[Solved] Enforce Aspect Ratio of Game Window standalone for Mac OSx

If anyone is able to help me on this issue, I would appreciate it.
I am attempting to write a simple plugin that will allow me to set the window's aspect ratio (or the content's aspect ratio).
I believe I have the proper functions/methods to call for this written in Objective-C, but they are not working as I would hope/imagine.

-(void) setwindow
{

NSWindow *mainWindow = [[[NSApplication sharedApplication] windows] objectAtIndex:0];
[mainWindow setAspectRatio:NSMakeSize(4, 3)];​

}
I have an extern "C" function setup and can confirm that it's calling that (even tested with an int return value).
my extern...
extern "C" {
void setwindow(){

WindowPlugin *wp = [[WindowPlugin alloc] init];
[wp setwindow];
}​

}
However, the window is not keeping with the aspect ratio when it's resized.
Is there a problem to call this function from a Mac .bundle? Does it not know about the main window?
Or is it something else that I'm missing or could try.
Any help is appreciated. Thank-you in advance.

 

Wow, I appreciate very much your response. I knew that there could be more than 1 window, but did not realize that I had more than 1 window in my game
I did know the part about setting the frame/window ; but I left that as a follow-up, had I gotten the first part done.
This is working just as I had hoped. Thank-you very much.

This is the behaviour I thought, before testing, that I would get with the player settings of allowing only certain aspect ratios

Thanks, again. Hopefully this answer may help some other Mac users looking for a similar feat.

 

Inside : WindowPlugin.mm

Code (ObjC):

1. @implementation WindowPlugin
2. -(void)setwindow
3. {
4.  
5.     for (NSWindow* window in NSApplication.sharedApplication.windows)
6.     {
7.         if (window.isVisible)
8.         {
9.             [window setAspectRatio: NSMakeSize(4, 3)];
10.             NSRect frame = window.frame;
11.             frame.size.width = frame.size.height * 4 / 3;
12.             [window setFrame: frame display: YES animate: NO];
13.         }
14.     }
15. }
16. @end
17. extern "C" {
18.     void setwindow(){
19.     WindowPlugin *wp = [[WindowPlugin alloc] init];
20.     [wp setwindow];
21.     }
22. }
23.  

Header.h

Code (ObjC):

1. @interface WindowPlugin : NSObject
2. -(void) setwindow;
3. @end
4.  

Inside a script

Code (CSharp):

1.  
2. [DllImport ("UnityMacWindowPlugin", CallingConvention = CallingConvention.Cdecl)]
3.    private static extern void setwindow ();
4.  
5. void Awake(){
6. setwindow();
7. }
8.  

Compiled this as a bundle in XCode, and added it to a folder "Plugins" in my Unity Project.