An Eventful Weekend
Entry posted by Josh ·
1,989 views
The windows class on OSX has been a bit neglected, so i spent some time getting it ready for the final release. Creating a full-screen window on Mac is a little funny. There's a fullscreen mode that's been around a while, but it locks the system so that CMD+TAB doesn't work. That means if your application crashes, or you don't program it to close with the escape key, you'll be stuck in fullscreen mode, with no way out but a computer restart! 
You can create a window on top of everything else, and CMD+TAB will still work, but the borderless style you use for this makes it so no keyboard input is recognized! If you press escape, the system just beeps and the window doesn't catch an event. 
:o
There's also a new full-screen mode for apps in OSX Lion, but it's for GUI apps, and I wanted this to work on Snow Leopard. I knew it was possible because Left 4 Dead 2 on Mac does this. Using the Google, I was finally able to find the information I needed. I had to create a new subclasses NSWindow class to get keyboard input working.
Another problem I had was that when a window was resized, the NSOpenGLContext wasn't sizing with it. Many, many search queries later I found what I needed, and added a couple of methods to my OpenGL view class.
Objective-C may be the greatest thing in the world for writing GUI applications for Mac, but I found it very complex for simply creating a window. It takes about 700 lines of code to create a window that has OpenGL rendering and keyboard and mouse input. Out of all that code, you guys end up with one or two functions that do exactly what you need to create a window and get events. B)
Let's talk events. Event queues are the most compatible with all languages, but a callback is really better. When a window is being resized, the application loses control and doesn't get it back until the user lets up the mouse. That means an event queue system doesn't allow the window to be re-rendered as it is sized, and you get ugly artifacts as it is sizing. Therefore, I think we need a hook system where you can add your own hooks like this:
System::AddHook(int hookid, char* funcptr, Object* extra) System::AddHook(HOOK_EVENT, myfunction, NULL)
I think we're also going to set up the App class so that it has a ProcessEvent method, which automatically gets added as a hook:
App::ProcessEvent(int eventid, int data, iVec2 position)
{
switch (eventid)
{
case EVENT_WINDOWSIZE:
world->Render();
context->Sync();
}
}
Your thoughts?
2 Comments
Recommended Comments