API: Knockback (#1069)

README.md

@@ -132,6 +132,7 @@ This means that plugins that do binary code analysis (Orpheu for example) probab
 | mp_randomspawn                     | 0       | 0   | 1            | Random player spawns<br/>`0` disabled <br/>`1` enabled<br/>`NOTE`: Navigation `maps/.nav` file required |
 | mp_playerid_showhealth             | 1       | 0   | 2            | Player ID display mode.<br/>`0` don't show health<br/>`1` show health for teammates only (default CS behaviour)<br/>`2` show health for all players |
 | mp_playerid_field                  | 3       | 0   | 3            | Player ID field display mode.<br/>`0` don't show additional information<br/>`1` show team name<br/>`2` show health percentage<br/>`3` show both team name and health percentage |
+| mp_knockback                       | 170     | -   | -            | Knockback force applied to the victim when damaged by strong weapons (e.g. `AWP`, `AK47`).<br/>Works only if not crouching, and not hit in the legs.<br/>Set to `0` to disable. |
 
 </details>
 

dist/game.cfg

@@ -680,3 +680,10 @@ mp_playerid_showhealth "1"
 //
 // Default value: "3"
 mp_playerid_field "3"
+
+// Knockback force applied to the victim when damaged by strong weapons (e.g. AWP, AK47).
+// Works only if not crouching, and not hit in the legs.
+// Set to "0" to disable.
+//
+// Default: "170"
+mp_knockback "170"

regamedll/dlls/API/CAPI_Impl.cpp

@@ -337,6 +337,7 @@ GAMEHOOK_REGISTRY(CBasePlayer_PlayerDeathThink);
 GAMEHOOK_REGISTRY(CBasePlayer_Observer_Think);
 GAMEHOOK_REGISTRY(CBasePlayer_RemoveAllItems);
 GAMEHOOK_REGISTRY(CBasePlayer_UpdateStatusBar);
+GAMEHOOK_REGISTRY(CBasePlayer_TakeDamageImpulse);
 
 int CReGameApi::GetMajorVersion() {
 	return REGAMEDLL_API_VERSION_MAJOR;

regamedll/dlls/API/CAPI_Impl.h

@@ -753,6 +753,10 @@ typedef IHookChainRegistryClassImpl<void, CBasePlayer, BOOL> CReGameHookRegistry
 typedef IHookChainClassImpl<void, CBasePlayer> CReGameHook_CBasePlayer_UpdateStatusBar;
 typedef IHookChainRegistryClassImpl<void, CBasePlayer> CReGameHookRegistry_CBasePlayer_UpdateStatusBar;
 
+// CBasePlayer::TakeDamageImpulse hook
+typedef IHookChainClassImpl<void, CBasePlayer, CBasePlayer *, float, float> CReGameHook_CBasePlayer_TakeDamageImpulse;
+typedef IHookChainRegistryClassImpl<void, CBasePlayer, CBasePlayer *, float, float> CReGameHookRegistry_CBasePlayer_TakeDamageImpulse;
+
 class CReGameHookchains: public IReGameHookchains {
 public:
 	// CBasePlayer virtual
@@ -915,6 +919,7 @@ public:
 	CReGameHookRegistry_CBasePlayer_Observer_Think m_CBasePlayer_Observer_Think;
 	CReGameHookRegistry_CBasePlayer_RemoveAllItems m_CBasePlayer_RemoveAllItems;
 	CReGameHookRegistry_CBasePlayer_UpdateStatusBar m_CBasePlayer_UpdateStatusBar;
+	CReGameHookRegistry_CBasePlayer_TakeDamageImpulse m_CBasePlayer_TakeDamageImpulse;
 
 public:
 	virtual IReGameHookRegistry_CBasePlayer_Spawn *CBasePlayer_Spawn();
@@ -1076,6 +1081,7 @@ public:
 	virtual IReGameHookRegistry_CBasePlayer_Observer_Think *CBasePlayer_Observer_Think();
 	virtual IReGameHookRegistry_CBasePlayer_RemoveAllItems *CBasePlayer_RemoveAllItems();
 	virtual IReGameHookRegistry_CBasePlayer_UpdateStatusBar *CBasePlayer_UpdateStatusBar();
+	virtual IReGameHookRegistry_CBasePlayer_TakeDamageImpulse *CBasePlayer_TakeDamageImpulse();
 };
 
 extern CReGameHookchains g_ReGameHookchains;

regamedll/dlls/API/CSPlayer.cpp

@@ -539,6 +539,11 @@ EXT_FUNC bool CCSPlayer::CheckActivityInGame()
 	return (fabs(deltaYaw) >= 0.1f && fabs(deltaPitch) >= 0.1f);
 }
 
+EXT_FUNC void CCSPlayer::TakeDamageImpulse(CBasePlayer *pAttacker, float flKnockbackForce, float flVelModifier)
+{
+	BasePlayer()->TakeDamageImpulse(pAttacker, flKnockbackForce, flVelModifier);
+}
+
 void CCSPlayer::ResetVars()
 {
 	m_szModel[0] = '\0';

regamedll/dlls/game.cpp

@@ -199,6 +199,8 @@ cvar_t randomspawn             = { "mp_randomspawn", "0", FCVAR_SERVER, 0.0f, nu
 cvar_t playerid_showhealth     = { "mp_playerid_showhealth", "1", 0, 1.0f, nullptr };
 cvar_t playerid_field          = { "mp_playerid_field", "3", 0, 3.0f, nullptr };
 
+cvar_t knockback               = { "mp_knockback", "170", 0, 170.0f, nullptr };
+
 void GameDLL_Version_f()
 {
 	if (Q_stricmp(CMD_ARGV(1), "version") != 0)
@@ -485,6 +487,8 @@ void EXT_FUNC GameDLLInit()
 
 	CVAR_REGISTER(&flymove_method);
 
+	CVAR_REGISTER(&knockback);
+
 	// print version
 	CONSOLE_ECHO("ReGameDLL version: " APP_VERSION "\n");
 

regamedll/dlls/game.h

@@ -216,6 +216,7 @@ extern cvar_t logkills;
 extern cvar_t randomspawn;
 extern cvar_t playerid_showhealth;
 extern cvar_t playerid_field;
+extern cvar_t knockback;
 
 #endif
 

regamedll/dlls/player.cpp

@@ -1233,7 +1233,7 @@ BOOL EXT_FUNC CBasePlayer::__API_HOOK(TakeDamage)(entvars_t *pevInflictor, entva
 
 		if (!ShouldDoLargeFlinch(m_LastHitGroup, iGunType))
 		{
-			m_flVelocityModifier = 0.5f;
+			TakeDamageImpulse(pAttack, 0.0f, 0.5f);
 
 			if (m_LastHitGroup == HITGROUP_HEAD)
 				m_bHighDamage = (flDamage > 60);
@@ -1246,10 +1246,13 @@ BOOL EXT_FUNC CBasePlayer::__API_HOOK(TakeDamage)(entvars_t *pevInflictor, entva
 		{
 			if (pev->velocity.Length() < 300)
 			{
-				Vector attack_velocity = (pev->origin - pAttack->pev->origin).Normalize() * 170;
+#ifdef REGAMEDLL_ADD
-				pev->velocity = pev->velocity + attack_velocity;
+				float knockbackValue = knockback.value;
+#else
+				float knockbackValue = 170;
+#endif
 
-				m_flVelocityModifier = 0.65f;
+				TakeDamageImpulse(pAttack, knockbackValue, 0.65f);
 			}
 
 			SetAnimation(PLAYER_LARGE_FLINCH);
@@ -10867,6 +10870,17 @@ bool CBasePlayer::Kill()
 	return true;
 }
 
+LINK_HOOK_CLASS_VOID_CHAIN(CBasePlayer, TakeDamageImpulse, (CBasePlayer *pAttacker, float flKnockbackForce, float flVelModifier), pAttacker, flKnockbackForce, flVelModifier)
+
+void EXT_FUNC CBasePlayer::__API_HOOK(TakeDamageImpulse)(CBasePlayer *pAttacker, float flKnockbackForce, float flVelModifier)
+{
+	if (flKnockbackForce != 0.0f)
+		pev->velocity += (pev->origin - pAttacker->pev->origin).Normalize() * flKnockbackForce;
+
+	if (flVelModifier != 0.0f)
+		m_flVelocityModifier = flVelModifier;
+}
+
 const usercmd_t *CBasePlayer::GetLastUserCommand() const
 {
 #ifdef REGAMEDLL_API

regamedll/dlls/player.h

@@ -451,6 +451,7 @@ public:
 	void Observer_Think_OrigFunc();
 	void RemoveAllItems_OrigFunc(BOOL removeSuit);
 	void UpdateStatusBar_OrigFunc();
+	void TakeDamageImpulse_OrigFunc(CBasePlayer *pAttacker, float flKnockbackForce, float flVelModifier);
 
 	CCSPlayer *CSPlayer() const;
 #endif // REGAMEDLL_API
@@ -659,6 +660,7 @@ public:
 	void UseEmpty();
 	void DropIdlePlayer(const char *reason);
 	bool Kill();
+	void TakeDamageImpulse(CBasePlayer *pAttacker, float flKnockbackForce, float flVelModifier);
 
 	// templates
 	template<typename T = CBasePlayerItem, typename Functor>

regamedll/public/regamedll/API/CSPlayer.h

@@ -118,6 +118,7 @@ public:
 	virtual void OnSpawnEquip(bool addDefault = true, bool equipGame = true);
 	virtual void SetScoreboardAttributes(CBasePlayer *destination = nullptr);
 	virtual void Observer_FindNextPlayer(bool bReverse, const char *name = nullptr);
+	virtual void TakeDamageImpulse(CBasePlayer *pAttacker, float flKnockbackForce, float flVelModifier);
 
 	bool IsPlayerDominated(int iPlayerIndex) const;
 	void SetPlayerDominated(CBasePlayer *pPlayer, bool bDominated);

regamedll/public/regamedll/regamedll_api.h

@@ -38,7 +38,7 @@
 #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;
@@ -632,6 +632,10 @@ 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() {}
@@ -795,6 +799,7 @@ public:
 	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 {

regamedll/version/version.h

@@ -6,5 +6,5 @@
 #pragma once
 
 #define VERSION_MAJOR		5
-#define VERSION_MINOR		29
+#define VERSION_MINOR		30
 #define VERSION_MAINTENANCE	0