Implemented platform support for MacOS

src/window.m

@@ -0,0 +1,87 @@
+#import <Cocoa/Cocoa.h>
+#import <QuartzCore/CAMetalLayer.h>
+
+static NSWindow *window = nil;
+static bool window_closed = false;
+
+@interface WindowDelegate : NSObject <NSWindowDelegate>
+@end
+
+@implementation WindowDelegate
+- (void)windowWillClose:(NSNotification *)notification {
+  window_closed = true;
+}
+@end
+
+static WindowDelegate *window_delegate = nil;
+
+@interface MetalView : NSView
+@end
+
+@implementation MetalView
++ (Class)layerClass {
+  return [CAMetalLayer class];
+}
+- (instancetype)initWithFrame:(NSRect)frame {
+  if ((self = [super initWithFrame:frame])) {
+    self.wantsLayer = YES;
+    self.layer = [CAMetalLayer layer];
+  }
+  return self;
+}
+@end
+
+static MetalView *metal_view = nil;
+
+static void initialize_app(void) {
+  static BOOL initialized = NO;
+  if (!initialized) {
+    [NSApplication sharedApplication];
+    initialized = YES;
+  }
+}
+
+void create_window(void) {
+  initialize_app();
+  window_closed = false;
+  if (window != nil) {
+    [window makeKeyAndOrderFront:nil];
+    return;
+  }
+
+  NSRect frame = NSMakeRect(100, 100, 800, 600);
+
+  window = [[NSWindow alloc]
+      initWithContentRect:frame
+                styleMask:(NSWindowStyleMaskTitled | NSWindowStyleMaskClosable |
+                           NSWindowStyleMaskResizable)
+                  backing:NSBackingStoreBuffered
+                    defer:NO];
+
+  [window setTitle:@"Sideros"];
+
+  metal_view = [[MetalView alloc] initWithFrame:frame];
+  [window setContentView:metal_view];
+  NSLog(@"Layer class: %@", NSStringFromClass([metal_view.layer class]));
+
+  window_delegate = [[WindowDelegate alloc] init];
+  [window setDelegate:window_delegate];
+
+  [window makeKeyAndOrderFront:nil];
+  [window orderFrontRegardless];
+}
+
+void poll_cocoa_events(void) {
+  @autoreleasepool {
+    NSEvent *event;
+    while ((event = [NSApp nextEventMatchingMask:NSEventMaskAny
+                                       untilDate:[NSDate distantPast]
+                                          inMode:NSDefaultRunLoopMode
+                                         dequeue:YES])) {
+      [NSApp sendEvent:event];
+    }
+  }
+}
+
+bool is_window_closed(void) { return window_closed; }
+void *get_metal_layer(void) { return (__bridge void *)metal_view.layer; }