added support for OGL on non-Windows platforms
added support for OGL on non-Windows platforms

markraz/vtp,markraz/vtp,seanisom/vtp,seanisom/vtp,seanisom/vtp,nakijun/vtp,markraz/vtp,nakijun/vtp,markraz/vtp,seanisom/vtp,nakijun/vtp,markraz/vtp,nakijun/vtp,seanisom/vtp,nakijun/vtp