width) * 4;

dImageData.data[dpos] = sImageData.data[spos];     //R

dImageData.data[dpos+1] = sImageData.data[spos+1]; //G

dImageData.data[dpos+2] = sImageData.data[spos+2]; //B

dImageData.data[dpos+3] = sImageData.data[spos+3]; //A

}

</script>

希望这篇文章可以帮助到你。总之，同学们，你想要的职坐标IT频道都能找到！