int gl_combine_extension = false;
// GL_EXT_compiled_vertex_array
int gl_supportslockarrays = false;
-// GLX_SGI_video_sync or WGL_EXT_swap_control
+// GLX_SGI_swap_control or WGL_EXT_swap_control
int gl_videosyncavailable = false;
// stencil available
int gl_stencil = false;