From 3688d62a46661dd593d575fc9a990d4d606d3c7f Mon Sep 17 00:00:00 2001
From: Irineu <mako@paranoid.rezurrection>
Date: Sun, 20 Sep 2026 18:12:23 -0300
Subject: [PATCH] Replace the UTIL_DecalTrace memory patches with a detour to
 make it easier to maintain

---
 extension.cpp         | 54 +++++++++++++++++++++----------------------
 gamedata/CSSFixes.txt |  6 +++++
 2 files changed, 32 insertions(+), 28 deletions(-)

diff --git a/extension.cpp b/extension.cpp
index 3c875d8..1677af0 100644
--- a/extension.cpp
+++ b/extension.cpp
@@ -290,34 +290,6 @@ static struct SrcdsPatch
         "x?xx",
         (unsigned char *)"\x90\x90\x8B\x09",
         "bin/dedicated_srv.so"
-    },
-    // 17: void CBaseGrenade::Explode( trace_t *pTrace, int bitsDamageType ) NOP out UTIL_DecalTrace( pTrace, "Scorch" ); to stop grenades from causing
-    // "Too many indices for index buffer. Tell a programmer". Grenades cause decals on too many faces for the client to handle.
-    {
-        "_ZN12CBaseGrenade7ExplodeEP10CGameTracei",
-        (unsigned char *)"\xE8\xEA\x8E\x21\x00",
-        "xxxxx",
-        (unsigned char *)"\x90\x90\x90\x90\x90",
-        "cstrike/bin/server_srv.so"
-    },
-
-    // 18: void CPlantedC4::Explode( trace_t *pTrace, int bitsDamageType ) NOP out UTIL_DecalTrace( pTrace, "Scorch" ); same reason as 17.
-    {
-        "_ZN10CPlantedC47ExplodeEP10CGameTracei",
-        (unsigned char *)"\xE8\x72\xBE\xEB\xFF",
-        "xxxxx",
-        (unsigned char *)"\x90\x90\x90\x90\x90",
-        "cstrike/bin/server_srv.so"
-    },
-    // 19: void CEnvExplosion::InputExplode( inputdata_t &inputdata ) NOP out UTIL_DecalTrace( &tr, "Scorch" ); same reason as 17.
-    {
-        "_ZN13CEnvExplosion12InputExplodeER11inputdata_t",
-        (unsigned char *)"\xE8\xEA\x2A\x1A\x00",
-        "xxxxx",
-        (unsigned char *)"\x90\x90\x90\x90\x90",
-        "cstrike/bin/server_srv.so",
-        0x800,
-        1
     }
 };
 
@@ -370,6 +342,8 @@ CDetour *g_pDetour_CTraceFilterSimple = NULL;
 CDetour *g_pDetour_KeyValue = NULL;
 CDetour *g_pDetour_FireBullets = NULL;
 CDetour *g_pDetour_SwingOrStab = NULL;
+CDetour *g_pDetour_UTIL_DecalTrace = NULL;
+
 int g_SH_SkipTwoEntitiesShouldHitEntity = 0;
 int g_SH_SimpleShouldHitEntity = 0;
 
@@ -575,6 +549,15 @@ DETOUR_DECL_MEMBER3(DETOUR_CTraceFilterSimple, void, const IHandleEntity *, pass
 		*(uintptr_t *)this = g_CTraceFilterNoNPCsOrPlayer;
 }
 
+DETOUR_DECL_STATIC2(DETOUR_UTIL_DecalTrace, void, void *, pTrace, char *, decalName)
+{
+	// to stop grenades from causing "Too many indices for index buffer. Tell a programmer". Grenades cause decals on too many faces for the client to handle.
+	if (strcmp(decalName, "Scorch") == 0)
+		return;
+
+	DETOUR_STATIC_CALL(DETOUR_UTIL_DecalTrace)(pTrace, decalName);
+}
+
 /* Make bullets ignore teammates */
 char *g_pPhysboxToClientMap = NULL;
 bool g_InFireBullets = false;
@@ -801,6 +784,14 @@ bool CSSFixes::SDK_OnLoad(char *error, size_t maxlength, bool late)
 		return false;
 	}
 
+	g_pDetour_UTIL_DecalTrace =  DETOUR_CREATE_STATIC(DETOUR_UTIL_DecalTrace, "UTIL_DecalTrace");
+	if (g_pDetour_UTIL_DecalTrace == NULL)
+	{
+		snprintf(error, maxlength, "Could not create detour for UTIL_DecalTrace");
+		SDK_OnUnload();
+		return false;
+	}
+
 	g_pDetour_InputTestActivator->EnableDetour();
 	g_pDetour_PostConstructor->EnableDetour();
 	g_pDetour_CreateEntityByName->EnableDetour();
@@ -810,6 +801,7 @@ bool CSSFixes::SDK_OnLoad(char *error, size_t maxlength, bool late)
 	g_pDetour_KeyValue->EnableDetour();
 	g_pDetour_FireBullets->EnableDetour();
 	g_pDetour_SwingOrStab->EnableDetour();
+	g_pDetour_UTIL_DecalTrace->EnableDetour();
 
 	// Find VTable for CTraceFilterSkipTwoEntities
 	uintptr_t pCTraceFilterSkipTwoEntities;
@@ -1012,6 +1004,12 @@ void CSSFixes::SDK_OnUnload()
 		g_pDetour_SwingOrStab = NULL;
 	}
 
+	if (g_pDetour_UTIL_DecalTrace != NULL)
+	{
+		g_pDetour_UTIL_DecalTrace->Destroy();
+		g_pDetour_UTIL_DecalTrace = NULL;
+	}
+
 	if(g_SH_SkipTwoEntitiesShouldHitEntity)
 		SH_REMOVE_HOOK_ID(g_SH_SkipTwoEntitiesShouldHitEntity);
 
diff --git a/gamedata/CSSFixes.txt b/gamedata/CSSFixes.txt
index b04b961..660d47f 100644
--- a/gamedata/CSSFixes.txt
+++ b/gamedata/CSSFixes.txt
@@ -81,6 +81,12 @@
 				"library"	"server"
 				"linux"		"@_ZN6CKnife11SwingOrStabEb"
 			}
+
+			"UTIL_DecalTrace"
+			{
+				"library"	"server"
+				"linux"		"@_Z15UTIL_DecalTraceP10CGameTracePKc"
+			}
 		}
 	}
 }
-- 
2.47.3