/// <summary>
/// Returns a modifier scalar value that is the result of an intrinsic animation function.
/// </summary>
/// <param name="functionToken">animation function to use</param>
/// <param name="period">period in seconds</param>
/// <param name="phase">phase shift in seconds</param>
/// <returns>coordinate modifier</returns>
protected static float Animate(short functionToken, float period, float phase)
{
PMath.Phase = phase;
switch (functionToken)
{
case 0x0: // one
return(PMath.One());
case 0x1: // zero
return(PMath.Zero());
case 0x2: // cosine
case 0x3:
return(Math.Abs(PMath.Cosine(period * 2.0f, 1.0f)));
//case 0x3: // cosine (variable period)
// return Math.Abs(PMath.Cosine(Math.Abs(PMath.Cosine(period, 2.0f)) * 2.0f, 1.0f));
case 0x4: // diagonal wave
case 0x5:
return(PMath.Triangle(period, 1.0f));
//case 0x5: // diagonal wave (variable period)
// return PMath.Triangle(PMath.Cosine(period, 2.0f), 1.0f);
case 0x6: // slide
case 0x7:
return(PMath.Sawtooth(period, 1.0f));
//case 0x7: // slide (variable period)
// return PMath.Sawtooth(PMath.Cosine(period, 2.0f), 1.0f);
case 0x8: // noise
return(PMath.Noise(1.0f));
case 0x9: // jitter
return(PMath.Jitter(1.0f));
case 0xa: // wander
return(PMath.Wander(period, 1.0f));
case 0xb: // spark
return(PMath.Spark(1.0f));
default:
throw new ArgumentException(functionToken.ToString() + " is not a valid Halo shader animation function token.", "functionToken");
}
}