/**
 * Gaussian
 * By Raphael Rouvinov-Kats
 * 
 * Draws gaussian distribution values
 * https://en.wikipedia.org/wiki/Multivariate_normal_distribution
 * */

frameRate(0);

var addGaussianAtPosition = function(posX, posY) {
    if (!this.loadPixels) { return; }
    this.loadPixels();
    var pix=this.imageData.data;
    
    var l = 401 * 401;
    while(l--) {
        var x = l % 401;
        var y = (l-x)/401;
        var dx = posX - x;
        var dy = posY - y;
        
        var ang = atan2(dx, dy);
        
        var ind = (x + y * 400) << 2;
        pix[ind] = map(ang, -180, 180, 0, 255);
        pix[ind+1] = 0;
        pix[ind+2] = 0;
    }
    
    this.updatePixels();
};

var mousePressed = function() {
    addGaussianAtPosition(mouseX, mouseY);
};