Merge pull request #5851 from Laserlicht/max_range_spell

max range for spell cast

docs/modders/Bonus/Bonus_Types.md

@@ -888,7 +888,7 @@ Affected unit will not use spellcast as default attack option
 
 ### SPELLCASTER
 
-Affected units can cast a spell as targeted action (Archangel, Faerie Dragon). Use CASTS bonus to specify how many times per combat creature can use spellcasting. Use SPECIFIC_SPELL_POWER, CREATURE_SPELL_POWER or CREATURE_ENCHANT_POWER bonuses to set spell power.
+Affected units can cast a spell as targeted action (Archangel, Faerie Dragon). Use CASTS bonus to specify how many times per combat creature can use spellcasting. Use SPECIFIC_SPELL_POWER, CREATURE_SPELL_POWER or CREATURE_ENCHANT_POWER bonuses to set spell power. SPECIFIC_SPELL_RANGE bonus can be used to limit range of spell.
 
 - subtype: spell identifier
 - val: spell mastery level
@@ -939,6 +939,11 @@ Determines how many times per combat affected creature can cast its targeted spe
 - value: Used for Thunderbolt and Resurrection cast by units (multiplied by stack size). Also used for Healing secondary skill (for core:spell.firstAid used by First Aid tent)
 - subtype - spell id
 
+### SPECIFIC_SPELL_RANGE
+
+- value: Can be used to limit range of spells casted by creatures.
+- subtype - spell id
+
 ### CREATURE_SPELL_POWER
 
 - value: Spell Power of offensive spell cast unit, multiplied by 100. ie. Faerie Dragons have value fo 500, which gives them 5 Spell Power for each unit in the stack.

include/vcmi/spells/Caster.h

@@ -10,6 +10,8 @@
 
 #pragma once
 
+#include "../../../lib/battle/BattleHex.h"
+
 VCMI_LIB_NAMESPACE_BEGIN
 
 class PlayerColor;
@@ -60,6 +62,9 @@ public:
 	///damage/heal override(ignores spell configuration, effect level and effect power)
 	virtual int64_t getEffectValue(const Spell * spell) const = 0;
 
+	///maximal range of effect
+	virtual int64_t getEffectRange(const Spell * spell) const = 0;
+
 	virtual PlayerColor getCasterOwner() const = 0;
 
 	///only name substitution

lib/battle/CUnitState.cpp

@@ -453,6 +453,11 @@ int64_t CUnitState::getEffectValue(const spells::Spell * spell) const
 	return static_cast<int64_t>(getCount()) * valOfBonuses(BonusType::SPECIFIC_SPELL_POWER, BonusSubtypeID(spell->getId()));
 }
 
+int64_t CUnitState::getEffectRange(const spells::Spell * spell) const
+{
+	return valOfBonuses(BonusType::SPECIFIC_SPELL_RANGE, BonusSubtypeID(spell->getId()));
+}
+
 PlayerColor CUnitState::getCasterOwner() const
 {
 	return env->unitEffectiveOwner(this);

lib/battle/CUnitState.h

@@ -180,6 +180,7 @@ public:
 	int32_t getEffectPower(const spells::Spell * spell) const override;
 	int32_t getEnchantPower(const spells::Spell * spell) const override;
 	int64_t getEffectValue(const spells::Spell * spell) const override;
+	int64_t getEffectRange(const spells::Spell * spell) const override;
 
 	PlayerColor getCasterOwner() const override;
 	const CGHeroInstance * getHeroCaster() const override;

lib/bonuses/BonusEnum.h

@@ -193,6 +193,7 @@ class JsonNode;
 	BONUS_NAME(FULL_MAP_DARKNESS) /*opposite to Skyship*/\
 	BONUS_NAME(TRANSMUTATION_IMMUNITY) /*blocks TRANSMUTATION bonus*/\
 	BONUS_NAME(COMBAT_MANA_BONUS) /* Additional mana per combat */ \
+	BONUS_NAME(SPECIFIC_SPELL_RANGE) /* value used for allowed spell range, subtype - spell id */\
 	/* end of list */
 
 

lib/json/JsonBonus.cpp

@@ -130,6 +130,7 @@ static void loadBonusSubtype(BonusSubtypeID & subtype, BonusType type, const Jso
 		case BonusType::SPECIAL_PECULIAR_ENCHANT:
 		case BonusType::SPECIAL_SPELL_LEV:
 		case BonusType::SPECIFIC_SPELL_DAMAGE:
+		case BonusType::SPECIFIC_SPELL_RANGE:
 		case BonusType::SPELL:
 		case BonusType::OPENING_BATTLE_SPELL:
 		case BonusType::SPELL_LIKE_ATTACK:

lib/mapObjects/CGHeroInstance.cpp

@@ -859,6 +859,11 @@ int64_t CGHeroInstance::getEffectValue(const spells::Spell * spell) const
 	return 0;
 }
 
+int64_t CGHeroInstance::getEffectRange(const spells::Spell * spell) const
+{
+	return 0;
+}
+
 PlayerColor CGHeroInstance::getCasterOwner() const
 {
 	return tempOwner;

lib/mapObjects/CGHeroInstance.h

@@ -289,6 +289,7 @@ public:
 	int32_t getEffectPower(const spells::Spell * spell) const override;
 	int32_t getEnchantPower(const spells::Spell * spell) const override;
 	int64_t getEffectValue(const spells::Spell * spell) const override;
+	int64_t getEffectRange(const spells::Spell * spell) const override;
 
 	PlayerColor getCasterOwner() const override;
 	const CGHeroInstance * getHeroCaster() const override;

lib/spells/BattleSpellMechanics.cpp

@@ -16,6 +16,7 @@
 
 #include "../battle/IBattleState.h"
 #include "../battle/CBattleInfoCallback.h"
+#include "../battle/Unit.h"
 #include "../networkPacks/PacksForClientBattle.h"
 #include "../networkPacks/SetStackEffect.h"
 #include "../CStack.h"
@@ -208,6 +209,46 @@ bool BattleSpellMechanics::canBeCast(Problem & problem) const
 	return effects->applicable(problem, this);
 }
 
+bool BattleSpellMechanics::canCastAtTarget(const battle::Unit * target) const
+{
+	if(mode == Mode::HERO)
+		return true;
+
+	if(!target)
+		return true;
+
+	auto spell = getSpell();
+	int range = caster->getEffectRange(spell);
+
+	if(range <= 0)
+		return true;
+
+	auto casterStack = battle()->battleGetStackByID(caster->getCasterUnitId(), false);
+	std::vector<BattleHex> casterPos = { casterStack->getPosition() };
+	BattleHex casterWidePos = casterStack->occupiedHex();
+	if(casterWidePos != BattleHex::INVALID)
+		casterPos.push_back(casterWidePos);
+
+	std::vector<BattleHex> destPos = { target->getPosition() };
+	BattleHex destWidePos = target->occupiedHex();
+	if(destWidePos != BattleHex::INVALID)
+		destPos.push_back(destWidePos);
+	
+	int minDistance = std::numeric_limits<int>::max();
+	for(auto & caster : casterPos)
+		for(auto & dest : destPos)
+		{
+			int distance = BattleHex::getDistance(caster, dest);
+			if(distance < minDistance)
+				minDistance = distance;
+		}
+
+	if(minDistance > range)
+		return false;
+	
+	return true;
+}
+
 bool BattleSpellMechanics::canBeCastAt(const Target & target, Problem & problem) const
 {
 	if(!canBeCast(problem))
@@ -226,6 +267,9 @@ bool BattleSpellMechanics::canBeCastAt(const Target & target, Problem & problem)
 		mainTarget = battle()->battleGetUnitByPos(target.front().hexValue, true);
 	}
 
+	if(!canCastAtTarget(mainTarget))
+		return false;
+
 	if (!getSpell()->canCastOnSelf() && !getSpell()->canCastOnlyOnSelf())
 	{
 		if(mainTarget && mainTarget == caster)

lib/spells/BattleSpellMechanics.h

@@ -83,6 +83,8 @@ private:
 	BattleHexArray spellRangeInHexes(const BattleHex & centralHex) const;
 
 	Target transformSpellTarget(const Target & aimPoint) const;
+
+	bool canCastAtTarget(const battle::Unit * target) const;
 };
 
 }

lib/spells/ObstacleCasterProxy.cpp

@@ -58,6 +58,14 @@ int64_t ObstacleCasterProxy::getEffectValue(const Spell * spell) const
 		return obs.minimalDamage;
 }
 
+int64_t ObstacleCasterProxy::getEffectRange(const Spell * spell) const
+{
+	if(actualCaster)
+		actualCaster->getEffectRange(spell);
+
+	return 0;
+}
+
 int32_t SilentCaster::manaLimit() const
 {
 	return 0;

lib/spells/ObstacleCasterProxy.h

@@ -42,6 +42,7 @@ public:
 	int32_t getEffectPower(const Spell * spell) const override;
 	int32_t getEnchantPower(const Spell * spell) const override;
 	int64_t getEffectValue(const Spell * spell) const override;
+	int64_t getEffectRange(const Spell * spell) const override;
 
 private:
 	const SpellCreatedObstacle & obs;

lib/spells/ProxyCaster.cpp

@@ -92,6 +92,14 @@ int64_t ProxyCaster::getEffectValue(const Spell * spell) const
 	return 0;
 }
 
+int64_t ProxyCaster::getEffectRange(const Spell * spell) const
+{
+	if(actualCaster)
+		return actualCaster->getEffectRange(spell);
+
+	return 0;
+}
+
 PlayerColor ProxyCaster::getCasterOwner() const
 {
 	if(actualCaster)

lib/spells/ProxyCaster.h

@@ -31,6 +31,7 @@ public:
 	int32_t getEffectPower(const Spell * spell) const override;
 	int32_t getEnchantPower(const Spell * spell) const override;
 	int64_t getEffectValue(const Spell * spell) const override;
+	int64_t getEffectRange(const Spell * spell) const override;
 	PlayerColor getCasterOwner() const override;
 	void getCasterName(MetaString & text) const override;
 	void getCastDescription(const Spell * spell, const battle::Units & attacked, MetaString & text) const override;

test/mock/mock_battle_Unit.h

@@ -26,6 +26,7 @@ public:
 	MOCK_CONST_METHOD1(getEffectPower, int32_t(const spells::Spell *));
 	MOCK_CONST_METHOD1(getEnchantPower, int32_t(const spells::Spell *));
 	MOCK_CONST_METHOD1(getEffectValue, int64_t(const spells::Spell *));
+	MOCK_CONST_METHOD1(getEffectRange, int64_t(const spells::Spell *));
 	MOCK_CONST_METHOD0(getCasterOwner, PlayerColor());
 	MOCK_CONST_METHOD1(getCasterName, void(MetaString &));
 	MOCK_CONST_METHOD3(getCastDescription, void(const spells::Spell *, const battle::Units &, MetaString &));