From 9a17d335793546e53d4da385b95beb9e92eec85c Mon Sep 17 00:00:00 2001
From: Mitchell Richters <mjr4077au@gmail.com>
Date: Thu, 16 Mar 2023 22:15:11 +1100
Subject: [PATCH] - Duke: Ensure spawned player actor has view height baked in
 up until the first `getzrange()` call.

* The original game spawning the player's sprite/actor would set the sprite's pos with the Z matching the player's, which had a height offset already applied.
* This baked in height offset was carried through up until the `SetActor()` call in `processinput()`, where the original game would then strip off `gs.playerheight`.
* This baked in height offset within the actor is critical on the first tic for pre-activated elevators on level spawn to function right, such as E1L2 and E2L3.
* Properly setting the player actor's Z immediately after the initial `getzrange()` call, but before other functions like `movement()`, etc further down in `processinput()` is the best spot.
* Fixes #870.
---
 source/games/duke/src/player_d.cpp |  9 ++++++++-
 source/games/duke/src/player_r.cpp | 16 ++++++++++------
 source/games/duke/src/premap.cpp   |  3 +--
 3 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/source/games/duke/src/player_d.cpp b/source/games/duke/src/player_d.cpp
index 335e0e750..9a3969f30 100644
--- a/source/games/duke/src/player_d.cpp
+++ b/source/games/duke/src/player_d.cpp
@@ -2620,6 +2620,13 @@ void processinput_d(int snum)
 	shrunk = (pact->spr.scale.Y < 0.5);
 	getzrange(p->GetActor()->getPosWithOffsetZ(), psectp, &ceilingz, chz, &floorz, clz, 10.1875, CLIPMASK0);
 
+	if (!PlayClock)
+	{
+		pact->spr.pos.Z += gs.playerheight;
+		pact->opos.Z += gs.playerheight;
+		pact->oviewzoffset = pact->viewzoffset = -gs.playerheight;
+	}
+
 	p->truefz = getflorzofslopeptr(psectp, p->GetActor()->getPosWithOffsetZ());
 	p->truecz = getceilzofslopeptr(psectp, p->GetActor()->getPosWithOffsetZ());
 
@@ -2910,7 +2917,7 @@ HORIZONLY:
 	}
 
 	// RBG***
-	SetActor(pact, p->GetActor()->spr.pos);
+	SetActor(pact, pact->spr.pos);
 
 	if (psectlotag < 3)
 	{
diff --git a/source/games/duke/src/player_r.cpp b/source/games/duke/src/player_r.cpp
index 59a0da549..d678c3bf7 100644
--- a/source/games/duke/src/player_r.cpp
+++ b/source/games/duke/src/player_r.cpp
@@ -3235,22 +3235,26 @@ void processinput_r(int snum)
 	p->spritebridge = 0;
 
 	shrunk = (pact->spr.scale.Y < 0.125);
-	double tempfz;
 	if (pact->clipdist == 16)
 	{
 		getzrange(p->GetActor()->getPosWithOffsetZ(), psectp, &ceilingz, chz, &floorz, clz, 10.1875, CLIPMASK0);
-		tempfz = getflorzofslopeptr(psectp, p->GetActor()->getPosWithOffsetZ());
 	}
 	else
 	{
 		getzrange(p->GetActor()->getPosWithOffsetZ(), psectp, &ceilingz, chz, &floorz, clz, 0.25, CLIPMASK0);
-		tempfz = getflorzofslopeptr(psectp, p->GetActor()->getPosWithOffsetZ());
 	}
 
-	p->truefz = tempfz;
+	if (!PlayClock)
+	{
+		pact->spr.pos.Z += gs.playerheight;
+		pact->opos.Z += gs.playerheight;
+		pact->oviewzoffset = pact->viewzoffset = -gs.playerheight;
+	}
+
+	p->truefz = getflorzofslopeptr(psectp, p->GetActor()->getPosWithOffsetZ());
 	p->truecz = getceilzofslopeptr(psectp, p->GetActor()->getPosWithOffsetZ());
 
-	double truefdist = abs(p->GetActor()->getOffsetZ() - tempfz);
+	double truefdist = abs(p->GetActor()->getOffsetZ() - p->truefz);
 	if (clz.type == kHitSector && psectlotag == 1 && truefdist > gs.playerheight + 16)
 		psectlotag = 0;
 
@@ -3700,7 +3704,7 @@ HORIZONLY:
 	}
 
 	// RBG***
-	SetActor(pact, p->GetActor()->spr.pos);
+	SetActor(pact, pact->spr.pos);
 
 	if (psectlotag == 800 && (!isRRRA() || !p->lotag800kill))
 	{
diff --git a/source/games/duke/src/premap.cpp b/source/games/duke/src/premap.cpp
index 91051c6d8..cf7b6d72f 100644
--- a/source/games/duke/src/premap.cpp
+++ b/source/games/duke/src/premap.cpp
@@ -503,11 +503,10 @@ void resetpspritevars(int g, const DVector3& startpos, const DAngle startang)
 	int aimmode[MAXPLAYERS];
 	STATUSBARTYPE tsbar[MAXPLAYERS];
 
-	auto newActor = CreateActor(ps[0].cursector, startpos.plusZ(gs.playerheight),
+	auto newActor = CreateActor(ps[0].cursector, startpos,
 		TILE_APLAYER, 0, DVector2(0, 0), startang, 0., 0., nullptr, 10);
 
 	newActor->spr.Angles.Pitch = DAngle::fromDeg(-17.354);
-	newActor->viewzoffset = -gs.playerheight;
 	newActor->backuploc();
 
 	if (ud.recstat != 2) for (i = 0; i < MAXPLAYERS; i++)