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/**
* Wave oscillators by Ken Fyrstenberg Nilsen
* http://abdiassoftware.com/
*
* CC-Attribute 3.0 License
*/
$(function () {
var ctx = canvas.getContext('2d');
var w, h;
canvas.width = w = window.innerWidth * 0.9;
canvas.height = h = window.innerHeight * 0.9;
var hOffset = h - 10;
var wOffset = w - 10;
var osc1 = new osc(0, 400, 0.09);
var count = 1000; // 40
var step = 1; //Math.ceil(w / count);
var buffer = new ArrayBuffer(count * 4);
var points = new Float32Array(buffer);
function fill() {
for (var i = 0; i < count; i++) {
points[i] = osc1.getAmp();
}
}
ctx.lineWidth = 1;
ctx.strokeStyle = '#ffffff';
ctx.fillStyle = 'rgb(50, 50, 80)';
$("#minPulseLength").on('keydown', function (e) {
if (e.keyCode == 13) {
var v = $("#minPulseLength").val();
osc1.min = v;
console.log("minP: " + v);
}
});
function loop() {
var i;
/// move points to the left
for (i = 0; i < count - 1; i++) {
points[i] = points[i + 1];
}
/// get a new point
points[count - 1] = osc1.getAmp(); //, osc2, osc3);
//ctx.clearRect(0, 0, w, h);
ctx.fillRect(0, 0, w, h);
/// render wave
ctx.beginPath();
ctx.moveTo(0, points[0]);
for (i = 1; i < count; i++) {
ctx.lineTo(i * step, points[i]);
}
ctx.strokeStyle = '#ffffff';
ctx.stroke();
var gradients = 5;
for (var z = -1; z < gradients; z++) {
ctx.beginPath();
ctx.moveTo(10, hOffset - (hOffset / 2 * ((z+1) / gradients)) );
ctx.lineTo(w, hOffset - (hOffset / 2 * ((z+1) / gradients)) );
ctx.strokeStyle = '#ff0000';
ctx.stroke();
}
requestAnimationFrame(loop);
}
loop();
/// oscillator object
function osc(minn, maxx, spd) {
var me = this,
a = 0,
max = getMax(),
min = getMin(),
speed = 0;
setMax(maxx);
setMin(minn);
setSpeed(spd);
this.getAmp = function () {
a += this.speed;
if (a >= 2.0) {
a = 0;
}
//return max * Math.sin(a * Math.PI);
var waveVal = a < 1 ? this.min : this.max;
// console.log(waveVal);
return waveVal;
}
function getMax() {
return me.max;
}
function getMin() {
return me.min;
}
function setMax(x) {
me.max = hOffset - x;
}
function setMin(x) {
me.min = hOffset - x;
}
function setSpeed(x) {
me.speed = x;
}
return this;
}
}
)
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