public void AddForce(Vector3 force, ForceMode mode = ForceMode.Force, decimal deltaTime = -1m)
{
if (deltaTime < 0.0m)
{
deltaTime = (decimal)Time.deltaTime;
}
//Debug.Log($"deltaTime: {deltaTime}, force: {force}");
switch (mode)
{
case ForceMode.Acceleration:
vel += force * (decimal)deltaTime;
return;
case ForceMode.Force:
vel += (force / (decimal)mass) * (decimal)deltaTime;
return;
case ForceMode.Impulse:
vel += force / mass;
return;
case ForceMode.VelocityChange:
vel += force;
return;
}
}
void Update()
{
for (int i = 0; i < bodies.Count - 1; i++)
{
for (int j = i + 1; j < bodies.Count; j++)
{
VirtualPhysicsTransform bodyA = bodies[i].PhysicsTransform, bodyB = bodies[j].PhysicsTransform;
decimal squardDist = Vector3.DistanceSquared(bodyA.Position, bodyB.Position);
decimal forceMagnitude = 0m;
if (squardDist > 0.001m)
{
forceMagnitude = (G * bodyA.Mass * bodyB.Mass) / squardDist;
}
Vector3 force = (bodyA.Position - bodyB.Position).Normalized * forceMagnitude;
//Two birds with one stone
bodyA.AddForce(-force);
Debug.DrawRay(bodyA.Position, -force / bodyA.Mass, Color.green, Time.deltaTime, false);
bodyB.AddForce(force);
Debug.DrawRay(bodyB.Position, force / bodyB.Mass, Color.yellow, Time.deltaTime, false);
}
}
}
public virtual void Tick(decimal deltaTime)
{
prevPos = pos;
prevVel = vel;
prevRot = rot;
prevRotVel = rotVel;
pos += vel * deltaTime;
rot *= Quaternion.Lerp(Quaternion.Identity, RotationalVelocity, deltaTime);
}
void Start()
{
GravitySim.Instance.Add(this);
if (orbitTarget != null)
{
physicsTransform.Velocity =
Vector3.Cross((physicsTransform.Position - orbitTarget.PhysicsTransform.Position), Vector3.Up).Normalized *
MathHelper.DSqrt((GravitySim.G * orbitTarget.PhysicsTransform.Mass) / Vector3.Distance(physicsTransform.Position, orbitTarget.PhysicsTransform.Position));
}
Debug.Log(physicsTransform.Velocity);
}
public void Initialise(Vector3 initPos, Vector3 initVel, Quaternion initRot, Quaternion initRotVel)
{
pos = initPos;
prevPos = initPos;
vel = initVel;
prevVel = initVel;
rot = initRot;
prevRot = initRot;
rotVel = initRotVel;
prevRotVel = initRotVel;
}
public void Translate(Vector3 dist) => Position += dist;
//public void LookAt(Vector3 pos) => LookAt(pos, Vector3.Up);
//public void LookAt(Vector3 pos, Vector3 up) => Rotation = Quaternion.LookRotation(pos - Position, up);
public void RotateAround(Vector3 axis, decimal degrees) => rot *= Quaternion.CreateFromAxisAngle(axis, (decimal)degrees);
public VirtualPhysicsTransform(Vector3 initPos, Vector3 initVel, Quaternion initRot, Quaternion initRotVel)
{
Initialise(initPos, initVel, initRot, initRotVel);
}