/// <summary>
/// Checks if there are any obstructions in close proximity which must be dodged
/// </summary>
/// <param name="AIObject">ai object to check around</param>
/// <returns>list of possible obstructions</returns>
private List<StaticObject> obstructionsInCloseProximity(DynamicObject AIObject)
{
List<StaticObject> results = new List<StaticObject>();
foreach (GridObjectInterface obj in this.spatialGrid.checkNeighbouringBlocks(AIObject))
{
if (obj is StaticObject && !(obj is Bullet || obj is Missile))
{
float radiusToCheck = (obj.getBoundingSphere().Radius + AIObject.getBoundingSphere().Radius) * DODGE_DISTANCE_MULTIPLIER;
if ((AIObject.Position - obj.Position).Length() <= radiusToCheck)
{
results.Add(obj as StaticObject);
}
}
}
return results;
}
/// <summary>
/// Method to set the path of an ai unit in order to dodge an object
/// </summary>
/// <param name="callingAI">ai to perform dodge</param>
/// <param name="closestObstruction">closest obstruction</param>
private void dodgeObject(DynamicObject callingAI, StaticObject closestObstruction)
{
if (!this.isObjectRegistered(callingAI)) return;
PathInformation pathInfo = objectPaths[callingAI];
if (pathInfo.currentWaypoint == null) return;
if (!dodgeInactiveCountDown.Keys.Contains(callingAI))
dodgeInactiveCountDown.Add(callingAI, RETAIN_DODGE_PATH_TICKS);
else
return;
Vector3 dodgeWp = new Vector3();
bool bFlag = false;
// Set the new path:
float dodgeDistance = (callingAI.getBoundingSphere().Radius + closestObstruction.getBoundingSphere().Radius) * DODGE_DISTANCE_MULTIPLIER;
float distanceToObject = (callingAI.Position - closestObstruction.Position).Length();
float distanceToCurrentWp = (callingAI.Position - pathInfo.currentWaypoint.Position).Length();
float dodgeAngle = (float)Math.Abs(Math.Atan2(distanceToObject, dodgeDistance));
for (int i = (int)Math.Ceiling(dodgeAngle); i * dodgeAngle < Math.PI; ++i)
{
for (int j = (int)Math.Ceiling(dodgeAngle); j * dodgeAngle < Math.PI; ++j)
{
if (isDodgeValid(callingAI, dodgeAngle, i, j, pathInfo, closestObstruction, dodgeDistance, ref dodgeWp))
{
bFlag = true;
break;
}
if (isDodgeValid(callingAI, -dodgeAngle, i, j, pathInfo, closestObstruction, dodgeDistance, ref dodgeWp))
{
bFlag = true;
break;
}
}
if (bFlag)
break;
}
List<Node> path = pathInfo.remainingPath;
if (path.Count > 0)
path.Remove(path.Last());
path.Add(new Node(dodgeWp, -1));
pathInfo.remainingPath = path;
}
/// <summary>
/// Checks if a particular dodge is valid
/// </summary>
private bool isDodgeValid(DynamicObject callingAI,float dodgeAngle,int dodgeAngleMultiplierYaw,int dodgeAngleMultiplierPitch,PathInformation pathInfo, StaticObject closestObstruction,float dodgeDistance, ref Vector3 dodgeWp)
{
bool bFlag = false;
//Define a conal area around the current path to choose another path from
Quaternion qRot = Quaternion.CreateFromYawPitchRoll(dodgeAngle * dodgeAngleMultiplierYaw, dodgeAngle * dodgeAngleMultiplierPitch, 0);
Vector3 choiceVector = Vector3.Normalize(
Vector3.Transform(pathInfo.currentWaypoint.Position - callingAI.Position,
Matrix.CreateFromQuaternion(qRot)));
dodgeWp = callingAI.Position + choiceVector * dodgeDistance;
if ((dodgeWp - closestObstruction.Position).Length() > dodgeDistance)
{
foreach (GridObjectInterface o in spatialGrid.checkNeighbouringBlocks(dodgeWp))
{
if (o != callingAI)
{
if (o is StaticObject)
{
if ((o.Position - dodgeWp).Length() > (o.getBoundingSphere().Radius + callingAI.getBoundingSphere().Radius * (DODGE_DISTANCE_MULTIPLIER)))
bFlag = true;
}
if (o is DynamicObject)
{
if (isObjectRegistered(o as DynamicObject))
{
Node otherObjectsWaypoint = objectPaths[o as DynamicObject].currentWaypoint;
if (otherObjectsWaypoint != null)
{
if ((otherObjectsWaypoint.Position - dodgeWp).Length() < (o.getBoundingSphere().Radius + callingAI.getBoundingSphere().Radius * (DODGE_DISTANCE_MULTIPLIER)))
bFlag = false;
}
}
}
if (!spatialGrid.isInGrid(new Node(dodgeWp,-1)))
bFlag = false;
}
}
}
return bFlag;
}
/// <summary>
/// Performs a dogfight move against the opponent
/// </summary>
/// <param name="ti">Team on which the ai is registered</param>
/// <param name="ai">Character to perform move</param>
/// <param name="target">Opponent of the ai</param>
public void doDogfightMove(TeamInformation ti, DynamicObject ai, StaticObject target)
{
if (!this.isObjectRegistered(ai)) return;
float radiusToGoBehindTarget = (target.getBoundingSphere().Radius + ai.getBoundingSphere().Radius) * RADIUS_MULTIPLIER_TO_GO_BEHIND_TARGET;
Vector3 wpPosition = target.Position + Vector3.Normalize(Matrix.CreateFromQuaternion(target.rotation).Forward) * radiusToGoBehindTarget;
Vector3 wpDPosition = target.Position + Vector3.Normalize(Matrix.CreateFromQuaternion(target.rotation).Up) * radiusToGoBehindTarget / RADIUS_FACTOR_TO_GO_ABOVE_TARGET;
if (Vector3.Dot(Vector3.Normalize(wpPosition - target.Position), Vector3.Normalize(ai.Position - target.Position)) < DOT_ANGLE_TO_STOP_DOGFIGHT_MOVE ||
(ai.Position - target.Position).Length() > CHASE_WHEN_FURTHER)
{
PathInformation fighterPath = objectPaths[ai];
List<Node> waypointList = fighterPath.remainingPath;
//we clear the waypoint list and add new waypoints:
if (waypointList.Count > 0)
{
bool shouldAddTopWaypt = (Vector3.Dot(Vector3.Normalize(Matrix.CreateFromQuaternion(target.rotation).Forward), Vector3.Normalize(target.Position - ai.Position)) > 0);
if ((wpPosition - waypointList.ElementAt(0).Position).Length() > TARGET_WP_BUFFER || shouldAddTopWaypt)
{
waypointList.Clear();
if (shouldAddTopWaypt)
waypointList.Insert(0, new Node(wpDPosition, -1));
waypointList.Insert(0, new Node(wpPosition, -1));
}
}
else
{
if (Vector3.Dot(Vector3.Normalize(Matrix.CreateFromQuaternion(target.rotation).Forward), Vector3.Normalize(target.Position - ai.Position)) > 0)
waypointList.Insert(0, new Node(wpDPosition, -1));
waypointList.Insert(0, new Node(wpPosition, -1));
}
fighterPath.remainingPath = waypointList;
}
else //stop navigation (we are behind the target so we can start shooting it)
getPath(ai).Clear();
}