source-engine/game/server/NextBot/simple_bot.h

//========= Copyright Valve Corporation, All rights reserved. ============//
// simple_bot.h
// A mininal example of a NextBotCombatCharacter (ie: non-player) bot
// Michael Booth, February 2009

#ifndef SIMPLE_BOT_H
#define SIMPLE_BOT_H

#include "NextBot.h"
#include "NextBotBehavior.h"
#include "NextBotGroundLocomotion.h"
#include "Path/NextBotPathFollow.h"


//----------------------------------------------------------------------------
/**
 * A Simple Bot
 */
class CSimpleBot : public NextBotCombatCharacter
{
public:
	DECLARE_CLASS( CSimpleBot, NextBotCombatCharacter );

	CSimpleBot();
	virtual ~CSimpleBot();

	virtual void Precache();
	virtual void Spawn( void );

	// INextBot
	DECLARE_INTENTION_INTERFACE( CSimpleBot )
	virtual NextBotGroundLocomotion	*GetLocomotionInterface( void ) const	{ return m_locomotor; }

private:
	NextBotGroundLocomotion	*m_locomotor;
};


//--------------------------------------------------------------------------------------------------------------
/**
 * Functor used with the A* algorithm of NavAreaBuildPath() to determine the "cost" of moving from one area to another.
 * "Cost" is generally the weighted distance between the centers of the areas. If you want the bot
 * to avoid an area/ladder/elevator, increase the cost.  If you want to disallow an area/ladder/elevator, return -1.
 */
class CSimpleBotPathCost : public IPathCost
{
public:
	CSimpleBotPathCost( CSimpleBot *me )
	{
		m_me = me;
	}

	// return the cost (weighted distance between) of moving from "fromArea" to "area", or -1 if the move is not allowed
	virtual float operator()( CNavArea *area, CNavArea *fromArea, const CNavLadder *ladder, const CFuncElevator *elevator, float length ) const
	{
		if ( fromArea == NULL )
		{
			// first area in path, no cost
			return 0.0f;
		}
		else
		{
			if ( !m_me->GetLocomotionInterface()->IsAreaTraversable( area ) )
			{
				// our locomotor says we can't move here
				return -1.0f;
			}

			// compute distance traveled along path so far
			float dist;

			if ( ladder )
			{
				dist = ladder->m_length;
			}
			else if ( length > 0.0 )
			{
				// optimization to avoid recomputing length
				dist = length;
			}
			else
			{
				dist = ( area->GetCenter() - fromArea->GetCenter() ).Length();
			}

			float cost = dist + fromArea->GetCostSoFar();

			// check height change
			float deltaZ = fromArea->ComputeAdjacentConnectionHeightChange( area );
			if ( deltaZ >= m_me->GetLocomotionInterface()->GetStepHeight() )
			{
				if ( deltaZ >= m_me->GetLocomotionInterface()->GetMaxJumpHeight() )
				{
					// too high to reach
					return -1.0f;
				}

				// jumping is slower than flat ground
				const float jumpPenalty = 5.0f;
				cost += jumpPenalty * dist;
			}
			else if ( deltaZ < -m_me->GetLocomotionInterface()->GetDeathDropHeight() )
			{
				// too far to drop
				return -1.0f;
			}

			return cost;
		}
	}

	CSimpleBot *m_me;
};


#endif // SIMPLE_BOT_H