From 92924cefeed80f0e0992175cd70dcd8cf3523988 Mon Sep 17 00:00:00 2001
From: Krzyhau <contact@krzyhau.pl>
Date: Wed, 23 Oct 2024 20:15:39 +0200
Subject: [PATCH] feat: implement slope boost ensurance cheat

---
 src/Cheats.cpp                | 25 ++++++++++++++++++++++++-
 src/Cheats.hpp                |  1 +
 src/Modules/Server.cpp        | 11 +++++++++++
 src/Modules/Server.hpp        |  3 +++
 src/Offsets/Portal 2 8491.hpp |  1 +
 5 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/src/Cheats.cpp b/src/Cheats.cpp
index 1e7f2cc5..00fd55d2 100644
--- a/src/Cheats.cpp
+++ b/src/Cheats.cpp
@@ -29,7 +29,8 @@
 Variable sar_autorecord("sar_autorecord", "0", -1, 1, "Enables or disables automatic demo recording.\n");
 Variable sar_autojump("sar_autojump", "0", "Enables automatic jumping on the server.\n");
 Variable sar_autostrafe("sar_autostrafe", "0", "Automatically strafes in your current wishdir.\n");
-Variable sar_jumpboost("sar_jumpboost", "0", 0,
+Variable sar_ensure_slope_boost("sar_ensure_slope_boost", "0", "Ensures a successful slope boost.");
+	Variable sar_jumpboost("sar_jumpboost", "0", 0,
                        "Enables special game movement on the server.\n"
                        "0 = Default,\n"
                        "1 = Orange Box Engine,\n"
@@ -434,3 +435,25 @@ void Cheats::AutoStrafe(int slot, void *player, CUserCmd *cmd) {
 	}
 	tasPlayer->ApplyMoveAnalog(fb.moveAnalog, cmd);
 }
+
+void Cheats::EnsureSlopeBoost(const CHLMoveData *move, void *player, CGameTrace **tr) {
+	if ((*tr) == NULL) {
+		return;
+	}
+	
+	if (!server->AllowsMovementChanges() || !sar_ensure_slope_boost.GetBool()) {
+		return;
+	}
+	
+	bool goingDown = move->m_vecVelocity.z < 0;
+	bool isntAlreadyGrounded = !(SE(player)->ground_entity());
+	bool landedOnSlope = (*tr)->plane.normal.z < 1.0f;
+	bool wantsToSnapToGround = (*tr)->fraction >= 0.000001f;
+
+	if (goingDown && isntAlreadyGrounded && landedOnSlope && wantsToSnapToGround) {
+		// Nulling out pointer by reference, so that it's passed in CGameMovement::SetGroundEntity, 
+		// preventing being grounded on this call, letting the player to boost off slope
+		*tr = NULL;
+	}
+
+}
\ No newline at end of file
diff --git a/src/Cheats.hpp b/src/Cheats.hpp
index 039a7941..75d03e85 100644
--- a/src/Cheats.hpp
+++ b/src/Cheats.hpp
@@ -9,6 +9,7 @@ class Cheats {
 
 	static void PatchBhop(int slot, void *player, CUserCmd *cmd);
 	static void AutoStrafe(int slot, void *player, CUserCmd *cmd);
+	static void EnsureSlopeBoost(const CHLMoveData *move, void *player, CGameTrace **tr);
 };
 
 extern Variable sar_autorecord;
diff --git a/src/Modules/Server.cpp b/src/Modules/Server.cpp
index 45c9b1b0..db0b8490 100644
--- a/src/Modules/Server.cpp
+++ b/src/Modules/Server.cpp
@@ -77,6 +77,7 @@ REDECL(Server::CheckJumpButtonBase);
 REDECL(Server::StepMove);
 REDECL(Server::TryPlayerMove);
 REDECL(Server::CheckStuck);
+REDECL(Server::SetGroundEntity);
 REDECL(Server::PlayerMove);
 REDECL(Server::FinishGravity);
 REDECL(Server::AirMove);
@@ -223,6 +224,15 @@ DETOUR_T(int, Server::CheckStuck) {
 	return result;
 }
 
+// CGameMovement::SetGroundEntity
+DETOUR(Server::SetGroundEntity, CGameTrace* tr) {
+	auto player = *reinterpret_cast<void **>((uintptr_t)thisptr + Offsets::player);
+	auto mv = *reinterpret_cast<const CHLMoveData **>((uintptr_t)thisptr + Offsets::mv);
+
+	Cheats::EnsureSlopeBoost(mv, player, &tr);
+	return Server::SetGroundEntity(thisptr, tr);
+}
+
 // CGameMovement::PlayerMove
 DETOUR(Server::PlayerMove) {
 	auto player = *reinterpret_cast<void **>((uintptr_t)thisptr + Offsets::player);
@@ -817,6 +827,7 @@ bool Server::Init() {
 		this->g_GameMovement->Hook(Server::StepMove_Hook, Server::StepMove, Offsets::StepMove);
 		this->g_GameMovement->Hook(Server::TryPlayerMove_Hook, Server::TryPlayerMove, Offsets::TryPlayerMove);
 		this->g_GameMovement->Hook(Server::CheckStuck_Hook, Server::CheckStuck, Offsets::CheckStuck);
+		this->g_GameMovement->Hook(Server::SetGroundEntity_Hook, Server::SetGroundEntity, Offsets::SetGroundEntity);
 		this->g_GameMovement->Hook(Server::ProcessMovement_Hook, Server::ProcessMovement, Offsets::ProcessMovement);
 		this->g_GameMovement->Hook(Server::GetPlayerViewOffset_Hook, Server::GetPlayerViewOffset, Offsets::GetPlayerViewOffset);
 		this->g_GameMovement->Hook(Server::FinishGravity_Hook, Server::FinishGravity, Offsets::FinishGravity);
diff --git a/src/Modules/Server.hpp b/src/Modules/Server.hpp
index fcec4497..04f44d00 100644
--- a/src/Modules/Server.hpp
+++ b/src/Modules/Server.hpp
@@ -108,6 +108,9 @@ class Server : public Module {
 	// CGameMovement::CheckStuck
 	DECL_DETOUR_T(int, CheckStuck);
 
+	// CGameMovement::SetGroundEntity
+	DECL_DETOUR(SetGroundEntity, CGameTrace* tr);
+
 	// CGameMovement::TryPlayerMove
 	DECL_DETOUR_T(int, TryPlayerMove, Vector *pFirstDest, CGameTrace *pFirstTrace);
 
diff --git a/src/Offsets/Portal 2 8491.hpp b/src/Offsets/Portal 2 8491.hpp
index d09c00bc..b1489b3f 100644
--- a/src/Offsets/Portal 2 8491.hpp	
+++ b/src/Offsets/Portal 2 8491.hpp	
@@ -114,6 +114,7 @@ OFFSET_DEFAULT(CheckJumpButton, 36, 37)
 OFFSET_DEFAULT(FullTossMove, -1, 38)
 OFFSET_DEFAULT(TryPlayerMove, 39, 40)
 OFFSET_DEFAULT(CheckStuck, 47, 48)
+OFFSET_DEFAULT(SetGroundEntity, 69, 70)
 OFFSET_DEFAULT(StepMove, 70, 71)
 OFFSET_DEFAULT(mv, 8, 8)
 OFFSET_DEFAULT(player, 4, 4)