Bugfix/Refactor: Min-Max Damage Range Calculations (#7022)

Source/missiles.cpp

@@ -195,7 +195,7 @@ void MoveMissilePos(Missile &missile)
 int ProjectileMonsterDamage(Missile &missile)
 {
 	const Monster &monster = *missile.sourceMonster();
-	return monster.minDamage + GenerateRnd(monster.maxDamage - monster.minDamage + 1);
+	return RandomIntBetween(monster.minDamage, monster.maxDamage);
 }
 
 int ProjectileTrapDamage()
@@ -240,7 +240,7 @@ bool MonsterMHit(const Player &player, int monsterId, int mindam, int maxdam, in
 	if (t == MissileID::BoneSpirit) {
 		dam = monster.hitPoints / 3 >> 6;
 	} else {
-		dam = mindam + GenerateRnd(maxdam - mindam + 1);
+		dam = RandomIntBetween(mindam, maxdam);
 	}
 
 	if (missileData.isArrow() && damageType == DamageType::Physical) {
@@ -353,7 +353,7 @@ bool Plr2PlrMHit(const Player &player, Player &target, int mindam, int maxdam, i
 	if (mtype == MissileID::BoneSpirit) {
 		dam = target._pHitPoints / 3;
 	} else {
-		dam = mindam + GenerateRnd(maxdam - mindam + 1);
+		dam = RandomIntBetween(mindam, maxdam);
 		if (missileData.isArrow() && damageType == DamageType::Physical)
 			dam += player._pIBonusDamMod + player._pDamageMod + dam * player._pIBonusDam / 100;
 		if (!shift)
@@ -956,7 +956,7 @@ bool MonsterTrapHit(int monsterId, int mindam, int maxdam, int dist, MissileID t
 	}
 
 	bool resist = monster.isResistant(t, damageType);
-	int dam = mindam + GenerateRnd(maxdam - mindam + 1);
+	int dam = RandomIntBetween(mindam, maxdam);
 	if (!shift)
 		dam <<= 6;
 	if (resist)
@@ -1064,13 +1064,14 @@ bool PlayerMHit(Player &player, Monster *monster, int dist, int mind, int maxd,
 		dam = player._pHitPoints / 3;
 	} else {
 		if (!shift) {
-			dam = (mind << 6) + GenerateRnd(((maxd - mind) << 6) + 1);
+			// New method fixes a bug which caused the maximum possible damage value to be 63/64ths too low.
+			dam = RandomIntBetween(mind << 6, maxd << 6);
 			if (monster == nullptr)
 				if (HasAnyOf(player._pIFlags, ItemSpecialEffect::HalfTrapDamage))
 					dam /= 2;
 			dam += player._pIGetHit * 64;
 		} else {
-			dam = mind + GenerateRnd(maxd - mind + 1);
+			dam = RandomIntBetween(mind, maxd);
 			if (monster == nullptr)
 				if (HasAnyOf(player._pIFlags, ItemSpecialEffect::HalfTrapDamage))
 					dam /= 2;
@@ -2587,7 +2588,7 @@ void AddInferno(Missile &missile, AddMissileParameter &parameter)
 		missile._midam = 8 * i + 16 + ((8 * i + 16) / 2);
 	} else {
 		Monster &monster = Monsters[missile._misource];
-		missile._midam = monster.minDamage + GenerateRnd(monster.maxDamage - monster.minDamage + 1);
+		missile._midam = RandomIntBetween(monster.minDamage, monster.maxDamage);
 	}
 }
 
@@ -3264,7 +3265,7 @@ void ProcessLightningControl(Missile &missile)
 		dam = (GenerateRnd(2) + GenerateRnd(Players[missile._misource].getCharacterLevel()) + 2) << 6;
 	} else {
 		Monster &monster = Monsters[missile._misource];
-		dam = 2 * (monster.minDamage + GenerateRnd(monster.maxDamage - monster.minDamage + 1));
+		dam = 2 * RandomIntBetween(monster.minDamage, monster.maxDamage);
 	}
 
 	SpawnLightning(missile, dam);

Source/monster.cpp

@@ -151,7 +151,7 @@ void InitMonster(Monster &monster, Direction rd, size_t typeIndex, Point positio
 	monster.animInfo.tickCounterOfCurrentFrame = GenerateRnd(monster.animInfo.ticksPerFrame - 1);
 	monster.animInfo.currentFrame = GenerateRnd(monster.animInfo.numberOfFrames - 1);
 
-	int maxhp = monster.data().hitPointsMinimum + GenerateRnd(monster.data().hitPointsMaximum - monster.data().hitPointsMinimum + 1);
+	int maxhp = RandomIntBetween(monster.data().hitPointsMinimum, monster.data().hitPointsMaximum);
 	if (monster.type().type == MT_DIABLO && !gbIsHellfire) {
 		maxhp /= 2;
 	}
@@ -1051,7 +1051,7 @@ void MonsterAttackMonster(Monster &attacker, Monster &target, int hper, int mind
 	if (hit >= hper)
 		return;
 
-	int dam = (mind + GenerateRnd(maxd - mind + 1)) << 6;
+	int dam = RandomIntBetween(mind, maxd) << 6;
 	ApplyMonsterDamage(DamageType::Physical, target, dam);
 
 	if (attacker.isPlayerMinion()) {
@@ -1156,7 +1156,8 @@ void MonsterAttackPlayer(Monster &monster, Player &player, int hit, int minDam,
 			}
 		}
 	}
-	int dam = (minDam << 6) + GenerateRnd(((maxDam - minDam) << 6) + 1);
+	// New method fixes a bug which caused the maximum possible damage value to be 63/64ths too low.
+	int dam = RandomIntBetween(minDam << 6, maxDam << 6);
 	dam = std::max(dam + (player._pIGetHit << 6), 64);
 	if (&player == MyPlayer) {
 		if (player.wReflections > 0) {
@@ -2612,7 +2613,7 @@ void CounselorAi(Monster &monster)
 		if (distanceToEnemy >= 2) {
 			if (v < 5 * (monster.intelligence + 10) && LineClearMissile(monster.position.tile, monster.enemyPosition)) {
 				constexpr MissileID MissileTypes[4] = { MissileID::Firebolt, MissileID::ChargedBolt, MissileID::LightningControl, MissileID::Fireball };
-				StartRangedAttack(monster, MissileTypes[monster.intelligence], monster.minDamage + GenerateRnd(monster.maxDamage - monster.minDamage + 1));
+				StartRangedAttack(monster, MissileTypes[monster.intelligence], RandomIntBetween(monster.minDamage, monster.maxDamage));
 			} else if (GenerateRnd(100) < 30) {
 				monster.goal = MonsterGoal::Move;
 				monster.goalVar1 = 0;

Source/player.cpp

@@ -546,12 +546,13 @@ bool PlrHitMonst(Player &player, Monster &monster, bool adjacentDamage = false)
 	}
 
 	if (gbIsHellfire && HasAllOf(player._pIFlags, ItemSpecialEffect::FireDamage | ItemSpecialEffect::LightningDamage)) {
+		// Fixed off by 1 error from Hellfire
 		int midam = RandomIntBetween(player._pIFMinDam, player._pIFMaxDam);
 		AddMissile(player.position.tile, player.position.temp, player._pdir, MissileID::SpectralArrow, TARGET_MONSTERS, player, midam, 0);
 	}
 	int mind = player._pIMinDam;
 	int maxd = player._pIMaxDam;
-	int dam = GenerateRnd(maxd - mind + 1) + mind;
+	int dam = RandomIntBetween(mind, maxd);
 	dam += dam * player._pIBonusDam / 100;
 	dam += player._pIBonusDamMod;
 	int dam2 = dam << 6;
@@ -719,7 +720,7 @@ bool PlrHitPlr(Player &attacker, Player &target)
 
 	int mind = attacker._pIMinDam;
 	int maxd = attacker._pIMaxDam;
-	int dam = GenerateRnd(maxd - mind + 1) + mind;
+	int dam = RandomIntBetween(mind, maxd);
 	dam += (dam * attacker._pIBonusDam) / 100;
 	dam += attacker._pIBonusDamMod + attacker._pDamageMod;
 
@@ -866,6 +867,7 @@ bool DoRangeAttack(Player &player)
 			mistype = MissileID::LightningArrow;
 		}
 		if (HasAllOf(player._pIFlags, ItemSpecialEffect::FireArrows | ItemSpecialEffect::LightningArrows)) {
+			// Fixed off by 1 error from Hellfire
 			dmg = RandomIntBetween(player._pIFMinDam, player._pIFMaxDam);
 			mistype = MissileID::SpectralArrow;
 		}