const Util = {

//inheritance function

inherits(childClass, parentClass) {

childClass.prototype = Object.create(parentClass.prototype);

childClass.prototype.constructor = childClass;

},

//random vector

randomVec(length) {

const deg = 2 * Math.PI * Math.random();

return Util.scale([Math.sin(deg), Math.cos(deg)], length);

},

// Scale the length of a vector by the given amount.

scale(vec, m) {

return [vec[0] * m, vec[1] * m];

},

//random Position in canvas space

randomPos(radius){

return [Math.floor(Math.random()*(1000- radius)), Math.floor(Math.random()*(600 - radius))];

},

//random color

randRGB(){

let r = Math.floor(Math.random()*255);

let g = Math.floor(Math.random()*255);

let b = Math.floor(Math.random()*255);

return `rgb(${r}, ${g}, ${b})`;

},

//wrap helper function

wrap(posPt, max){

if(posPt < 0){

return max - (Math.floor(posPt) % max);

}

else if (posPt > max){

return Math.floor(posPt) % max;

}

else{

return posPt;

}

},

//calculate distance between two points

distBetweenTwoPositions(pos1, pos2){

return Math.sqrt((pos1[0] - pos2[0])**2 + (pos1[1] - pos2[1])**2);

},

//calculate norm (magnitude or length)

norm(velocity){

return this.distBetweenTwoPositions([0,0], velocity);

},

fiftyPercentChance(){

return ((Math.random()*10) % 2) !== 0

}

};

module.exports = Util;