Take magic-capability into account for overall strength-estimation of hero-lead-armies

The magic-strength of a hero now checks if the hero has a spellbook and at least one combat-spell.
The impact of knowledge and spellpower to the hero's magic-strength is now also depending on it's current and max mana-pool-size as an empty mana-pool does not exactly contribute well to fights.

Replaced every call of getFightingStrength() with getHeroStrength() which uses both the fightingStrength and the (reworked) magicStrength to guess how much stronger a hero-lead army is.

AI/Nullkiller/AIUtility.cpp

@@ -149,7 +149,7 @@ bool HeroPtr::operator==(const HeroPtr & rhs) const
 
 bool isSafeToVisit(const CGHeroInstance * h, const CCreatureSet * heroArmy, uint64_t dangerStrength)
 {
-	const ui64 heroStrength = h->getFightingStrength() * heroArmy->getArmyStrength();
+	const ui64 heroStrength = h->getHeroStrength() * heroArmy->getArmyStrength();
 
 	if(dangerStrength)
 	{

AI/Nullkiller/Analyzers/HeroManager.cpp

@@ -109,7 +109,7 @@ void HeroManager::update()
 	for(auto & hero : myHeroes)
 	{
 		scores[hero] = evaluateFightingStrength(hero);
-		knownFightingStrength[hero->id] = hero->getFightingStrength();
+		knownFightingStrength[hero->id] = hero->getHeroStrength();
 	}
 
 	auto scoreSort = [&](const CGHeroInstance * h1, const CGHeroInstance * h2) -> bool
@@ -205,7 +205,7 @@ float HeroManager::getFightingStrengthCached(const CGHeroInstance * hero) const
 	auto cached = knownFightingStrength.find(hero->id);
 
 	//FIXME: fallback to hero->getFightingStrength() is VERY slow on higher difficulties (no object graph? map reveal?)
-	return cached != knownFightingStrength.end() ? cached->second : hero->getFightingStrength();
+	return cached != knownFightingStrength.end() ? cached->second : hero->getHeroStrength();
 }
 
 float HeroManager::getMagicStrength(const CGHeroInstance * hero) const
@@ -298,7 +298,7 @@ const CGHeroInstance * HeroManager::findWeakHeroToDismiss(uint64_t armyLimit) co
 			continue;
 		}
 
-		if(!weakestHero || weakestHero->getFightingStrength() > existingHero->getFightingStrength())
+		if(!weakestHero || weakestHero->getHeroStrength() > existingHero->getHeroStrength())
 		{
 			weakestHero = existingHero;
 		}

AI/Nullkiller/Pathfinding/Actors.cpp

@@ -46,7 +46,7 @@ ChainActor::ChainActor(const CGHeroInstance * hero, HeroRole heroRole, uint64_t
 	initialMovement = hero->movementPointsRemaining();
 	initialTurn = 0;
 	armyValue = getHeroArmyStrengthWithCommander(hero, hero);
-	heroFightingStrength = hero->getFightingStrength();
+	heroFightingStrength = hero->getHeroStrength();
 	tiCache.reset(new TurnInfo(hero));
 }
 

lib/mapObjects/CGHeroInstance.cpp

@@ -651,7 +651,20 @@ double CGHeroInstance::getFightingStrength() const
 
 double CGHeroInstance::getMagicStrength() const
 {
-	return sqrt((1.0 + 0.05*getPrimSkillLevel(PrimarySkill::KNOWLEDGE)) * (1.0 + 0.05*getPrimSkillLevel(PrimarySkill::SPELL_POWER)));
+	if (!hasSpellbook())
+		return 1;
+	bool atLeastOneCombatSpell = false;
+	for (auto spell : spells)
+	{
+		if (spellbookContainsSpell(spell) && spell.toSpell()->isCombat())
+		{
+			atLeastOneCombatSpell = true;
+			break;
+		}
+	}
+	if (!atLeastOneCombatSpell)
+		return 1;
+	return sqrt((1.0 + 0.05*getPrimSkillLevel(PrimarySkill::KNOWLEDGE) * mana / manaLimit()) * (1.0 + 0.05*getPrimSkillLevel(PrimarySkill::SPELL_POWER) * mana / manaLimit()));
 }
 
 double CGHeroInstance::getHeroStrength() const
@@ -661,7 +674,7 @@ double CGHeroInstance::getHeroStrength() const
 
 ui64 CGHeroInstance::getTotalStrength() const
 {
-	double ret = getFightingStrength() * getArmyStrength();
+	double ret = getHeroStrength() * getArmyStrength();
 	return static_cast<ui64>(ret);
 }