Finding Closest Objects Example

[kevin]

Finding Closest Objects Example

   

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   Type tCharacter
         x#,y#      ; world position 
         colour
         nearestcharacter   
   EndType


   Dim Character(10) as tCharacter


   Init_Scene()

   ; ---------------------------------------------------------------------------
   ; ---[ MAIN LOOp ]-----------------------------------------------------------
   ; ---------------------------------------------------------------------------

   ; make a camer to view the scene with
   cam=newcamera()

   Do
      cls 


      if Spacekey()
         Init_Scene()
         flushkeys   
      endif

      ; find what characters are closest to what charcters
      Resolve_Closest_Characters()


      ; draw the scene   
      Draw_Characters()
   
   
      drawcamera cam
   
      Sync
   loop esckey()
   
   
   end
   
   
   
Function Init_Scene()


   For lp=1 to 10
         Character(lp)   = new tCharacter         

         ; give this character a random position
         Character(lp).x=rnd(800)
         Character(lp).y=rnd(600)
         Character(lp).colour= rnd($ffffff)
         Character(lp).nearestcharacter =-1
   next



EndFunction   
   

   ; ---------------------------------------------------------------------------
   ; ---[ Resolve Closest Characters ]------------------------------------------
   ; ---------------------------------------------------------------------------


Function Resolve_Closest_Characters()

   for lp=1 to GetArrayElements(Character())
         if Character(lp)
            ; find the character that is closest to this character
            Character(lp).nearestcharacter =Find_Closest_Characters_To_Character(lp)
         endif
   next
   
EndFUnction


   ; ---------------------------------------------------------------------------
   ; ---[ Finde Closest Character To Character ]------------------------------------------
   ; ---------------------------------------------------------------------------

Function Find_Closest_Characters_To_Character(TargetCharacter)

   ClosestID=-1
   ClosestDistance=1000000   

   PointX=character(TargetCharacter).x
   PointY=character(TargetCharacter).y

   for lp=1 to GetArrayElements(Character())
      if TargetCharacter<>lp
         if Character(lp) 
            dist=getdistance2d(character(lp).x,character(lp).y,pointX,pointY)                     
            if Dist<ClosestDistance
                ClosestDistance=Dist
                ClosestID=LP
            endif
         endif
      endif
   next
   
EndFUnction ClosestID


Function  Draw_Characters()

   capturetoscene
   clsscene
   for lp=0 to GetArrayElements(Character())
         if Character(lp)
               x      =Character(lp).x                     
               y      =Character(lp).y                     
               col   =Character(lp).colour                  
               ClosestID=Character(lp).nearestcharacter

               capturedepth 100
               circlec x,y,30,true,col

               ; ClosestID
               if ClosestID>0
                  Targetx      =Character(ClosestID).x                     
                  Targety      =Character(ClosestID).y                     
                  capturedepth 50

                  LineC x,y,TargetX,TargetY,$00ff00
               endif

               capturedepth 10
               centertext x,y,"Me#"+Digits$(lp,2)+" -> "+digits$(ClosestID,2)

         endif
   next   

EndFUnction