The SpaceShoot server

var clamp = function(value, min, max) {
	if(value > max)
		return max;
	else if(value < min)
		return min;
	return value;
};

var collisionQ2Q = function(sx, sy, sw, sh, dx, dy, dw, dh) {//Method to detect collisions for rectangle with rectangle
	var sleft = sx - sw / 2,
		dright = dx + dw / 2;
	if(sleft > dright)
		return false;
	var sright = sx + sw / 2,
		dleft = dx - dw / 2;
	if(sright < dleft)
		return false;
	var sup = sy - sh / 2,
		dbottom = dy + dh / 2;
	if(sup > dbottom)
		return false;
	var sbottom = sy + sh / 2,
		dup = dy - dh / 2;
	if(sbottom < dup)
		return false;
	return true;
};

var collisionC2Q = function(sx, sy, sd, dx, dy, dw, dh) {//Method to detect collisions for circle with rectangle
	var sradius = sd / 2;
	var closestX = clamp(sx, dx - dw / 2, dx + dw / 2),
		closestY = clamp(sy, dy - dh / 2, dy + dh / 2);
	var distanceX = sx - closestX,
		distanceY = sy - closestY;
	var distanceSquared = (distanceX * distanceX) + (distanceY * distanceY);
	return distanceSquared < (sradius * sradius);
};

var collisionC2C = function(sx, sy, sd, dx, dy, dd) {//Method to detect collisions for circle with circle
	var sradius = sd / 2,
		dradius = dd / 2;
	var length = sradius + dradius,
		distanceX = sx - dx,
		distanceY = sy - dy;
	var distanceSquared = (distanceX * distanceX) + (distanceY * distanceY);
	return distanceSquared < (length * length);
};

var pbc = function(obj) {
	var s = obj.size / 2;
	if(obj.y + s < 0)
		obj.y = c.canvas.height + s;
	else if(obj.y - s > c.canvas.height)
		obj.y = -s;
	
	if(obj.x + s < 0)
		obj.x = c.canvas.width + s;
	else if(obj.x - s > c.canvas.width)
		obj.x = -s;
};

var d2g = function(angle) {		//Helper to calculate degree -> rad
	return Math.PI / 180 * angle;
};