EAGLDepthBufferedView.h

//
//  EAGLDepthBufferedView.h
//  DepthBufferTest
//
//  Created by narumij on 11/04/16.
//

#import "EAGLView.h"

@interface EAGLDepthBufferedView : EAGLView {
 	GLuint depthRenderbuffer;
}

@end

EAGLDepthBufferedView.m

//
//  EAGLDepthBufferedView.m
//  DepthBufferTest
//
//  Created by narumij on 11/04/16.
//

#import <QuartzCore/QuartzCore.h>

#import "EAGLDepthBufferedView.h"


@interface EAGLDepthBufferedView (PrivateMethods)
- (void)createFramebuffer;
- (void)deleteFramebuffer;
@end

@implementation EAGLDepthBufferedView

- (void)createFramebuffer
{
    if (self.context && !defaultFramebuffer) {
        [EAGLContext setCurrentContext:self.context];
        
        // Create default framebuffer object.
        glGenFramebuffers(1, &defaultFramebuffer);
        glBindFramebuffer(GL_FRAMEBUFFER, defaultFramebuffer);
        
        // Create color render buffer and allocate backing store.
        glGenRenderbuffers(1, &colorRenderbuffer);
        glBindRenderbuffer(GL_RENDERBUFFER, colorRenderbuffer);
        [self.context renderbufferStorage:GL_RENDERBUFFER fromDrawable:(CAEAGLLayer *)self.layer];
        glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_WIDTH, &framebufferWidth);
        glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_HEIGHT, &framebufferHeight);
        
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, colorRenderbuffer);
        
		glGenRenderbuffers(1, &depthRenderbuffer);
		glBindRenderbuffer(GL_RENDERBUFFER, depthRenderbuffer);
		glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthRenderbuffer);
		glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, framebufferWidth, framebufferHeight);
		
        if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
            NSLog(@"Failed to make complete framebuffer object %x", glCheckFramebufferStatus(GL_FRAMEBUFFER));
    }
}

- (void)deleteFramebuffer
{
    if (self.context) {
        [EAGLContext setCurrentContext:self.context];
        
        if (defaultFramebuffer) {
            glDeleteFramebuffers(1, &defaultFramebuffer);
            defaultFramebuffer = 0;
        }
        
        if (colorRenderbuffer) {
            glDeleteRenderbuffers(1, &colorRenderbuffer);
            colorRenderbuffer = 0;
        }
		
		if (depthRenderbuffer)
        {
            glDeleteRenderbuffers(1, &depthRenderbuffer);
            depthRenderbuffer = 0;
        }
    }
}

@end

EAGLView.h

//
//  EAGLView.h
//  OpenGLES_iPhone
//
//  Created by mmalc Crawford on 11/18/10.
//  Copyright 2010 Apple Inc. All rights reserved.
//

#import <UIKit/UIKit.h>

#import <OpenGLES/ES1/gl.h>
#import <OpenGLES/ES1/glext.h>
#import <OpenGLES/ES2/gl.h>
#import <OpenGLES/ES2/glext.h>

@class EAGLContext;

// This class wraps the CAEAGLLayer from CoreAnimation into a convenient UIView subclass.
// The view content is basically an EAGL surface you render your OpenGL scene into.
// Note that setting the view non-opaque will only work if the EAGL surface has an alpha channel.
@interface EAGLView : UIView {
@protected
    // The pixel dimensions of the CAEAGLLayer.
    GLint framebufferWidth;
    GLint framebufferHeight;
    
    // The OpenGL ES names for the framebuffer and renderbuffer used to render to this view.
    GLuint defaultFramebuffer, colorRenderbuffer;
}

@property (nonatomic, retain) EAGLContext *context;

- (void)setFramebuffer;
- (BOOL)presentFramebuffer;

@end