From 7a7cee7ca575246d2b01632977dd886484b589f3 Mon Sep 17 00:00:00 2001
From: SMS Alfredo <65426124+SMS-Alfredo@users.noreply.github.com>
Date: Wed, 31 May 2023 23:03:22 -0500
Subject: [PATCH] Expose P_CheckSkyHit to Lua

---
 src/lua_baselib.c | 15 +++++++++++++++
 src/p_local.h     |  1 +
 src/p_mobj.c      | 21 +++++++++++----------
 3 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/src/lua_baselib.c b/src/lua_baselib.c
index 25fa38769..1a189fabd 100644
--- a/src/lua_baselib.c
+++ b/src/lua_baselib.c
@@ -1030,6 +1030,20 @@ static int lib_pRailThinker(lua_State *L)
 	return 1;
 }
 
+static int lib_pCheckSkyHit(lua_State *L)
+{
+	mobj_t *mobj = *((mobj_t **)luaL_checkudata(L, 1, META_MOBJ));
+	line_t *line = *((line_t **)luaL_checkudata(L, 2, META_LINE));
+	//HUDSAFE
+	INLEVEL
+	if (!mobj)
+		return LUA_ErrInvalid(L, "mobj_t");
+	if (!line)
+		return LUA_ErrInvalid(L, "line_t");
+	lua_pushboolean(L, P_CheckSkyHit(mobj, line));
+	return 1;
+}
+
 static int lib_pXYMovement(lua_State *L)
 {
 	mobj_t *actor = *((mobj_t **)luaL_checkudata(L, 1, META_MOBJ));
@@ -4059,6 +4073,7 @@ static luaL_Reg lib[] = {
 	{"P_CreateFloorSpriteSlope",lib_pCreateFloorSpriteSlope},
 	{"P_RemoveFloorSpriteSlope",lib_pRemoveFloorSpriteSlope},
 	{"P_RailThinker",lib_pRailThinker},
+	{"P_CheckSkyHit",lib_pCheckSkyHit},
 	{"P_XYMovement",lib_pXYMovement},
 	{"P_RingXYMovement",lib_pRingXYMovement},
 	{"P_SceneryXYMovement",lib_pSceneryXYMovement},
diff --git a/src/p_local.h b/src/p_local.h
index cc060e4ee..91634e803 100644
--- a/src/p_local.h
+++ b/src/p_local.h
@@ -297,6 +297,7 @@ void P_RunOverlays(void);
 void P_HandleMinecartSegments(mobj_t *mobj);
 void P_MobjThinker(mobj_t *mobj);
 boolean P_RailThinker(mobj_t *mobj);
+boolean P_CheckSkyHit(mobj_t *mo, line_t *line);
 void P_PushableThinker(mobj_t *mobj);
 void P_SceneryThinker(mobj_t *mobj);
 
diff --git a/src/p_mobj.c b/src/p_mobj.c
index eeaf54776..fad4f7743 100644
--- a/src/p_mobj.c
+++ b/src/p_mobj.c
@@ -1753,14 +1753,15 @@ bustupdone:
 //
 // P_CheckSkyHit
 //
-static boolean P_CheckSkyHit(mobj_t *mo)
+boolean P_CheckSkyHit(mobj_t *mo, line_t *line)
 {
-	if (ceilingline && ceilingline->backsector
-		&& ceilingline->backsector->ceilingpic == skyflatnum
-		&& ceilingline->frontsector
-		&& ceilingline->frontsector->ceilingpic == skyflatnum
-		&& (mo->z >= ceilingline->frontsector->ceilingheight
-		|| mo->z >= ceilingline->backsector->ceilingheight))
+	if (line && (line->special == 41 ||
+		(line->backsector
+		&& line->backsector->ceilingpic == skyflatnum
+		&& line->frontsector
+		&& line->frontsector->ceilingpic == skyflatnum
+		&& (mo->z >= line->frontsector->ceilingheight
+		|| mo->z >= line->backsector->ceilingheight))))
 			return true;
 	return false;
 }
@@ -1867,7 +1868,7 @@ void P_XYMovement(mobj_t *mo)
 					mo->fuse += ((5 - mo->threshold) * TICRATE);
 
 				// Check for hit against sky here
-				if (P_CheckSkyHit(mo))
+				if (P_CheckSkyHit(mo, ceilingline))
 				{
 					// Hack to prevent missiles exploding
 					// against the sky.
@@ -1887,7 +1888,7 @@ void P_XYMovement(mobj_t *mo)
 			mo->flags &= ~MF_STICKY; //Don't check again!
 
 			// Check for hit against sky here
-			if (P_CheckSkyHit(mo))
+			if (P_CheckSkyHit(mo, ceilingline))
 			{
 				// Hack to prevent missiles exploding
 				// against the sky.
@@ -1946,7 +1947,7 @@ void P_XYMovement(mobj_t *mo)
 		else if (mo->flags & MF_MISSILE)
 		{
 			// explode a missile
-			if (P_CheckSkyHit(mo))
+			if (P_CheckSkyHit(mo, ceilingline))
 			{
 				// Hack to prevent missiles exploding
 				// against the sky.