From cc79808aba39bb56a5c05cf850d48deecfbd2055 Mon Sep 17 00:00:00 2001
From: Ashnal <ashnal52@gmail.com>
Date: Thu, 31 Jul 2025 18:37:38 -0400
Subject: [PATCH] New MFE_DONTSLOPELAUNCH flag Makes mobj immune to slope
 launching Also 32 bit eflags woo

---
 src/lua_mobjlib.c | 2 +-
 src/p_mobj.c      | 3 +++
 src/p_mobj.h      | 4 +++-
 src/p_saveg.cpp   | 4 ++--
 src/p_slopes.c    | 8 ++++++++
 5 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/lua_mobjlib.c b/src/lua_mobjlib.c
index 158909815..fc0d1b3d9 100644
--- a/src/lua_mobjlib.c
+++ b/src/lua_mobjlib.c
@@ -709,7 +709,7 @@ static int mobj_set(lua_State *L)
 		mo->flags2 = (UINT32)luaL_checkinteger(L, 3);
 		break;
 	case mobj_eflags:
-		mo->eflags = (UINT16)luaL_checkinteger(L, 3);
+		mo->eflags = (UINT32)luaL_checkinteger(L, 3);
 		break;
 	case mobj_renderflags:
 		mo->renderflags = (UINT32)luaL_checkinteger(L, 3);
diff --git a/src/p_mobj.c b/src/p_mobj.c
index 179a5e550..12a439230 100644
--- a/src/p_mobj.c
+++ b/src/p_mobj.c
@@ -4138,6 +4138,8 @@ static void P_PlayerMobjThinker(mobj_t *mobj)
 		mobj->eflags &= ~MFE_JUSTHITFLOOR;
 	}
 
+	mobj->eflags &= ~MFE_DONTSLOPELAUNCH;
+
 	P_SquishThink(mobj);
 	K_UpdateTerrainOverlay(mobj);
 
@@ -10909,6 +10911,7 @@ void P_MobjThinker(mobj_t *mobj)
 		P_ButteredSlope(mobj);
 	}
 
+	mobj->eflags &= ~MFE_DONTSLOPELAUNCH;
 	P_SquishThink(mobj);
 	K_UpdateTerrainOverlay(mobj);
 
diff --git a/src/p_mobj.h b/src/p_mobj.h
index 34a52d3fd..a79c3ef7d 100644
--- a/src/p_mobj.h
+++ b/src/p_mobj.h
@@ -262,6 +262,8 @@ typedef enum
 	MFE_SLOPELAUNCHED     = 1<<14,
 	// Thinker is paused due to hitlag
 	MFE_PAUSED            = 1<<15,
+	// Don't launch off of slopes
+	MFE_DONTSLOPELAUNCH   = 1<<16,
 } mobjeflag_t;
 
 //
@@ -339,7 +341,7 @@ struct mobj_t
 	state_t *state;
 	UINT32 flags; // flags from mobjinfo tables
 	UINT32 flags2; // MF2_ flags
-	UINT16 eflags; // extra flags
+	UINT32 eflags; // extra flags
 
 	mtag_t tid;
 	mobj_t *tid_next;
diff --git a/src/p_saveg.cpp b/src/p_saveg.cpp
index 688556420..25f6d3bae 100644
--- a/src/p_saveg.cpp
+++ b/src/p_saveg.cpp
@@ -3469,7 +3469,7 @@ static void SaveMobjThinker(savebuffer_t *save, const thinker_t *th, const UINT8
 		WRITEUINT16(save->p, mobj->anim_duration);
 	}
 	if (diff & MD_EFLAGS)
-		WRITEUINT16(save->p, mobj->eflags);
+		WRITEUINT32(save->p, mobj->eflags);
 	if (diff & MD_PLAYER)
 		WRITEUINT8(save->p, mobj->player-players);
 	if (diff & MD_MOVEDIR)
@@ -4744,7 +4744,7 @@ static thinker_t* LoadMobjThinker(savebuffer_t *save, actionf_p1 thinker)
 		mobj->anim_duration = (UINT16)mobj->state->var2;
 	}
 	if (diff & MD_EFLAGS)
-		mobj->eflags = READUINT16(save->p);
+		mobj->eflags = READUINT32(save->p);
 	if (diff & MD_PLAYER)
 	{
 		i = READUINT8(save->p);
diff --git a/src/p_slopes.c b/src/p_slopes.c
index a64ebfaa0..c1a767a63 100644
--- a/src/p_slopes.c
+++ b/src/p_slopes.c
@@ -989,6 +989,14 @@ boolean P_CanApplySlopeLaunch(mobj_t *mo, pslope_t *slope)
 		return false;
 	}
 
+	if (mo->eflags & MFE_DONTSLOPELAUNCH)
+	{
+		CONS_Printf("MFE_DONTSLOPELAUNCH\n");
+		mo->eflags &= ~MFE_DONTSLOPELAUNCH; // You get one cancelled launch
+		// Don't launch off of slopes.
+		return false;
+	}
+
 	// We can do slope launching.
 	return true;
 }