vcmi: add native terrain entity

Add interface which should be used on any object with native terrain

So far, it is faction, hero, creature and battle stack

include/vcmi/Creature.h

@@ -18,7 +18,7 @@ class CreatureID;
 class ResourceSet;
 enum class EGameResID : int8_t;
 
-class DLL_LINKAGE Creature : public EntityWithBonuses<CreatureID>
+class DLL_LINKAGE Creature : public EntityWithNativeTerrain<CreatureID>
 {
 protected:
 	// use getNamePlural/Singular instead

include/vcmi/Entity.h

@@ -13,6 +13,9 @@
 VCMI_LIB_NAMESPACE_BEGIN
 
 class IBonusBearer;
+class FactionID;
+enum class ETerrainId;
+template<typename T> class Identifier;
 
 class DLL_LINKAGE WithBonuses
 {
@@ -20,6 +23,13 @@ public:
 	virtual const IBonusBearer * getBonusBearer() const = 0;
 };
 
+class DLL_LINKAGE WithNativeTerrain
+{
+public:
+	virtual Identifier<ETerrainId> getNativeTerrain() const = 0;
+	virtual FactionID getFaction() const = 0;
+};
+
 class DLL_LINKAGE Entity
 {
 public:
@@ -48,4 +58,9 @@ class DLL_LINKAGE EntityWithBonuses : public EntityT<IdType>, public WithBonuses
 {
 };
 
+template <typename IdType>
+class DLL_LINKAGE EntityWithNativeTerrain : public EntityWithBonuses<IdType>, public WithNativeTerrain
+{
+};
+
 VCMI_LIB_NAMESPACE_END

include/vcmi/Faction.h

@@ -15,15 +15,12 @@
 VCMI_LIB_NAMESPACE_BEGIN
 
 class FactionID;
-enum class ETerrainId;
 enum class EAlignment : uint8_t;
-template<typename T> class Identifier;
 
-class DLL_LINKAGE Faction : public EntityT<FactionID>
+class DLL_LINKAGE Faction : public EntityT<FactionID>, public WithNativeTerrain
 {
 public:
 	virtual bool hasTown() const = 0;
-	virtual Identifier<ETerrainId> getNativeTerrain() const = 0;
 	virtual EAlignment getAlignment() const = 0;
 };
 

lib/CCreatureHandler.cpp

@@ -114,6 +114,11 @@ int32_t CCreature::getFactionIndex() const
 	return faction;
 }
 
+FactionID CCreature::getFaction() const
+{
+	return FactionID(faction);
+}
+
 int32_t CCreature::getBaseAttack() const
 {
 	static const auto SELECTOR = Selector::typeSubtype(Bonus::PRIMARY_SKILL, PrimarySkill::ATTACK).And(Selector::sourceTypeSel(Bonus::CREATURE_ABILITY));

lib/CCreatureHandler.h

@@ -163,10 +163,11 @@ public:
 	std::string getNameSingularTextID() const override;
 
 	bool isItNativeTerrain(TerrainId terrain) const;
+	FactionID getFaction() const override;
 	/**
 	Returns creature native terrain considering some terrain bonuses.
 	*/
-	TerrainId getNativeTerrain() const;
+	TerrainId getNativeTerrain() const override;
 	int32_t getIndex() const override;
 	int32_t getIconIndex() const override;
 	std::string getJsonKey() const override;

lib/CTownHandler.cpp

@@ -157,6 +157,11 @@ FactionID CFaction::getId() const
 	return FactionID(index);
 }
 
+FactionID CFaction::getFaction() const
+{
+	return FactionID(index);
+}
+
 bool CFaction::hasTown() const
 {
 	return town != nullptr;

lib/CTownHandler.h

@@ -192,6 +192,8 @@ class DLL_LINKAGE CFaction : public Faction
 
 	TFaction index = 0;
 
+	FactionID getFaction() const override; //This function should not be used
+
 public:
 	TerrainId nativeTerrain;
 	EAlignment alignment = EAlignment::NEUTRAL;