/// <summary>
/// Search for all objects that are or can be in collision with each other.
/// Must be called when step was already performed, so collisions are already there.
/// If there is no collision, returns empty list.
/// </summary>
/// <returns>List of list of all potentially colliding objects.</returns>
public List<List<IPhysicalEntity>> CollisionGroups()
{
List<HashSet<IPhysicalEntity>> listOfSets = new List<HashSet<IPhysicalEntity>>();
foreach (IPhysicalEntity physicalEntity in m_physicalEntities)
{
if (Collides(physicalEntity))
{
var circle = new Circle(physicalEntity.Position,
2 * MaximumGameObjectRadius + MaximumGameObjectSpeed);
var physicalEntities = new HashSet<IPhysicalEntity>(m_objectLayer.GetPhysicalEntities(circle));
listOfSets.Add(physicalEntities);
}
}
// consolidation
for (int i = 0; i < listOfSets.Count - 1; i++)
{
HashSet<IPhysicalEntity> firstList = listOfSets[i];
for (int j = i + 1; j < listOfSets.Count; j++)
{
HashSet<IPhysicalEntity> secondList = listOfSets[j];
if (firstList.Overlaps(secondList))
{
firstList.UnionWith(secondList);
listOfSets.RemoveAt(j);
j--;
}
}
}
// To List
List<List<IPhysicalEntity>> collisionGroups = new List<List<IPhysicalEntity>>();
foreach (HashSet<IPhysicalEntity> hashSet in listOfSets)
{
collisionGroups.Add(hashSet.ToList());
}
return collisionGroups;
}
public bool CollidesWithPhysicalEntity(IPhysicalEntity physicalEntity)
{
var circle = new Circle(physicalEntity.Position, 2 * MaximumGameObjectRadius);
List<IPhysicalEntity> physicalEntities = m_objectLayer.GetPhysicalEntities(circle);
return physicalEntities.Any(physicalEntity.CollidesWith);
}