Flip

Changes the current video display page

Syntax
	KeyPgDeclareDeclare KeyPgFunctionFunction Flip ( KeyPgByvalByVal frompage KeyPgAsAs KeyPgLongLong = -1, KeyPgByvalByVal topage KeyPgAsAs KeyPgLongLong
	= -1 ) KeyPgAsAs KeyPgLong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 KeyPgPcopyPCopy and KeyPgScreencopyScreenCopy. See 
	KeyPgScreencopy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 KeyPgErrErr in the next 
	line. The function version of  Flip returns directly the error code as a 
	32 bit KeyPgLong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 CompilerOptlang-lang qb dialect unless referenced with the 
	  alias __Flip.

Differences from QB
	* New to FreeBASIC

