CGHeroInstance: move native terrain check into getNativeTerrain

That make it easier to use that code independently in TurnInfo

lib/CPathfinder.cpp

@@ -732,6 +732,7 @@ TurnInfo::TurnInfo(const CGHeroInstance * Hero, const int turn)
 
 	bonuses = hero->getAllBonuses(Selector::days(turn), nullptr, nullptr, cachingStr.str());
 	bonusCache = make_unique<BonusCache>(bonuses);
+	nativeTerrain = hero->getNativeTerrain();
 }
 
 bool TurnInfo::isLayerAvailable(const EPathfindingLayer layer) const

lib/CPathfinder.h

@@ -227,6 +227,7 @@ struct DLL_LINKAGE TurnInfo
 	TBonusListPtr bonuses;
 	mutable int maxMovePointsLand;
 	mutable int maxMovePointsWater;
+	int nativeTerrain;
 
 	TurnInfo(const CGHeroInstance * Hero, const int Turn = 0);
 	bool isLayerAvailable(const EPathfindingLayer layer) const;

lib/mapObjects/CGHeroInstance.cpp

@@ -80,28 +80,38 @@ ui32 CGHeroInstance::getTileCost(const TerrainTile &dest, const TerrainTile &fro
 			break;
 		}
 	}
-	else if(!ti->hasBonusOfType(Bonus::NO_TERRAIN_PENALTY, from.terType))
+	else if(ti->nativeTerrain != from.terType && !ti->hasBonusOfType(Bonus::NO_TERRAIN_PENALTY, from.terType))
 	{
-		// NOTE: in H3 neutral stacks will ignore terrain penalty only if placed as topmost stack(s) in hero army.
-		// This is clearly bug in H3 however intended behaviour is not clear.
-		// Current VCMI behaviour will ignore neutrals in calculations so army in VCMI
-		// will always have best penalty without any influence from player-defined stacks order
+		ret = VLC->heroh->terrCosts[from.terType];
+		ret -= getSecSkillLevel(SecondarySkill::PATHFINDING) * 25;
+		if(ret < GameConstants::BASE_MOVEMENT_COST)
+			ret = GameConstants::BASE_MOVEMENT_COST;
+	}
+	return ret;
+}
 
-		for(auto stack : stacks)
-		{
-			int nativeTerrain = VLC->townh->factions[stack.second->type->faction]->nativeTerrain;
-			if(nativeTerrain != -1 && nativeTerrain != from.terType)
-			{
-				ret = VLC->heroh->terrCosts[from.terType];
-				ret -= getSecSkillLevel(SecondarySkill::PATHFINDING) * 25;
-				if(ret < GameConstants::BASE_MOVEMENT_COST)
-					ret = GameConstants::BASE_MOVEMENT_COST;
+int CGHeroInstance::getNativeTerrain() const
+{
+	// NOTE: in H3 neutral stacks will ignore terrain penalty only if placed as topmost stack(s) in hero army.
+	// This is clearly bug in H3 however intended behaviour is not clear.
+	// Current VCMI behaviour will ignore neutrals in calculations so army in VCMI
+	// will always have best penalty without any influence from player-defined stacks order
 
-				break;
-			}
-		}
+	// TODO: What should we do if all hero stacks are neutral creatures?
+	int nativeTerrain = -1;
+	for(auto stack : stacks)
+	{
+		int stackNativeTerrain = VLC->townh->factions[stack.second->type->faction]->nativeTerrain;
+		if(stackNativeTerrain == -1)
+			continue;
+
+		if(nativeTerrain == -1)
+			nativeTerrain = stackNativeTerrain;
+		else if(nativeTerrain != stackNativeTerrain)
+			return -1;
 	}
-	return ret;
+
+	return nativeTerrain;
 }
 
 int3 CGHeroInstance::convertPosition(int3 src, bool toh3m) //toh3m=true: manifest->h3m; toh3m=false: h3m->manifest

lib/mapObjects/CGHeroInstance.h

@@ -131,6 +131,7 @@ public:
 	const std::string &getBiography() const;
 	bool needsLastStack()const override;
 	ui32 getTileCost(const TerrainTile &dest, const TerrainTile &from, const TurnInfo * ti) const; //move cost - applying pathfinding skill, road and terrain modifiers. NOT includes diagonal move penalty, last move levelling
+	int getNativeTerrain() const;
 	ui32 getLowestCreatureSpeed() const;
 	int3 getPosition(bool h3m = false) const; //h3m=true - returns position of hero object; h3m=false - returns position of hero 'manifestation'
 	si32 manaRegain() const; //how many points of mana can hero regain "naturally" in one day