imclab/renderpluginmanager

Unity iOS render plugin middleware

RenderPluginManager

Unity 4.3 introduced a new RenderPluginDelegate protocol which allows native plugins to connect to rendering events. However, there are a few problems with their implementation. In particular, neither of the provided delegates are actually registered. It's completely fine to set the delegate after Unity has already launched, but you won't have a reference to the rendering surface.

RenderPluginManager is a simple extension of the built in RenderPluginArrayDelegate implementation. It contains an array of other delegates, and forwards events to them. The default implementation provides no interface for registering, no reference to the rendering surface, and is not automatically set as the delegate.

This tool exists in an attempt to prevent the RenderPluginDelegate interface from becoming like PostProcessBuildPlayer. While there will be far fewer plugins using these delegates, it is still source for conflict. For users, debugging conflicting render plugins could be very difficult. Hopefully, other plugins will use this manager to register their delegates, and save some of the headache further down the road.

If you don't want to deal with the full project, you can download a Unity package of the plugin from the releases page.

Contributions and feedback are extremely welcome!

Lifecycle

We use a category on UnityAppController to add a method to the app startup where we set the delegate. The choice to use applicationWillFinishLaunching was mostly arbitrary, but it is not implemented by default and will hopefully not conflict with other plugins.

-(BOOL)application:(UIApplication *)application willFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    NSLog(@"Injecting RenderPluginManager");
    self.renderDelegate = [RenderPluginManager sharedManager];
 
    return true;
}

Now the delegate is set before the engine initializes, so our method to get the rendering surface actually gets called:

- (void)mainDisplayInited:(struct UnityRenderingSurface*)surface {
    ...
}

RenderPluginManager keeps a reference to the surface and passes it back to new delegates when they register with it.

Registration

To register or unregister a delegate with the manager, use these methods:

-(struct UnityRenderingSurface*)registerDelegate:(id<RenderPluginDelegate>)delegate;

Adds the new delegate to the array. It will start receiving events immediately. Returns a pointer to the rendering surface. As noted in the documentation, this reference should never change.

-(void)unregisterDelegate:(id<RenderPluginDelegate>)delegate;

Removes the specified delegate from the array. It will no longer receive events.

We've also enabled a define to check if RenderPluginManager is available, just in case. You could use this to check whether you should register your delegate directly with UnityAppController or not:

#define __RENDER_PLUGIN_MANAGER__ 

Example

void _registerPlugin() {
    pluginInstance = [[SamplePlugin alloc] init];
    pluginInstance.surface = [[RenderPluginManager sharedManager] registerDelegate:pluginInstance];
}

Or, if you want, you can also request the surface separately:

void _registerPlugin() {
    pluginInstance = [[SamplePlugin alloc] init];
    [[RenderPluginManager sharedManager] registerDelegate:pluginInstance];
    pluginInstance.surface = [[RenderPluginManager sharedManager] getRenderingSurface];
}