Inertia in Flash MX (re: article)

talk open source
1

I checked out this article only to find that the trick he’s used apparently only works in Flash 5. I’ve added one line to the script so it works in Flash 6+. This initialises two variables, xp and yp, as new numbers.

The script is now:

onClipEvent (load) {
	// inertia relates to the quantity of energy that 
	// the spring will carry
	// inertia = 1 would mean that the spring doesn't 
	// loose any energy, and that it will oscillate
	// forever
	inertia = 0.9;
	// k relates to the spring, and how "hard" it will be.
	// The higher k the faster the mass will come back.
	k = 0.1;
	xp = yp = new Number();
}
onClipEvent (enterFrame) {
	// We calculate the distance to the mouse
	x = -_x+_root._xmouse;
	y = -_y+_root._ymouse;
	//We calculate the amount by which the mass will to move
	xp = (xp*inertia)+(x*k);
	yp = (yp*inertia)+(y*k);
	//We move it
	_x += xp;
	_y += yp;
}

FLA attached.

Perhaps an amendment could be made to the article? :slight_smile: