From 1b41b53d78cd0ad8e668db651f10e091c09d9e34 Mon Sep 17 00:00:00 2001
From: ineed bots <ineedbots@pbot.org>
Date: Sat, 29 Apr 2023 13:54:00 -0600
Subject: [PATCH] usercall detour test!

---
 src/component/test.cpp | 37 +++++++++++++++++++++++++++++++++++++
 src/game/game.cpp      |  6 ++----
 src/game/game.hpp      |  3 ++-
 3 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/src/component/test.cpp b/src/component/test.cpp
index 444e346..9d4cafd 100644
--- a/src/component/test.cpp
+++ b/src/component/test.cpp
@@ -11,6 +11,9 @@ namespace test
 {
 	utils::hook::detour gscr_spawn_hook;
 
+	// a __usercall detour! :o
+	utils::hook::detour scr_getentityid_hook;
+
 	namespace
 	{
 		game::dvar_s* custom_dvar;
@@ -91,6 +94,37 @@ namespace test
 				retn;
 			}
 		}
+
+		unsigned int __stdcall scr_getentityid_call(game::scriptInstance_t inst, game::classNum_e classnum, unsigned int clientnum, unsigned int entnum)
+		{
+			// minhook allocated space for the original asm, we want to execute that instead because the original gamecode has the jump from the detour
+			return game::Scr_GetEntityId(inst, entnum, classnum, clientnum, scr_getentityid_hook.get_original());
+		}
+
+		unsigned int __declspec(naked) __cdecl scr_getentityid_stub(game::scriptInstance_t inst, game::classNum_e classnum, unsigned int clientnum)
+		{
+			// 00692520 unsigned int __usercall Scr_GetEntityId@<eax>(unsigned int entnum@<eax>, scriptInstance_t inst, classNum_e classnum, unsigned int clientnum)
+			__asm
+			{
+				// prol
+				push ebp;
+				mov ebp, esp;
+
+				// push shit for our call, remember eax is a param in the usercall, rest was on stack
+				// we can access params like this in naked because we correctly setup the ebp
+				push eax;
+				push clientnum;
+				push classnum;
+				push inst;
+				call scr_getentityid_call;
+				// we made this a __stdcall, so we dont need to clean up stack
+
+				// epil
+				mov esp, ebp;
+				pop ebp;
+				ret;
+			}
+		}
 	}
 
 	class component final : public component_interface
@@ -137,6 +171,9 @@ namespace test
 
 			// fix NEGOTIATION links
 			//utils::hook::jump(0x4D3296, our_funny_hook);
+
+			// test usercall detour!
+			scr_getentityid_hook.create(0x692520, scr_getentityid_stub);
 		}
 
 	private:
diff --git a/src/game/game.cpp b/src/game/game.cpp
index 48d65d5..81c34af 100644
--- a/src/game/game.cpp
+++ b/src/game/game.cpp
@@ -303,10 +303,8 @@ namespace game
 		}
 	}
 
-	unsigned int Scr_GetEntityId(scriptInstance_t inst, int entNum, classNum_e classnum, unsigned int clientnum)
+	unsigned int Scr_GetEntityId(scriptInstance_t inst, unsigned int entnum, classNum_e classnum, unsigned int clientnum, void* call_addr)
 	{
-		static const auto call_addr = SELECT(0x0, 0x692520);
-
 		unsigned int answer;
 
 		__asm
@@ -314,7 +312,7 @@ namespace game
 			push clientnum;
 			push classnum;
 			push inst;
-			mov eax, entNum;
+			mov eax, entnum;
 			call call_addr;
 			add esp, 0xC;
 			mov answer, eax;
diff --git a/src/game/game.hpp b/src/game/game.hpp
index 689f43a..321a6a0 100644
--- a/src/game/game.hpp
+++ b/src/game/game.hpp
@@ -3,6 +3,7 @@
 #include "structs.hpp"
 
 #define SELECT(mp, sp) (game::environment::t4mp() ? mp : sp)
+#define CALL_ADDR(mp, sp) reinterpret_cast<void*>(SELECT(mp, sp))
 
 namespace game
 {
@@ -50,7 +51,7 @@ namespace game
 	void Scr_AddUndefined(game::scriptInstance_t inst);
 	gentity_s* Scr_GetEntity(unsigned int arg_index);
 	void Scr_AddEntity(game::scriptInstance_t inst, gentity_s* ent);
-	unsigned int Scr_GetEntityId(scriptInstance_t inst, int entNum, classNum_e classnum, unsigned int clientnum);
+	unsigned int Scr_GetEntityId(scriptInstance_t inst, unsigned int entnum, classNum_e classnum, unsigned int clientnum, void* call_addr = CALL_ADDR(0x0, 0x692520));
 	void Scr_AddEntityNum(scriptInstance_t inst, unsigned int entid);
 	pathnode_t* Scr_GetPathnode(scriptInstance_t inst);
 	void Scr_AddPathnode(scriptInstance_t inst, pathnode_t* node);