script.js

var audioArray = null;

var root = {
  wavecolor: {  
    r: 125,
    g: 52,
    b: 253
    },
    rainbowSpeed: 0.5,
    rainbow: true,
    matrixspeed: 50
};

var c = document.getElementById("c");
var ctx = c.getContext("2d");

var hueFw = false;
var hue = -0.01;

// making the canvas full screen
c.height = window.innerHeight;
c.width = window.innerWidth;

// the characters
var konkani  = "゠アイウエオカキクケコサシスセソタチツテトナニヌネノハヒフヘホマミムメモヤユヨラリルレワヰヱヲンヺ・ーヽヿ0123456789"
// converting the string into an array of single characters
var characters = konkani.split("");
var font_size = 14;
var columns = c.width/font_size;    // number of columns for the rain
var gradient = ctx.createLinearGradient(0,10, 0,200);
// an array of drops - one per column
var drops = [];
// x below is the x coordinate
// 1 = y-coordinate of the drop (same for every drop initially)
for (var x = 0; x < columns; x++)
    drops[x] = 1;

// drawing the characters
function draw() {
    // Get the BG color based on the current time i.e. rgb(hh, mm, ss)
    // translucent BG to show trail

    ctx.fillStyle = "rgba(0,0,0, 0.05)";
    ctx.fillRect(0, 0, c.width, c.height);

    ctx.fillStyle = "#BBB"; // grey text
    ctx.font = font_size + "px arial";

    // looping over drops
    for (var i = 0; i < drops.length; i++)
    {
        // background color
        ctx.fillStyle = "rgba(10,10,10, 1)";
        ctx.fillRect(i * font_size, drops[i] * font_size,font_size,font_size);
        // a random chinese character to print
        var text = characters[Math.floor(Math.random() * characters.length)];
        // x = i * font_size, y = value of drops[i] * font_size

        if (root.rainbow) {
          hue += (hueFw) ? 0.01 : -0.01;
          var rr = Math.floor(127 * Math.sin(root.rainbowSpeed * hue + 0) + 128);
          var rg = Math.floor(127 * Math.sin(root.rainbowSpeed * hue + 2) + 128);
          var rb = Math.floor(127 * Math.sin(root.rainbowSpeed * hue + 4) + 128);
          ctx.fillStyle = 'rgba(' + rr + ',' + rg + ',' + rb + ')';
        } else {
          ctx.fillStyle = 'rgba(' + root.wavecolor.r + ',' + root.wavecolor.g + ',' + root.wavecolor.b + ')';
        }

        ctx.fillText(text, i * font_size, drops[i] * font_size);
        // Apply the speed change based on the audio data
        drops[i] += root.matrixspeed / (audioArray.length / columns);

        // sending the drop back to the top randomly after it has crossed the screen
        // adding randomness to the reset to make the drops scattered on the Y axis
       if (drops[i] * font_size > c.height && Math.random() > 0.975)
			      drops[i] = 0;
    }
}

setInterval(draw, root.matrixspeed);

function livelyAudioListener(audioArray) {
  // Copy the audio data into the global variable
  audioArray = audioArray;
}

function livelyPropertyListener(name, val)
{
  switch(name) {
    case "matrixColor":
      root.wavecolor =  hexToRgb(val);
      break;
    case "rainBow":
      root.rainbow = val;
      break;   
    case "rainbowSpeed":
      root.rainbowSpeed = val/100;
      break;
    case "matrixSpeed":
      root.matrixspeed = val;
      clearInterval(intervalId);
      intervalId = setInterval(draw, root.matrixspeed);        
      break;
  }
}

function hexToRgb(hex) {
  var result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
  return result ? {
    r: parseInt(result[1], 16),
    g: parseInt(result[2], 16),
    b: parseInt(result[3], 16)
  } : null;
}