From 21a37d2c07deac92f09552e8d8beefd8d95fb6c6 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Sun, 30 Apr 2023 08:11:30 +0200
Subject: [PATCH] - added helpers needed to run CON replacement code.

* killit must exit to the top level right away. Use an exception for this.
* two new flags to make checking easier.
* do not export killit_flag to scripting.
---
 source/games/duke/src/constants.h             |  2 ++
 source/games/duke/src/game.cpp                |  2 +-
 source/games/duke/src/types.h                 | 12 +++++++++++
 source/games/duke/src/vmexports.cpp           | 21 +++++++++++++++++--
 wadsrc/static/zscript/games/duke/dukeactor.zs |  3 ++-
 5 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/source/games/duke/src/constants.h b/source/games/duke/src/constants.h
index 5e0592eab..bb2bc8423 100644
--- a/source/games/duke/src/constants.h
+++ b/source/games/duke/src/constants.h
@@ -448,6 +448,8 @@ enum sflags4_t
 {
 	SFLAG4_DOUBLEHITDAMAGE = 0x00000001,
 	SFLAG4_NODAMAGETURN = 0x00000002,
+	SFLAG4_CONOVERRIDE = 0x00000004,	// this is strictly internal
+	SFLAG4_INRUNSTATE = 0x00000008,		// exception throwing guard.
 };
 
 using EDukeFlags4 = TFlags<sflags4_t, uint32_t>;
diff --git a/source/games/duke/src/game.cpp b/source/games/duke/src/game.cpp
index b906c8481..da7b9dc83 100644
--- a/source/games/duke/src/game.cpp
+++ b/source/games/duke/src/game.cpp
@@ -498,7 +498,7 @@ void GameInterface::FinalizeSetup()
 
 			}
 		}
-		//ScriptCode[actinf.scriptaddress] = 0; // ignore strength values for hashing the script code. (later, we still need this.)
+		ScriptCode[actinf.scriptaddress] = 0; // ignore strength values for hashing the script code.
 		// todo: hash the entire script code and compare against precalculated value for the current game.
 		// If identical, remove all ScriptAddresses from the class list.
 
diff --git a/source/games/duke/src/types.h b/source/games/duke/src/types.h
index 52976378b..6d1333429 100644
--- a/source/games/duke/src/types.h
+++ b/source/games/duke/src/types.h
@@ -170,6 +170,18 @@ public:
 using HitInfo = THitInfo<DDukeActor>;
 using Collision = TCollision<DDukeActor>;
 
+
+// This is to satisfy the CON-based requirement of 'killit' immediately aborting all script code execution.
+class CDukeKillEvent : public std::exception
+{
+	int Type_;
+public:
+	CDukeKillEvent(int type): Type_(type) {}
+	int Type() const { return Type_; }
+	// to print a meaningful message if killit got called from the wrong place.
+	const char* what() const override { return "killit called from outside RunState!"; }
+};
+
 struct animwalltype
 {
 	walltype* wall;
diff --git a/source/games/duke/src/vmexports.cpp b/source/games/duke/src/vmexports.cpp
index 62139a1f8..c1f6abd93 100644
--- a/source/games/duke/src/vmexports.cpp
+++ b/source/games/duke/src/vmexports.cpp
@@ -293,7 +293,7 @@ DEFINE_FIELD(DDukeActor, curAction)
 DEFINE_FIELD(DDukeActor, curMove)
 DEFINE_FIELD(DDukeActor, curAI)
 DEFINE_FIELD(DDukeActor, actioncounter)
-DEFINE_FIELD(DDukeActor, killit_flag)
+//DEFINE_FIELD(DDukeActor, killit_flag)
 
 void TickActor(DDukeActor*);
 DEFINE_ACTION_FUNCTION(DDukeActor, Tick)
@@ -604,7 +604,7 @@ DEFINE_ACTION_FUNCTION_NATIVE(DDukeActor, badguy, badguy)
 
 int duke_scripted(const DDukeActor* act)
 {
-	return act->conInfo() != nullptr;
+	return act->conInfo() != nullptr || (act->flags4 & SFLAG4_CONOVERRIDE);
 }
 
 DEFINE_ACTION_FUNCTION_NATIVE(DDukeActor, scripted, duke_scripted)
@@ -927,6 +927,23 @@ DEFINE_ACTION_FUNCTION_NATIVE(DDukeActor, subkill, subkill)
 	return 0;
 }
 
+DEFINE_ACTION_FUNCTION(DDukeActor, killit)
+{
+	PARAM_SELF_PROLOGUE(DDukeActor);
+	if (self->flags4 & SFLAG4_INRUNSTATE)
+	{
+		// this has to be done the hard way. The original CON interpreter stops running commands once an actor is set to be killed.
+		// The only safe way to handle this in native code while exiting all nested functions is throwing an exception.
+		throw CDukeKillEvent(1);
+	}
+	else
+	{
+		// if it is something else than the currently ticked actor we can outright destroy it.
+		self->Destroy();
+	}
+	return 0;
+}
+
 //---------------------------------------------------------------------------
 //
 // DukePlayer
diff --git a/wadsrc/static/zscript/games/duke/dukeactor.zs b/wadsrc/static/zscript/games/duke/dukeactor.zs
index 2123fbd41..4b8c9539f 100644
--- a/wadsrc/static/zscript/games/duke/dukeactor.zs
+++ b/wadsrc/static/zscript/games/duke/dukeactor.zs
@@ -312,7 +312,7 @@ class DukeActor : CoreActor native
 	native ActorMove curMove;
 	native Name curAI;
 	native int16 actioncounter;
-	native uint8 killit_flag;
+	//native uint8 killit_flag;
 
 	// flags are implemented natively to avoid the prefixes.
 	
@@ -402,6 +402,7 @@ class DukeActor : CoreActor native
 	native double GetAmbientDist();
 	native void addkill();
 	native void subkill();
+	native void killit();