/// <summary>
/// separationBehavior.Update infuences the owning animal to move away from
/// the otherAnimal is it’s too close, in this case if it’s inside
/// AIParameters.separationDistance.
/// </summary>
/// <param name="otherAnimal">the Animal to react to</param>
/// <param name="aiParams">the Behaviors' parameters</param>
public override void Update(Animal otherAnimal, AIParameters aiParams)
{
base.ResetReaction();
Vector2 pushDirection = Vector2.Zero;
float weight = aiParams.PerMemberWeight;
if (Animal.ReactionDistance > 0.0f &&
Animal.ReactionDistance <= aiParams.SeparationDistance)
{
//The otherAnimal is too close so we figure out a pushDirection
//vector in the opposite direction of the otherAnimal and then weight
//that reaction based on how close it is vs. our separationDistance
pushDirection = Animal.Location - Animal.ReactionLocation;
Vector2.Normalize(ref pushDirection, out pushDirection);
//push away
weight *= (1 -
(float)Animal.ReactionDistance / aiParams.SeparationDistance);
pushDirection *= weight;
reacted = true;
reaction += pushDirection;
}
}
/// <summary>
/// CohesionBehavior.Update infuences the owning animal to move towards the
/// otherAnimal that it sees as long as it isn’t too close, in this case
/// that means inside the separationDist in the passed in AIParameters.
/// </summary>
/// <param name="otherAnimal">the Animal to react to</param>
/// <param name="aiParams">the Behaviors' parameters</param>
public override void Update(Animal otherAnimal, AIParameters aiParams)
{
base.ResetReaction();
Vector2 pullDirection = Vector2.Zero;
float weight = aiParams.PerMemberWeight;
//if the otherAnimal is too close we dont' want to fly any
//closer to it
if (Animal.ReactionDistance > 0.0f
&& Animal.ReactionDistance > aiParams.SeparationDistance)
{
//We want to make the animal move closer the the otherAnimal so we
//create a pullDirection vector pointing to the otherAnimal bird and
//weigh it based on how close the otherAnimal is relative to the
//AIParameters.separationDistance.
pullDirection = -(Animal.Location - Animal.ReactionLocation);
Vector2.Normalize(ref pullDirection, out pullDirection);
weight *= (float)Math.Pow((double)
(Animal.ReactionDistance - aiParams.SeparationDistance) /
(aiParams.DetectionDistance - aiParams.SeparationDistance), 2);
pullDirection *= weight;
reacted = true;
reaction = pullDirection;
}
}
/// <summary>
/// separationBehavior.Update infuences the owning animal to move away from
/// the otherAnimal is it’s too close, in this case if it’s inside
/// AIParameters.separationDistance.
/// </summary>
/// <param name="otherAnimal">the Animal to react to</param>
/// <param name="aiParams">the Behaviors' parameters</param>
public override void Update(Animal otherAnimal, AIParameters aiParams)
{
base.ResetReaction();
Vector2 pushDirection = Vector2.Zero;
float weight = aiParams.PerMemberWeight;
if (Animal.ReactionDistance > 0.0f &&
Animal.ReactionDistance <= aiParams.SeparationDistance)
{
//The otherAnimal is too close so we figure out a pushDirection
//vector in the opposite direction of the otherAnimal and then weight
//that reaction based on how close it is vs. our separationDistance
pushDirection = Animal.Location - Animal.ReactionLocation;
Vector2.Normalize(ref pushDirection, out pushDirection);
//push away
weight *= (1 -
(float)Animal.ReactionDistance / aiParams.SeparationDistance);
pushDirection *= weight;
reacted = true;
reaction += pushDirection;
}
}
/// <summary>
/// CohesionBehavior.Update infuences the owning animal to move towards the
/// otherAnimal that it sees as long as it isn’t too close, in this case
/// that means inside the separationDist in the passed in AIParameters.
/// </summary>
/// <param name="otherAnimal">the Animal to react to</param>
/// <param name="aiParams">the Behaviors' parameters</param>
public override void Update(Animal otherAnimal, AIParameters aiParams)
{
base.ResetReaction();
Vector2 pullDirection = Vector2.Zero;
float weight = aiParams.PerMemberWeight;
//if the otherAnimal is too close we dont' want to fly any
//closer to it
if (Animal.ReactionDistance > 0.0f &&
Animal.ReactionDistance > aiParams.SeparationDistance)
{
//We want to make the animal move closer the the otherAnimal so we
//create a pullDirection vector pointing to the otherAnimal bird and
//weigh it based on how close the otherAnimal is relative to the
//AIParameters.separationDistance.
pullDirection = -(Animal.Location - Animal.ReactionLocation);
Vector2.Normalize(ref pullDirection, out pullDirection);
weight *= (float)Math.Pow((double)
(Animal.ReactionDistance - aiParams.SeparationDistance) /
(aiParams.DetectionDistance - aiParams.SeparationDistance), 2);
pullDirection *= weight;
reacted = true;
reaction = pullDirection;
}
}
/// <summary>
/// React to an Animal based on it's type
/// </summary>
/// <param name="animal"></param>
public void ReactTo(Animal animal, ref AIParameters AIparams)
{
if (animal != null)
{
//setting the the reactionLocation and reactionDistance here is
//an optimization, many of the possible reactions use the distance
//and location of theAnimal, so we might as well figure them out
//only once !
Vector2 otherLocation = animal.Location;
ClosestLocation(ref location, ref otherLocation,
out reactionLocation);
reactionDistance = Vector2.Distance(location, reactionLocation);
//we only react if theAnimal is close enough that we can see it
if (reactionDistance < AIparams.DetectionDistance)
{
Behaviors reactions = behaviors[animal.AnimalType];
foreach (Behavior reaction in reactions)
{
reaction.Update(animal, AIparams);
if (reaction.Reacted)
{
aiNewDir += reaction.Reaction;
aiNumSeen++;
}
}
}
}
}
/// <summary>
/// AlignBehavior.Update infuences the owning animal to move in same the
/// direction as the otherAnimal that it sees.
/// </summary>
/// <param name="otherAnimal">the Animal to react to</param>
/// <param name="aiParams">the Behaviors' parameters</param>
public override void Update(Animal otherAnimal, AIParameters aiParams)
{
base.ResetReaction();
if (otherAnimal != null)
{
reacted = true;
reaction = otherAnimal.Direction * aiParams.PerMemberWeight;
}
}
/// <summary>
/// update bird position, wrapping around the screen edges
/// </summary>
/// <param name="gameTime"></param>
public void Update(GameTime gameTime, ref AIParameters aiParams)
{
float elapsedTime = (float)gameTime.ElapsedGameTime.TotalSeconds;
Vector2 randomDir = Vector2.Zero;
randomDir.X = (float)random.NextDouble() - 0.5f;
randomDir.Y = (float)random.NextDouble() - 0.5f;
Vector2.Normalize(ref randomDir, out randomDir);
if (aiNumSeen > 0)
{
aiNewDir = (direction * aiParams.MoveInOldDirectionInfluence) +
(aiNewDir * (aiParams.MoveInFlockDirectionInfluence /
(float)aiNumSeen));
}
else
{
aiNewDir = direction * aiParams.MoveInOldDirectionInfluence;
}
aiNewDir += (randomDir * aiParams.MoveInRandomDirectionInfluence);
Vector2.Normalize(ref aiNewDir, out aiNewDir);
aiNewDir = ChangeDirection(direction, aiNewDir,
aiParams.MaxTurnRadians * elapsedTime);
direction = aiNewDir;
if (direction.LengthSquared() > .01f)
{
Vector2 moveAmount = direction * moveSpeed * elapsedTime;
location = location + moveAmount;
//wrap bird to the other side of the screen if needed
if (location.X < 0.0f)
{
location.X = boundryWidth + location.X;
}
else if (location.X > boundryWidth)
{
location.X = location.X - boundryWidth;
}
location.Y += direction.Y * moveSpeed * elapsedTime;
if (location.Y < 0.0f)
{
location.Y = boundryHeight + location.Y;
}
else if (location.Y > boundryHeight)
{
location.Y = location.Y - boundryHeight;
}
}
}
/// <summary>
/// update bird position, wrapping around the screen edges
/// </summary>
/// <param name="gameTime"></param>
public void Update(GameTime gameTime, ref AIParameters aiParams)
{
float elapsedTime = (float)gameTime.ElapsedGameTime.TotalSeconds;
Vector2 randomDir = Vector2.Zero;
randomDir.X = (float)random.NextDouble() - 0.5f;
randomDir.Y = (float)random.NextDouble() - 0.5f;
Vector2.Normalize(ref randomDir, out randomDir);
if (aiNumSeen > 0)
{
aiNewDir = (direction * aiParams.MoveInOldDirectionInfluence) +
(aiNewDir * (aiParams.MoveInFlockDirectionInfluence /
(float)aiNumSeen));
}
else
{
aiNewDir = direction * aiParams.MoveInOldDirectionInfluence;
}
aiNewDir += (randomDir * aiParams.MoveInRandomDirectionInfluence);
Vector2.Normalize(ref aiNewDir, out aiNewDir);
aiNewDir = ChangeDirection(direction, aiNewDir,
aiParams.MaxTurnRadians * elapsedTime);
direction = aiNewDir;
if (direction.LengthSquared() > .01f)
{
Vector2 moveAmount = direction * moveSpeed * elapsedTime;
location = location + moveAmount;
//wrap bird to the other side of the screen if needed
if (location.X < 0.0f)
{
location.X = boundryWidth + location.X;
}
else if (location.X > boundryWidth)
{
location.X = location.X - boundryWidth;
}
location.Y += direction.Y * moveSpeed * elapsedTime;
if (location.Y < 0.0f)
{
location.Y = boundryHeight + location.Y;
}
else if (location.Y > boundryHeight)
{
location.Y = location.Y - boundryHeight;
}
}
}
/// <summary>
/// Setup the flock boundaries and generate individual members of the flock
/// </summary>
/// <param name="tex"> The texture to be used by the birds</param>
/// <param name="screenWidth">Width of the screen</param>
/// <param name="screenHeight">Height of the screen</param>
/// <param name="flockParameters">Behavior of the flock</param>
public Flock(Texture2D tex, int screenWidth, int screenHeight,
AIParameters flockParameters)
{
boundryWidth = screenWidth;
boundryHeight = screenHeight;
birdTexture = tex;
flock = new List<Bird>();
flockParams = flockParameters;
ResetFlock();
}
public FlockingSample()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
inputState = new InputState();
flock = null;
cat = null;
flockParams = new AIParameters();
ResetAIParams();
}
/// <summary>
/// Setup the flock boundaries and generate individual members of the flock
/// </summary>
/// <param name="tex"> The texture to be used by the birds</param>
/// <param name="screenWidth">Width of the screen</param>
/// <param name="screenHeight">Height of the screen</param>
/// <param name="flockParameters">Behavior of the flock</param>
public Flock(Texture2D tex, int screenWidth, int screenHeight,
AIParameters flockParameters)
{
boundryWidth = screenWidth;
boundryHeight = screenHeight;
birdTexture = tex;
flock = new List <Bird>();
flockParams = flockParameters;
ResetFlock();
}
public FlockingSample()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
#if WINDOWS_PHONE || IOS
// Frame rate is 30 fps by default for Windows Phone.
TargetElapsedTime = TimeSpan.FromTicks(333333);
graphics.IsFullScreen = true;
#endif
inputState = new InputState();
flock = null;
cat = null;
flockParams = new AIParameters();
ResetAIParams();
}
public override void Update(Animal otherAnimal, AIParameters aiParams)
{
base.ResetReaction();
Vector2 dangerDirection = Vector2.Zero;
//Vector2.Dot will return a negative result in this case if the
//otherAnimal is behind the animal, in that case we don’t have to
//worry about it because we’re already moving away from it.
if (Vector2.Dot(
Animal.Location, Animal.ReactionLocation) >= -(Math.PI / 2))
{
//set the animal to fleeing so that it flashes red
Animal.Fleeing = true;
reacted = true;
dangerDirection = Animal.Location - Animal.ReactionLocation;
Vector2.Normalize(ref dangerDirection, out dangerDirection);
reaction = (aiParams.PerDangerWeight * dangerDirection);
}
}
public override void Update(Animal otherAnimal, AIParameters aiParams)
{
base.ResetReaction();
Vector2 dangerDirection = Vector2.Zero;
//Vector2.Dot will return a negative result in this case if the
//otherAnimal is behind the animal, in that case we don’t have to
//worry about it because we’re already moving away from it.
if (Vector2.Dot(
Animal.Location, Animal.ReactionLocation) >= -(Math.PI / 2))
{
//set the animal to fleeing so that it flashes red
Animal.Fleeing = true;
reacted = true;
dangerDirection = Animal.Location - Animal.ReactionLocation;
Vector2.Normalize(ref dangerDirection, out dangerDirection);
reaction = (aiParams.PerDangerWeight * dangerDirection);
}
}
/// <summary> /// Abstract function that the subclass must impliment. Figure out the /// Behavior reaction here. /// </summary> /// <param name="otherAnimal">the Animal to react to</param> /// <param name="aiParams">the Behaviors' parameters</param> public abstract void Update(Animal otherAnimal, AIParameters aiParams);
public FlockingSample()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
#if WINDOWS_PHONE || IOS
// Frame rate is 30 fps by default for Windows Phone.
TargetElapsedTime = TimeSpan.FromTicks(333333);
graphics.IsFullScreen = true;
#endif
inputState = new InputState();
flock = null;
cat = null;
flockParams = new AIParameters();
ResetAIParams();
}
/// <summary> /// Abstract function that the subclass must impliment. Figure out the /// Behavior reaction here. /// </summary> /// <param name="otherAnimal">the Animal to react to</param> /// <param name="aiParams">the Behaviors' parameters</param> public abstract void Update(Animal otherAnimal, AIParameters aiParams);
/// <summary>
/// React to an Animal based on it's type
/// </summary>
/// <param name="animal"></param>
public void ReactTo(Animal animal, ref AIParameters AIparams)
{
if (animal != null)
{
//setting the the reactionLocation and reactionDistance here is
//an optimization, many of the possible reactions use the distance
//and location of theAnimal, so we might as well figure them out
//only once !
Vector2 otherLocation = animal.Location;
ClosestLocation(ref location, ref otherLocation,
out reactionLocation);
reactionDistance = Vector2.Distance(location, reactionLocation);
//we only react if theAnimal is close enough that we can see it
if (reactionDistance < AIparams.DetectionDistance)
{
Behaviors reactions = behaviors[animal.AnimalType];
foreach (Behavior reaction in reactions)
{
reaction.Update(animal, AIparams);
if (reaction.Reacted)
{
aiNewDir += reaction.Reaction;
aiNumSeen++;
}
}
}
}
}
