//update the rigidbodies position based on currently applied force, velocity, and gravity
public void Step(float dt, Vector2D gravity)
{
//tick the cooldown
if (multiUseCooldown > 0.0f)
{
multiUseCooldown -= dt;
}
//only update position if the object can move
if (moveable)
{
Vector2D acceleration = Force / Mass;
if (obeysGravity)
{
acceleration += gravity;
}
//update velocity, locking it below maximum speed
LinearVelocity = LinearVelocity + acceleration * dt;
if (LinearVelocity.Length() > maxSpeed)
{
LinearVelocity = LinearVelocity.Normalised() * maxSpeed;
}
//Update position based on velocity (uses Runge Kutta integration)
Vector2D k1 = LinearVelocity + acceleration * dt;
Vector2D k2 = LinearVelocity + k1 * (dt / 2);
Vector2D k3 = LinearVelocity + k2 * (dt / 2);
Vector2D k4 = LinearVelocity + k3 * dt;
SetPosition(Position + (k1 + k2 * 2 + k3 * 2 + k4) * (dt / 6));
//reset force
Force.X = 0;
Force.Y = 0;
//reset collision information (assumes collision detection will take place immediately after stepping all rigidbodies)
otherBody = null;
collisionNormal = null;
}
}
