private Vector2 FleeFromPredator(Boid me)
{
if (me.ToString() == "BoidSimulation.Predator")
{
return(Vector2.Zero);
}
else
{
Vector2 FleeVel = Vector2.Zero;
int PredCnt = 0;
float percent = 0.01f;
List <Boid> boidList = SimWorld.GetInstance().GetBoidList();
foreach (Boid b in boidList)
{
if (b.ToString() == "BoidSimulation.Predator")
{
Vector2 diff = b.GetPosition() - me.GetPosition();
if (diff.Length() <= me.StayAwayRadius)
{
FleeVel -= diff;
PredCnt++;
}
}
}
if (PredCnt > 0)
{
FleeVel /= PredCnt;
return(FleeVel * percent);
}
return(Vector2.Zero);
}
}
//can we merge this with a general collision avoidance algorithm?
private Vector2 KeepApart(Boid me)
{
Vector2 KeepApartVel = Vector2.Zero;
List <Boid> boidList = SimWorld.GetInstance().GetBoidList();
foreach (Boid b in boidList)
{
if (me == b)
{
continue;
}
else
{
//test to see if we are smaller than a certain range (circle test)
Vector2 diff = b.GetPosition() - me.GetPosition();
if (diff.Length() <= me.Radius)
{
KeepApartVel -= diff;
}
}
}
return(KeepApartVel);
}
private Vector2 FleeFromPredator( Boid me )
{
if (me.ToString() == "BoidSimulation.Predator")
{
return Vector2.Zero;
}
else
{
Vector2 FleeVel = Vector2.Zero;
int PredCnt = 0;
float percent = 0.01f;
List<Boid> boidList = SimWorld.GetInstance().GetBoidList();
foreach (Boid b in boidList)
{
if (b.ToString() == "BoidSimulation.Predator")
{
Vector2 diff = b.GetPosition() - me.GetPosition();
if(diff.Length() <= me.StayAwayRadius )
{
FleeVel -= diff;
PredCnt++;
}
}
}
if (PredCnt > 0)
{
FleeVel /= PredCnt;
return FleeVel * percent;
}
return Vector2.Zero;
}
}
//find the center of the screen and go there.
private Vector2 FollowMouse(Boid me)
{
MouseState mouse = Mouse.GetState();
Vector2 mousePos = new Vector2(mouse.X, mouse.Y);
return((mousePos - me.GetPosition()) * 0.05f);
//return Vector2.Zero;
}
public override Vector2 UpdateAI(GameTime gameTime, Boid me)
{
//get distance between me and the wander point.
Vector2 wanderPoint = GetNewWanderPoint(me);
Vector2 diff = wanderPoint - me.GetPosition();
diff += KeepApart(me);
diff += CollisionTest(me);
return(diff * 0.01f);
//return base.UpdateAI(gameTime, boidList);
}
private Vector2 Flock(Boid me)
{
Vector2 CenterOfMassVel = Vector2.Zero;
Vector2 KeepApartVel = Vector2.Zero;
Vector2 MatchBoidVel = Vector2.Zero;
List <Boid> boidList = SimWorld.GetInstance().GetBoidList();
foreach (Boid b in boidList)
{
if (me == b)
{
continue;
}
else
{
//sum up the positions
CenterOfMassVel += b.GetPosition();
//sum up the velocities.
MatchBoidVel += b.GetVelocity();
//test to see if we are smaller than a certain range (circle test)
Vector2 diff = b.GetPosition() - me.GetPosition();
if (diff.Length() <= me.Radius)
{
KeepApartVel -= diff;
}
}
}
CenterOfMassVel /= boidList.Count - 1;
CenterOfMassVel *= 0.01f;
MatchBoidVel /= boidList.Count - 1;
MatchBoidVel *= me.Strength;
MatchBoidVel *= 0.01f;
Vector2 totalVel = (CenterOfMassVel + MatchBoidVel + KeepApartVel + FollowMouse(me)) * 0.001f;
totalVel += FleeFromPredator(me) * 0.05f;
totalVel += CollisionTest(me);
return(totalVel);
}
protected Vector2 CollisionTest(Boid me)
{
List <Plane> collisionList = SimWorld.GetInstance().GetCollisionList();
Vector4 pos = new Vector4(me.GetPosition(), 0.0f, 1.0f);
Vector3 avoidCollisionVel = Vector3.Zero;
foreach (Plane p in collisionList)
{
float distance = p.Dot(pos) / p.Normal.Length();
if (distance <= 5.0f)
{
avoidCollisionVel += p.Normal * (me.Radius - distance);
}
}
return(new Vector2(avoidCollisionVel.X, avoidCollisionVel.Y) * 0.001f);
}
private Vector2 GetNewWanderPoint(Boid me)
{
Vector2 mForward = me.GetVelocity();
if (mForward.Length() <= 0.0f)
{
return(Vector2.Zero);
}
mForward.Normalize();
Vector2 circleCenter = me.GetPosition() + mForward * 10.0f;
Random rand = new Random();
float angle = rand.Next(360);
float radius = 10.0f;
Vector2 circlePoint = new Vector2((float)Math.Cos(MathHelper.ToRadians(angle) * radius),
(float)Math.Sin(MathHelper.ToRadians(angle) * radius));
return(circleCenter + circlePoint);
}
private Vector2 Flock(Boid me)
{
Vector2 CenterOfMassVel = Vector2.Zero;
Vector2 KeepApartVel = Vector2.Zero;
Vector2 MatchBoidVel = Vector2.Zero;
List<Boid> boidList = SimWorld.GetInstance().GetBoidList();
foreach (Boid b in boidList)
{
if (me == b)
{
continue;
}
else
{
//sum up the positions
CenterOfMassVel += b.GetPosition();
//sum up the velocities.
MatchBoidVel += b.GetVelocity();
//test to see if we are smaller than a certain range (circle test)
Vector2 diff = b.GetPosition() - me.GetPosition();
if (diff.Length() <= me.Radius)
{
KeepApartVel -= diff;
}
}
}
CenterOfMassVel /= boidList.Count - 1;
CenterOfMassVel *= 0.01f;
MatchBoidVel /= boidList.Count - 1;
MatchBoidVel *= me.Strength;
MatchBoidVel *= 0.01f;
Vector2 totalVel = (CenterOfMassVel + MatchBoidVel + KeepApartVel + FollowMouse( me )) * 0.001f;
totalVel += FleeFromPredator(me) * 0.05f;
totalVel += CollisionTest(me);
return totalVel;
}
//can we merge this with a general collision avoidance algorithm?
private Vector2 KeepApart(Boid me)
{
Vector2 KeepApartVel = Vector2.Zero;
List<Boid> boidList = SimWorld.GetInstance().GetBoidList();
foreach (Boid b in boidList)
{
if (me == b)
{
continue;
}
else
{
//test to see if we are smaller than a certain range (circle test)
Vector2 diff = b.GetPosition() - me.GetPosition();
if (diff.Length() <= me.Radius)
{
KeepApartVel -= diff;
}
}
}
return KeepApartVel;
}
private Vector2 GetNewWanderPoint( Boid me )
{
Vector2 mForward = me.GetVelocity();
if (mForward.Length() <= 0.0f)
{
return Vector2.Zero;
}
mForward.Normalize();
Vector2 circleCenter = me.GetPosition() + mForward * 10.0f;
Random rand = new Random();
float angle = rand.Next(360);
float radius = 10.0f;
Vector2 circlePoint = new Vector2((float)Math.Cos(MathHelper.ToRadians(angle) * radius),
(float)Math.Sin(MathHelper.ToRadians(angle) * radius));
return circleCenter + circlePoint;
}
public override Vector2 UpdateAI(GameTime gameTime, Boid me)
{
//get distance between me and the wander point.
Vector2 wanderPoint = GetNewWanderPoint(me);
Vector2 diff = wanderPoint - me.GetPosition();
diff += KeepApart(me);
diff += CollisionTest(me);
return diff * 0.01f;
//return base.UpdateAI(gameTime, boidList);
}
protected Vector2 CollisionTest(Boid me)
{
List<Plane> collisionList = SimWorld.GetInstance().GetCollisionList();
Vector4 pos = new Vector4( me.GetPosition(), 0.0f, 1.0f );
Vector3 avoidCollisionVel = Vector3.Zero;
foreach( Plane p in collisionList )
{
float distance = p.Dot(pos) / p.Normal.Length();
if (distance <= 5.0f)
{
avoidCollisionVel += p.Normal * (me.Radius - distance);
}
}
return new Vector2(avoidCollisionVel.X, avoidCollisionVel.Y) * 0.001f;
}
//find the center of the screen and go there.
private Vector2 FollowMouse(Boid me)
{
MouseState mouse = Mouse.GetState();
Vector2 mousePos = new Vector2(mouse.X, mouse.Y);
return( ( mousePos - me.GetPosition() ) * 0.05f);
//return Vector2.Zero;
}