Microsoft Small Basic

Program Listing:

' Krueg -- Starfield -- Sept. 2012

Delay = 60        'Delay for smooth framrate
StarQty = 80      'Number of stars, Too many and it slows the program
SetupWindow()
CreateStars()

While ("True")
  MoveStars()
  RefreshRate()   'Comment out this line to see the jerkiness of the array proccessing
EndWhile

Sub RefreshRate
  While Clock.ElapsedMilliseconds < FrameRate
  EndWhile
  FrameRate = Clock.ElapsedMilliseconds + Delay
EndSub

Sub MoveStars
  For i = 1 To StarQty
    StarY[i] = StarY[i] + StarHeight[i] * 1.5
    If StarY[i] > gh Then
      StarY[i] = StarY[i] - gh
      StarX[i] = Math.GetRandomNumber(gw - 10) + 5
    EndIf
    Shapes.Move(Star[i],StarX[i],StarY[i])      'Checking which moves smother, Shapes.Move or Shapes.Animate
    'Shapes.Animate(Star[i],StarX[i],StarY[i],0)
  EndFor
EndSub

Sub CreateStars
  For i = 1 To StarQty
    GraphicsWindow.PenColor = "White"
    GraphicsWindow.BrushColor = "White"
    StarWidth[i] = Math.GetRandomNumber(2)
    If i < (StarQty * .9) Then
      StarHeight[i] = Math.GetRandomNumber(3)   'Create more small stars than big
    Else
      StarHeight[i] = Math.GetRandomNumber(4)+4
    EndIf
    Star[i] = Shapes.AddEllipse(StarWidth[i],StarHeight[i])
    Shapes.SetOpacity(Star[i],StarHeight[i]*5+50)
    StarX[i] = Math.GetRandomNumber(gw - 10) + 5
    StarY[i] = Math.GetRandomNumber(gh)
    Shapes.Move(Star[i],StarX[i],StarY[i])
  EndFor
EndSub

Sub SetupWindow
  gw = 800
  gh = 600
  GraphicsWindow.Top = 5
  GraphicsWindow.Left = 5
  GraphicsWindow.Width = gw
  GraphicsWindow.Height = gh
  GraphicsWindow.BackgroundColor = "Black"
EndSub