====== Sequences ======

Many of the events that happen throughout SOMA are triggered sequences - a sound plays, then the player's FoV changes, then a light starts flashing etc. etc. We control all of those through a set of wrappers we call Sequences, which hide a bunch of timers away and make things easier to read.

For each sequence you need a map property to store the state - a ''cSequenceStatesData'' property e.g.
<code>
cSequenceStatesData mSequenceAlert;
</code>

Then you create a sequence function. This will be repeatedly called until the whole sequence is over. It looks something like this:
<code>
void Sequence_Alert(const tString& in asName)
{
    Sequence_Begin("Sequence_Alert", mSequenceAlert);
    
    if(Sequence_DoStepAndWait(1.0f))  // Do this step and then wait for 1 second
    {
        MakeALoudNoise();
    }
    else if (Sequence_DoStepAndWait(2.5f)) // Do this and then wait for 2.5 seconds
    {
        FlashABrightLight();
    }
    else if (Sequence_DoStepAndPause()) // Do this and then pause until told otherwise
    {
        SaySomethingAndCallBack("OnSayingSomethingComplete");
    }
    else if (Sequence_DoStepAndWait(10.0f)) // Do this and then wait for 10s
    {
        CrushPlayerLikeAnAnt();
    }
    else if (Sequence_DoStepAndContinue()) // Do this and go on to the next step (in this case there isn't one)
    {
        ApologiseToPlayer();
    }
    
    Sequence_End();
}

void OnSayingSomethingComplete()
{
    // Saying something is now complete - poke the sequence to continue processing
    SequenceStates_Resume("Sequence_Alert");
}
</code>

As you can see, ''Sequence_DoStepAndPause()'' in there actually pauses the whole sequence until some external event - in this case the callback from the voice playing code - calls ''SequenceStates_Resume()'' and asks it to continue.

To start the sequence, you just call the sequence function **once** with an empty argument when you want it to trigger e.g.
<code>
Sequence_Alert("");
</code>

no need to call it every frame or anything! Once started, timers will automatically make sure that the sequence steps get followed when they need to be.

We use this a lot, all the way through SOMA, sometimes running multiple sequences in parallel, as they're totally independent of each other. (Which is perfectly possible, but can get very confusing - we really wouldn't recommend it, it more grew out of level complexity than anything else!)

==== Important Functions ====

=== Sequence_Begin ===
Mark the start of a sequence block.
=== Sequence_End ===
Mark the end of the current sequence block.
=== Sequence_Stop ===
Stop the current sequence immediately (sort of like an abort).
=== Sequence_DoStepAndWait ===
Do the step within the following brackets and then wait for the specified time.
=== Sequence_DoStepWaitAndRepeat ===
Do the step within the following brackets and then wait for the specified time; repeat for a number of iterations.
=== Sequence_DoStepAndContinue ===
Do the step within the following brackets and then immediately carry on to the next step.
=== Sequence_DoStepAndPause ===
Do the step within the following brackets and then pause until ''Sequence_Resume'' is called.
=== Sequence_Wait ===
Just wait for a set period of time (no step in brackets).
=== Sequence_Pause ===
Pause the sequence until ''Sequence_Resume'' is called.
=== Sequence_SkipNextSteps ===
Skip the specified number of sequence steps.
=== Sequence_SkipNextStep ===
Skip the next sequence step.
=== SequenceStates_Pause ===
Pause a specified sequence.
=== SequenceStates_Resume ===
Resume the specified sequence.
=== SequenceStates_Stop ===
Stop the specified sequence.
=== SequenceStates_IsActive ===
Returns true if a particular sequence is active.