| simon.fraser@apple.com | 099f65f | 2016-09-09 00:51:06 +0000 | [diff] [blame] | 1 | <!DOCTYPE html> |
| 2 | |
| 3 | <html> |
| 4 | <head> |
| 5 | <meta name="viewport" content="initial-scale=1.0"> |
| 6 | <style> |
| 7 | body { |
| 8 | margin: 0; |
| 9 | } |
| 10 | #stage { |
| 11 | position: relative; |
| 12 | width: 320px; |
| 13 | height: 320px; |
| 14 | border: 1px solid black; |
| 15 | overflow: hidden; |
| 16 | z-index: 0; |
| 17 | } |
| 18 | |
| 19 | .particle-h { |
| 20 | position: absolute; |
| 21 | animation: horizontal infinite 2s alternate ease-in-out; |
| 22 | } |
| 23 | |
| 24 | .particle-v { |
| 25 | position: absolute; |
| 26 | height: 20px; |
| 27 | width: 20px; |
| 28 | background-color: blue; |
| 29 | border-radius: 50%; |
| 30 | animation: vertical infinite 2s alternate ease-in-out; |
| 31 | } |
| 32 | |
| 33 | @keyframes horizontal { |
| 34 | from { |
| 35 | transform: translateX(0); |
| 36 | } |
| 37 | 50% { |
| 38 | transform: translateX(300px); |
| 39 | } |
| 40 | to { |
| 41 | transform: translateX(0); |
| 42 | } |
| 43 | } |
| 44 | |
| 45 | @keyframes vertical { |
| 46 | from { |
| 47 | transform: translateY(0); |
| 48 | } |
| 49 | 50% { |
| 50 | transform: translateY(300px); |
| 51 | } |
| 52 | to { |
| 53 | transform: translateY(0); |
| 54 | } |
| 55 | } |
| 56 | </style> |
| 57 | <script> |
| 58 | |
| 59 | var animationDuration = 2; |
| 60 | |
| 61 | function randomInt(min, max) |
| 62 | { |
| 63 | return Math.round(this.random(min, max)); |
| 64 | } |
| 65 | |
| 66 | function random(min, max) |
| 67 | { |
| 68 | return (Math.random() * (max - min)) + min; |
| 69 | } |
| 70 | |
| 71 | function randomColor() |
| 72 | { |
| 73 | var min = 32; |
| 74 | var max = 256 - 32; |
| 75 | return "#" |
| 76 | + this.randomInt(min, max).toString(16) |
| 77 | + this.randomInt(min, max).toString(16) |
| 78 | + this.randomInt(min, max).toString(16); |
| 79 | } |
| 80 | |
| 81 | function Point(x, y) |
| 82 | { |
| 83 | this.x = x; |
| 84 | this.y = y; |
| 85 | } |
| 86 | |
| 87 | Point.pointOnCircle = function(angle, radius) |
| 88 | { |
| 89 | return new Point(radius * Math.cos(angle), radius * Math.sin(angle)); |
| 90 | } |
| 91 | |
| 92 | Point.prototype = |
| 93 | { |
| 94 | add: function(other) |
| 95 | { |
| 96 | if(isNaN(other.x)) |
| 97 | return new Point(this.x + other, this.y + other); |
| 98 | return new Point(this.x + other.x, this.y + other.y); |
| 99 | }, |
| 100 | |
| 101 | subtract: function(other) |
| 102 | { |
| 103 | if(isNaN(other.x)) |
| 104 | return new Point(this.x - other, this.y - other); |
| 105 | return new Point(this.x - other.x, this.y - other.y); |
| 106 | }, |
| 107 | |
| 108 | move: function(angle, velocity, timeDelta) |
| 109 | { |
| 110 | return this.add(Point.pointOnCircle(angle, velocity * (timeDelta / 1000))); |
| 111 | }, |
| 112 | |
| 113 | multiply: function(other) |
| 114 | { |
| 115 | if(isNaN(other.x)) |
| 116 | return new Point(this.x * other, this.y * other); |
| 117 | return new Point(this.x * other.x, this.y * other.y); |
| 118 | }, |
| 119 | |
| 120 | length: function() { |
| 121 | return Math.sqrt( this.x * this.x + this.y * this.y ); |
| 122 | }, |
| 123 | |
| 124 | normalize: function() { |
| 125 | var l = Math.sqrt( this.x * this.x + this.y * this.y ); |
| 126 | this.x /= l; |
| 127 | this.y /= l; |
| 128 | return this; |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | function Particle(maxPosition) |
| 133 | { |
| 134 | this.horizontalContainer = document.createElement('div'); |
| 135 | this.horizontalContainer.className = 'particle-h'; |
| 136 | |
| 137 | var delay = random(0, animationDuration); |
| 138 | this.horizontalContainer.style.animationDuration = random(animationDuration - slop, animationDuration + slop) + 's'; |
| 139 | this.horizontalContainer.style.animationDelay = '-' + delay + 's'; |
| 140 | |
| 141 | this.element = document.createElement('div'); |
| 142 | this.element.className = 'particle-v'; |
| 143 | this.element.style.backgroundColor = randomColor(); |
| 144 | |
| 145 | this.horizontalContainer.appendChild(this.element); |
| 146 | |
| 147 | var slop = 0.2; |
| 148 | this.element.style.animationDuration = random(animationDuration - slop, animationDuration + slop) + 's'; |
| 149 | this.element.style.animationDelay = '-' + delay + 's'; |
| 150 | |
| 151 | this.maxPosition = maxPosition; |
| 152 | this.reset(); |
| 153 | this.move(); |
| 154 | } |
| 155 | |
| 156 | Particle.prototype = |
| 157 | { |
| 158 | reset: function() |
| 159 | { |
| 160 | this.size = new Point(20, 20); |
| 161 | this.maxLocation = this.maxPosition.subtract(this.size); |
| 162 | this.position = new Point(0, 0); |
| 163 | }, |
| 164 | |
| 165 | move: function() |
| 166 | { |
| 167 | this.horizontalContainer.style.transform = "translateX(" + this.position.x + "px)"; |
| 168 | this.element.style.transform = "translateY(" + this.position.y + "px) "; |
| 169 | } |
| 170 | } |
| 171 | |
| 172 | var numParticles = 20; |
| 173 | var particles = []; |
| 174 | |
| 175 | function makeParticles() |
| 176 | { |
| 177 | var stage = document.getElementById('stage'); |
| 178 | var maxPosition = new Point(320, 320); |
| 179 | for (var i = 0; i < numParticles; ++i) { |
| 180 | particles.push(new Particle(maxPosition)); |
| 181 | stage.appendChild(particles[i].horizontalContainer); |
| 182 | } |
| 183 | } |
| 184 | |
| 185 | function setupAnimation() |
| 186 | { |
| 187 | makeParticles(); |
| 188 | } |
| 189 | |
| 190 | window.addEventListener('load', setupAnimation, false); |
| 191 | </script> |
| 192 | </head> |
| 193 | <body> |
| 194 | |
| 195 | <div id="stage"> |
| 196 | </div> |
| 197 | |
| 198 | </body> |
| 199 | </html> |
