public Spring(float stiffness, float damping, PhysicEntity pEntityA, PhysicEntity pEntityB, float restLength)
: base()
{
this.stiffness = stiffness;
this.damping = damping;
this.pEntityA = pEntityA;
this.pEntityB = pEntityB;
this.restLength = restLength;
}
public void ApplyForce(PhysicEntity pEntity = null)
{
//get the direction vector
direction = pEntityA.CurrPosition - pEntityB.CurrPosition;
//check for zero vector
if (direction != Vector2.zero)
{
//get length
currLength = direction.magnitude;
//normalize
direction.Normalize();
//add spring force
force = -stiffness * ((currLength - restLength) * direction);
//add spring damping force
force += -damping *Vector2.Dot(pEntityA.CurrVelocity - pEntityB.CurrVelocity, direction) * direction;
//apply the equal and opposite forces to the objects
pEntityA.ResultantForce += force;
pEntityB.ResultantForce += -force;
}
}
public Spring(float stiffness, float damping, PhysicEntity pEntityA, PhysicEntity pEntityB)
: this(stiffness, damping, pEntityA, pEntityB, (pEntityA.CurrPosition - pEntityB.CurrPosition).magnitude)
{
}
public abstract void Process(Vector2 acceleration, PhysicEntity pEntity, float time);
public override void Process(Vector2 acceleration, PhysicEntity pEntity, float time)
{
pEntity.CurrPosition += pEntity.CurrVelocity * time;
pEntity.CurrVelocity += acceleration * time;
}
public void AddPhysEnity(PhysicEntity simObject)
{
pEntities.Add(simObject);
}
public void ApplyForce(PhysicEntity pEntity)
{
pEntity.ResultantForce += pEntity.Mass * acceleration;
}
public void ApplyForce(PhysicEntity pEntity)
{
pEntity.ResultantForce += -dragCoefficient * pEntity.CurrVelocity;
}
