Flip

Changes the current video display page

Syntax
   Declare Function Flip ( ByVal frompage As Long = -1, ByVal topage As Long
   = -1 ) As Long

Usage
   Flip [ frompage ] [, topage ]

Parameters
   frompage
      previous page
   topage
      new page to display

Return Value
   Returns zero (0) if successful, or a non-zero error code to indicate a 
   failure.

Description
   In normal graphics mode, Flip is an alias for PCopy and ScreenCopy. See 
   ScreenCopy for details.

   In OpenGL mode, Flip does a hardware page flip and displays the contents 
   of the backbuffer. It is recommended that you call Flip regularly while 
   in OpenGL mode, otherwise your app may also become unresponsive.

   The error code returned by Flip can be checked using Err in the next 
   line. The function version of  Flip returns directly the error code as a 
   32 bit Long.

Example
   ScreenRes 320, 240, 32, 2    'Sets up the screen to be 320x240 in 32-bit color with 2 video pages.
   ScreenSet 1,0                'Sets the working page to 1 and the displayed page to 0

   For n As Integer = 50 To 270

      Cls
      Circle (n, 50),50 ,RGB(255,255,0) 'Draws a circle with a 50 pixel radius in yellow on page 1
      Flip 1,0    'Copies our circle from page 1 to page 0

      Sleep 25
   Next

   Print "Now wasn't that neat!"
   Print "Push any key."
   Flip 1,0    'Copies our text from page 1 to page 0
   Sleep

Dialect Differences
   * Not available in the -lang qb dialect unless referenced with the 
     alias __Flip.

Differences from QB
   * New to FreeBASIC

