static void createWindow() {
    NSUInteger windowStyle = NSTitledWindowMask  | NSClosableWindowMask | NSResizableWindowMask | NSMiniaturizableWindowMask;
    
    NSRect screenRect = [[NSScreen mainScreen] frame];
    NSRect viewRect = NSMakeRect(0, 0, 1024, 768);
    NSRect windowRect = NSMakeRect(NSMidX(screenRect) - NSMidX(viewRect),
                                   NSMidY(screenRect) - NSMidY(viewRect),
                                   viewRect.size.width,
                                   viewRect.size.height);
    
    window = [[NSWindow alloc] initWithContentRect:windowRect
                                                    styleMask:windowStyle
                                                      backing:NSBackingStoreBuffered
                                                        defer:NO];
    
    [NSApp setActivationPolicy:NSApplicationActivationPolicyRegular];
    
    id menubar = [[NSMenu new] autorelease];
    id appMenuItem = [[NSMenuItem new] autorelease];
    [menubar addItem:appMenuItem];
    [NSApp setMainMenu:menubar];
    
    // Then we add the quit item to the menu. Fortunately the action is simple since terminate: is
    // already implemented in NSApplication and the NSApplication is always in the responder chain.
    id appMenu = [[NSMenu new] autorelease];
    id appName = [[NSProcessInfo processInfo] processName];
    id quitTitle = [@"Quit " stringByAppendingString:appName];
    id quitMenuItem = [[[NSMenuItem alloc] initWithTitle:quitTitle
                                                  action:@selector(terminate:) keyEquivalent:@"q"] autorelease];
    [appMenu addItem:quitMenuItem];
    [appMenuItem setSubmenu:appMenu];
    
    NSWindowController * windowController = [[NSWindowController alloc] initWithWindow:window];
    [windowController autorelease];
    
    //View
    view = [[[View alloc] initWithFrame:viewRect] autorelease];
    [window setContentView:view];

    //Window Delegate
    windowDelegate = [[WindowDelegate alloc] init];
    [window setDelegate:windowDelegate];
    
    [window setAcceptsMouseMovedEvents:YES];
    [window setDelegate:view];
    
    // Set app title
    [window setTitle:appName];
    
    // Add fullscreen button
    [window setCollectionBehavior: NSWindowCollectionBehaviorFullScreenPrimary];
    [window makeKeyAndOrderFront:nil];
}

void initApp() {
    [NSApplication sharedApplication];
    
    appDelegate = [[AppDelegate alloc] init];
    [NSApp setDelegate:appDelegate];
    
    running = true;
    
    [NSApp finishLaunching];
}

void frame() {
    @autoreleasepool {
        NSEvent* ev;
        do {
            ev = [NSApp nextEventMatchingMask: NSAnyEventMask
                                    untilDate: nil
                                       inMode: NSDefaultRunLoopMode
                                      dequeue: YES];
            if (ev) {
                // handle events here
                [NSApp sendEvent: ev];
            }
        } while (ev);
    }
}

int main(int argc, const char * argv[])  {
    initApp();
    createWindow();
    while (running) {
        frame();
        RenderWeirdGradient(XOffset, YOffset);
        [view setNeedsDisplay:YES];
        XOffset++;
        YOffset++;
    }
    
    return (0);

void frame() {
    @autoreleasepool {
        NSEvent* ev;
        do {
            ev = [NSApp nextEventMatchingMask: NSAnyEventMask
                                    untilDate: nil
                                       inMode: NSDefaultRunLoopMode
                                      dequeue: YES];
            if (ev) {
                // handle events here
                [NSApp sendEvent: ev];
            }
        } while (ev);
    }
}

@implementation WindowDelegate

- (void)windowDidBecomeKey:(NSNotification *)notification {
    NSLog(@"Window: become key");
}

- (void)windowDidBecomeMain:(NSNotification *)notification {
    NSLog(@"Window: become main");
}

- (void)windowDidResignKey:(NSNotification *)notification {
    NSLog(@"Window: resign key");
}

- (void)windowDidResignMain:(NSNotification *)notification {
    NSLog(@"Window: resign main");
}

// This will close/terminate the application when the main window is closed.
- (void)windowWillClose:(NSNotification *)notification {
    Window *window = notification.object;
    if (window.isMainWindow) {
        [NSApp terminate:nil];
    }
}

@end

// Empty implementations here so that the window doesn't complain when the events aren't handled or passed on to its view. 
// i.e. A traditional Cocoa app expects to pass events on to its view(s).
- (void)keyDown:(NSEvent *)theEvent {}
- (void)keyUp:(NSEvent *)theEvent {}

- (BOOL)acceptsFirstResponder { return YES; }
- (BOOL)canBecomeKeyWindow { return YES; }
- (BOOL)canBecomeMainWindow { return YES; }

NSCAssert([NSThread isMainThread], @"Processing Application events must occur on main thread.");
BOOL eventsProcessed = NO;
NSEvent *event;
while ((event = [NSApp nextEventMatchingMask:NSAnyEventMask untilDate:nil inMode:NSDefaultRunLoopMode dequeue:YES])) {
    // Process event..
    
    [NSApp sendEvent:event];
    [NSApp updateWindows];
    eventsProcessed = YES;
}

return eventsProcessed;

[NSApplication sharedApplication];
[NSApp setActivationPolicy:NSApplicationActivationPolicyRegular];
[NSApp setPresentationOptions:NSApplicationPresentationDefault];
[NSApp activateIgnoringOtherApps:YES];

appDelegate = [[FSAppDelegate alloc] init];
[NSApp setDelegate:appDelegate];
[NSApp finishLaunching];

void frame() {
    @autoreleasepool {
        NSEvent* ev;
        do {
            ev = [NSApp nextEventMatchingMask: NSAnyEventMask
                                    untilDate: nil
                                       inMode: NSDefaultRunLoopMode
                                      dequeue: YES];
            if (ev) {
                // handle events here
                [NSApp sendEvent: ev];
            }
        } while (ev);
    }
}

switch (event.type) {
    case NSLeftMouseDown:
        // do something when left mouse is down
        break;
    case NSKeyDown:
        if (event.keyCode == kVK_Escape) { // virtual key code for Esc
            // do something when escape is down
        }
        break;
    case ...:
}

// This registers an instance (target) which implements the given selector (doSomething:, which has one argument of type NSNotification*) when the notification with the 
// name NSWindowWillCloseNotification is posted. Whenever this happens, the selector is invoked on the target.
[[NSNotificationCenter defaultCenter] addObserver:target selector:@selector(doSomething:) name:NSWindowWillCloseNotification object:nil];

// This removes the target from receiving this notification (required for cleanup so you don't leak resources).
[[NSNotificationCenter defaultCenter] removeObserver:target name:NSWindowWillCloseNotification object:nil];

NSEvent* ev;
while (NULL != (ev = [NSApp nextEventMatchingMask: NSAnyEventMask untilDate: nil inMode: NSDefaultRunLoopMode dequeue: YES]))
{
    [NSApp sendEvent: ev];
}

- (CVReturn) getFrameForTime:(const CVTimeStamp*)outputTime {
    return kCVReturnSuccess;
}

int main() {
 while (running) {
   render()
 }
}

void frame() {
    @autoreleasepool {
        NSEvent* ev;
        do {
            ev = [NSApp nextEventMatchingMask: NSAnyEventMask
                                    untilDate: nil
                                       inMode: NSDefaultRunLoopMode
                                      dequeue: YES];
            if (ev) {
                // handle events here
                [NSApp sendEvent: ev];
            }
        } while (ev);
    }
}

int main(int argc, const char * argv[])  {
    initApp();
    createWindow();
    while (running) {
        frame();
        RenderWeirdGradient(XOffset, YOffset);
        [view setNeedsDisplay:YES];
        XOffset = XOffset + 10;
        YOffset++;
    }
    
    return (0);
}

- (CVReturn)getFrameForTime:(const CVTimeStamp *)outputTime
{
    double deltaTime = (double)(outputTime->hostTime - lastFrame) / CVGetHostClockFrequency();
    ...
}