I'm trying to add multisampling to my app, but it seems that I've made a mistake, but I can't find what I did wrong.
This is how I setup my frame buffers and render buffers
- (void)setupBuffers {
glGenFramebuffers(1, &_framebuffer);
glGenRenderbuffers(1, &_renderbuffer);
glBindFramebuffer(GL_FRAMEBUFFER, _framebuffer);
glBindRenderbuffer(GL_RENDERBUFFER, _renderbuffer);
[_context renderbufferStorage:GL_RENDERBUFFER fromDrawable:_eaglLayer]; // I already set the current context to _context, and _eaglLayer is just self.layer
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, _renderbuffer);
if (YES) { // note if I set this to no, my app properly displays (I don't even have to remove the code in my render method)
glGenFramebuffers(1, &_msaa_framebuffer);
glGenRenderbuffers(1, &_msaa_renderbuffer);
glBindFramebuffer(GL_FRAMEBUFFER, _msaa_framebuffer);
glBindRenderbuffer(GL_RENDERBUFFER, _msaa_renderbuffer);
glRenderbufferStorageMultisampleAPPLE(GL_RENDERBUFFER, 2, GL_RGBA8_OES, [AppDelegate screenWidth], [AppDelegate screenHeight]); // yes, this is the proper width and height I tested it
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, _msaa_renderbuffer);
}
GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
if(status != GL_FRAMEBUFFER_COMPLETE) {
NSLog(@"Failed to make complete framebuffer object %x", status);
exit(1);
}
}
After viewDidLoad
is called on my ViewController
I call the method setupDisplayLink
on my UIView
subclass.
- (void)setupDisplayLink {
CADisplayLink* displayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(render:)];
//displayLink.frameInterval = [[NSNumber numberWithInt:1] integerValue];
[displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
}
This calls my render method which is pretty simple:
- (void)render:(CADisplayLink*)displayLink {
glBindRenderbuffer(GL_RENDERBUFFER, _msaa_framebuffer);
glViewport(0, 0, [AppDelegate screenWidth], [AppDelegate screenHeight]);
glClearColor(188.0f / 255.0f, 226.0f / 255.0f, 232.0f / 255.0f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
[[OpenGLViewController instance].menu draw:displayLink]; // drawing happens here
glBindFramebuffer(GL_DRAW_FRAMEBUFFER_APPLE, _framebuffer);
glBindFramebuffer(GL_READ_FRAMEBUFFER_APPLE, _msaa_framebuffer);
glResolveMultisampleFramebufferAPPLE();
glDiscardFramebufferEXT(GL_READ_FRAMEBUFFER_APPLE, 1, (GLenum[1]) { GL_COLOR_ATTACHMENT0 });
glBindRenderbuffer(GL_RENDERBUFFER, _renderbuffer);
NSLog(@"%@", @"HI");
[_context presentRenderbuffer:GL_RENDERBUFFER];
}
It's not hanging at all (the app keeps printing "HI" in the console because I told it to in the render method). For some reason only the first frame is drawn when I add the extra frame buffer and render buffer for multisampling and I can't figure out why. It just freezes on that frame. Why will my app only draw the first frame with MSAA?