From 75853dae60dc6812f1b94edf32adeabf7fcafba1 Mon Sep 17 00:00:00 2001
From: Arkshine <hv.contact@gmail.com>
Date: Sun, 26 Jul 2015 19:55:10 +0200
Subject: [PATCH] Cstrike: Add cs_find_ent_by_owner() native

---
 modules/cstrike/cstrike/CstrikeNatives.cpp | 37 ++++++++++++++++++++++
 modules/cstrike/cstrike/CstrikeUtils.h     | 11 +++++++
 plugins/include/cstrike.inc                | 20 ++++++++++++
 3 files changed, 68 insertions(+)

diff --git a/modules/cstrike/cstrike/CstrikeNatives.cpp b/modules/cstrike/cstrike/CstrikeNatives.cpp
index 06ae45a8..1c62e6fe 100644
--- a/modules/cstrike/cstrike/CstrikeNatives.cpp
+++ b/modules/cstrike/cstrike/CstrikeNatives.cpp
@@ -1740,6 +1740,42 @@ static cell AMX_NATIVE_CALL cs_find_ent_by_class(AMX* amx, cell* params)
 	return 0;
 }
 
+// cs_find_ent_by_owner(start_index, const classname[], owner)
+static cell AMX_NATIVE_CALL cs_find_ent_by_owner(AMX* amx, cell* params)
+{
+	if (CS_UTIL_FindEntityByString <= 0)
+	{
+		MF_LogError(amx, AMX_ERR_NATIVE, "Native cs_find_ent_by_owner() is disabled");
+		return 0;
+	}
+
+	int owner = params[3];
+	CHECK_ENTITY_SIMPLE(params[3]);
+
+	int length;
+	void* pEntity = G_HL_TypeConversion.id_to_cbase(params[1]);
+	const char* value = MF_GetAmxString(amx, params[2], 0, &length);
+	
+	edict_t *pOwner = GETEDICT(owner);
+
+	while ((pEntity = CS_UTIL_FindEntityByString(pEntity, "classname", value)))
+	{
+		edict_t *pev = G_HL_TypeConversion.cbase_to_edict(pEntity);
+
+		if (!FNullEnt(pev) && pev->v.owner == pOwner)
+		{
+			int index = ENTINDEX(pev);
+
+			if (index != -1)
+			{
+				return index;
+			};
+		}
+	}
+
+	return 0;
+}
+
 // native any:cs_get_item_id(const name[], &CsWeaponClassType:classid = CS_WEAPONCLASS_NONE);
 static cell AMX_NATIVE_CALL cs_get_item_id(AMX* amx, cell* params)
 {
@@ -1926,6 +1962,7 @@ AMX_NATIVE_INFO CstrikeNatives[] =
 	{"cs_set_c4_defusing",			cs_set_c4_defusing},
 	{"cs_create_entity",			cs_create_entity },	
 	{"cs_find_ent_by_class",		cs_find_ent_by_class},
+	{"cs_find_ent_by_owner",        cs_find_ent_by_owner},
 	{"cs_get_item_id",		        cs_get_item_id},
 	{"cs_get_translated_item_alias",cs_get_translated_item_alias},
 	{"cs_get_weapon_info",          cs_get_weapon_info},
diff --git a/modules/cstrike/cstrike/CstrikeUtils.h b/modules/cstrike/cstrike/CstrikeUtils.h
index ac94a113..f1a59c53 100644
--- a/modules/cstrike/cstrike/CstrikeUtils.h
+++ b/modules/cstrike/cstrike/CstrikeUtils.h
@@ -27,6 +27,17 @@ bool UTIL_CheckForPublic(const char *publicname);
 #define GETCLIENTKEYVALUE	(*g_engfuncs.pfnInfoKeyValue)
 #define CREATENAMEDENTITY	(*g_engfuncs.pfnCreateNamedEntity)
 
+#define CHECK_ENTITY_SIMPLE(x) \
+	if (x < 0 || x > gpGlobals->maxEntities) { \
+		MF_LogError(amx, AMX_ERR_NATIVE, "Entity out of range (%d)", x); \
+		return 0; \
+	} else { \
+		if (x != 0 && FNullEnt(INDEXENT(x))) { \
+			MF_LogError(amx, AMX_ERR_NATIVE, "Invalid entity %d", x); \
+			return 0; \
+		} \
+	}
+
 #define CHECK_ENTITY(x) \
 	if (x < 0 || x > gpGlobals->maxEntities) { \
 		MF_LogError(amx, AMX_ERR_NATIVE, "Entity out of range (%d)", x); \
diff --git a/plugins/include/cstrike.inc b/plugins/include/cstrike.inc
index b97d9400..d45fb904 100755
--- a/plugins/include/cstrike.inc
+++ b/plugins/include/cstrike.inc
@@ -1025,6 +1025,26 @@ native cs_create_entity(const classname[]);
  */
 native cs_find_ent_by_class(start_index, const classname[]);
 
+/**
+ * Finds an entity in the world using Counter-Strike's custom FindEntityByString
+ * wrapper, matching by owner.
+ *
+ * @note Unlike other mods CS keeps track of entities using a custom hashtable.
+ *       This function utilizes the hasthable and allows for considerably faster
+ *       classname lookup compared to the default FindEntityByString (used by
+ *       find_ent_by_owner() 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
+ * @param owner         Entity index to search for entity's owner
+ *
+ * @return              Entity index > 0 if found, 0 otherwise
+ */
+native cs_find_ent_by_owner(start_index, const classname[], owner);
+
 /**
  * Returns the item id associated with an item name and its aliases.
  *