// Undo objects to previous state
private void Undo()
{
if (undoCount <= 0)
{
return;
}
undoCount--;
stepIndex--;
if (stepIndex < 0)
{
stepIndex = STORAGE_SIZE - 1;
}
for (int i = 0; i < rigidBodies.Length; i++)
{
NewRigidBody rigidBody = rigidBodies [i];
RigidbodyState state = storage [stepIndex].states [i];
rigidBody.acceleration = state.acceleration;
rigidBody.velocity = state.velocity;
rigidBody.position = state.position;
rigidBody.angularVelocity = state.angularVelocity;
rigidBody.orientation = state.orientation;
rigidBody.transform.rotation = Quaternion.Euler(state.orientation);
rigidBody.transform.position = rigidBody.position;
}
}
// Store current state of objects
private void StoreState()
{
RigidbodyState[] objectStates = new RigidbodyState[rigidBodies.Length];
for (int i = 0; i < rigidBodies.Length; i++)
{
NewRigidBody rigidBody = rigidBodies[i];
RigidbodyState state = new RigidbodyState();
state.acceleration = rigidBody.acceleration;
state.velocity = rigidBody.velocity;
state.position = rigidBody.position;
state.angularVelocity = rigidBody.angularVelocity;
state.orientation = rigidBody.transform.rotation.eulerAngles;
objectStates[i] = state;
}
storage[stepIndex].states = objectStates;
undoCount++;
if (undoCount >= STORAGE_SIZE)
{
undoCount = STORAGE_SIZE - 1;
}
stepIndex++;
if (stepIndex >= STORAGE_SIZE)
{
stepIndex = 0;
}
}
void PositionCorrection(NewRigidBody a, NewRigidBody b, float penetrationDepth, Vector3 collisionNormal)
{
// reference on how to correct position once an impulse is applied
// https://gamedevelopment.tutsplus.com/tutorials/how-to-create-a-custom-2d-physics-engine-the-basics-and-impulse-resolution--gamedev-6331
const float percent = 0.8f;
const float thresholdToPreventJitter = 0.01f;
Vector3 correction = Mathf.Max(penetrationDepth - thresholdToPreventJitter, 0.0f) / (a._inverseMass + b._inverseMass) * percent * collisionNormal;
// Apply
if (a._isKinematic == false)
{
a.position -= a._inverseMass * correction;
}
if (b._isKinematic == false)
{
b.position += b._inverseMass * correction;
}
}
// Reset objects to the initial state
public void Reset()
{
for (int i = 0; i < rigidBodies.Length; i++)
{
NewRigidBody rigidBody = rigidBodies [i];
RigidbodyState state = _initialStates[i];
rigidBody.acceleration = state.acceleration;
rigidBody.velocity = state.velocity;
rigidBody.position = state.position;
rigidBody.angularVelocity = state.angularVelocity;
rigidBody.orientation = state.orientation;
rigidBody.transform.rotation = Quaternion.Euler(state.orientation);
rigidBody.transform.position = rigidBody.position;
rigidBody.transform.GetComponent <MeshRenderer> ().material = rigidBody._originalMaterial;
}
firstPlay = false;
_initialConditions.SetActive(true);
pause = true;
}
void Update()
{
// Initial refresh
if (_start == false)
{
_massInput.text = _selectedObject.mass.ToString();
_positionX.text = _selectedObject.position.x.ToString();
_positionY.text = _selectedObject.position.y.ToString();
_positionZ.text = _selectedObject.position.z.ToString();
_orienX.text = _selectedObject.orientation.x.ToString();
_orienY.text = _selectedObject.orientation.y.ToString();
_orienZ.text = _selectedObject.orientation.z.ToString();
_isKinematic.isOn = _selectedObject._isKinematic;
_start = true;
}
// Prevent ray from going through UI
if (EventSystem.current.IsPointerOverGameObject())
{
return;
}
// Select object
if (Input.GetKeyDown(KeyCode.Mouse0))
{
RaycastHit hit;
Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
if (Physics.Raycast(ray, out hit, 100.0f))
{
_selectedObject = hit.transform.gameObject.GetComponent <NewRigidBody> ();
_massInput.text = _selectedObject.mass.ToString();
_positionX.text = _selectedObject.position.x.ToString();
_positionY.text = _selectedObject.position.y.ToString();
_positionZ.text = _selectedObject.position.z.ToString();
_orienX.text = _selectedObject.orientation.x.ToString();
_orienY.text = _selectedObject.orientation.y.ToString();
_orienZ.text = _selectedObject.orientation.z.ToString();
_isKinematic.isOn = _selectedObject._isKinematic;
RefreshUI();
}
}
// Apply torque
if (Input.GetKey(KeyCode.Mouse1))
{
RaycastHit hit;
Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
if (Physics.Raycast(ray, out hit, 100.0f))
{
hit.transform.gameObject.GetComponent <NewRigidBody> ().ApplyTorqueForce(hit.point, hit.normal);
}
}
if (_selectedObject == null)
{
return;
}
// Refresh the selected object's UI
RefreshUI();
}
