Created
August 4, 2012 07:31
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just another inlet to tributary
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//laser math | |
//http://spot.colorado.edu/~lessley/pdf%20stuff/lasermath2.pdf | |
d3.select("#header").style("background-color","#000000") | |
var x0 = 616; | |
var y0 = 334; | |
var a = 565; | |
var b = 760; | |
//var b = (n-1)/(n+10); | |
var hx = -0.32; | |
var hy = 59; | |
var fbase = 1004; | |
var omega0 = 223 * Math.PI * fbase; | |
var om = omega0 * 0.19477; | |
var tempo = 0.25325; | |
var erasing = 0.2; | |
var linen = -34; | |
var cs = d3.interpolateHsl("#EC3F3F", "#E9D70C"); | |
var sopacity = 0.728; | |
var cf = d3.interpolateHsl("#BC00F8", "#ADFF00"); | |
var fopacity = 0.7; | |
var radius = 6; | |
var nt = 1740; | |
var to = 10; | |
function x(t, o) { | |
//return (a - b) * Math.cos(omega0*t) + h * Math.cos(omega0*t*(a/b-1)); | |
return (a - b) * Math.tan(2*o*t) + hx * Math.cos(o*t*(a-b)/b); | |
//return h * Math.cos(t*Math.PI); | |
} | |
function y(t, o) { | |
//return (a - b) * Math.sin(omega0*t) - h * Math.sin(omega0*t*(a/b-1)); | |
return (a - b) * Math.cos(o*t) - hy * Math.sin(o*t*(a-b)/b); | |
//return h * Math.sin(t*Math.PI); | |
} | |
function circle(ctx, p) { | |
//ctx.fillStyle = 'hsla(0,0%,' + 70 +'%,' + 1 + ')'; | |
ctx.beginPath(); | |
ctx.arc(p[0],p[1],radius,0,2*Math.PI); | |
ctx.fill(); | |
} | |
function line(ctx) { | |
ctx.beginPath(); | |
var i; | |
for(i=0;i<linen;i++) { | |
//ctx.strokeStyle = c(i/linen); | |
ctx.lineTo(x0 + x(i/linen, omega0), y0 + y(i/linen, omega0)); | |
} | |
ctx.stroke(); | |
} | |
tributary.init = function(ctx) { | |
d3.select("#display").style("background-color", "#000000") | |
ctx.globalCompositeOperation = 'source-over'; | |
}; | |
tributary.run = function(ctx,t) { | |
//tributary.clear(); //helper function to clear the canvas | |
ctx.fillStyle = "rgba(9,9,9," + erasing + ")"; | |
ctx.fillRect(0,0,tributary.sw,tributary.sh); | |
var tt = (t % 10)/tempo; | |
var p; | |
ctx.strokeStyle = cs(tt); | |
line(ctx); | |
p = [x0 + x(tt, om), y0 + y(tt, om)]; | |
ctx.fillStyle = cf(tt); | |
circle(ctx, p); | |
var i = 0; | |
for(i = 0; i < nt; i++) { | |
//p = [x0 + x(tt+i*tt/2, om), y0 + y(tt+i*tt/2, om)]; | |
p = [x0 + x(tt+i*to, om), y0 + y(tt+i*to, om)]; | |
ctx.fillStyle = cf(tt); | |
circle(ctx, p); | |
} | |
}; |
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