From 488ee03f5333b3c6c94971f237acde6da596055d Mon Sep 17 00:00:00 2001
From: ephphatha <ephphatha@thelettereph.com>
Date: Fri, 16 Jul 2021 23:33:15 +1000
Subject: [PATCH] Use bound functions for LineClear test function pointer

---
 Source/missiles.cpp |  2 +-
 Source/monster.cpp  | 23 +++++++++++------------
 Source/monster.h    |  4 ++--
 3 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/Source/missiles.cpp b/Source/missiles.cpp
index faad81851..1e0f7ebd6 100644
--- a/Source/missiles.cpp
+++ b/Source/missiles.cpp
@@ -4323,7 +4323,7 @@ void MI_Fireman(int i)
 	} else {
 		j = dMonster[b.x][b.y];
 	}
-	if (!PosOkMissile(0, b) || (j > 0 && (Missiles[i]._miVar1 & 1) == 0)) {
+	if (!PosOkMissile(b) || (j > 0 && (Missiles[i]._miVar1 & 1) == 0)) {
 		Missiles[i].position.velocity *= -1;
 		Missiles[i]._mimfnum = opposite[Missiles[i]._mimfnum];
 		Missiles[i]._miAnimData = monster.MType->GetAnimData(MonsterGraphic::Walk).CelSpritesForDirections[Missiles[i]._mimfnum]->Data();
diff --git a/Source/monster.cpp b/Source/monster.cpp
index c9ced0543..0bef46700 100644
--- a/Source/monster.cpp
+++ b/Source/monster.cpp
@@ -1942,14 +1942,14 @@ int SpawnSkeleton(Point position, Direction dir)
 	return skel;
 }
 
-bool IsNotSolid(int /*entity*/, Point position)
+bool IsNotSolid(Point position)
 {
 	return !nSolidTable[dPiece[position.x][position.y]];
 }
 
 bool IsLineNotSolid(Point startPoint, Point endPoint)
 {
-	return LineClear(IsNotSolid, 0, startPoint, endPoint);
+	return LineClear(IsNotSolid, startPoint, endPoint);
 }
 
 void GroupUnity(int i)
@@ -2207,8 +2207,7 @@ bool AiPlanPath(int i)
 	}
 
 	bool clear = LineClear(
-	    MonsterIsTileClear,
-	    i,
+	    std::bind(MonsterIsTileAvalible, i, std::placeholders::_1),
 	    monster.position.tile,
 	    monster.enemyPosition);
 	if (!clear || (monster._pathcount >= 5 && monster._pathcount < 8)) {
@@ -2644,7 +2643,7 @@ void RhinoAi(int i)
 	if (monster._mgoal == MGOAL_NORMAL) {
 		if (dist >= 5
 		    && v < 2 * monster._mint + 43
-		    && LineClear(MonsterIsTileAvailable, i, monster.position.tile, { fx, fy })) {
+		    && LineClear(std::bind(MonsterIsTileAvailable, i, std::placeholders::_1), monster.position.tile, { fx, fy })) {
 			if (AddMissile(monster.position.tile, { fx, fy }, md, MIS_RHINO, monster._menemy, i, 0, 0) != -1) {
 				if (monster.MData->snd_special)
 					PlayEffect(monster, 3);
@@ -2847,7 +2846,7 @@ void BatAi(int i)
 	if (monster.MType->mtype == MT_GLOOM
 	    && (abs(xd) >= 5 || abs(yd) >= 5)
 	    && v < 4 * monster._mint + 33
-	    && LineClear(MonsterIsTileAvailable, i, monster.position.tile, { fx, fy })) {
+	    && LineClear(std::bind(MonsterIsTileAvailable, i, std::placeholders::_1), monster.position.tile, { fx, fy })) {
 		if (AddMissile(monster.position.tile, { fx, fy }, md, MIS_RHINO, pnum, i, 0, 0) != -1) {
 			dMonster[monster.position.tile.x][monster.position.tile.y] = -(i + 1);
 			monster._mmode = MM_CHARGE;
@@ -3176,7 +3175,7 @@ void SnakeAi(int i)
 	Direction md = GetDirection(monster.position.tile, monster.position.last);
 	monster._mdir = md;
 	if (abs(mx) >= 2 || abs(my) >= 2) {
-		if (abs(mx) < 3 && abs(my) < 3 && LineClear(MonsterIsTileAvailable, i, monster.position.tile, { fx, fy }) && monster._mVar1 != MM_CHARGE) {
+		if (abs(mx) < 3 && abs(my) < 3 && LineClear(std::bind(MonsterIsTileAvailable, i, std::placeholders::_1), monster.position.tile, { fx, fy }) && monster._mVar1 != MM_CHARGE) {
 			if (AddMissile(monster.position.tile, { fx, fy }, md, MIS_RHINO, pnum, i, 0, 0) != -1) {
 				PlayEffect(monster, 0);
 				dMonster[monster.position.tile.x][monster.position.tile.y] = -(i + 1);
@@ -4646,17 +4645,17 @@ bool DirOK(int i, Direction mdir)
 	return mcount == monster.packsize;
 }
 
-bool PosOkMissile(int /*entity*/, Point position)
+bool PosOkMissile(Point position)
 {
 	return !nMissileTable[dPiece[position.x][position.y]] && (dFlags[position.x][position.y] & BFLAG_MONSTLR) == 0;
 }
 
 bool LineClearMissile(Point startPoint, Point endPoint)
 {
-	return LineClear(PosOkMissile, 0, startPoint, endPoint);
+	return LineClear(PosOkMissile, startPoint, endPoint);
 }
 
-bool LineClear(bool (*clear)(int, Point), int entity, Point startPoint, Point endPoint)
+bool LineClear(const std::function<bool(Point)> &clear, Point startPoint, Point endPoint)
 {
 	Point position = startPoint;
 
@@ -4692,7 +4691,7 @@ bool LineClear(bool (*clear)(int, Point), int entity, Point startPoint, Point en
 				position.y += yincD;
 			}
 			position.x++;
-			done = position != startPoint && !clear(entity, position);
+			done = position != startPoint && !clear(position);
 		}
 	} else {
 		if (dy < 0) {
@@ -4724,7 +4723,7 @@ bool LineClear(bool (*clear)(int, Point), int entity, Point startPoint, Point en
 				position.x += xincD;
 			}
 			position.y++;
-			done = position != startPoint && !clear(entity, position);
+			done = position != startPoint && !clear(position);
 		}
 	}
 	return position == endPoint;
diff --git a/Source/monster.h b/Source/monster.h
index 622b773e3..c80100405 100644
--- a/Source/monster.h
+++ b/Source/monster.h
@@ -255,9 +255,9 @@ void DeleteMonsterList();
 void ProcessMonsters();
 void FreeMonsters();
 bool DirOK(int i, Direction mdir);
-bool PosOkMissile(int entity, Point position);
+bool PosOkMissile(Point position);
 bool LineClearMissile(Point startPoint, Point endPoint);
-bool LineClear(bool (*Clear)(int, Point), int entity, Point startPoint, Point endPoint);
+bool LineClear(const std::function<bool(Point)> &clear, Point startPoint, Point endPoint);
 void SyncMonsterAnim(MonsterStruct &monster);
 void M_FallenFear(Point position);
 void PrintMonstHistory(int mt);