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"Simple Finite State Machine", by rick

This is a simple example, where the state of an enemy changes as the player<->enemy distance is changing.

Code

;This is my first try to create a Finite Sate Machine for the enemy
;If the enemy is within a range of 50 tot 30 from the player, the enemy sees you and gets suspisious, and start walking towards you.
;If the enemy is within a range of lower than 30 from the player, the enemy knows you are the enemy, and he runs towards you.
;Rick Overman

;init
Graphics3D 800,600,0,2
SetBuffer BackBuffer()

;constants
Const  GROUND = 1, ENEMYBODY = 2, PLAYERBODY = 4 ; Entity types
Const  SLEEPSTATE = 1, SUSPISIOUSSTATE = 2, DETECTEDSTATE = 3 ; FSM States

;collisions (who, what and how)
Collisions PAYERBODY,GROUND,2,3
Collisions ENEMYBODY,GROUND,2,3
Collisions PLAYERBODY,ENEMYBODY,2,3

;types
Type Enemy
     Field entity
     Field x#,y#,z#
     Field state%, statetxt$
     Field playerdistance#
End Type

Type Player
     Field entity
     Field x#,y#,z#
End Type

;ground surface 
plane = CreatePlane()
EntityType plane,GROUND

;light please
light = CreateLight()

;camera
cam = CreateCamera()
PositionEntity cam,0,70,0
RotateEntity cam,90,0,0

;player
Player1.Player=CreatePlayer(0,5,0)
;enemies
Enemy1.Enemy=CreateEnemy(30,5,30)
Enemy2.Enemy=CreateEnemy(10,5,30)

;And ..... action
While Not KeyHit(1)
    UpdateGame()
     
     UpdateWorld
     RenderWorld
     
     ;Just some debugging output
     Color  0,0,255
     Text 100,0,"player_x: "+EntityX(Player1\entity)
     Text 100,10,"player_y: "+EntityY(Player1\entity)
     Text 100,20,"p_z: "+EntityZ(Player1\entity)
     
     Color  255,0,0
     Text 400,0,"enemy1_state(FSM): "+Enemy1\state+" >> "+Enemy1\statetxt;
     Text 400,10,"enemy1_playerdistance: "+Enemy1\playerdistance;
     Text 400,20,"enemy2_state(FSM): "+Enemy2\state+" >> "+Enemy2\statetxt;
     Text 400,30,"enemy2_playerdistance: "+Enemy2\playerdistance;
     Flip
     
Wend 
End

Function UpdateGame()
     For p.Player=Each Player
          UpdatePlayer( p )
     Next
     
     For e.Enemy=Each Enemy
          UpdateEnemy( e )
     Next
End Function

Function CreatePlayer.Player(x#,y#,z#)
     p.Player=New Player
     p\entity=CreateCube();
     EntityColor p\entity,0,0,255
     PositionEntity p\entity,x,y,z
     EntityType p\entity,PLAYERBODY
     ResetEntity p\entity
     Return p
End Function

Function UpdatePlayer( p.Player )
     ;player movement
     If KeyDown(200);up
          MoveEntity p\entity,0,0,1
     ElseIf KeyDown(208);down
          MoveEntity p\entity,0,0,-1
     EndIf
     
     If KeyDown(203);left
          TurnEntity p\entity,0,2,0
     ElseIf KeyDown(205);right
          TurnEntity p\entity,0,-2,0
     EndIf
End Function

Function CreateEnemy.Enemy(x#,y#,z#)
     e.Enemy=New Enemy
     e\entity=CreateCube();
     RotateEntity e\entity,0,0,90
     e\state = SLEEPSTATE;
     EntityColor e\entity,255,0,0
     PositionEntity e\entity,x,y,z
     EntityType e\entity,ENEMYBODY
     ResetEntity e\entity
     Return e
End Function

Function UpdateEnemy( e.Enemy )
     For p.Player=Each Player
          e\playerdistance = EntityDistance(e\entity,p\entity)
          
          If e\playerdistance<50 And e\playerdistance>30 ; Enemy is Suspisious
               PointEntity e\entity,p\entity,90
               MoveEntity e\entity,0,0,.05
               e\state=SUSPISIOUSSTATE
               e\statetxt = "Carefull he is Suspisious!"
          ElseIf e\playerdistance<30 ; Enemy Angry
               PointEntity e\entity,p\entity,90
               MoveEntity e\entity,0,0,.7
               e\state=DETECTEDSTATE
               e\statetxt = "Run You are DETECTED!!!!"
          Else ; Enemy does nothing
               e\state=SLEEPSTATE
               e\statetxt = "zzzzz (sleeping)"
          End If
     Next     
End Function

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