Added AI for culture strategies with Mastery Victory.

When the Mastery victory condition is enabled, the AI will now try to
calculate the best number of legendary cities to aim for; and then use
full-culture mode only in the final stages of the game to achieve their
target.

CvGameCoreDLL/CvPlayerAI.cpp

@@ -18722,7 +18722,16 @@ int CvPlayerAI::AI_calculateCultureVictoryStage() const
 		}
 	}
 
-	if( iLegendaryCount >= iVictoryCities )
+	// K-Mod. check for Mastery victory
+	bool bMasteryVictory = false;
+	for (VictoryTypes i = (VictoryTypes)0; !bMasteryVictory && i < GC.getNumVictoryInfos(); i=(VictoryTypes)(i+1))
+	{
+		if (GC.getGameINLINE().isVictoryValid(i) && GC.getVictoryInfo(i).isTotalVictory())
+			bMasteryVictory = true;
+	}
+	// K-Mod end
+
+	if (iLegendaryCount >= iVictoryCities && (!bMasteryVictory || GC.getGameINLINE().getGameState() == GAMESTATE_EXTENDED))
 	{
 		// Already won, keep playing culture heavy but do some tech to keep pace if human wants to keep playing
 		return 3;
@@ -18826,11 +18835,16 @@ int CvPlayerAI::AI_calculateCultureVictoryStage() const
 	}
 
 	int iWinningCountdown = INT_MAX;
-	if ((int)countdownList.size() >= iVictoryCities && iVictoryCities > 0)
+	if (bMasteryVictory)
+	{
+		std::sort(countdownList.begin(), countdownList.end());
+	}
+	else if ((int)countdownList.size() >= iVictoryCities && iVictoryCities > 0)
 	{
 		std::partial_sort(countdownList.begin(), countdownList.begin() + iVictoryCities, countdownList.end());
 		iWinningCountdown = countdownList[iVictoryCities-1];
 	}
+
     if (iCloseToLegendaryCount >= iVictoryCities || getCurrentEra() >= (GC.getNumEraInfos() - (2 + AI_getStrategyRand(1) % 2)))
     {
 		bool bAt3 = false;
@@ -18858,9 +18872,30 @@ int CvPlayerAI::AI_calculateCultureVictoryStage() const
 			{
 				return 4;
 			}*/
-			// K-Mod. Do full culture if our winning countdown is below the countdown target.
-			int iCountdownTarget = 180;
+			// K-Mod.
+			if (bMasteryVictory)
 			{
+				// work out how many legendary cities we should aim for. (please excuse the arbitrary numbers used here)
+				int iTurnsRemaining = GC.getGameINLINE().getEstimateEndTurn() - GC.getGameINLINE().getGameTurn();
+				if (iTurnsRemaining > 0 && iTurnsRemaining <= GC.getGameINLINE().getMaxTurns()/3)
+				{
+					int iTarget = 0;
+					for (size_t i = 0; i < countdownList.size(); i++)
+					{
+						if (countdownList[i] < iTurnsRemaining - 10 && (i < iVictoryCities + iLegendaryCount || countdownList[i] - countdownList[iTarget] < 15))
+						{
+							iTarget = i;
+						}
+					}
+					if (iTurnsRemaining < countdownList[iTarget]+12)
+						return 4;
+				}
+			}
+			else
+			{
+				// Do full culture if our winning countdown is below the countdown target.
+				int iCountdownTarget = 180;
+
 				// The countdown target depends on what other victory strategies we have in mind. The target is 180 turns * 100 / iDenominator.
 				// For example, if we're already at war, and going for conquest 4, the target countdown is then ~ 180 * 100 / 470 == 38 turns.
 				// Note: originally culture 4 was blocked completely by stage 4 of any other victory strategy. But this is no longer the case.
@@ -18886,10 +18921,11 @@ int CvPlayerAI::AI_calculateCultureVictoryStage() const
 
 				iCountdownTarget *= GC.getGameSpeedInfo(GC.getGame().getGameSpeedType()).getVictoryDelayPercent();
 				iCountdownTarget /= std::max(1, iDemoninator);
-			}
-			if (iWinningCountdown < iCountdownTarget)
-			{
-				return 4;
+
+				if (iWinningCountdown < iCountdownTarget)
+				{
+					return 4;
+				}
 			}
 			// K-Mod end