Bots intercept enemy ghost carrier path

src/game/server/CMakeLists.txt

@@ -1527,6 +1527,7 @@ set(UNITY_SOURCE_NEO_BOT
     neo/bot/behavior/neo_bot_ctg_capture.cpp
     neo/bot/behavior/neo_bot_ctg_carrier.cpp
     neo/bot/behavior/neo_bot_ctg_enemy.cpp
+    neo/bot/behavior/neo_bot_ctg_enemy_intercept_cap_path.cpp
     neo/bot/behavior/neo_bot_ctg_escort.cpp
     neo/bot/behavior/neo_bot_ctg_lone_wolf.cpp
     neo/bot/behavior/neo_bot_ctg_seek.cpp
@@ -1587,6 +1588,7 @@ target_sources_grouped(
     neo/bot/behavior/neo_bot_ctg_capture.h
     neo/bot/behavior/neo_bot_ctg_carrier.h
     neo/bot/behavior/neo_bot_ctg_enemy.h
+    neo/bot/behavior/neo_bot_ctg_enemy_intercept_cap_path.h
     neo/bot/behavior/neo_bot_ctg_escort.h
     neo/bot/behavior/neo_bot_ctg_lone_wolf.h
     neo/bot/behavior/neo_bot_ctg_lone_wolf_ambush.cpp

src/game/server/neo/bot/behavior/neo_bot_ctg_enemy.cpp

@@ -1,22 +1,92 @@
 #include "cbase.h"
 #include "neo_player.h"
+#include "neo_gamerules.h"
+#include "neo_ghost_cap_point.h"
 #include "bot/neo_bot.h"
 #include "bot/behavior/neo_bot_ctg_enemy.h"
+#include "bot/behavior/neo_bot_ctg_enemy_intercept_cap_path.h"
 #include "bot/behavior/neo_bot_attack.h"
 #include "bot/neo_bot_path_compute.h"
-#include "neo_gamerules.h"
 
+// --- pressure vs. block --------------------------------------------------------------------------
+// CNEOBotCtgSeek hands every enemy-carrier defender to CNEOBotCtgEnemy; the choice of whether to
+// chase the carrier directly or peel off into CNEOBotCtgEnemyInterceptCapPath to hold a cut-off is
+// made here, tick by tick, from observable state only -- no lookup of the carrier's real path.
+// Routing every defender to interception pulls the last body off the carrier and, in testing,
+// conceded more ghost captures rather than fewer, so the nearest few defenders always chase.
+ConVar sv_neo_bot_ctg_pressure_slots( "sv_neo_bot_ctg_pressure_slots", "2", FCVAR_CHEAT,
+	"CTG defence: the N friendly defenders nearest the enemy ghost carrier chase it directly; the "
+	"rest peel off to hold a cut-off on its predicted path.", true, 0, true, 8 );
 
 //---------------------------------------------------------------------------------------------
 CNEOBotCtgEnemy::CNEOBotCtgEnemy( void )
 {
 }
 
+//---------------------------------------------------------------------------------------------
+// true => this bot should hold a cut-off (interception) rather than chase directly.
+bool CNEOBotCtgEnemy::ShouldInterceptInsteadOfChase( CNEOBot *me, CNEO_Player *pGhostCarrier ) const
+{
+	CNavArea *pCarrierArea = pGhostCarrier->GetLastKnownArea();
+	if ( !pCarrierArea )
+	{
+		// No observable fix on the carrier -- just chase; do not go set up a cut-off off stale data.
+		return false;
+	}
+
+	// Nothing to intercept toward unless some cap zone is actually enemy-reachable this round
+	// (owningTeamAlternate() flips on odd rounds). If none is, chasing is all there is.
+	const int myTeam = me->GetTeamNumber();
+	bool bAnyEnemyCap = false;
+	for ( int i = 0; i < NEORules()->m_pGhostCaps.Count(); ++i )
+	{
+		CNEOGhostCapturePoint *pCapPoint = dynamic_cast< CNEOGhostCapturePoint* >( UTIL_EntityByIndex( NEORules()->m_pGhostCaps[i] ) );
+		// The GetActive() guard has to match the interception behaviour's own cap scan. If the only
+		// enemy zone is disabled, that behaviour finds nothing to cut off and hands straight back,
+		// so peeling off to it here would churn between chase and interception every few seconds.
+		if ( pCapPoint && pCapPoint->GetActive() && pCapPoint->owningTeamAlternate() != myTeam )
+		{
+			bAnyEnemyCap = true;
+			break;
+		}
+	}
+	if ( !bAnyEnemyCap )
+	{
+		return false;
+	}
+
+	// Rank this bot among living friendly defenders by distance to the carrier's last-known spot.
+	// The nearest sv_neo_bot_ctg_pressure_slots chase; everyone farther peels off to a cut-off.
+	// Tactically sound (near bodies pursue, rear bodies cut off) and stable frame to frame.
+	const Vector vecCarrier = pCarrierArea->GetCenter();
+	const float myDistSq = me->GetAbsOrigin().DistToSqr( vecCarrier );
+	int iNearerTeammates = 0;
+	for ( int i = 1; i <= gpGlobals->maxClients; ++i )
+	{
+		CNEO_Player *pTeammate = ToNEOPlayer( UTIL_PlayerByIndex( i ) );
+		if ( !pTeammate || pTeammate == me || !pTeammate->IsAlive() || pTeammate->GetTeamNumber() != myTeam )
+		{
+			continue;
+		}
+		if ( pTeammate->GetAbsOrigin().DistToSqr( vecCarrier ) < myDistSq )
+		{
+			++iNearerTeammates;
+		}
+	}
+
+	return iNearerTeammates >= sv_neo_bot_ctg_pressure_slots.GetInt();
+}
+
 //---------------------------------------------------------------------------------------------
 ActionResult< CNEOBot >	CNEOBotCtgEnemy::OnStart( CNEOBot *me, Action< CNEOBot > *priorAction )
 {
 	m_chasePath.SetMinLookAheadDistance( me->GetDesiredPathLookAheadRange() );
 
+	// Give positions a moment to settle before the first chase-vs-intercept decision, so the
+	// "nearest N" ranking is meaningful rather than whatever the spawn order happened to be.
+	m_roleReviewTimer.Start( 0.5f );
+	m_forcePursueTimer.Invalidate();
+
 	return Continue();
 }
 
@@ -39,6 +109,27 @@ ActionResult< CNEOBot >	CNEOBotCtgEnemy::Update( CNEOBot *me, float interval )
 		return Done( "Ghost carrier is friendly" );
 	}
 
+	// Chase-vs-intercept: once the initial settle delay has passed, and unless we are inside the
+	// post-interception "keep chasing" window, a bot that is not one of the nearest defenders peels
+	// off to hold a cut-off. Going the other way (intercept -> chase) is driven by the interception
+	// behaviour handing control back on contact / timeout, handled in OnResume.
+	//
+	// This sits ahead of the threat check below because interception is a repositioning job, not a
+	// disengagement: a bot that peels off still shoots at whatever it can see, since
+	// CNEOBotMainAction::Update calls FireWeaponAtEnemy() every tick whatever behaviour is running.
+	const bool bForcedPursue = m_forcePursueTimer.HasStarted() && !m_forcePursueTimer.IsElapsed();
+	if ( m_roleReviewTimer.IsElapsed() && !bForcedPursue )
+	{
+		// Re-decide a few times a second rather than every tick. The ranking below walks every
+		// player and every capture zone, and the answer cannot meaningfully change tick to tick.
+		m_roleReviewTimer.Start( 0.5f );
+
+		if ( ShouldInterceptInsteadOfChase( me, pGhostCarrier ) )
+		{
+			return SuspendFor( new CNEOBotCtgEnemyInterceptCapPath, "Repositioning to cut off the carrier" );
+		}
+	}
+
 	const CKnownEntity *threat = me->GetVisionInterface()->GetPrimaryKnownThreat(true);
 	if ( threat && !threat->IsObsolete() && me->GetIntentionInterface()->ShouldAttack( me, threat ) )
 	{
@@ -47,7 +138,7 @@ ActionResult< CNEOBot >	CNEOBotCtgEnemy::Update( CNEOBot *me, float interval )
 
 	// Investigate the ghost carrier's position
 	CNEOBotPathUpdateChase( me, m_chasePath, pGhostCarrier, DEFAULT_ROUTE );
-	
+
 	return Continue();
 }
 
@@ -56,6 +147,15 @@ ActionResult< CNEOBot >	CNEOBotCtgEnemy::Update( CNEOBot *me, float interval )
 //---------------------------------------------------------------------------------------------
 ActionResult< CNEOBot > CNEOBotCtgEnemy::OnResume( CNEOBot *me, Action< CNEOBot > *interruptingAction )
 {
+	// Coming back from the interception behaviour (it hands control back on real contact, on the
+	// carrier slipping past, or on its give-up timer): chase directly for a bit before this bot is
+	// eligible to peel off again, so it does not immediately abandon a contact it just made or
+	// bounce straight back to a cut-off it just failed to hold.
+	if ( interruptingAction && FStrEq( interruptingAction->GetName(), "ctgEnemyInterceptCapPath" ) )
+	{
+		m_forcePursueTimer.Start( 5.0f );
+	}
+
 	return Continue();
 }
 

src/game/server/neo/bot/behavior/neo_bot_ctg_enemy.h

@@ -4,7 +4,12 @@
 #include "bot/neo_bot.h"
 #include "Path/NextBotChasePath.h"
 
+class CNEO_Player;
+
 //--------------------------------------------------------------------------------------------------------
+// "An enemy has the ghost" behaviour. Owns the tactical choice between chasing the carrier directly
+// (the ChasePath below) and peeling off into CNEOBotCtgEnemyInterceptCapPath to hold a cut-off on the
+// carrier's predicted path -- CNEOBotCtgSeek just hands off to here, it does not decide.
 class CNEOBotCtgEnemy : public Action< CNEOBot >
 {
 public:
@@ -21,7 +26,14 @@ class CNEOBotCtgEnemy : public Action< CNEOBot >
 	virtual const char *GetName( void ) const override { return "ctgEnemy"; }
 
 private:
+	// true => this bot should peel off to hold a cut-off (interception) rather than chase directly.
+	// Observable state only: this bot's distance rank among living friendly defenders to the
+	// carrier's last-known area, versus sv_neo_bot_ctg_pressure_slots.
+	bool ShouldInterceptInsteadOfChase( CNEOBot *me, CNEO_Player *pGhostCarrier ) const;
+
 	ChasePath m_chasePath;
+	CountdownTimer m_roleReviewTimer;	// throttle the chase-vs-intercept re-decision
+	CountdownTimer m_forcePursueTimer;	// after returning from interception, chase directly for a bit before peeling again
 };
 
 #endif // NEO_BOT_CTG_ENEMY_H