void Start()
{
//create a chaser and flock unit on each path
for (int i = 0; i < paths.Count; ++i)
{
//first we create the chaser
Vector3 startPos = paths[i].GetComponent <pathPoints>().points[25];
GameObject chaser = (GameObject)Instantiate(chaserPrefab, startPos, Quaternion.identity);
//manually initialize the chaser's followPath component with the desired properties
followPath fp = chaser.GetComponent <followPath>();
fp.path = paths[i];
fp.curPt = 25;
fp.init();
//now we create as many flock units as desired
for (int r = 0; r < numUnitsPerFlock; ++r)
{
GameObject flockUnit = (GameObject)Instantiate(flockUnitPrefab, startPos, Quaternion.identity);
flockUnit.GetComponent <SpriteRenderer>().sprite = flockSprites[i];
//initialize the flock unit's followChaser component with the desired properties
followChaser fc = flockUnit.GetComponent <followChaser>();
fc.leader = chaser;
fc.init();
//ofset each flock unit by a different amount, so that they do not begin on top of each other
Vector3 curPos = fc.transform.position;
fc.transform.position = new Vector3(curPos.x + .4f * (numUnitsPerFlock / 2f + .5f - r), curPos.y, curPos.z);
//give each flock unit a tag so we can poll through them for collisions
flockUnit.tag = "flockUnit";
}
}
}
/**
* perform a cone collision check against all specified objects, avoiding them if necessary
* @param a: the object from which to perform a cone check
* @param objs: the list of objects to check against
*/
public static void avoidConeCollisions(GameObject a, List <GameObject> objs)
{
//perform a cone check on each passed in object
followChaser fc = a.GetComponent <followChaser>();
fc.coneHitsThisFrame = 0;
foreach (GameObject o in objs)
{
if (coneCheck(a, o))
{
//cone check returned a collision; turn at a rate inversely proportional to our distance from the object
++fc.coneHitsThisFrame;
}
}
}
/**
* use collision prediction to determine the nearest future collision between the input object and list of other objects
* @param a: the object for which we wish to predict the nearesst collision
* @param objs: the list of objects against which we should check for future collisions
*/
public static Vector3 predictNearestCollision(GameObject a, List <GameObject> objs)
{
followChaser afc = a.GetComponent <followChaser>();
float closestPredictedDistance = -1;
afc.closestPredictedUnit = null;
Vector3 closestPredictedLoc = Vector3.zero;
//iterate over all passed in objects to find the one which will collide with us the soonest
for (var i = 0; i < objs.Count; ++i)
{
GameObject b = objs[i];
followChaser bfc = b.GetComponent <followChaser>();
//calculate our collision prediction between a and b now
Vector3 dp = b.transform.position - a.transform.position;
Vector3 vt = bfc.spd * b.transform.up;
Vector3 vc = afc.spd * a.transform.up;
Vector3 dv = vt - vc;
float tClosest = -(Vector3.Dot(dp, dv) / Mathf.Pow(Mathf.Abs(dv.magnitude), 2));
//ignore collisions in the past
if (tClosest < 0)
{
continue;
}
Vector3 pcf = a.transform.position + vc * tClosest;
Vector3 ptf = b.transform.position + vt * tClosest;
float colDist = Vector3.Distance(pcf, ptf);
if (colDist < (afc.radius + bfc.radius))
{
//check if the distance at the time of collision will cause an intersection
if (closestPredictedDistance == -1 || colDist < closestPredictedDistance)
{
closestPredictedDistance = colDist;
afc.closestPredictedUnit = b;
closestPredictedLoc = pcf;
}
}
}
return(closestPredictedLoc);
}
