Resizing of viewport

The drawing area(viewport) is set in the range of 640x480 pixels from the upper left of the Form in Sub InitializeGraphics.

Sub InitializeGraphics()
    Call SetViewPort(0, 0, 640, 480)
    Call SetGraphicsWindow(0, 0, 640, 480)
  ......
End Sub

You can change the size of the drawing area by changing the argument value of Sub SetViewPort

Example  Setting to the range of 800 x 600 pixels from the upper left

    Call SetViewPort(0, 0, 800, 600)

If you want to always set the different size of the drawing area, change the argument of SetViewPort in Sub InitializeGraphics.

When a range of 800 x 600 pixels from the upper left is used as the drawing area and the upper right specifies a positive coordinate system.

Sub InitializeGraphics()
    Call SetViewPort(0, 0, 800,600)
    Call SetGraphicsWindow(-4, 3, 4, -3)
  ......
End Sub