/// <summary>
/// Used when WorldState objects are put in the open list priority queue
/// </summary>
/// <param name="other"></param>
/// <returns></returns>
public virtual int CompareTo(IBinaryHeapItem other)
{
WorldState that = (WorldState)other;
/*
* if (conflictRange == -1)
* return CompareToPRobust(that);
*/
int thisF = this.h + this.g;
int thatF = that.h + that.g;
if (thisF < thatF)
{
return(-1);
}
if (thisF > thatF)
{
return(1);
}
// Tie breaking:
bool thisIsGoal = this.GoalTest();
bool thatIsGoal = that.GoalTest();
if (thisIsGoal == true && thatIsGoal == false) // The elaborate form is necessary to keep the comparison consistent. Otherwise goalA<goalB and goalB<goalA
{
return(-1);
}
if (thatIsGoal == true && thisIsGoal == false)
{
return(1);
}
// Independence Detection framework conflicts:
if (this.potentialConflictsCount < that.potentialConflictsCount)
{
return(-1);
}
if (this.potentialConflictsCount > that.potentialConflictsCount)
{
return(1);
}
// CBS framework conflicts:
// It makes sense to prefer nodes that conflict less, and not just nodes that don't conflict at all,
// because a 3-way conflict takes more work to resolve than
if (this.cbsInternalConflictsCount < that.cbsInternalConflictsCount)
{
return(-1);
}
if (this.cbsInternalConflictsCount > that.cbsInternalConflictsCount)
{
return(1);
}
// //M-Star: prefer nodes with smaller collision sets:
//if (this.collisionSets != null) // than M-Star is running
//{
// // The collision sets change during collision set backpropagation and closed list hits.
// // Backpropagation goes from a node's child to the node, so it's tempting to think
// // it only happens when the node is already expanded and out of the open list,
// // but partial expansion makes that false.
// // Closed list hits can also happen while the node is waiting to be expanded.
// // So the max rank can change while the node is in the open list -
// // it can't be used for tie breaking :(.
// if (this.collisionSets.maxRank < that.collisionSets.maxRank)
// return -1;
// if (that.collisionSets.maxRank > this.collisionSets.maxRank)
// return 1;
//}
// f, collision sets, conflicts and internal conflicts being equal, prefer nodes with a larger g
// - they're closer to the goal so less nodes would probably be generated by them on the way to it.
if (this.g < that.g)
{
return(1);
}
if (this.g > that.g)
{
return(-1);
}
return(0);
}
/// <summary>
/// Used when WorldState objects are put in the open list priority queue
/// </summary>
/// <param name="other"></param>
/// <returns></returns>
public virtual int CompareTo(IBinaryHeapItem other)
{
WorldState that = (WorldState)other;
int thisF = this.h + this.g;
int thatF = that.h + that.g;
if (thisF < thatF)
{
return(-1);
}
if (thisF > thatF)
{
return(1);
}
// Tie breaking:
bool thisIsGoal = this.GoalTest();
bool thatIsGoal = that.GoalTest();
if (thisIsGoal == true && thatIsGoal == false) // The elaborate form is necessary to keep the comparison consistent. Otherwise goalA<goalB and goalB<goalA
{
return(-1);
}
if (thatIsGoal == true && thisIsGoal == false)
{
return(1);
}
// Independence Detection framework conflicts:
if (this.potentialConflictsCount < that.potentialConflictsCount)
{
return(-1);
}
if (this.potentialConflictsCount > that.potentialConflictsCount)
{
return(1);
}
// CBS framework conflicts:
// It makes sense to prefer nodes that conflict less, and not just nodes that don't conflict at all,
// because a 3-way conflict takes more work to resolve than
if (this.cbsInternalConflictsCount < that.cbsInternalConflictsCount)
{
return(-1);
}
if (this.cbsInternalConflictsCount > that.cbsInternalConflictsCount)
{
return(1);
}
// f, conflicts and internal conflicts being equal, prefer nodes with a larger g
// - they're closer to the goal so less nodes would probably be generated by them on the way to it.
if (this.g < that.g)
{
return(1);
}
if (this.g > that.g)
{
return(-1);
}
return(0);
}
