Add max_size checks when adding missiles to allow for limited size containers

This doesn't handle failed allocations (e.g. if the platform runs out of memory) but makes it easier to use a fixed size container on limited memory devices.

Source/loadsave.cpp

@@ -715,7 +715,9 @@ void LoadMissile(LoadHelper *file)
 	missile.var7 = file->NextLE<int32_t>();
 	missile.limitReached = file->NextBool32();
 	missile.lastCollisionTargetHash = 0;
-	Missiles.push_back(missile);
+	if (Missiles.size() < Missiles.max_size()) {
+		Missiles.push_back(missile);
+	}
 }
 
 void LoadObject(LoadHelper &file, Object &object)

Source/missiles.cpp

@@ -2692,9 +2692,11 @@ void AddDiabApoca(Missile &missile, const AddMissileParameter & /*parameter*/)
 	missile._miDelFlag = true;
 }
 
-Missile &AddMissile(Point src, Point dst, Direction midir, missile_id mitype, mienemy_type micaster, int id, int midam, int spllvl, Missile *pParent /*= nullptr*/)
+Missile *AddMissile(Point src, Point dst, Direction midir, missile_id mitype, mienemy_type micaster, int id, int midam, int spllvl, Missile *pParent /*= nullptr*/)
 {
-	constexpr int32_t MaxMissiles = std::numeric_limits<int32_t>::max();
+	if (Missiles.size() >= Missiles.max_size()) {
+		return nullptr;
+	}
 
 	Missiles.emplace_back(Missile {});
 	auto &missile = Missiles.back();
@@ -2726,7 +2728,7 @@ Missile &AddMissile(Point src, Point dst, Direction midir, missile_id mitype, mi
 	AddMissileParameter parameter = { dst, midir, pParent };
 	missileData.mAddProc(missile, parameter);
 
-	return missile;
+	return &missile;
 }
 
 void MI_LArrow(Missile &missile)

Source/missiles.h

@@ -341,7 +341,7 @@ void AddTelekinesis(Missile &missile, const AddMissileParameter &parameter);
 void AddBoneSpirit(Missile &missile, const AddMissileParameter &parameter);
 void AddRportal(Missile &missile, const AddMissileParameter &parameter);
 void AddDiabApoca(Missile &missile, const AddMissileParameter &parameter);
-Missile &AddMissile(Point src, Point dst, Direction midir, missile_id mitype, mienemy_type micaster, int id, int midam, int spllvl, Missile *pParent = nullptr);
+Missile *AddMissile(Point src, Point dst, Direction midir, missile_id mitype, mienemy_type micaster, int id, int midam, int spllvl, Missile *pParent = nullptr);
 void MI_Golem(Missile &missile);
 void MI_Manashield(Missile &missile);
 void MI_LArrow(Missile &missile);

Source/monster.cpp

@@ -1616,16 +1616,18 @@ bool MonsterRangedSpecialAttack(int i)
 	assert(monster.MData != nullptr);
 
 	if (monster.AnimInfo.CurrentFrame == monster.MData->mAFNum2 && monster.AnimInfo.TickCounterOfCurrentFrame == 0) {
-		AddMissile(
-		    monster.position.tile,
-		    monster.enemyPosition,
-		    monster._mdir,
-		    static_cast<missile_id>(monster._mVar1),
-		    TARGET_PLAYERS,
-		    i,
-		    monster._mVar3,
-		    0);
-		PlayEffect(monster, 3);
+		if (AddMissile(
+		        monster.position.tile,
+		        monster.enemyPosition,
+		        monster._mdir,
+		        static_cast<missile_id>(monster._mVar1),
+		        TARGET_PLAYERS,
+		        i,
+		        monster._mVar3,
+		        0)
+		    != nullptr) {
+			PlayEffect(monster, 3);
+		}
 	}
 
 	if (monster._mAi == AI_MEGA && monster.AnimInfo.CurrentFrame == monster.MData->mAFNum2) {
@@ -2556,11 +2558,12 @@ void RhinoAi(int i)
 		if (dist >= 5
 		    && v < 2 * monster._mint + 43
 		    && LineClear([&monster](Point position) { return IsTileAvailable(monster, position); }, monster.position.tile, { fx, fy })) {
-			AddMissile(monster.position.tile, { fx, fy }, md, MIS_RHINO, TARGET_PLAYERS, i, 0, 0);
-			if (monster.MData->snd_special)
-				PlayEffect(monster, 3);
-			dMonster[monster.position.tile.x][monster.position.tile.y] = -(i + 1);
-			monster._mmode = MonsterMode::Charge;
+			if (AddMissile(monster.position.tile, { fx, fy }, md, MIS_RHINO, TARGET_PLAYERS, i, 0, 0) != nullptr) {
+				if (monster.MData->snd_special)
+					PlayEffect(monster, 3);
+				dMonster[monster.position.tile.x][monster.position.tile.y] = -(i + 1);
+				monster._mmode = MonsterMode::Charge;
+			}
 		} else {
 			if (dist >= 2) {
 				v = GenerateRnd(100);
@@ -2758,9 +2761,10 @@ void BatAi(int i)
 	    && (abs(xd) >= 5 || abs(yd) >= 5)
 	    && v < 4 * monster._mint + 33
 	    && LineClear([&monster](Point position) { return IsTileAvailable(monster, position); }, monster.position.tile, { fx, fy })) {
-		AddMissile(monster.position.tile, { fx, fy }, md, MIS_RHINO, TARGET_PLAYERS, i, 0, 0);
-		dMonster[monster.position.tile.x][monster.position.tile.y] = -(i + 1);
-		monster._mmode = MonsterMode::Charge;
+		if (AddMissile(monster.position.tile, { fx, fy }, md, MIS_RHINO, TARGET_PLAYERS, i, 0, 0) != nullptr) {
+			dMonster[monster.position.tile.x][monster.position.tile.y] = -(i + 1);
+			monster._mmode = MonsterMode::Charge;
+		}
 	} else if (abs(xd) >= 2 || abs(yd) >= 2) {
 		if ((monster._mVar2 > 20 && v < monster._mint + 13)
 		    || (IsAnyOf(static_cast<MonsterMode>(monster._mVar1), MonsterMode::MoveNorthwards, MonsterMode::MoveSouthwards, MonsterMode::MoveSideways)
@@ -3026,10 +3030,11 @@ void SnakeAi(int i)
 	monster._mdir = md;
 	if (abs(mx) >= 2 || abs(my) >= 2) {
 		if (abs(mx) < 3 && abs(my) < 3 && LineClear([&monster](Point position) { return IsTileAvailable(monster, position); }, monster.position.tile, { fx, fy }) && static_cast<MonsterMode>(monster._mVar1) != MonsterMode::Charge) {
-			AddMissile(monster.position.tile, { fx, fy }, md, MIS_RHINO, TARGET_PLAYERS, i, 0, 0);
-			PlayEffect(monster, 0);
-			dMonster[monster.position.tile.x][monster.position.tile.y] = -(i + 1);
-			monster._mmode = MonsterMode::Charge;
+			if (AddMissile(monster.position.tile, { fx, fy }, md, MIS_RHINO, TARGET_PLAYERS, i, 0, 0) != nullptr) {
+				PlayEffect(monster, 0);
+				dMonster[monster.position.tile.x][monster.position.tile.y] = -(i + 1);
+				monster._mmode = MonsterMode::Charge;
+			}
 		} else if (static_cast<MonsterMode>(monster._mVar1) == MonsterMode::Delay || GenerateRnd(100) >= 35 - 2 * monster._mint) {
 			if (pattern[monster._mgoalvar1] == -1)
 				md = Left(md);

Source/portal.cpp

@@ -51,11 +51,13 @@ void AddWarpMissile(int i, Point position)
 {
 	MissilesData[MIS_TOWN].mlSFX = SFX_NONE;
 
-	auto &missile = AddMissile({ 0, 0 }, position, Direction::South, MIS_TOWN, TARGET_MONSTERS, i, 0, 0);
-	SetMissDir(missile, 1);
+	auto *missile = AddMissile({ 0, 0 }, position, Direction::South, MIS_TOWN, TARGET_MONSTERS, i, 0, 0);
+	if (missile != nullptr) {
+		SetMissDir(*missile, 1);
 
-	if (currlevel != 0)
-		missile._mlid = AddLight(missile.position.tile, 15);
+		if (currlevel != 0)
+			missile->_mlid = AddLight(missile->position.tile, 15);
+	}
 
 	MissilesData[MIS_TOWN].mlSFX = LS_SENTINEL;
 }