; PureBasic 4.20
 
#SW=800
#SH=600
#Deg2Rad = #PI/180 
 
InitSprite() : InitKeyboard() : InitMouse()
OpenScreen(#SW,#SH,32,"")
 
CompilerIf #PB_Compiler_OS = #PB_OS_Linux
  Structure point ; Déjà déclarée dans les résidents sous windows
    x.f
    y.f
  EndStructure
CompilerEndIf
  
;-Structures
Structure VECTOR2
  x.f
  y.f
EndStructure
 
Structure ENTITY
  Position.VECTOR2
  Angle.f
EndStructure
  
;-Declarations des fonctions
Declare DrawArrow(Lenght.l , x.f , y.f , Angle.f)
Declare.f curveangle(newangle.f,oldangle.f,increments.f)
Declare.f ReturnDegAngle(x1.f,y1.f,x2.f,y2.f)
Declare track_SmoothPoint(*A.ENTITY,*B.ENTITY, turnspeed.f=1.0)
  
 
; ************************************************************************************
#NB_ARROW = 3
Dim Arrow.ENTITY(#NB_ARROW)
 
For i = 1 To #NB_ARROW
  Arrow(i)\Position\x = Random(#SW)
  Arrow(i)\Position\y = Random(#SH)
  Arrow(i)\Angle      = 0
Next

; Cible des "arrow" , coordonnées de la souris pour la position
Target.ENTITY
 
Repeat
  ClearScreen(0)
  ExamineKeyboard()
  ExamineMouse()
  
  Target\Position\x = MouseX()
  Target\Position\y = MouseY()
 
  StartDrawing(ScreenOutput())
    Circle(Target\Position\x,Target\Position\y,2,255)
  StopDrawing()

  For i = 1 To #NB_ARROW
    DrawArrow(50 , Arrow(i)\Position\x , Arrow(i)\Position\y , Arrow(i)\Angle)
    track_SmoothPoint(Arrow(i),Target,20)
   
    Arrow(i)\Position\x + 1 *Cos(Arrow(i)\Angle*#PI/180)
    Arrow(i)\Position\y + 1 *Sin(Arrow(i)\Angle*#PI/180)
  Next
 
  If KeyboardPushed(#PB_Key_Escape)<>#Null : Quit=1 : EndIf

  FlipBuffers()

Until Quit=1

End
 
Procedure.f curveangle(newangle.f,oldangle.f,increments.f)
  If increments>1
    If (oldangle+360)-newangle<newangle-oldangle
      oldangle=360+oldangle
    EndIf
    If (newangle+360)-oldangle<oldangle-newangle
      newangle=360+newangle
    EndIf
    oldangle=oldangle-(oldangle-newangle)/increments
  EndIf
 
  If increments<=1
    ProcedureReturn newangle
  EndIf
  ProcedureReturn oldangle
EndProcedure
  
Procedure.f ReturnDegAngle(x1.f,y1.f,x2.f,y2.f) ; DEGREE
  A.f = x1-x2
  b.f = y1-y2
  c.f = -Sqr(A*A+b*b)
  Angle.f = ACos(A/c)*180/#PI
  If y1 < y2 : Angle=360-Angle : EndIf
  ProcedureReturn Abs(Angle - 360)
EndProcedure
  
Procedure track_SmoothPoint(*A.ENTITY,*B.ENTITY, turnspeed.f=1.0)
  AngDif = ReturnDegAngle(*A\position\x,*A\position\y,*B\position\x,*B\position\y)
  temp_yaw.f = curveangle(AngDif,*A\Angle,turnspeed)
  *A\Angle = temp_yaw
EndProcedure
 
Procedure DrawArrow(Lenght.l , x.f , y.f , Angle.f)
 
  Protected ArrowA.Point,ArrowB.Point
  Protected ArrowBranchA.Point,ArrowBranchB.Point
   
  ArrowA\x = x + (Lenght/2) * Cos(Angle*#PI/180)
  ArrowA\y = y + (Lenght/2) * Sin(Angle*#PI/180)
  
  ArrowB\x = x - (Lenght/2) * Cos(Angle*#PI/180)
  ArrowB\y = y - (Lenght/2) * Sin(Angle*#PI/180)
   
  ArrowBranchA\x = ArrowA\x - (Lenght/3) * Cos((Angle+45)*#PI/180)
  ArrowBranchA\y = ArrowA\y - (Lenght/3) * Sin((Angle+45)*#PI/180)
  
  ArrowBranchB\x = ArrowA\x - (Lenght/3) * Cos((Angle-45)*#PI/180)
  ArrowBranchB\y = ArrowA\y - (Lenght/3) * Sin((Angle-45)*#PI/180)
   
  StartDrawing(ScreenOutput())
    LineXY(ArrowA\x,ArrowA\y,ArrowB\x,ArrowB\y,255)
    LineXY(ArrowA\x,ArrowA\y,ArrowBranchA\x,ArrowBranchA\y,255)
    LineXY(ArrowA\x,ArrowA\y,ArrowBranchB\x,ArrowBranchB\y,255)
    Circle(x+1,y+1,2,255)
  StopDrawing()
EndProcedure