2 questions about Application Services, 1 about backend

[Julien Isorce]

Hi,

I am playing with GNUstep for some hours now and I still wondering about 3 things that I discarded at start.

** 1. Using GNUstep,  CGDisplayIDToOpenGLDisplayMask(kCGDirectMainDisplay) seems to be not supported.

According to the documentation it seems that 
uint32_t display_id = [[[NSScreen mainScreen] deviceDescription] objectForKey:@"NSScreenNumber"]; //can compile with GNUstep
is equivalent to
CGDirectDisplayID display_id = kCGDirectMainDisplay;  //cannot compile with GNUstep

But I cannot find a workaround to CGDisplayIDToOpenGLDisplayMask.
Any idea ?


** 2. CGCaptureAllDisplays and CGReleaseAllDisplays seem to be not supported on GNUstep.
(from ApplicationServices/ApplicationServices.h)
Any workaround ?


** 3. How can I check at runtime if a function is implemented by the platform backend ?
For example "setValues" is not implemented on win32:
 [[self openGLContext] setValues:&swapInterval forParameter:NSOpenGLCPSwapInterval];


Sincerely

Julien