public override cVector3 force(cCritter pcritter)
{
cVector3 evadedirection, evadeforcevector;
cCritter pclosestcritter = pcritter.OwnerBiota.pickClosestCritter <DataType>(pcritter,
_includechildclasses);
//Case (1) No enemies to evade ----------------------------------------------
if (pclosestcritter == null) //NULL if there aren't any of these guys around
{
pcritter.restoreMaxspeed(); //Go back to my normal non-darting speed and bail.
return(new cVector3(0.0f, 0.0f, 0.0f));
}
evadedirection = pclosestcritter.directionTo(pcritter); /* Start with a unit vector that
* points from my enemy towards me. */
float cosangle = evadedirection * (pclosestcritter.Tangent); /* Dot product of two
* unit vectors is the cosine of the angle between them. I can use the cosine to figure
* out if the enemy is headed away from me (cosangle < 0) , generally towards me
* (cosangle > 0), or directly towards me (cosangle near 1.0). */
//Case (2) Closest enemy is moving away from me. ------------------------------
if (cosangle < cForceClassEvade <DataType> .COSINEIGNOREANGLE) // If nearest enemy is moving away, relax.
{
pcritter.restoreMaxspeed(); //Go back to my normal non-darting speed and bail.
return(new cVector3(0.0f, 0.0f, 0.0f));
}
//Case (3a) Closest enemy is directly towards me. ------------------------------
if (cosangle > cForceClassEvade <DataType> .COSINESMALLANGLE) /* If the nearest enemy is heading close
* to straight towards me, I shouldn't run straight away like a rabbit down a railorad
* track. So in this case I'll head off at a 90 degree angle. I'll use a bit of the
* pointer as a "personality trait" to consistently act like a "righty" or a "lefty" in
* terms of which side of the railroad track I jump off of. */
{
evadedirection.turn(
((cForceClassEvade <DataType> .TURNPERSONALITYBIT & pcritter.Personality) != 0)?
(float)Math.PI / 2
: (float)-Math.PI / 2);
}
//Case (3a and 3b) Closest enemy is moving towards me, directly or otherwise.
pcritter.TempMaxSpeed = _dartspeedup * pcritter.MaxSpeedStandard;
//Go faster while I'm darting away.
evadeforcevector = evadedirection * pcritter.MaxSpeed - pcritter.Velocity;
evadeforcevector.Magnitude = _intensity;
evadeforcevector *= pcritter.Mass;
return(evadeforcevector * _intensity);
}