Add cs_find_ent_by_class and fix documentation

dlls/cstrike/cstrike/AMBuilder

@@ -14,6 +14,7 @@ binary.sources = [
   'CstrikeNatives.cpp',
   'CstrikeHacks.cpp',
   'CstrikeUtils.cpp',
+  'CstrikeHLTypeConversion.cpp',
   '../../../public/memtools/MemoryUtils.cpp',
   '../../../public/memtools/CDetour/detours.cpp',
   '../../../public/memtools/CDetour/asm/asm.c',

dlls/cstrike/cstrike/CstrikeDatas.h

@@ -141,23 +141,26 @@
 #endif
 
 #if defined(__linux__)
-	#define CS_IDENT_GIVENSHIELD        "_ZN11CBasePlayer10GiveShieldEb"		// CS_OnBuy forward 
+	#define CS_IDENT_GIVENSHIELD              "_ZN11CBasePlayer10GiveShieldEb"                  // CS_OnBuy forward 
-	#define CS_IDENT_GIVENAMEDITEM		"_ZN11CBasePlayer13GiveNamedItemEPKc"   // CS_OnBuy forward 
+	#define CS_IDENT_GIVENAMEDITEM		      "_ZN11CBasePlayer13GiveNamedItemEPKc"             // CS_OnBuy forward 
-	#define CS_IDENT_ADDACCOUNT			"_ZN11CBasePlayer10AddAccountEib"       // CS_OnBuy forward 
+	#define CS_IDENT_ADDACCOUNT			      "_ZN11CBasePlayer10AddAccountEib"                 // CS_OnBuy forward 
-	#define CS_IDENT_CREATENAMEDENTITY  "_Z19CREATE_NAMED_ENTITYj"              // cs_create_entity
+	#define CS_IDENT_CREATENAMEDENTITY        "_Z19CREATE_NAMED_ENTITYj"                        // cs_create_entity
-	#define CS_IDENT_HIDDEN_STATE		false
+	#define CS_IDENTI_UTIL_FINDENTITYBYSTRING "_Z23UTIL_FindEntityByStringP11CBaseEntityPKcS2_" // cs_create_entity
+	#define CS_IDENT_HIDDEN_STATE		      false
 #elif defined(__APPLE__)
-	#define CS_IDENT_GIVENSHIELD        "_ZN11CBasePlayer10GiveShieldEb"
+	#define CS_IDENT_GIVENSHIELD              "_ZN11CBasePlayer10GiveShieldEb"
-	#define CS_IDENT_GIVENAMEDITEM		"_ZN11CBasePlayer13GiveNamedItemEPKc"
+	#define CS_IDENT_GIVENAMEDITEM		      "_ZN11CBasePlayer13GiveNamedItemEPKc"
-	#define CS_IDENT_ADDACCOUNT			"_ZN11CBasePlayer10AddAccountEib"
+	#define CS_IDENT_ADDACCOUNT			      "_ZN11CBasePlayer10AddAccountEib"
-	#define CS_IDENT_CREATENAMEDENTITY  "_Z19CREATE_NAMED_ENTITYj"
+	#define CS_IDENT_CREATENAMEDENTITY        "_Z19CREATE_NAMED_ENTITYj"
-	#define CS_IDENT_HIDDEN_STATE		true
+	#define CS_IDENTI_UTIL_FINDENTITYBYSTRING "_Z23UTIL_FindEntityByStringP11CBaseEntityPKcS2_"
+	#define CS_IDENT_HIDDEN_STATE		      true
 #elif defined(WIN32)
-	#define CS_IDENT_GIVENSHIELD        "\\x56\\x8B\\x2A\\x57\\x33\\x2A\\x8B\\x2A\\x2A\\x2A\\x2A\\x2A\\xB0"
+	#define CS_IDENT_GIVENSHIELD              "\\x56\\x8B\\x2A\\x57\\x33\\x2A\\x8B\\x2A\\x2A\\x2A\\x2A\\x2A\\xB0"
-	#define CS_IDENT_GIVENAMEDITEM		"\\x8B\\x2A\\x2A\\x2A\\x56\\x57\\x8B\\x2A\\x8B\\x2A\\x2A\\x2A\\x2A\\x2A\\x2B"
+	#define CS_IDENT_GIVENAMEDITEM            "\\x8B\\x2A\\x2A\\x2A\\x56\\x57\\x8B\\x2A\\x8B\\x2A\\x2A\\x2A\\x2A\\x2A\\x2B"
-	#define CS_IDENT_ADDACCOUNT			"\\x8B\\x2A\\x2A\\x2A\\x56\\x8B\\x2A\\x8B\\x2A\\x2A\\x2A\\x2A\\x2A\\x03"
+	#define CS_IDENT_ADDACCOUNT               "\\x8B\\x2A\\x2A\\x2A\\x56\\x8B\\x2A\\x8B\\x2A\\x2A\\x2A\\x2A\\x2A\\x03"
-	#define CS_IDENT_CREATENAMEDENTITY  "\\x56\\x57\\x8B\\x2A\\x2A\\x2A\\x57\\xFF\\x2A\\x2A\\x2A\\x2A\\x2A\\x8B"
+	#define CS_IDENT_CREATENAMEDENTITY        "\\x56\\x57\\x8B\\x2A\\x2A\\x2A\\x57\\xFF\\x2A\\x2A\\x2A\\x2A\\x2A\\x8B"
-	#define CS_IDENT_HIDDEN_STATE		false
+	#define CS_IDENT_UTIL_FINDENTITYBYSTRING  "\\x51\\x8B\\x2A\\x2A\\x2A\\x53\\x55\\x56\\x85\\x2A\\x57"
+	#define CS_IDENT_HIDDEN_STATE		      false
 #endif
 
 #define CSI_P228						CSW_P228
@@ -349,6 +352,7 @@ typedef enum
 
 } Menu;
 
-typedef edict_t* (*CreateNamedEntityFunc)(string_t);
+typedef edict_t* (*CreateNamedEntityFunc)(string_t iszClassname);
+typedef void*    (*UTIL_FindEntityByStringFunc)(void* pStartEntity, const char *szKeyword, const char *szValue);
 
 #endif // CSTRIKE_DATA_H

dlls/cstrike/cstrike/CstrikeHLTypeConversion.cpp

@@ -0,0 +1,118 @@
+//
+// AMX Mod X, based on AMX Mod by Aleksander Naszko ("OLO").
+// Copyright (C) The AMX Mod X Development Team.
+//
+// This software is licensed under the GNU General Public License, version 3 or higher.
+// Additional exceptions apply. For full license details, see LICENSE.txt or visit:
+//     https://alliedmods.net/amxmodx-license
+
+//
+// Counter-Strike Module
+//
+
+#include "CstrikeHLTypeConversion.h"
+
+OffsetHandler*     G_OffsetHandler;
+HL_TypeConversion  G_HL_TypeConversion;
+
+void OffsetHandler::search_pev()
+{
+	edict_t* edict = INDEXENT(0);
+	entvars_t* entvars = &edict->v;
+
+	byte* private_c = (byte*)edict->pvPrivateData;
+
+	for (int i = 0; i < 0xFFF; i++)
+	{
+		uintptr_t val = *((uintptr_t*)(private_c + i));
+
+		if (val == (uintptr_t)entvars)
+		{
+			this->pev = i;
+			return;
+		}
+	}
+
+	// This should not happen.
+	this->pev = 0;
+}
+
+inline edict_t* HL_TypeConversion::INDEXENT2(int iEdictNum)
+{
+	if (iEdictNum >= 1 && iEdictNum <= gpGlobals->maxClients)
+	{
+		return MF_GetPlayerEdict(iEdictNum);
+	}
+	else
+	{
+		return (*g_engfuncs.pfnPEntityOfEntIndex)(iEdictNum);
+	}
+}
+
+edict_t* HL_TypeConversion::entvar_to_edict(entvars_t *pev)
+{
+	if (!pev)
+	{
+		return nullptr;
+	}
+
+	return pev->pContainingEntity;
+}
+
+int HL_TypeConversion::entvar_to_id(entvars_t *pev)
+{
+	if (!pev)
+	{
+		return -1;
+	}
+
+	if (!pev->pContainingEntity)
+	{
+		return -1;
+	}
+
+	return ENTINDEX(pev->pContainingEntity);
+}
+
+void* HL_TypeConversion::id_to_cbase(int index)
+{
+	edict_t* edict = INDEXENT2(index);
+	return edict ? edict->pvPrivateData : nullptr;
+}
+
+entvars_t* HL_TypeConversion::id_to_entvar(int index)
+{
+	return &(INDEXENT2(index)->v);
+}
+
+entvars_t* HL_TypeConversion::cbase_to_entvar(void* cbase)
+{
+	if (!cbase)
+	{
+		return nullptr;
+	}
+
+	return *(entvars_t **)((char *)(cbase) + G_OffsetHandler->pev);
+}
+
+int HL_TypeConversion::cbase_to_id(void *cbase)
+{
+	if (!cbase)
+	{
+		return -1;
+	}
+
+	entvars_t* pev = this->cbase_to_entvar(cbase);
+
+	if (!pev)
+	{
+		return -1;
+	}
+
+	if (!pev->pContainingEntity || FNullEnt(pev->pContainingEntity))
+	{
+		return -1;
+	}
+
+	return ENTINDEX(pev->pContainingEntity);
+}

dlls/cstrike/cstrike/CstrikeHLTypeConversion.h

@@ -0,0 +1,49 @@
+//
+// AMX Mod X, based on AMX Mod by Aleksander Naszko ("OLO").
+// Copyright (C) The AMX Mod X Development Team.
+//
+// This software is licensed under the GNU General Public License, version 3 or higher.
+// Additional exceptions apply. For full license details, see LICENSE.txt or visit:
+//     https://alliedmods.net/amxmodx-license
+
+//
+// Counter-Strike Module
+//
+
+#ifndef HL_TYPE_CONVERSION_H
+#define HL_TYPE_CONVERSION_H
+
+#include "amxxmodule.h"
+
+struct OffsetHandler
+{
+	int pev;
+
+	void search_pev();
+
+	OffsetHandler()
+	{
+		search_pev();
+	}
+};
+
+class HL_TypeConversion
+{
+	public:
+
+		inline edict_t* INDEXENT2(int iEdictNum);
+
+		edict_t* entvar_to_edict(entvars_t *pev);
+		int entvar_to_id(entvars_t *pev);
+
+		void* id_to_cbase(int index);
+		int cbase_to_id(void *cbase);
+
+		entvars_t* id_to_entvar(int index);
+		entvars_t* cbase_to_entvar(void* cbase);
+};
+
+extern OffsetHandler*     G_OffsetHandler;
+extern HL_TypeConversion  G_HL_TypeConversion;
+
+#endif // HL_TYPE_CONVERSION_H

dlls/cstrike/cstrike/CstrikeNatives.cpp

@@ -14,6 +14,7 @@
 #include "CstrikeDatas.h"
 #include "CstrikePlayer.h"
 #include "CstrikeUtils.h"
+#include "CstrikeHLTypeConversion.h"
 
 CCstrikePlayer g_players[33];
 int g_zooming[33] = {0};
@@ -1708,6 +1709,7 @@ static cell AMX_NATIVE_CALL cs_set_c4_defusing(AMX* amx, cell* params)
 }
 
 extern CreateNamedEntityFunc CS_CreateNamedEntity;
+extern UTIL_FindEntityByStringFunc CS_UTIL_FindEntityByString;
 
 // cs_create_entity(const classname[])
 static cell AMX_NATIVE_CALL cs_create_entity(AMX* amx, cell* params)
@@ -1728,6 +1730,26 @@ static cell AMX_NATIVE_CALL cs_create_entity(AMX* amx, cell* params)
 	return 0;
 }
 
+// cs_find_ent_by_class(start_index, const classname[])
+static cell AMX_NATIVE_CALL cs_find_ent_by_class(AMX* amx, cell* params)
+{
+	if (CS_UTIL_FindEntityByString > 0)
+	{
+		int len;
+		void* pEntity = G_HL_TypeConversion.id_to_cbase(params[1]);
+		const char* value = MF_GetAmxString(amx, params[2], 0, &len);
+
+		int index = G_HL_TypeConversion.cbase_to_id(CS_UTIL_FindEntityByString(pEntity, "classname", value));
+
+		if (index != -1)
+		{
+			return index;
+		}
+	}
+
+	return 0;
+}
+
 
 #else
 
@@ -1814,6 +1836,7 @@ AMX_NATIVE_INFO CstrikeNatives[] = {
 	{"cs_get_c4_defusing",			cs_get_c4_defusing},
 	{"cs_set_c4_defusing",			cs_set_c4_defusing},
 	{"cs_create_entity",			cs_create_entity },	
+	{"cs_find_ent_by_class",		cs_find_ent_by_class },	
 
 	{NULL,							NULL}
 };

dlls/cstrike/cstrike/Makefile

@@ -15,7 +15,7 @@ PUBLIC_ROOT = ../../../public
 
 PROJECT = cstrike
 
-OBJECTS = amxxmodule.cpp amxx_api.cpp CstrikePlayer.cpp CstrikeNatives.cpp CstrikeHacks.cpp CstrikeUtils.cpp \
+OBJECTS = amxxmodule.cpp amxx_api.cpp CstrikePlayer.cpp CstrikeNatives.cpp CstrikeHacks.cpp CstrikeUtils.cpp CstrikeHLTypeConversion.cpp \
 			MemoryUtils.cpp detours.cpp asm.c
 
 ##############################################

dlls/cstrike/cstrike/amxx_api.cpp

@@ -14,6 +14,7 @@
 #include "amxxmodule.h"
 #include "CstrikeUtils.h"
 #include "CstrikeDatas.h"
+#include "CstrikeHLTypeConversion.h"
 
 extern AMX_NATIVE_INFO CstrikeNatives[];
 
@@ -26,7 +27,8 @@ void ShutdownHacks();
 void ToggleDetour_ClientCommands(bool enable);
 void ToggleDetour_BuyCommands(bool enable);
 
-CreateNamedEntityFunc CS_CreateNamedEntity = NULL;
+CreateNamedEntityFunc CS_CreateNamedEntity = nullptr;
+UTIL_FindEntityByStringFunc CS_UTIL_FindEntityByString = nullptr;
 
 int AmxxCheckGame(const char *game)
 {
@@ -44,8 +46,14 @@ void OnAmxxAttach()
 
 	InitializeHacks();
 
-	// cs_create_entity().
+	// cs_create_entity()
 	CS_CreateNamedEntity = reinterpret_cast<CreateNamedEntityFunc>(UTIL_FindAddressFromEntry(CS_IDENT_CREATENAMEDENTITY, CS_IDENT_HIDDEN_STATE));
+	
+	// cs_find_ent_by_class()
+	CS_UTIL_FindEntityByString = reinterpret_cast<UTIL_FindEntityByStringFunc>(UTIL_FindAddressFromEntry(CS_IDENT_UTIL_FINDENTITYBYSTRING, CS_IDENT_HIDDEN_STATE));
+
+	// Search pev offset automatically.
+	G_OffsetHandler = new OffsetHandler;
 }
 
 void OnPluginsLoaded()

plugins/include/cstrike.inc

@@ -351,14 +351,20 @@ native bool:cs_get_c4_defusing(c4index);
 native cs_set_c4_defusing(c4index, bool:defusing);
 
 /**
- * Creates an entity.
+ * Creates an entity using Counter-Strike's custom CreateNamedEntity wrapper.
  *
- * @note  Similar as create_entity() native from engine module, with the difference that in Counter-Strike
+ * @note Unlike other mods CS keeps track of entities using a custom hashtable.
- *        to improve lookup performance on entities, the classname is hashed and saved in a global list.
+ *       This function will add entities to this hashtable, providing benefits
- *        This means for classname, game uses a custom function which checks that list instead of calling pfnFindEntityByString.
+ *       over the default engine functions (used by create_entity() for example):
- *        You would want to use this native if you want having custom entities to be known by the game.
+ *       - Storing entities in a hashtable allows CS to improve classname lookup
- *        E.g. By creating a "weaponbox" entity, this will be automatically deleted by game on map restart.
+ *         performance compared to functions like FindEntityByString that usually
- *             With engine version, you would have to remove it manually.
+ *         have to loop incrementally through all entities.
+ *       - As CS exclusively uses the hashtable for classname lookup, entities
+ *         created using the default engine functions will not be found by the
+ *         game. For example "weaponbox" entities are supposed to be
+ *         automatically cleaned up on round restart but are not considered if
+ *         they have not been added to the hashtable.
+ * @note CS's faster hashtable lookup can be utilized with cs_find_ent_by_class()
  *
  * @param classname     Entity class name
  *
@@ -366,6 +372,25 @@ native cs_set_c4_defusing(c4index, bool:defusing);
  */
 native cs_create_entity(const classname[]);
 
+/** 
+ * Finds an entity in the world using Counter-Strike's custom FindEntityByString
+ * wrapper.
+ *
+ * @note Unlike other mods CS keeps track of entities using a custom hashtable.
+ *       This function utilizes the custom hasthable and allows for considerably
+ *       faster classname lookup compared to the default engine functions (used
+ *       by find_ent_by_class() for example).
+ * @note This exclusively considers entities in the hashtable, created by the
+ *       game itself or using cs_create_entity().
+ *
+ * @param start_index   Entity index to start searching from. -1 to start from
+ *                      the first entity
+ * @param classname     Classname to search for
+ *
+ * @return              Entity index > 0 if found, 0 otherwise
+ */
+native cs_find_ent_by_class(start_index, const classname[]);
+
 /**
  * Called when CS internally fires a command to a player.  It does this for a few 
  * functions, most notably rebuy/autobuy functionality.  This is also used to pass