On 10/05/12 16:03, Mike Werner wrote:
> I'm fairly sure FLTK is written with OpenGL.

	FLTK supports opengl, but does not use it for implementing widgets.
	For that, FLTK uses the native graphics libraries:

		Linux: Xlib
		Windows: Win32
		OSX: Cocoa

	This allows FLTK apps that don't need openGL to run on machines
	that don't have openGL.

> But I wanted to check on this forum.
> Is it so?

	If I understand your question correctly, no -- fltk's widgets
	are not all implemented in opengl. But fltk provides a way for
	apps to use openGL, so that one can have FLTK widgets around
	opengl windows in which your opengl can run.
> 
> If so, what version of OpenGL?

	In the way that FLTK lets you use opengl within your fltk app,
	it will use whatever openGL installation is available on the
	end user's machine.

	When you compile an FLTK app that uses opengl, you would need
	to have an opengl development environment available on the machine,
	and the end users would need opengl on the machines that run your
	FLTK/opengl app.

	For regular FLTK apps that don't use opengl, you don't need an opengl
	environment (FLTK and non-opengl FLTK apps can build just fine without it),
	and end user machines don't need openGL for the non-opengl FLTK apps to run.

	When you write an FLTK app that uses openGL, your app is making
	direct calls to the openGL library.. FLTK's job is to provide you
	an openGL window into which you can make your opengl calls.