UseJPEGImageEncoder()

#Window1   = 0
#Image1    = 0
#ImgGadget = 0

#NUM_PARTICLES = 8000
#width         = 800
#height        = 800
#xmax          = #width  -3
#ymax          = #height -3
Define.i Event ,i ,x,y

Declare Draw_Image(*Value)

If OpenWindow(#Window1, 0, 0, #width, #height, "Brownian Tree PureBasic Example", #PB_Window_SystemMenu | #PB_Window_ScreenCentered )
     If CreateImage(#Image1, #width, #height)
          ; --- Off
          ;ImageGadget(#ImgGadget, 0, 0, #width, #height, ImageID(#Image1))
          StartDrawing(ImageOutput(#Image1))
          FrontColor($FFFFFF)
          Plot( #xmax/2 , #ymax/2)
          StopDrawing()
          ; --- Off
          ; SetGadgetState(#ImgGadget, ImageID(#Image1))
          CreateThread(@Draw_Image(), *Value)
     EndIf
     Repeat
          Event = WaitWindowEvent()
     Until Event = #PB_Event_CloseWindow

     ; --- Save and display result file.
     SetCurrentDirectory(GetTemporaryDirectory())
     File_Name.s = "BROWNIAN_"+FormatDate("%yyyy%mm%dd_%hh%ii%ss", Date())+".jpg"
     SaveImage(0, File_Name, #PB_ImagePlugin_JPEG, 9)
     RunProgram(File_Name)
EndIf


Procedure Draw_Image(*Value)
     For i = 1 To #NUM_PARTICLES
          SetWindowTitle(#Window1, "Loop: " + Str(i) + "/" + Str(#NUM_PARTICLES) + " (Close before end if you want)")
          x = Random(#xmax)+1 : y = Random (#ymax)+1
          StartDrawing(ImageOutput(#Image1))
          While Point(x+1, y+1) + Point(x, y+1)+Point(x+1, y)+Point(x-1, y-1)+Point(x-1, y)+Point(x, y-1)+Point(x+1,y-1)+Point(x-1,y+1) = 0
               x = x + (Random(2)-1) : y = y + (Random(2)-1)
               If x < 1 Or x > #xmax Or y < 1 Or y > #ymax
                    x = Random(#xmax)+1 : y = Random (#ymax)+1
               EndIf
          Wend
          Plot(x,y)
          StopDrawing()
          ; --- Off
          ;SetGadgetState(#ImgGadget, ImageID(#Image1))
     Next
EndProcedure