This is a start to lag compensate the local player.

Normally,
this would be needed to be inside StartLagCompensation,
but for now, this is enough.

engine/host.cpp

@@ -2655,9 +2655,18 @@ void _Host_RunFrame_Input( float accumulated_extra_samples, bool bFinalTick )
 
 	g_HostTimes.EndFrameSegment( FRAME_SEGMENT_CMD_EXECUTE );
 
+	// TODO_ENHANCED: HACKHACK:
+	// the player is one frame in late because interpolation amount is calculated after CreateMove
+	// Just in case, we set it there too to interpolate with correct data!
+
+	float old_interpolation_amount = g_ClientGlobalVariables.interpolation_amount;
+	g_ClientGlobalVariables.interpolation_amount = cl.m_tickRemainder / host_state.interval_per_tick;
+
 	// Send any current movement commands to server and flush reliable buffer even if not moving yet.
 	CL_Move( accumulated_extra_samples, bFinalTick );
 
+	g_ClientGlobalVariables.interpolation_amount = old_interpolation_amount;
+
 #endif
 
 	g_HostTimes.EndFrameSegment( FRAME_SEGMENT_INPUT );

game/client/c_baseplayer.h

@@ -649,6 +649,7 @@ public:
 	float					m_fLastUpdateServerTime;
 	int						m_nLastUpdateTickBase;
 	int						m_nLastUpdateServerTickCount;
+	Vector 					m_vecPreviousShootPosition;
 };
 
 EXTERN_RECV_TABLE(DT_BasePlayer);

game/client/in_main.cpp

@@ -15,6 +15,8 @@
 #include <cstdio>
 #include "bone_setup.h"
 #include "convar.h"
+#include "imovehelper.h"
+#include "ipredictionsystem.h"
 #include "studio.h"
 #include "util_shared.h"
 #include "c_baseplayer.h"
@@ -1330,16 +1332,7 @@ void CInput::CreateMove ( int sequence_number, float input_sample_frametime, boo
     }
 #endif
 
-    C_BasePlayer* pPlayer = C_BasePlayer::GetLocalPlayer();
+    cmd->interpolated_amount = gpGlobals->interpolation_amount;
-
-    if (pPlayer)
-    {
-        cmd->interpolated_shoot_position = pPlayer->Weapon_ShootPosition();
-	}
-    else
-    {
-        cmd->interpolated_shoot_position.Init();
-    }
 
 	pVerified->m_cmd = *cmd;
 	pVerified->m_crc = cmd->GetChecksum();

game/client/prediction.cpp

@@ -769,6 +769,8 @@ void CPrediction::StartCommand( C_BasePlayer *player, CUserCmd *cmd )
 #if !defined( NO_ENTITY_PREDICTION )
 	VPROF( "CPrediction::StartCommand" );
 
+	player->m_vecPreviousShootPosition = player->Weapon_ShootPosition();
+
 	CPredictableId::ResetInstanceCounters();
 
 	player->m_pCurrentCommand = cmd;
@@ -919,12 +921,6 @@ void CPrediction::RunCommand( C_BasePlayer *player, CUserCmd *ucmd, IMoveHelper
 		player->SetLocalViewAngles( ucmd->viewangles );
     }
 
-    moveHelper->ProcessImpacts();
-
-	RunPostThink( player );
-
-    ServiceEventQueue( player );
-
 // TODO
 // TODO:  Check for impulse predicted?
 
@@ -994,6 +990,12 @@ void CPrediction::RunCommand( C_BasePlayer *player, CUserCmd *ucmd, IMoveHelper
 
 	FinishMove( player, ucmd, g_pMoveData );
 
+    moveHelper->ProcessImpacts();
+
+	RunPostThink( player );
+
+    ServiceEventQueue( player );
+
 	g_pGameMovement->FinishTrackPredictionErrors( player );
 
 	FinishCommand( player );

game/server/player.h

@@ -1211,6 +1211,7 @@ private:
 
 public:
 	virtual unsigned int PlayerSolidMask( bool brushOnly = false ) const;	// returns the solid mask for the given player, so bots can have a more-restrictive set
+	Vector m_vecPreviousShootPosition;
 };
 
 typedef CHandle<CBasePlayer> CBasePlayerHandle;

game/server/player_command.cpp

@@ -48,6 +48,8 @@ void CPlayerMove::StartCommand( CBasePlayer *player, CUserCmd *cmd )
 {
 	VPROF( "CPlayerMove::StartCommand" );
 
+	player->m_vecPreviousShootPosition = player->Weapon_ShootPosition();
+
 #if !defined( NO_ENTITY_PREDICTION )
 	CPredictableId::ResetInstanceCounters();
 #endif
@@ -353,15 +355,6 @@ void CPlayerMove::RunCommand ( CBasePlayer *player, CUserCmd *ucmd, IMoveHelper
 		ucmd->viewangles = vec3_angle;
 	}
 
-    // Let server invoke any needed impact functions
-	VPROF_SCOPE_BEGIN( "moveHelper->ProcessImpacts" );
-	moveHelper->ProcessImpacts();
-    VPROF_SCOPE_END();
-
-    RunPostThink( player );
-
-    ServiceEventQueue( player );
-
 	// Add and subtract buttons we're forcing on the player
 	ucmd->buttons |= player->m_afButtonForced;
 	ucmd->buttons &= ~player->m_afButtonDisabled;
@@ -457,6 +450,15 @@ void CPlayerMove::RunCommand ( CBasePlayer *player, CUserCmd *ucmd, IMoveHelper
 	// Copy output
 	FinishMove( player, ucmd, g_pMoveData );
 
+    // Let server invoke any needed impact functions
+	VPROF_SCOPE_BEGIN( "moveHelper->ProcessImpacts" );
+	moveHelper->ProcessImpacts();
+    VPROF_SCOPE_END();
+
+    RunPostThink( player );
+
+    ServiceEventQueue( player );
+
 	g_pGameMovement->FinishTrackPredictionErrors( player );
 
 	FinishCommand( player );

game/shared/cstrike/fx_cs_shared.cpp

@@ -7,6 +7,8 @@
 #include "cbase.h"
 #include "fx_cs_shared.h"
 #include "convar.h"
+#include "mathlib/vector.h"
+#include "usercmd.h"
 #include "weapon_csbase.h"
 
 #ifndef CLIENT_DLL
@@ -135,19 +137,26 @@ void FX_FireBullets(
 	CCSPlayer *pPlayer = ToCSPlayer( UTIL_PlayerByIndex( iPlayerIndex) );
 #endif
 
-    // TODO_ENHANCED:
+	// DevMsg("original shoot pos: %f %f %f\n", vHookedOrigin.x, vHookedOrigin.y, vHookedOrigin.z );
-    // Check if interpolated_shoot_position is within interpolation bounds! (between old shoot pos and new)
+
-    // This is to check for cheaters abusing the shooting position.
+	CUserCmd* playerCmd = NULL;
 
     if (pPlayer)
     {
 #ifdef CLIENT_DLL
-    if (pPlayer->m_pCurrentCommand) { vHookedOrigin = pPlayer->m_pCurrentCommand->interpolated_shoot_position; }
+		playerCmd = pPlayer->m_pCurrentCommand;
 #else
-    if (pPlayer->GetCurrentCommand()) { vHookedOrigin = pPlayer->GetCurrentCommand()->interpolated_shoot_position; }
+		playerCmd = pPlayer->GetCurrentCommand();
 #endif
 	}
-    
+
+	if (playerCmd)
+	{
+		vHookedOrigin = VectorLerp(pPlayer->m_vecPreviousShootPosition, vOrigin, playerCmd->interpolated_amount);
+	}
+
+	// DevMsg("new shoot pos: %f %f %f, has command: %s\n", vHookedOrigin.x, vHookedOrigin.y, vHookedOrigin.z, playerCmd ? "true" : "false" );
+
 	const char * weaponAlias =	WeaponIDToAlias( iWeaponID );
 
 	if ( !weaponAlias )

game/shared/cstrike/weapon_knife.cpp

@@ -339,7 +339,24 @@ bool CKnife::SwingOrStab( bool bStab )
 	float fRange = bStab ? 32 : 48; // knife range
 	
 	Vector vForward; AngleVectors( pPlayer->EyeAngles(), &vForward );
+
 	Vector vecSrc	= pPlayer->Weapon_ShootPosition();
+	CUserCmd* playerCmd = NULL;
+
+    if (pPlayer)
+    {
+#ifdef CLIENT_DLL
+		playerCmd = pPlayer->m_pCurrentCommand;
+#else
+		playerCmd = pPlayer->GetCurrentCommand();
+#endif
+	}
+
+	if (playerCmd)
+	{
+		vecSrc = VectorLerp(pPlayer->m_vecPreviousShootPosition, vecSrc, playerCmd->interpolated_amount);
+	}
+
 	Vector vecEnd	= vecSrc + vForward * fRange;
 
 	trace_t tr;

game/shared/usercmd.h

@@ -106,7 +106,7 @@ public:
 		entitygroundcontact.RemoveAll();
 #endif
 
-        interpolated_shoot_position.Init();
+        interpolated_amount = 0.0f;
 	}
 
 	CUserCmd& operator =( const CUserCmd& src )
@@ -139,7 +139,7 @@ public:
 		entitygroundcontact			= src.entitygroundcontact;
 #endif
 
-        interpolated_shoot_position = src.interpolated_shoot_position;
+        interpolated_amount = src.interpolated_amount;
 		return *this;
 	}
 
@@ -168,7 +168,7 @@ public:
         CRC32_ProcessBuffer(&crc, &mousedy, sizeof(mousedy));
         CRC32_ProcessBuffer(&crc, simulationdata, sizeof(simulationdata));
         CRC32_ProcessBuffer(&crc, &debug_hitboxes, sizeof(debug_hitboxes));
-        CRC32_ProcessBuffer( &crc, &interpolated_shoot_position, sizeof(interpolated_shoot_position));
+        CRC32_ProcessBuffer(&crc, &interpolated_amount, sizeof(interpolated_amount));
 		CRC32_Final( &crc );
 
 		return crc;
@@ -184,7 +184,7 @@ public:
 		buttons = 0;
 		impulse = 0;
         debug_hitboxes = DEBUG_HITBOXES_OFF;
-        interpolated_shoot_position.Init();
+        interpolated_amount = 0.0f;
 	}
 
 	// For matching server and client commands for debugging
@@ -232,7 +232,7 @@ public:
 	uint8 debug_hitboxes;
 
     // TODO_ENHANCED: check README_ENHANCED in host.cpp!
-    Vector interpolated_shoot_position;
+    float interpolated_amount;
 
 	// Back channel to communicate IK state
 #if defined( HL2_DLL ) || defined( HL2_CLIENT_DLL )