ExplorerCanvas Example 1 in Organigrams 8
File
js/ExplorerCanvas/examples/example1.html
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Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
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distributed under the License is distributed on an "AS IS" BASIS,
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limitations under the License.
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<html>
<head>
<title>ExplorerCanvas Example 1</title>
<!--[if IE]><script type="text/javascript" src="../excanvas.js"></script><![endif]-->
<script type="text/javascript">
var canvas, ctx;
var particles = [];
var NUM_PARTICLES = 20;
function Particle() {
this.x = Math.random() * canvas.width;
this.y = Math.random() * canvas.height;
this.xvel = Math.random() * 5 - 2.5;
this.yvel = Math.random() * 5 - 2.5;
}
Particle.prototype.update = function() {
this.x += this.xvel;
this.y += this.yvel;
this.yvel += 0.1;
if (this.x > canvas.width || this.x < 0) {
this.xvel = -this.xvel;
}
if (this.y > canvas.height || this.y < 0) {
this.yvel = -this.yvel;
}
}
function loop() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
for(var i = 0; i < NUM_PARTICLES; i++) {
particles[i].update();
ctx.beginPath();
ctx.moveTo(particles[i].x, particles[i].y);
ctx.lineTo(particles[i].x - particles[i].xvel,
particles[i].y - particles[i].yvel);
ctx.stroke();
ctx.closePath();
}
setTimeout(loop, 10);
}
function load() {
canvas = document.getElementById("cv");
ctx = canvas.getContext("2d");
for(var i = 0; i < NUM_PARTICLES; i++) {
particles[i] = new Particle();
}
ctx.lineWidth = "2";
ctx.strokeStyle = "rgb(255, 255, 255)";
loop();
}
</script>
<style>
body {
background-color:black;
margin:50px;
text-align:center;
}
canvas {
border:1px solid #444;
}
</style>
</head>
<body onload="load();">
<canvas id="cv" width="400" height="300"></canvas>
</body>
</html>
