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</div> | </div> | ||
</header> | </header> | ||
+ | |||
+ | <section class="breadcrumb_area"> | ||
+ | <div class="overlay bg-parallax" data-stellar-ratio="0.8" data-stellar-vertical-offset="0" data-background=""></div> | ||
+ | <div class="page-cover text-center"> | ||
+ | |||
+ | <canvas id="canvas"></canvas></ol> | ||
+ | </div> | ||
+ | |||
+ | </div> | ||
+ | |||
+ | </section> | ||
<!--================Header Area =================--> | <!--================Header Area =================--> | ||
<img style="position:absolute;top:0px;left:0px;width:100%" src="https://static.igem.org/mediawiki/2018/1/10/T--AHUT_China--_bgshengwu.jpg" width="1100" height="3550" alt=""/></div> | <img style="position:absolute;top:0px;left:0px;width:100%" src="https://static.igem.org/mediawiki/2018/1/10/T--AHUT_China--_bgshengwu.jpg" width="1100" height="3550" alt=""/></div> | ||
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<script src="https://2018.igem.org/Team:AHUT_China/contact_js?action=raw&ctype=text/javascript" type="text/javascript" ></script> | <script src="https://2018.igem.org/Team:AHUT_China/contact_js?action=raw&ctype=text/javascript" type="text/javascript" ></script> | ||
<script src="https://2018.igem.org/Team:AHUT_China/custom_js?action=raw&ctype=text/javascript" type="text/javascript" ></script> | <script src="https://2018.igem.org/Team:AHUT_China/custom_js?action=raw&ctype=text/javascript" type="text/javascript" ></script> | ||
+ | <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'; | ||
+ | |||
+ | var text = "Welcom to our pages"; | ||
+ | ctx.font = "50px sans-serif"; | ||
+ | var textData = ctx.measureText(text); | ||
+ | ctx.fillStyle = "rgba("+parseInt(random(0,255))+","+parseInt(random(0,255))+","+parseInt(random(0,255))+",0.3)"; | ||
+ | ctx.fillText(text,cw /2-textData.width/2,ch/2); | ||
+ | |||
+ | // 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 | ||
+ | |||
+ | for(var h=0;h<50;h++) | ||
+ | { | ||
+ | fireworks.push( new Firework( cw / 2, ch/2, random( 0, cw ), random( 0, ch ) ) ); | ||
+ | } | ||
+ | |||
+ | |||
+ | 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/2, 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> | ||
</html> | </html> |
Revision as of 02:17, 7 October 2018