var startradius = 15;
var width = 70;
var height = 90;
var frame_time = 30;
var straighten_factor = 0.95;
var curviness = 0.2;
var color_speed = 0.03;
var new_branch_frames = 20;
var branch_shrink = 0.65; //0.95
var branch_opacity = 0.4;

var paper;
var branches = [];
var direction_offset = 0;
var frame = 0;
var fadecheck;
var cyclecheck;
var randomizecheck;
var wrapcheck;

function paper_click(event) {
    create_tree(event.pageX - paper.canvas.offsetLeft, event.pageY - paper.canvas.offsetTop);
}

function create_tree(x, y) {
    branches.push(new Branch(x, y, 0, startradius));
    branches.push(new Branch(x, y, Math.PI * 2 / 3, startradius));
    branches.push(new Branch(x, y, Math.PI * 4 / 3, startradius));
}

function Branch(x, y, direction, radius) {
    this.x = x;
    this.y = y;
    this.radius = radius;
    this.original_radius = radius;
    this.direction = direction;
}

function clock_tick() {
    if (fadecheck) {
        paper.fillRect(0,0,width,height);
    }

    if (cyclecheck) {
        r = Math.floor(Math.sin(frame * color_speed) * 128 + 128)
        g = Math.floor(Math.sin(frame * color_speed + Math.PI * 2 / 3) * 128 + 128)
        b = Math.floor(Math.sin(frame * color_speed + Math.PI * 4 / 3) * 128 + 128)
        paper.strokeStyle = "rgba(" + r + "," + g + "," + b + ", " + branch_opacity + ")";
    }

    if(++frame % new_branch_frames == 0) {
        if (randomizecheck) {
            x = (Math.random() + 0.1) * width * 0.8;
            y = (Math.random() + 0.1) * height * 0.8
            create_tree(x, y);
        } else {
            create_tree(width / 2, height / 2);
        }
    }
    
    direction_offset += Math.random() * curviness - curviness / 2;
    direction_offset *= straighten_factor;
    
    for (var i = branches.length - 1; i >= 0; i--) {
        var branch = branches[i];

        paper.beginPath();
        paper.lineWidth = branch.radius;
        paper.moveTo(branch.x, branch.y);
        
        branch.radius *= branch_shrink;
        branch.direction += direction_offset;
        branch.x += Math.cos(branch.direction) * branch.radius;
        branch.y += Math.sin(branch.direction) * branch.radius;
        
        paper.lineTo(branch.x, branch.y);
        paper.stroke();
        
        if (wrapcheck) {
            if (branch.x > width) branch.x -= width;
            if (branch.x < 0) branch.x += width;
            if (branch.y > height) branch.y -= height;
            if (branch.y < 0) branch.y += height;
        }

        if (branch.radius < branch.original_radius / 2) {
            branches.splice(i, 1);
            var new_radius = branch.original_radius / 2;
            if (new_radius > 1) {
                branches.push(new Branch(branch.x, branch.y, branch.direction,     new_radius));
                branches.push(new Branch(branch.x, branch.y, branch.direction + 1, new_radius));
            }
        }
    }
}

$(document).ready(function(){
    fadecheck = true;
    cyclecheck = true;
    randomizecheck = false;
    wrapcheck = false;
    new_branch_frames = 20;

    if(document.getElementById("notepad").getContext)
    {
	    paper = document.getElementById("notepad").getContext("2d")
		paper.fillStyle = "rgb(0, 0, 0)";
		paper.fillRect(0,0,width,height);
		paper.fillStyle = "rgba(0,0, 0, 0.005)";
		
		paper.strokeStyle = "rgba(128,128,64," + branch_opacity + ")";
		
		setInterval(clock_tick, frame_time);
    }
});