Merge branch 'hotfix-pltz' into 'next'

Re-add/fix broken platform momz mobj code.

The changes in this branch re-add the platform's momentum to players and mobjs which leave the platform (eg. by jumping) so that they move with relative velocity as expected. This behavior was unintentionally broken in SRB2 2.0, which adds a lot of artificial difficulty to certain segments of the levels, where you have to jump between high velocity moving platforms which seemingly cut your jump height to nothing.

Not only has the behavior been fixed, but it has now been enhanced to move the camera while free-falling between platforms as well, completing the illusion of full relative velocity with minimal hiccups. [Observe.](http://i.imgur.com/zmSfUyp.gifv)

See merge request !14

src/dehacked.c

@@ -7207,6 +7207,7 @@ static const char *const MOBJEFLAG_LIST[] = {
 	"GOOWATER", // Goo water
 	"PUSHED", // Mobj was already pushed this tic
 	"SPRUNG", // Mobj was already sprung this tic
+	"APPLYPMOMZ", // Platform movement
 	NULL
 };
 

src/lua_mobjlib.c

@@ -449,6 +449,7 @@ static int mobj_set(lua_State *L)
 		break;
 	case mobj_pmomz:
 		mo->pmomz = (fixed_t)luaL_checkinteger(L, 3);
+		mo->eflags |= MFE_APPLYPMOMZ;
 		break;
 	case mobj_tics:
 		mo->tics = luaL_checkinteger(L, 3);

src/p_map.c

@@ -2042,6 +2042,7 @@ boolean P_SceneryTryMove(mobj_t *thing, fixed_t x, fixed_t y)
 //
 static boolean P_ThingHeightClip(mobj_t *thing)
 {
+	boolean floormoved;
 	fixed_t oldfloorz = thing->floorz;
 	boolean onfloor = P_IsObjectOnGround(thing);//(thing->z <= thing->floorz);
 
@@ -2053,6 +2054,9 @@ static boolean P_ThingHeightClip(mobj_t *thing)
 	if (P_MobjWasRemoved(thing))
 		return true;
 
+	floormoved = (thing->eflags & MFE_VERTICALFLIP && tmceilingz != thing->ceilingz)
+		|| (!(thing->eflags & MFE_VERTICALFLIP) && tmfloorz != thing->floorz);
+
 	thing->floorz = tmfloorz;
 	thing->ceilingz = tmceilingz;
 
@@ -2061,20 +2065,13 @@ static boolean P_ThingHeightClip(mobj_t *thing)
 	if (tmfloorz > oldfloorz+thing->height)
 		return true;
 
-	if (/*!tmfloorthing && */onfloor && !(thing->flags & MF_NOGRAVITY))
+	if (onfloor && !(thing->flags & MF_NOGRAVITY) && floormoved)
 	{
 		if (thing->eflags & MFE_VERTICALFLIP)
 			thing->pmomz = thing->ceilingz - (thing->z + thing->height);
 		else
 			thing->pmomz = thing->floorz - thing->z;
-
+		thing->eflags |= MFE_APPLYPMOMZ;
-		if (thing->player)
-		{
-			if (splitscreen && camera2.chase && thing->player == &players[secondarydisplayplayer])
-				camera2.z += thing->pmomz;
-			else if (camera.chase && thing->player == &players[displayplayer])
-				camera.z += thing->pmomz;
-		}
 
 		if (thing->eflags & MFE_VERTICALFLIP)
 			thing->z = thing->ceilingz - thing->height;

src/p_mobj.c

@@ -1493,10 +1493,10 @@ static void P_RingZMovement(mobj_t *mo)
 		P_AdjustMobjFloorZ_PolyObjs(mo, mo->subsector);
 
 	// adjust height
-	if (mo->pmomz && mo->z != mo->floorz)
+	if (mo->eflags & MFE_APPLYPMOMZ && !P_IsObjectOnGround(mo))
 	{
 		mo->momz += mo->pmomz;
-		mo->pmomz = 0;
+		mo->eflags &= ~MFE_APPLYPMOMZ;
 	}
 	mo->z += mo->momz;
 
@@ -1562,10 +1562,10 @@ static boolean P_ZMovement(mobj_t *mo)
 		P_AdjustMobjFloorZ_PolyObjs(mo, mo->subsector);
 
 	// adjust height
-	if (mo->pmomz && mo->z != mo->floorz)
+	if (mo->eflags & MFE_APPLYPMOMZ && !P_IsObjectOnGround(mo))
 	{
 		mo->momz += mo->pmomz;
-		mo->pmomz = 0;
+		mo->eflags &= ~MFE_APPLYPMOMZ;
 	}
 	mo->z += mo->momz;
 
@@ -1987,11 +1987,11 @@ static void P_PlayerZMovement(mobj_t *mo)
 	}
 
 	// adjust height
-/*	if (mo->pmomz && mo->z > mo->floorz && !(mo->player->pflags & PF_JUMPED))
+	if (mo->eflags & MFE_APPLYPMOMZ && !P_IsObjectOnGround(mo))
 	{
 		mo->momz += mo->pmomz;
-		mo->pmomz = 0;
+		mo->eflags &= ~MFE_APPLYPMOMZ;
-	}*/
+	}
 
 	mo->z += mo->momz;
 
@@ -2008,7 +2008,7 @@ static void P_PlayerZMovement(mobj_t *mo)
 		else
 			mo->z = mo->floorz;
 
-		if (mo->player && (mo->player->pflags & PF_NIGHTSMODE))
+		if (mo->player->pflags & PF_NIGHTSMODE)
 		{
 			if (mo->player->flyangle < 90 || mo->player->flyangle >= 270)
 				mo->player->flyangle += P_MobjFlip(mo)*90;
@@ -2023,12 +2023,11 @@ static void P_PlayerZMovement(mobj_t *mo)
 
 		if (P_MobjFlip(mo)*mo->momz < 0) // falling
 		{
+			mo->pmomz = 0; // We're on a new floor, don't keep doing platform movement.
+
 			// Squat down. Decrease viewheight for a moment after hitting the ground (hard),
-			if (mo->player)
+			if (P_MobjFlip(mo)*mo->momz < -FixedMul(8*FRACUNIT, mo->scale))
-			{
+				mo->player->deltaviewheight = (P_MobjFlip(mo)*mo->momz)>>3; // make sure momz is negative
-				if (P_MobjFlip(mo)*mo->momz < -FixedMul(8*FRACUNIT, mo->scale))
-					mo->player->deltaviewheight = (P_MobjFlip(mo)*mo->momz)>>3; // make sure momz is negative
-			}
 
 			if (!tmfloorthing || tmfloorthing->flags & (MF_PUSHABLE|MF_MONITOR)
 				|| tmfloorthing->flags2 & MF2_STANDONME || tmfloorthing->type == MT_PLAYER) // Spin Attack
@@ -2101,14 +2100,14 @@ static void P_PlayerZMovement(mobj_t *mo)
 
 					// Cut momentum in half when you hit the ground and
 					// aren't pressing any controls.
-					if (!mo->player || (!(mo->player->cmd.forwardmove || mo->player->cmd.sidemove) && !mo->player->cmomx && !mo->player->cmomy && !(mo->player->pflags & PF_SPINNING)))
+					if (!(mo->player->cmd.forwardmove || mo->player->cmd.sidemove) && !mo->player->cmomx && !mo->player->cmomy && !(mo->player->pflags & PF_SPINNING))
 					{
 						mo->momx = mo->momx/2;
 						mo->momy = mo->momy/2;
 					}
 				}
 
-				if (mo->health && mo->player)
+				if (mo->health)
 				{
 					if (mo->player->pflags & PF_GLIDING) // ground gliding
 					{
@@ -2154,7 +2153,7 @@ static void P_PlayerZMovement(mobj_t *mo)
 					mo->player->powers[pw_tailsfly] = 0;
 				}
 			}
-			if (mo->player && !(mo->player->pflags & PF_SPINNING))
+			if (!(mo->player->pflags & PF_SPINNING))
 				mo->player->pflags &= ~PF_STARTDASH;
 
 			if (tmfloorthing && (tmfloorthing->flags & (MF_PUSHABLE|MF_MONITOR)
@@ -2197,7 +2196,7 @@ nightsdone:
 		else
 			mo->z = mo->ceilingz - mo->height;
 
-		if (mo->player && (mo->player->pflags & PF_NIGHTSMODE))
+		if (mo->player->pflags & PF_NIGHTSMODE)
 		{
 			if (mo->player->flyangle < 90 || mo->player->flyangle >= 270)
 				mo->player->flyangle -= P_MobjFlip(mo)*90;
@@ -2212,7 +2211,7 @@ nightsdone:
 		{
 			msecnode_t *node;
 
-			if (CheckForMarioBlocks && mo->player && !(netgame && mo->player->spectator)) // Only let the player punch
+			if (CheckForMarioBlocks && !(netgame && mo->player->spectator)) // Only let the player punch
 			{
 				// Search the touching sectors, from side-to-side...
 				for (node = mo->touching_sectorlist; node; node = node->m_snext)
@@ -2240,7 +2239,7 @@ nightsdone:
 			if (mariomode)
 				S_StartSound(mo, sfx_mario1);
 
-			if (!(mo->player && mo->player->climbing))
+			if (!mo->player->climbing)
 				mo->momz = 0;
 		}
 	}
@@ -2255,10 +2254,10 @@ static boolean P_SceneryZMovement(mobj_t *mo)
 		P_AdjustMobjFloorZ_PolyObjs(mo, mo->subsector);
 
 	// adjust height
-	if (mo->pmomz && mo->z != mo->floorz)
+	if (mo->eflags & MFE_APPLYPMOMZ && !P_IsObjectOnGround(mo))
 	{
 		mo->momz += mo->pmomz;
-		mo->pmomz = 0;
+		mo->eflags &= ~MFE_APPLYPMOMZ;
 	}
 	mo->z += mo->momz;
 
@@ -2838,10 +2837,10 @@ boolean P_CameraThinker(player_t *player, camera_t *thiscam, boolean resetcalled
 	thiscam->floorz = tmfloorz;
 	thiscam->ceilingz = tmceilingz;
 
-	if (thiscam->momz)
+	if (thiscam->momz || player->mo->pmomz)
 	{
 		// adjust height
-		thiscam->z += thiscam->momz;
+		thiscam->z += thiscam->momz + player->mo->pmomz;
 
 		if (!itsatwodlevel && !(player->pflags & PF_NOCLIP))
 		{
@@ -2899,6 +2898,7 @@ static void P_PlayerMobjThinker(mobj_t *mobj)
 	msecnode_t *node;
 
 	I_Assert(mobj != NULL);
+	I_Assert(mobj->player != NULL);
 	I_Assert(!P_MobjWasRemoved(mobj));
 
 	P_MobjCheckWater(mobj);
@@ -2917,7 +2917,7 @@ static void P_PlayerMobjThinker(mobj_t *mobj)
 		P_CheckPosition(mobj, mobj->x, mobj->y);
 		goto animonly;
 	}
-	else if (mobj->player && (mobj->player->pflags & PF_MACESPIN) && mobj->tracer)
+	else if (mobj->player->pflags & PF_MACESPIN && mobj->tracer)
 	{
 		P_CheckPosition(mobj, mobj->x, mobj->y);
 		goto animonly;
@@ -2936,7 +2936,7 @@ static void P_PlayerMobjThinker(mobj_t *mobj)
 	else
 		P_TryMove(mobj, mobj->x, mobj->y, true);
 
-	if (!(netgame && mobj->player && mobj->player->spectator))
+	if (!(netgame && mobj->player->spectator))
 	{
 		// Crumbling platforms
 		for (node = mobj->touching_sectorlist; node; node = node->m_snext)
@@ -3019,18 +3019,14 @@ static void P_PlayerMobjThinker(mobj_t *mobj)
 	}
 	else
 	{
-		if (mobj->player)
+		mobj->player->jumping = 0;
+		mobj->player->pflags &= ~PF_JUMPED;
+		if (mobj->player->secondjump || mobj->player->powers[pw_tailsfly])
 		{
-			mobj->player->jumping = 0;
+			mobj->player->secondjump = 0;
-			mobj->player->pflags &= ~PF_JUMPED;
+			mobj->player->powers[pw_tailsfly] = 0;
-			if (mobj->player->secondjump || mobj->player->powers[pw_tailsfly])
+			P_SetPlayerMobjState(mobj, S_PLAY_RUN1);
-			{
-				mobj->player->secondjump = 0;
-				mobj->player->powers[pw_tailsfly] = 0;
-				P_SetPlayerMobjState(mobj, S_PLAY_RUN1);
-			}
 		}
-		mobj->pmomz = 0;
 		mobj->eflags &= ~MFE_JUSTHITFLOOR;
 	}
 
@@ -6648,17 +6644,6 @@ for (i = ((mobj->flags2 & MF2_STRONGBOX) ? strongboxamt : weakboxamt); i; --i) s
 	}
 	else
 	{
-		if (mobj->player)
-		{
-			mobj->player->jumping = 0;
-			mobj->player->pflags &= ~PF_JUMPED;
-			if (mobj->player->secondjump || mobj->player->powers[pw_tailsfly])
-			{
-				mobj->player->secondjump = 0;
-				mobj->player->powers[pw_tailsfly] = 0;
-				P_SetPlayerMobjState(mobj, S_PLAY_RUN1);
-			}
-		}
 		mobj->pmomz = 0; // to prevent that weird rocketing gargoyle bug
 		mobj->eflags &= ~MFE_JUSTHITFLOOR;
 	}
@@ -6859,17 +6844,6 @@ void P_SceneryThinker(mobj_t *mobj)
 	}
 	else
 	{
-		if (mobj->player)
-		{
-			mobj->player->jumping = 0;
-			mobj->player->pflags &= ~PF_JUMPED;
-			if (mobj->player->secondjump || mobj->player->powers[pw_tailsfly])
-			{
-				mobj->player->secondjump = 0;
-				mobj->player->powers[pw_tailsfly] = 0;
-				P_SetPlayerMobjState(mobj, S_PLAY_RUN1);
-			}
-		}
 		mobj->pmomz = 0; // to prevent that weird rocketing gargoyle bug
 		mobj->eflags &= ~MFE_JUSTHITFLOOR;
 	}

src/p_mobj.h

@@ -235,6 +235,8 @@ typedef enum
 	MFE_PUSHED            = 1<<7,
 	// Mobj was already sprung this tic
 	MFE_SPRUNG            = 1<<8,
+	// Platform movement
+	MFE_APPLYPMOMZ        = 1<<9,
 	// free: to and including 1<<15
 } mobjeflag_t;
 

src/p_user.c

@@ -3635,11 +3635,22 @@ void P_DoJump(player_t *player, boolean soundandstate)
 
 	// set just an eensy above the ground
 	if (player->mo->eflags & MFE_VERTICALFLIP)
+	{
 		player->mo->z--;
+		if (player->mo->pmomz < 0)
+			player->mo->momz += player->mo->pmomz; // Add the platform's momentum to your jump.
+		else
+			player->mo->pmomz = 0;
+	}
 	else
+	{
 		player->mo->z++;
-
+		if (player->mo->pmomz > 0)
-	player->mo->z += player->mo->pmomz; // Solves problem of 'hitting around again after jumping on a moving platform'.
+			player->mo->momz += player->mo->pmomz; // Add the platform's momentum to your jump.
+		else
+			player->mo->pmomz = 0;
+	}
+	player->mo->eflags &= ~MFE_APPLYPMOMZ;
 
 	player->pflags |= PF_JUMPED;
 
@@ -9046,7 +9057,6 @@ void P_PlayerThink(player_t *player)
 			player->mo->tracer->flags2 &= ~MF2_DONTDRAW;
 	}
 
-	player->mo->pmomz = 0;
 	player->pflags &= ~PF_SLIDING;
 
 /*
@@ -9399,4 +9409,7 @@ void P_PlayerAfterThink(player_t *player)
 		player->mo->flags2 |= MF2_DONTDRAW;
 		player->mo->flags |= MF_NOGRAVITY;
 	}
+
+	if (P_IsObjectOnGround(player->mo))
+		player->mo->pmomz = 0;
 }