Fix a few -Wsign-compare warnings

Source/lighting.cpp

@@ -362,7 +362,7 @@ void MakeLightTable()
 	} else if (IsAnyOf(leveltype, DTYPE_NEST, DTYPE_CRYPT)) {
 		// Make the lava fully bright
 		for (auto &lightTable : LightTables)
-			std::iota(lightTable.begin(), lightTable.begin() + 16, 0);
+			std::iota(lightTable.begin(), lightTable.begin() + 16, uint8_t { 0 });
 		LightTables[15][0] = 0;
 		std::fill_n(LightTables[15].begin() + 1, 15, 1);
 	}
@@ -438,7 +438,7 @@ void InitLighting()
 	DisableLighting = false;
 #endif
 
-	std::iota(ActiveLights.begin(), ActiveLights.end(), 0);
+	std::iota(ActiveLights.begin(), ActiveLights.end(), uint8_t { 0 });
 	VisionActive = {};
 	TransList = {};
 }

Source/loadsave.cpp

@@ -1002,7 +1002,7 @@ void LoadDroppedItems(LoadHelper &file, size_t savedItemCount)
 	file.Skip<uint8_t>(MAXITEMS * 2);
 
 	// Reset ActiveItems, the Items array will be populated from the start
-	std::iota(ActiveItems, ActiveItems + MAXITEMS, 0);
+	std::iota(ActiveItems, ActiveItems + MAXITEMS, uint8_t { 0 });
 	ActiveItemCount = 0;
 	// Clear dItem so we can populate valid drop locations
 	memset(dItem, 0, sizeof(dItem));
@@ -2171,8 +2171,8 @@ void LoadGame(bool firstflag)
 	// skip ahead for vanilla save compatibility (Related to bugfix where MonsterKillCounts[MaxMonsters] was changed to MonsterKillCounts[NUM_MTYPES]
 	file.Skip(4 * (MaxMonsters - NUM_MTYPES));
 	if (leveltype != DTYPE_TOWN) {
-		for (int &monsterId : ActiveMonsters)
-			monsterId = file.NextBE<int32_t>();
+		for (unsigned &monsterId : ActiveMonsters)
+			monsterId = file.NextBE<uint32_t>();
 		for (size_t i = 0; i < ActiveMonsterCount; i++)
 			LoadMonster(&file, Monsters[ActiveMonsters[i]]);
 		for (size_t i = 0; i < ActiveMonsterCount; i++)
@@ -2435,8 +2435,8 @@ void SaveGameData(SaveWriter &saveWriter)
 	file.Skip(4 * (MaxMonsters - NUM_MTYPES));
 
 	if (leveltype != DTYPE_TOWN) {
-		for (int monsterId : ActiveMonsters)
-			file.WriteBE<int32_t>(monsterId);
+		for (unsigned monsterId : ActiveMonsters)
+			file.WriteBE<uint32_t>(monsterId);
 		for (size_t i = 0; i < ActiveMonsterCount; i++)
 			SaveMonster(&file, Monsters[ActiveMonsters[i]]);
 		// Write ActiveMissiles
@@ -2572,8 +2572,8 @@ void SaveLevel(SaveWriter &saveWriter)
 	file.WriteBE<int32_t>(ActiveObjectCount);
 
 	if (leveltype != DTYPE_TOWN) {
-		for (int monsterId : ActiveMonsters)
-			file.WriteBE<int32_t>(monsterId);
+		for (unsigned monsterId : ActiveMonsters)
+			file.WriteBE<uint32_t>(monsterId);
 		for (size_t i = 0; i < ActiveMonsterCount; i++)
 			SaveMonster(&file, Monsters[ActiveMonsters[i]]);
 		for (int objectId : ActiveObjects)
@@ -2646,8 +2646,8 @@ void LoadLevel()
 	ActiveObjectCount = file.NextBE<int32_t>();
 
 	if (leveltype != DTYPE_TOWN) {
-		for (int &monsterId : ActiveMonsters)
-			monsterId = file.NextBE<int32_t>();
+		for (unsigned &monsterId : ActiveMonsters)
+			monsterId = file.NextBE<uint32_t>();
 		for (size_t i = 0; i < ActiveMonsterCount; i++) {
 			Monster &monster = Monsters[ActiveMonsters[i]];
 			LoadMonster(&file, monster);

Source/monster.cpp

@@ -11,6 +11,7 @@
 
 #include <algorithm>
 #include <array>
+#include <numeric>
 #include <string_view>
 
 #include <fmt/core.h>
@@ -57,7 +58,7 @@ namespace devilution {
 CMonster LevelMonsterTypes[MaxLvlMTypes];
 size_t LevelMonsterTypeCount;
 Monster Monsters[MaxMonsters];
-int ActiveMonsters[MaxMonsters];
+unsigned ActiveMonsters[MaxMonsters];
 size_t ActiveMonsterCount;
 /** Tracks the total number of monsters killed per monster_id. */
 int MonsterKillCounts[NUM_MTYPES];
@@ -631,7 +632,7 @@ void UpdateEnemy(Monster &monster)
 		}
 	}
 	for (size_t i = 0; i < ActiveMonsterCount; i++) {
-		const int monsterId = ActiveMonsters[i];
+		const unsigned monsterId = ActiveMonsters[i];
 		Monster &otherMonster = Monsters[monsterId];
 		if (&otherMonster == &monster)
 			continue;
@@ -659,7 +660,7 @@ void UpdateEnemy(Monster &monster)
 		    || ((sameroom || !bestsameroom) && dist < bestDist)
 		    || (menemy == -1)) {
 			monster.flags |= MFLAG_TARGETS_MONSTER;
-			menemy = monsterId;
+			menemy = static_cast<int>(monsterId);
 			target = otherMonster.position.future;
 			bestDist = dist;
 			bestsameroom = sameroom;
@@ -3143,8 +3144,8 @@ void EnsureMonsterIndexIsActive(size_t monsterId)
 			continue;
 		if (index < ActiveMonsterCount)
 			return; // monster is already active
-		int oldId = ActiveMonsters[ActiveMonsterCount];
-		ActiveMonsters[ActiveMonsterCount] = static_cast<int>(monsterId);
+		const unsigned oldId = ActiveMonsters[ActiveMonsterCount];
+		ActiveMonsters[ActiveMonsterCount] = static_cast<unsigned>(monsterId);
 		ActiveMonsters[index] = oldId;
 		ActiveMonsterCount += 1;
 	}
@@ -3292,10 +3293,7 @@ void InitLevelMonsters()
 	ActiveMonsterCount = 0;
 	totalmonsters = MaxMonsters;
 
-	for (size_t i = 0; i < MaxMonsters; i++) {
-		ActiveMonsters[i] = static_cast<int>(i);
-	}
-
+	std::iota(std::begin(ActiveMonsters), std::end(ActiveMonsters), 0u);
 	uniquetrans = 0;
 }
 
@@ -4081,7 +4079,7 @@ void DeleteMonsterList()
 
 	for (size_t i = MAX_PLRS; i < ActiveMonsterCount;) {
 		if (Monsters[ActiveMonsters[i]].isInvalid) {
-			if (pcursmonst == ActiveMonsters[i]) // Unselect monster if player highlighted it
+			if (pcursmonst == static_cast<int>(ActiveMonsters[i])) // Unselect monster if player highlighted it
 				pcursmonst = -1;
 			DeleteMonster(i);
 		} else {

Source/monster.h

@@ -474,7 +474,7 @@ struct Monster { // note: missing field _mAFNum
 
 extern size_t LevelMonsterTypeCount;
 extern Monster Monsters[MaxMonsters];
-extern int ActiveMonsters[MaxMonsters];
+extern unsigned ActiveMonsters[MaxMonsters];
 extern size_t ActiveMonsterCount;
 extern int MonsterKillCounts[NUM_MTYPES];
 extern bool sgbSaveSoundOn;

Source/msg.cpp

@@ -757,7 +757,7 @@ void DeltaLeaveSync(uint8_t bLevel)
 	DLevel &deltaLevel = GetDeltaLevel(bLevel);
 
 	for (size_t i = 0; i < ActiveMonsterCount; i++) {
-		int ma = ActiveMonsters[i];
+		const unsigned ma = ActiveMonsters[i];
 		auto &monster = Monsters[ma];
 		if (monster.hitPoints == 0)
 			continue;

Source/portal.cpp

@@ -112,9 +112,9 @@ bool PortalOnLevel(const Player &player)
 
 void RemovePortalMissile(const Player &player)
 {
-	size_t id = player.getId();
+	const size_t id = player.getId();
 	Missiles.remove_if([id](Missile &missile) {
-		if (missile._mitype == MissileID::TownPortal && missile._misource == id) {
+		if (missile._mitype == MissileID::TownPortal && missile._misource == static_cast<int>(id)) {
 			dFlags[missile.position.tile.x][missile.position.tile.y] &= ~DungeonFlag::Missile;
 
 			if (Portals[id].level != 0)

Source/sync.cpp

@@ -3,9 +3,10 @@
  *
  * Implementation of functionality for syncing game state with other players.
  */
-#include <climits>
 #include <cstdint>
 
+#include <limits>
+
 #include "levels/gendung.h"
 #include "lighting.h"
 #include "monster.h"
@@ -24,7 +25,7 @@ int sgnSyncPInv;
 void SyncOneMonster()
 {
 	for (size_t i = 0; i < ActiveMonsterCount; i++) {
-		int m = ActiveMonsters[i];
+		const unsigned m = ActiveMonsters[i];
 		auto &monster = Monsters[m];
 		sgnMonsterPriority[m] = MyPlayer->position.tile.ManhattanDistance(monster.position.tile);
 		if (monster.activeForTicks == 0) {
@@ -52,18 +53,18 @@ void SyncMonsterPos(TSyncMonster &monsterSync, int ndx)
 
 bool SyncMonsterActive(TSyncMonster &monsterSync)
 {
-	int ndx = -1;
+	unsigned ndx = std::numeric_limits<unsigned>::max();
 	uint32_t lru = 0xFFFFFFFF;
 
 	for (size_t i = 0; i < ActiveMonsterCount; i++) {
-		int m = ActiveMonsters[i];
+		const unsigned m = ActiveMonsters[i];
 		if (sgnMonsterPriority[m] < lru && sgwLRU[m] < 0xFFFE) {
 			lru = sgnMonsterPriority[m];
 			ndx = ActiveMonsters[i];
 		}
 	}
 
-	if (ndx == -1) {
+	if (ndx == std::numeric_limits<unsigned>::max()) {
 		return false;
 	}
 
@@ -73,22 +74,22 @@ bool SyncMonsterActive(TSyncMonster &monsterSync)
 
 bool SyncMonsterActive2(TSyncMonster &monsterSync)
 {
-	int ndx = -1;
+	unsigned ndx = std::numeric_limits<unsigned>::max();
 	uint32_t lru = 0xFFFE;
 
 	for (size_t i = 0; i < ActiveMonsterCount; i++) {
 		if (sgnMonsters >= ActiveMonsterCount) {
 			sgnMonsters = 0;
 		}
-		int m = ActiveMonsters[sgnMonsters];
+		const unsigned m = ActiveMonsters[sgnMonsters];
 		if (sgwLRU[m] < lru) {
 			lru = sgwLRU[m];
 			ndx = ActiveMonsters[sgnMonsters];
 		}
 		sgnMonsters++;
 	}
 
-	if (ndx == -1) {
+	if (ndx == std::numeric_limits<unsigned>::max()) {
 		return false;
 	}
 
@@ -184,7 +185,7 @@ void SyncMonster(bool isOwner, const TSyncMonster &monsterSync)
 				M_ClearSquares(monster);
 				monster.occupyTile(monster.position.tile, false);
 				Walk(monster, md);
-				monster.activeForTicks = UINT8_MAX;
+				monster.activeForTicks = std::numeric_limits<uint8_t>::max();
 			}
 		}
 	} else if (dMonster[position.x][position.y] == 0) {
@@ -196,7 +197,7 @@ void SyncMonster(bool isOwner, const TSyncMonster &monsterSync)
 		decode_enemy(monster, enemyId);
 		Direction md = GetDirection(position, monster.enemyPosition);
 		M_StartStand(monster, md);
-		monster.activeForTicks = UINT8_MAX;
+		monster.activeForTicks = std::numeric_limits<uint8_t>::max();
 	}
 
 	decode_enemy(monster, enemyId);