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game/server/ai_movesolver.h

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+//========= Copyright Valve Corporation, All rights reserved. ============//
+//
+// Purpose: "Force-field" obstacle avoidance & steering
+//
+// @Note (toml 06-18-02): Currently only controls direction. Ultimately could
+// also incorporate body facing (yaw), speed, and translational/rotational
+// acceleration.
+//
+// $NoKeywords: $
+//=============================================================================//
+
+#ifndef AI_MOVESOLVER_H
+#define AI_MOVESOLVER_H
+
+#if defined( _WIN32 )
+#pragma once
+#endif
+
+#include "utlvector.h"
+#include "ai_obstacle_type.h"
+
+
+//-----------------------------------------------------------------------------
+
+inline float NormalizeAngle( float angle )
+{
+	if ( angle < 0.0 )
+		angle += 360.0;
+	else if ( angle >= 360.0 )
+		angle -= 360.0;
+	return angle;
+}
+
+//-----------------------------------------------------------------------------
+// ENUMERATIONS
+//-----------------------------------------------------------------------------
+
+//-----------------------------------------------------------------------------
+// STRUCTURES
+//-----------------------------------------------------------------------------
+
+//-------------------------------------
+// AI_Arc_t
+//
+// Purpose: Represents an arc.
+//
+//-------------------------------------
+struct AI_Arc_t
+{
+	AI_Arc_t()
+	 : 	center( 0 ),
+	 	span( 0 )
+	{
+	}
+
+	// Set by center and span
+	void Set( float newCenter, float newSpan );
+
+	// Set by the right and left extremes (coordinates run counter clockwise)
+	void SetByLimits( float yawRight, float yawLeft );
+
+	// Center of the arc (as "yaw")
+	float center;
+
+	// Span of the arc (in degrees)
+	float span;
+};
+
+//-------------------------------------
+// AI_MoveSuggestion_t
+//
+// Purpose: Suggests a possible move/avoidance, with a range of acceptable alternatives
+//
+// @Note (toml 06-20-02): this probably will eventually want to incorporate facing and
+// destination of the motivating goal.
+//
+//-------------------------------------
+
+enum AI_MoveSuggestionFlags_t
+{
+	AIMS_FAVOR_LEFT		= 0x01,
+	AIMS_FAVOR_RIGHT	= 0x02
+};
+
+//-----------------
+
+struct AI_MoveSuggestion_t
+{
+	AI_MoveSuggestion_t();
+	AI_MoveSuggestion_t( AI_MoveSuggType_t newType, float newWeight, float newDir, float newSpan, CBaseEntity *pEntity = NULL );
+	AI_MoveSuggestion_t( AI_MoveSuggType_t newType, float newWeight, const AI_Arc_t &arc, CBaseEntity *pEntity = NULL );
+
+	void Set( AI_MoveSuggType_t newType, float newWeight, float newDir, float newSpan, CBaseEntity *pEntity = NULL );
+	void Set( AI_MoveSuggType_t newType, float newWeight, const AI_Arc_t &arc, CBaseEntity *pEntity = NULL );
+
+	//---------------------------------
+
+	// The kind of suggestion
+	AI_MoveSuggType_t	type;
+
+	// The unadjusted weight of the suggestion [0..1], although [-1..1] within the solver
+	float 				weight;
+
+	// The desired direction to move/avoid
+	AI_Arc_t			arc;
+
+	// The causing entity, if any
+	EHANDLE				hObstacleEntity;
+	
+	// Flags
+	unsigned			flags;
+
+};
+
+//-----------------
+
+typedef CUtlVector<AI_MoveSuggestion_t> CAI_MoveSuggestions;
+
+//-------------------------------------
+// AI_MoveSolution_t
+//
+// Purpose: The result of resolving suggestions
+//
+// @Note (toml 06-18-02): Currently, this is a very dopey little structure.
+// However, it will probably eventually incorporate much of the info
+// passed or calculated piecemeal between Move...() and Move...Execute()
+// functions. Once suggestions incorprate more information, the solution
+// may want to include a copy of the winning suggestion, so that the
+// caller need retain less state. If this is not the case, reduce it to just
+// a yaw.
+//
+//-------------------------------------
+struct AI_MoveSolution_t
+{
+	AI_MoveSolution_t()
+	 :	dir(0)
+	{
+	}
+
+	// The direction to move
+	float dir;
+};
+
+//-----------------------------------------------------------------------------
+// class CAI_MoveSolver
+//
+// Purpose: Given a set of precalculated "regulations" (typically negative),
+//			and a set of instantaneous suggestions (usually positive)
+//-----------------------------------------------------------------------------
+
+class CAI_MoveSolver
+{
+public:
+	CAI_MoveSolver();
+
+	//---------------------------------
+	// Purpose: A regulation is a suggestion that is kept around as a rule until
+	//			cleared. They are generally negative suggestions.
+	//---------------------------------
+	void AddRegulation( const AI_MoveSuggestion_t &suggestion );
+	void AddRegulations( const AI_MoveSuggestion_t *pSuggestion, int nSuggestions );
+
+	bool HaveRegulations() const;
+	void ClearRegulations();
+
+	//---------------------------------
+	// Purpose: Solve the move, picking the best direction from a set of suggestions,
+	//			after applying the regulations
+	//---------------------------------
+	bool Solve( const AI_MoveSuggestion_t *pSuggestions, int nSuggestions, AI_MoveSolution_t *pResult );
+	bool Solve( const AI_MoveSuggestion_t &suggestion, AI_MoveSolution_t *pResult );
+
+	//---------------------------------
+	bool HaveRegulationForObstacle( CBaseEntity *pEntity);
+
+	//---------------------------------
+	// Visualization
+	void VisualizeRegulations( const Vector& origin );
+
+private:
+	enum
+	{
+		REGS_RESERVE = 8,
+	};
+
+	//---------------------------------
+	void NormalizeSuggestions( AI_MoveSuggestion_t *pBegin, AI_MoveSuggestion_t *pEnd );
+
+	//---------------------------------
+	CAI_MoveSuggestions m_Regulations;
+};
+
+//-----------------------------------------------------------------------------
+// AI_Arc_t inline methods
+//-----------------------------------------------------------------------------
+
+inline void AI_Arc_t::Set( float newCenter, float newSpan )
+{
+	center = NormalizeAngle( newCenter );
+	span   = NormalizeAngle( newSpan );
+}
+
+//-------------------------------------
+
+inline void AI_Arc_t::SetByLimits( float yawRight, float yawLeft )
+{
+	// Yaw runs counter-clockwise
+	span = yawLeft - yawRight;
+
+	if ( span < 0 )
+		span += 360;
+
+	center = yawRight + span * 0.5;
+
+	if ( center >= 360 )
+		center -= 360;
+}
+
+//-----------------------------------------------------------------------------
+// AI_MoveSuggestion_t inline methods
+//-----------------------------------------------------------------------------
+
+inline void AI_MoveSuggestion_t::Set( AI_MoveSuggType_t newType, float newWeight, float newDir, float newSpan, CBaseEntity *pEntity )
+{
+	type		    = newType;
+	weight          = newWeight;
+	hObstacleEntity = pEntity;
+	flags           = 0;
+
+	arc.Set( newDir, newSpan );
+}
+
+//-------------------------------------
+
+inline AI_MoveSuggestion_t::AI_MoveSuggestion_t()
+ :	type( AIMS_INVALID ),
+  	weight( 0 ),
+  	flags( 0 )
+{
+}
+
+//-------------------------------------
+
+inline AI_MoveSuggestion_t::AI_MoveSuggestion_t( AI_MoveSuggType_t newType, float newWeight, float newDir, float newSpan, CBaseEntity *pEntity )
+{
+	Set( newType, newWeight, newDir, newSpan, pEntity );
+}
+
+//-------------------------------------
+
+inline AI_MoveSuggestion_t::AI_MoveSuggestion_t( AI_MoveSuggType_t newType, float newWeight, const AI_Arc_t &arc, CBaseEntity *pEntity  )
+{
+	Set( newType, newWeight, arc.center, arc.span, pEntity );
+}
+
+//-------------------------------------
+
+inline void AI_MoveSuggestion_t::Set( AI_MoveSuggType_t newType, float newWeight, const AI_Arc_t &arc, CBaseEntity *pEntity )
+{
+	Set( newType, newWeight, arc.center, arc.span, pEntity );
+}
+
+//-----------------------------------------------------------------------------
+// CAI_MoveSolver inline methods
+//-----------------------------------------------------------------------------
+
+inline CAI_MoveSolver::CAI_MoveSolver()
+{
+	m_Regulations.EnsureCapacity( REGS_RESERVE );
+}
+
+//-------------------------------------
+
+inline void CAI_MoveSolver::AddRegulation( const AI_MoveSuggestion_t &suggestion )
+{
+	m_Regulations.AddToTail( suggestion );
+}
+
+//-------------------------------------
+
+inline void CAI_MoveSolver::AddRegulations( const AI_MoveSuggestion_t *pSuggestions, int nSuggestions )
+{
+	for (int i = 0; i < nSuggestions; ++i)
+	{
+		m_Regulations.AddToTail( pSuggestions[i] );
+	}
+}
+
+//-------------------------------------
+
+inline bool CAI_MoveSolver::HaveRegulations() const
+{
+	return (m_Regulations.Count() > 0);
+}
+
+//-------------------------------------
+
+inline void CAI_MoveSolver::ClearRegulations()
+{
+	m_Regulations.RemoveAll();
+}
+
+//-------------------------------------
+
+inline bool CAI_MoveSolver::Solve( const AI_MoveSuggestion_t &suggestion, AI_MoveSolution_t *pResult)
+{
+	return Solve( &suggestion, 1, pResult);
+}
+
+//=============================================================================
+
+#endif // AI_MOVESOLVER_H