API: Knockback (#348)

Author: GLoOoccK

reapi/extra/amxmodx/scripting/include/reapi_gamedll.inc

@@ -1233,3 +1233,15 @@ native rg_player_relationship(const player, const target);
 * @noreturn
 */
 native rg_send_death_message(const pKiller, const pVictim, const pAssister, const pevInflictor, const killerWeaponName[], const DeathMessageFlags:iDeathMessageFlags, const KillRarity:iRarityOfKill);
+
+/*
+* Adds impulse to the player.
+*
+* @param player                 Player index.
+* @param attacker               Attacker index.
+* @param flKnockbackForce       Knockback force.
+* @param flVelModifier          Velocity modifier.
+*
+* @noreturn
+*/
+native rg_player_takedamage_impulse(const player, const attacker, const Float:flKnockbackForce, const Float:flVelModifier);

reapi/extra/amxmodx/scripting/include/reapi_gamedll_const.inc

@@ -946,6 +946,12 @@ enum GamedllFunc_CBasePlayer
 	* Params:           (const this)
 	*/
 	RG_CBasePlayer_UpdateStatusBar,
+
+	/*
+	* Description:      Called for the victim player after taking damage, when "knockback" and "pain shock" are applied.
+	* Params:           (const this, attacker, Float:flKnockbackForce, Float:flVelModifier)
+	*/
+	RG_CBasePlayer_TakeDamageImpulse,
 };
 
 /**

reapi/include/cssdk/dlls/API/CSPlayer.h

@@ -119,6 +119,7 @@ class CCSPlayer: public CCSMonster
 	virtual void OnSpawnEquip(bool addDefault = true, bool equipGame = true) = 0;
 	virtual void SetScoreboardAttributes(CBasePlayer *destination = nullptr) = 0;
 	virtual void Observer_FindNextPlayer(bool bReverse, const char *name = nullptr) = 0;
+	virtual void TakeDamageImpulse(CBasePlayer *pAttacker, float flKnockbackForce, float flVelModifier) = 0;
 
 	CBasePlayer *BasePlayer() const;
 

reapi/include/cssdk/dlls/regamedll_api.h

@@ -40,7 +40,7 @@
 #include <API/CSInterfaces.h>
 
 #define REGAMEDLL_API_VERSION_MAJOR 5
-#define REGAMEDLL_API_VERSION_MINOR 29
+#define REGAMEDLL_API_VERSION_MINOR 30
 
 // CBasePlayer::Spawn hook
 typedef IHookChainClass<void, class CBasePlayer> IReGameHook_CBasePlayer_Spawn;
@@ -634,6 +634,10 @@ typedef IHookChainRegistryClass<void, class CBasePlayer, BOOL> IReGameHookRegist
 typedef IHookChainClass<void, class CBasePlayer> IReGameHook_CBasePlayer_UpdateStatusBar;
 typedef IHookChainRegistryClass<void, class CBasePlayer> IReGameHookRegistry_CBasePlayer_UpdateStatusBar;
 
+// CBasePlayer::TakeDamageImpulse hook
+typedef IHookChainClass<void, class CBasePlayer, class CBasePlayer *, float, float> IReGameHook_CBasePlayer_TakeDamageImpulse;
+typedef IHookChainRegistryClass<void, class CBasePlayer, class CBasePlayer *, float, float> IReGameHookRegistry_CBasePlayer_TakeDamageImpulse;
+
 class IReGameHookchains {
 public:
 	virtual ~IReGameHookchains() {}
@@ -797,6 +801,7 @@ class IReGameHookchains {
 	virtual IReGameHookRegistry_CBasePlayer_Observer_Think *CBasePlayer_Observer_Think() = 0;
 	virtual IReGameHookRegistry_CBasePlayer_RemoveAllItems *CBasePlayer_RemoveAllItems() = 0;
 	virtual IReGameHookRegistry_CBasePlayer_UpdateStatusBar *CBasePlayer_UpdateStatusBar() = 0;
+	virtual IReGameHookRegistry_CBasePlayer_TakeDamageImpulse *CBasePlayer_TakeDamageImpulse() = 0;
 };
 
 struct ReGameFuncs_t {

reapi/src/hook_callback.cpp

@@ -1776,6 +1776,16 @@ void CBasePlayer_UpdateStatusBar(IReGameHook_CBasePlayer_UpdateStatusBar *chain,
 	callVoidForward(RG_CBasePlayer_UpdateStatusBar, original, indexOfEdict(pthis->pev));
 }
 
+void CBasePlayer_TakeDamageImpulse(IReGameHook_CBasePlayer_TakeDamageImpulse *chain, CBasePlayer *pthis, CBasePlayer *pAttacker, float flKnockbackForce, float flVelModifier)
+{
+	auto original = [chain](int _pthis, int _pAttacker, float _flKnockbackForce, float _flVelModifier)
+	{
+		chain->callNext(getPrivate<CBasePlayer>(_pthis), getPrivate<CBasePlayer>(_pAttacker), _flKnockbackForce, _flVelModifier);
+	};
+
+	callVoidForward(RG_CBasePlayer_TakeDamageImpulse, original, indexOfEdict(pthis->pev), indexOfEdict(pAttacker->pev), flKnockbackForce, flVelModifier);
+}
+
 /*
 * VTC functions
 */

reapi/src/hook_callback.h

@@ -575,6 +575,7 @@ void CBasePlayer_Observer_Think(IReGameHook_CBasePlayer_Observer_Think *chain, C
 void CBasePlayer_RemoveAllItems(IReGameHook_CBasePlayer_RemoveAllItems *chain, CBasePlayer *pthis, BOOL removeSuit);
 void CSGameRules_SendDeathMessage(IReGameHook_CSGameRules_SendDeathMessage *chain, CBaseEntity *pKiller, CBasePlayer *pVictim, CBasePlayer *pAssister, entvars_t *pevInflictor, const char *killerWeaponName, int iDeathMessageFlags, int iRarityOfKill);
 void CBasePlayer_UpdateStatusBar(IReGameHook_CBasePlayer_UpdateStatusBar *chain, CBasePlayer *pthis);
+void CBasePlayer_TakeDamageImpulse(IReGameHook_CBasePlayer_TakeDamageImpulse *chain, CBasePlayer *pthis, CBasePlayer *pAttacker, float flKnockbackForce, float flVelModifier);
 
 /*
 * VTC functions

reapi/src/hook_list.cpp

@@ -217,6 +217,7 @@ hook_t hooklist_player[] = {
 	DLL(CBasePlayer_Observer_Think),
 	DLL(CBasePlayer_RemoveAllItems),
 	DLL(CBasePlayer_UpdateStatusBar),
+	DLL(CBasePlayer_TakeDamageImpulse),
 };
 
 hook_t hooklist_gamerules[] = {

reapi/src/hook_list.h

@@ -241,6 +241,7 @@ enum GamedllFunc_CBasePlayer
 	RG_CBasePlayer_Observer_Think,
 	RG_CBasePlayer_RemoveAllItems,
 	RG_CBasePlayer_UpdateStatusBar,
+	RG_CBasePlayer_TakeDamageImpulse,
 
 	// [...]
 };

reapi/src/natives/natives_misc.cpp

@@ -3375,6 +3375,47 @@ cell AMX_NATIVE_CALL rg_send_death_message(AMX *amx, cell *params)
 	return TRUE;
 }
 
+/*
+* Adds impulse to the player.
+*
+* @param player                 Player index.
+* @param attacker               Attacker index.
+* @param flKnockbackForce       Knockback force.
+* @param flVelModifier          Velocity modifier.
+*
+* @noreturn
+*/
+cell AMX_NATIVE_CALL rg_player_takedamage_impulse(AMX *amx, cell *params)
+{
+	enum args_e { arg_count, arg_index, arg_attacker, arg_knockback_force, arg_vel_modifier };
+
+	CHECK_ISPLAYER(arg_index);
+	CHECK_ISPLAYER(arg_attacker);
+
+	CBasePlayer *pPlayer = UTIL_PlayerByIndex(params[arg_index]);
+	CHECK_CONNECTED(pPlayer, arg_index);
+
+	if (!pPlayer->IsAlive())
+	{
+		AMXX_LogError(amx, AMX_ERR_NATIVE, "%s: player %d not alive", __FUNCTION__, params[arg_index]);
+		return FALSE;
+	}
+
+	CBasePlayer *pAttacker = UTIL_PlayerByIndex(params[arg_attacker]);
+	CHECK_CONNECTED(pAttacker, arg_attacker);
+
+	if (!pAttacker->IsAlive())
+	{
+		AMXX_LogError(amx, AMX_ERR_NATIVE, "%s: attacker %d not alive", __FUNCTION__, params[arg_attacker]);
+		return FALSE;
+	}
+
+	CAmxArgs args(amx, params);
+	pPlayer->CSPlayer()->TakeDamageImpulse(pAttacker, args[arg_knockback_force], args[arg_vel_modifier]);
+
+	return TRUE;
+}
+
 AMX_NATIVE_INFO Misc_Natives_RG[] =
 {
 	{ "rg_set_animation",             rg_set_animation             },
@@ -3490,6 +3531,7 @@ AMX_NATIVE_INFO Misc_Natives_RG[] =
 	{ "rg_player_relationship",       rg_player_relationship       },
 
 	{ "rg_send_death_message",        rg_send_death_message        },
+	{ "rg_player_takedamage_impulse", rg_player_takedamage_impulse },
 
 	{ nullptr, nullptr }
 };

reapi/version/version.h

@@ -6,5 +6,5 @@
 #pragma once
 
 #define VERSION_MAJOR		5
-#define VERSION_MINOR		28
+#define VERSION_MINOR		29
 #define VERSION_MAINTENANCE	0