1d mass spring system

/*
tick:


    Step one:  loop through every spring and add the force of the spring.

    Step two:   loop through every mass and compute the new position.

    Step three:  loop through all springs and, given it's new end point, compute the new forces on the spring.


*/

//Code for Spring.  (p and q are the current positions for the mass on the endpoints of the spring.). (p1 and q1 are the positions for last tick)

    public float[] go(float p, float q) {
        float distance = p - q;
        float distanceDelta = (p - p1) - (q - q1);

        float a = springiness * (Math.abs(distance) - length);
        float b;
        float c;
        if (distance == 0) {
            c = 1;
            b = (damping * distanceDelta * distance) / .0000001f;
        } else {
            b = (damping * distanceDelta * distance) / Math.abs(distance);
            c = distance / Math.abs(distance);
        }

        float newForce = -(a + b) * c;

        p1 = p;
        q1 = q;

        return new float[] { newForce, -newForce };
    }



//Code for Mass
public float go() {
        if (fixed) {
            return defaultPos;
        }

        float newForce = runningForce * mass - n2 + 2f * n1;
        n2 = n1;
        n1 = newForce;
        runningForce = 0;


        return newForce;
    }