NSOpenGLLayer and multithreading

I have written a 3D viewer using Cocoa. The OpenGL renderings are performed in a separate thread that creates开发者_运维知识库 its own NSOpenGLContext.

Without layer handling, the 3D view drawRect method is called on refresh, and the OpenGL thread does its refresh and every things works perfectly...

Now, I have to implement the application using Cocoa layers. When the 3D NSView is created, a subclass of NSOpenGLLayer is created and attached to the view. The method

(void)drawInOpenGLContext:NSOpenGLContext *)ctx
              pixelFormat:(NSOpenGLPixelFormat *)pixelFormat
             forLayerTime:(CFTimeInterval)timeInterval
              displayTime:(const CVTimeStamp *)timeStamp; 

is called by Cocoa, but I am unable to make my OpenGL thread render anything.

I had tried to use the OpenGL context passed to drawInOpenGLContext in the OpenGL thread, I have tried to do a

[layer setOpenGLContext:ctx]

in the OpenGL thread with the OpenGL context created in the thread, and so on, but nothing works.

---

Did you remember to call setWantsLayer on your NSView? You need to call that from your NSView probably to make it a layer-hosted view. See the documentation for NSView setWantsLayer.

_testOglView = [[NSView alloc]initWithFrame:[self.view bounds]];
[_testOglView setLayer:[[TestOpenGLLayer alloc] init]];
[_testOglView setWantsLayer:YES];
[self.view addSubview:_testOglView];

In my TestOpenGLLayer class, I only had to define the drawInOpenGLContext function. I added my opeNGL commands to it and the view rendered the layer properly. I did not have to call [layer setContext].