/* The next best thing to a picture in the source code.
IsLegal()
||
||
IsKill
n/ \y
IsSuicide IsKo
n/ \y n/ \y
PLAY NO PLAY NO
*/
public IsLegalResponse IsLegal(Loc proposedLoc)
{
IsLegalResponse response = new IsLegalResponse();
if (isConflict(proposedLoc))
{
response.Reason = ReasonEnum.Conflict;
return response;
}
response.Killed = determineKills(proposedLoc);
if (response.Killed.Any())
{ // IsKill
if (isKo(proposedLoc, response.Killed))
{
response.Reason = ReasonEnum.Ko;
return response;
}
else
{ // Determine MergeResultant and AbsorbedByMerge for future use.
// Does proposedLoc have any friendly neighbors?
List<Chain> friendlyNeighborChains = findFriendlyNeighborChains(proposedLoc);
if (friendlyNeighborChains.Any())
{
// If so, merge
friendlyNeighborChains.Add(new Chain(new Stone(proposedLoc, IsWhiteMove),
this.findLiberties(proposedLoc)));
response.MergeResultant = this.merge(friendlyNeighborChains);
response.AbsorbedInMerge = friendlyNeighborChains;
}
else
{
response.MergeResultant = new Chain(new Stone(proposedLoc, IsWhiteMove), this.findLiberties(proposedLoc));
response.AbsorbedInMerge = new List<Chain>();
}
return response;
}
}
else
{ // !IsKill
this.determineSuicide(proposedLoc, response);
return response;
}
}
private void determineSuicide(Loc proposedLoc, IsLegalResponse response)
{
// Does proposedLoc have any friendly neighbors?
List<Chain> friendlyNeighborChains = findFriendlyNeighborChains(proposedLoc);
if (friendlyNeighborChains.Any())
{
// If so, merge
friendlyNeighborChains.Add(new Chain(new Stone(proposedLoc, IsWhiteMove), this.findLiberties(proposedLoc)));
Chain mergeResultant = this.merge(friendlyNeighborChains);
if (!mergeResultant.Liberties.Any())
{
response.Reason = ReasonEnum.Suicide;
return;
}
else
{
response.MergeResultant = mergeResultant;
response.AbsorbedInMerge = friendlyNeighborChains;
return;
}
}
else
{
// If not, if there are any liberties, it's playable
if (this.findLiberties(proposedLoc).Any())
{
response.MergeResultant = new Chain(new Stone(proposedLoc, IsWhiteMove),
this.findLiberties(proposedLoc));
response.AbsorbedInMerge = new List<Chain>();
return;
}
}
// else, it's suicide
response.Reason = ReasonEnum.Suicide;
}
// Updates lists accordingly with correct location and color.
public RequestResponse PlaceStone(Loc loc, IsLegalResponse isLegalResponse)
{
// By this point, we have MergeResult and KilledChains
this.Game.PossibleKoLoc = new Loc(-1, -1);
// Update logical groups of Chains by adding the mergeResult and removing what went into the merge
this.enactMerge(isLegalResponse.MergeResultant, isLegalResponse.AbsorbedInMerge);
// Update logical groups of Chains by removing the killed ones.
this.deadifyKilledChains(isLegalResponse.Killed);
if (IsWhiteMove)
{
this.Game.PrisonersTakenByWhite += isLegalResponse.Killed.Sum(chain => chain.Stones.Count);
foreach (Chain chain in this.Game.whiteChains)
this.reCalcLiberties(chain);
}
else
{
this.Game.PrisonersTakenByBlack += isLegalResponse.Killed.Sum(chain => chain.Stones.Count);
foreach (Chain chain in this.Game.blackChains)
this.reCalcLiberties(chain);
}
// Update logical groups of Opponent's Chains by removing breath for current Loc
this.takeMyBreathAwaaaaay(loc);
// Set possibleKoLoc.
if (isLegalResponse.Killed.Count == 1
&& isLegalResponse.Killed[0].Stones.Count == 1)
{
this.Game.PossibleKoLoc = isLegalResponse.Killed[0].Stones[0].Loc;
}
RequestResponse response = new RequestResponse(new Move(new Stone(loc, IsWhiteMove), isLegalResponse.Killed));
this.ChangeTurn();
return response;
}