网站背景放烟花代码

快过年的时候,必须安排一下自己的网站美化这一块

 

为大家安排网页背景放烟花特效代码

 

这代码属于html5特效,不支持html5的浏览器无效果

 

我把此代码加在了我的博客的首页文件处,效果看本站

 

复制下方的代码放到你的模板文件中去

 

推荐放在模板的首页文件处

 

代码

<canvas id="canvas" style="position:fixed;top:0;left:0;width:100%;overflow:hidden;z-index:-9999;"></canvas>

<script>

// when animating on canvas, it is best to use requestAnimationFrame instead of setTimeout or setInterval

// not supported in all browsers though and sometimes needs a prefix, so we need a shim

window.requestAnimFrame = ( function() {

 return window.requestAnimationFrame ||

    window.webkitRequestAnimationFrame ||

    window.mozRequestAnimationFrame ||

    function( callback ) {

     window.setTimeout( callback, 1000 / 60 );

    };

})();



// now we will setup our basic variables for the demo

var canvas = document.getElementById( 'canvas' ),

  ctx = canvas.getContext( '2d' ),

  // full screen dimensions

  cw = window.innerWidth,

  ch = window.innerHeight,

  // firework collection

  fireworks = [],

  // particle collection

  particles = [],

  // starting hue

  hue = 120,

  // when launching fireworks with a click, too many get launched at once without a limiter, one launch per 5 loop ticks

  limiterTotal = 5,

  limiterTick = 0,

  // this will time the auto launches of fireworks, one launch per 80 loop ticks

  timerTotal = 80,

  timerTick = 0,

  mousedown = false,

  // mouse x coordinate,

  mx,

  // mouse y coordinate

  my;

  

// set canvas dimensions

canvas.width = cw;

canvas.height = ch;



// now we are going to setup our function placeholders for the entire demo



// get a random number within a range

function random( min, max ) {

 return Math.random() * ( max - min ) + min;

}



// calculate the distance between two points

function calculateDistance( p1x, p1y, p2x, p2y ) {

 var xDistance = p1x - p2x,

   yDistance = p1y - p2y;

 return Math.sqrt( Math.pow( xDistance, 2 ) + Math.pow( yDistance, 2 ) );

}



// create firework

function Firework( sx, sy, tx, ty ) {

 // actual coordinates

 this.x = sx;

 this.y = sy;

 // starting coordinates

 this.sx = sx;

 this.sy = sy;

 // target coordinates

 this.tx = tx;

 this.ty = ty;

 // distance from starting point to target

 this.distanceToTarget = calculateDistance( sx, sy, tx, ty );

 this.distanceTraveled = 0;

 // track the past coordinates of each firework to create a trail effect, increase the coordinate count to create more prominent trails

 this.coordinates = [];

 this.coordinateCount = 3;

 // populate initial coordinate collection with the current coordinates

 while( this.coordinateCount-- ) {

  this.coordinates.push( [ this.x, this.y ] );

 }

 this.angle = Math.atan2( ty - sy, tx - sx );

 this.speed = 2;

 this.acceleration = 1.05;

 this.brightness = random( 50, 70 );

 // circle target indicator radius

 this.targetRadius = 1;

}



// update firework

Firework.prototype.update = function( index ) {

 // remove last item in coordinates array

 this.coordinates.pop();

 // add current coordinates to the start of the array

 this.coordinates.unshift( [ this.x, this.y ] );

	

 // cycle the circle target indicator radius

 if( this.targetRadius < 8 ) {

  this.targetRadius += 0.3;

 } else {

  this.targetRadius = 1;

 }

	

 // speed up the firework

 this.speed *= this.acceleration;

	

 // get the current velocities based on angle and speed

 var vx = Math.cos( this.angle ) * this.speed,

   vy = Math.sin( this.angle ) * this.speed;

 // how far will the firework have traveled with velocities applied?

 this.distanceTraveled = calculateDistance( this.sx, this.sy, this.x + vx, this.y + vy );

	

 // if the distance traveled, including velocities, is greater than the initial distance to the target, then the target has been reached

 if( this.distanceTraveled >= this.distanceToTarget ) {

  createParticles( this.tx, this.ty );

  // remove the firework, use the index passed into the update function to determine which to remove

  fireworks.splice( index, 1 );

 } else {

  // target not reached, keep traveling

  this.x += vx;

  this.y += vy;

 }

}



// draw firework

Firework.prototype.draw = function() {

 ctx.beginPath();

 // move to the last tracked coordinate in the set, then draw a line to the current x and y

 ctx.moveTo( this.coordinates[ this.coordinates.length - 1][ 0 ], this.coordinates[ this.coordinates.length - 1][ 1 ] );

 ctx.lineTo( this.x, this.y );

 ctx.strokeStyle = 'hsl(' + hue + ', 100%, ' + this.brightness + '%)';

 ctx.stroke();

	

 ctx.beginPath();

 // draw the target for this firework with a pulsing circle

 ctx.arc( this.tx, this.ty, this.targetRadius, 0, Math.PI * 2 );

 ctx.stroke();

}



// create particle

function Particle( x, y ) {

 this.x = x;

 this.y = y;

 // track the past coordinates of each particle to create a trail effect, increase the coordinate count to create more prominent trails

 this.coordinates = [];

 this.coordinateCount = 5;

 while( this.coordinateCount-- ) {

  this.coordinates.push( [ this.x, this.y ] );

 }

 // set a random angle in all possible directions, in radians

 this.angle = random( 0, Math.PI * 2 );

 this.speed = random( 1, 10 );

 // friction will slow the particle down

 this.friction = 0.95;

 // gravity will be applied and pull the particle down

 this.gravity = 1;

 // set the hue to a random number +-20 of the overall hue variable

 this.hue = random( hue - 20, hue + 20 );

 this.brightness = random( 50, 80 );

 this.alpha = 1;

 // set how fast the particle fades out

 this.decay = random( 0.015, 0.03 );

}



// update particle

Particle.prototype.update = function( index ) {

 // remove last item in coordinates array

 this.coordinates.pop();

 // add current coordinates to the start of the array

 this.coordinates.unshift( [ this.x, this.y ] );

 // slow down the particle

 this.speed *= this.friction;

 // apply velocity

 this.x += Math.cos( this.angle ) * this.speed;

 this.y += Math.sin( this.angle ) * this.speed + this.gravity;

 // fade out the particle

 this.alpha -= this.decay;

	

 // remove the particle once the alpha is low enough, based on the passed in index

 if( this.alpha <= this.decay ) {

  particles.splice( index, 1 );

 }

}



// draw particle

Particle.prototype.draw = function() {

 ctx. beginPath();

 // move to the last tracked coordinates in the set, then draw a line to the current x and y

 ctx.moveTo( this.coordinates[ this.coordinates.length - 1 ][ 0 ], this.coordinates[ this.coordinates.length - 1 ][ 1 ] );

 ctx.lineTo( this.x, this.y );

 ctx.strokeStyle = 'hsla(' + this.hue + ', 100%, ' + this.brightness + '%, ' + this.alpha + ')';

 ctx.stroke();

}



// create particle group/explosion

function createParticles( x, y ) {

 // increase the particle count for a bigger explosion, beware of the canvas performance hit with the increased particles though

 var particleCount = 30;

 while( particleCount-- ) {

  particles.push( new Particle( x, y ) );

 }

}



// main demo loop

function loop() {

 // this function will run endlessly with requestAnimationFrame

 requestAnimFrame( loop );

	

 // increase the hue to get different colored fireworks over time

 hue += 0.5;

	

 // normally, clearRect() would be used to clear the canvas

 // we want to create a trailing effect though

 // setting the composite operation to destination-out will allow us to clear the canvas at a specific opacity, rather than wiping it entirely

 ctx.globalCompositeOperation = 'destination-out';

 // decrease the alpha property to create more prominent trails

 ctx.fillStyle = 'rgba(0, 0, 0, 0.5)';

 ctx.fillRect( 0, 0, cw, ch );

 // change the composite operation back to our main mode

 // lighter creates bright highlight points as the fireworks and particles overlap each other

 ctx.globalCompositeOperation = 'lighter';

	

 // loop over each firework, draw it, update it

 var i = fireworks.length;

 while( i-- ) {

  fireworks[ i ].draw();

  fireworks[ i ].update( i );

 }

	

 // loop over each particle, draw it, update it

 var i = particles.length;

 while( i-- ) {

  particles[ i ].draw();

  particles[ i ].update( i );

 }

	

 // launch fireworks automatically to random coordinates, when the mouse isn't down

 if( timerTick >= timerTotal ) {

  if( !mousedown ) {

   // start the firework at the bottom middle of the screen, then set the random target coordinates, the random y coordinates will be set within the range of the top half of the screen

   fireworks.push( new Firework( cw / 2, ch, random( 0, cw ), random( 0, ch / 2 ) ) );

   timerTick = 0;

  }

 } else {

  timerTick++;

 }

	

 // limit the rate at which fireworks get launched when mouse is down

 if( limiterTick >= limiterTotal ) {

  if( mousedown ) {

   // start the firework at the bottom middle of the screen, then set the current mouse coordinates as the target

   fireworks.push( new Firework( cw / 2, ch, mx, my ) );

   limiterTick = 0;

  }

 } else {

  limiterTick++;

 }

}



// mouse event bindings

// update the mouse coordinates on mousemove

canvas.addEventListener( 'mousemove', function( e ) {

 mx = e.pageX - canvas.offsetLeft;

 my = e.pageY - canvas.offsetTop;

});



// toggle mousedown state and prevent canvas from being selected

canvas.addEventListener( 'mousedown', function( e ) {

 e.preventDefault();

 mousedown = true;

});



canvas.addEventListener( 'mouseup', function( e ) {

 e.preventDefault();

 mousedown = false;

});



// once the window loads, we are ready for some fireworks!

window.onload = loop;

</script>

 

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未经允许不得转载:作者: 小新, 转载或复制请以 超链接形式 并注明出处 小新博客
原文地址: 《网站背景放烟花代码》 发布于2020年4月18日

本文链接:网站背景放烟花代码 - http://ais521.com/?post=109

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