hide cursor on OSX

PanoPainter-OSX/main.cpp

@@ -124,6 +124,11 @@ std::mutex task_mutex;
     self = [super initWithFrame:frameRect pixelFormat:pf];
     [self setPixelFormat:pf];
     [self setOpenGLContext:context];
+
+    NSTrackingArea* trackingArea = [[NSTrackingArea alloc] initWithRect:frameRect
+            options: (NSTrackingMouseEnteredAndExited | NSTrackingMouseMoved | NSTrackingActiveInKeyWindow )
+            owner:self userInfo:nil];
+    [self addTrackingArea:trackingArea];
     return self;
 }
 - (void)prepareOpenGL
@@ -374,6 +379,17 @@ static CVReturn MyDisplayLinkCallback(CVDisplayLinkRef displayLink, const CVTime
         App::I.mouse_move(mouseLoc.x, App::I.height - mouseLoc.y - 1, p, kEventSource::Mouse, 0);
     });
 }
+-(void)mouseExited:(NSEvent *)event
+{
+    self->cursor_visible = CGCursorIsVisible();
+    if (!self->cursor_visible)
+        [NSCursor unhide];
+}
+-(void)mouseEntered:(NSEvent *)event
+{
+    if (!self->cursor_visible)
+        [NSCursor hide];
+}
 - (void)scrollWheel:(NSEvent *)theEvent
 {
     auto mouseLoc = [self convertPoint:[theEvent locationInWindow] fromView:nil];