// Call this as you would call MonoBehaviour.StartCoroutine
public SCoroutine StartCoroutine(IEnumerator ie)
{
var sc = new SCoroutine();
sc.Start(ie);
runningCoroutines.Add(sc);
return(sc);
}
public void Start(IEnumerator routine)
{
ienumeratorStack.Clear();
ienumeratorStack.Push(routine);
nestedCoroutine = null;
yieldFrame = -1;
Update();
}
// Execute a single step of the coroutine. Unity equivalent is the MoveNext you see in coroutine stack traces
// Returns true if the coroutine should continue running
public bool Update()
{
// This ensures yield return null waits a frame in all situations
if (yieldFrame > Time.frameCount)
{
return(true);
}
// Do not continue with the IEnumerators until the last returned SCoroutine has finished running
if (nestedCoroutine != null && nestedCoroutine.IsRunning())
{
return(true);
}
nestedCoroutine = null;
if (ienumeratorStack.Count > 0)
{
var ie = ienumeratorStack.Peek(); // The top of the stack is the currently executing IEnumerator
if (ie.MoveNext()) // Execute IEnumerator until next yield (true) or break/end (false)
{
// ie.Current is what was yield returned in the IEnumerator
object yielded = ie.Current;
if (yielded is IEnumerator)
{
// Move to execute a nested IEnumerator
ienumeratorStack.Push(yielded as IEnumerator);
return(Update()); // Start nested IEnumerator execution without frame delay
}
else if (yielded is SCoroutine)
{
// Start waiting on a nested SCoroutine
nestedCoroutine = yielded as SCoroutine;
}
else
{
// Yielding anything else (like null) causes execution to resume next frame
yieldFrame = Time.frameCount + 1;
}
// TODO: Support Unity's YieldInstruction by starting a real coroutine and yielding it there
// TODO: Add logic for custom yieldable objects here
}
else
{
ienumeratorStack.Pop();
return(Update()); // Immediately continue the previous IEnumerator in the stack without frame delay
}
return(true);
}
else
{
return(false);
}
}