ScreenGLProc

Gets the address of an OpenGLOpenGL procedure

Syntax
	KeyPgDeclareDeclare KeyPgFunctionFunction ScreenGLProc ( KeyPgByrefByRef procname KeyPgAsAs KeyPgConstQualifierConst KeyPgStringString ) KeyPgAsAs KeyPgAnyAny 
	KeyPgPtrPtr

Parameters
	procname
		name of the procedure to retrieve the address of

Description
	This function can be used to get the address of any OpenGL procedure, to 
	be used to retrieve the pointers to new functions associated with OpenGL 
	extensions. If given procedure named procname cannot be found, 
	ScreenGLProc will return NULL (0).

Example
	'' include fbgfx.bi for some useful definitions
	#include "fbgfx.bi"

	Dim SwapInterval As Function(ByVal interval As Integer) As Integer
	Dim extensions As String

	'' Setup OpenGL and retrieve supported extensions
	ScreenRes 640, 480, 32,, FB.GFX_OPENGL
	ScreenControl FB.GET_GL_EXTENSIONS, extensions

	If (InStr(extensions, "WGL_EXT_swap_control") <> 0) Then
	   '' extension supported, retrieve proc address
	   SwapInterval = ScreenGLProc("wglSwapIntervalEXT")
	   If (SwapInterval <> 0) Then
	      '' Ok, we got it. Set OpenGL to wait for vertical sync on buffer swaps
	      SwapInterval(1)
	   End If
	End If

Dialect Differences
	* Not available in the CompilerOptlang-lang qb dialect unless referenced with the 
	  alias __Screenglproc.

Platform Differences
	* Not available for DOS target.

Differences from QB
	* New to FreeBASIC

See also
	* KeyPgScreengraphicsScreen (Graphics)
	* KeyPgScreencontrolScreenControl

