mcpe/platforms/ios/EAGLView.m

//
//  EAGLView.m
//  GLBase
//

#import <QuartzCore/QuartzCore.h>

#import "EAGLView.h"

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

@implementation EAGLView

@dynamic context;

// You must implement this method
+ (Class)layerClass
{
    return [CAEAGLLayer class];
}

//The EAGL view is stored in the nib file. When it's unarchived it's sent -initWithCoder:.
- (id)initWithCoder:(NSCoder*)coder
{
    self = [super initWithCoder:coder];
	if (self)
    {
        CAEAGLLayer *eaglLayer = (CAEAGLLayer *)self.layer;
        
        eaglLayer.opaque = TRUE;
        eaglLayer.drawableProperties = [NSDictionary dictionaryWithObjectsAndKeys:
                                        [NSNumber numberWithBool:FALSE], kEAGLDrawablePropertyRetainedBacking,
                                        kEAGLColorFormatRGBA8, kEAGLDrawablePropertyColorFormat,
                                        nil];
        self->viewScale = 1.0;
        if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)])
        {
            self->viewScale = [[UIScreen mainScreen] scale];
            if ([self respondsToSelector:@selector(setContentScaleFactor:)])
            {
                [self setContentScaleFactor:self->viewScale];
                [eaglLayer setContentsScale:self->viewScale];
            }
        }
        NSLog(@"Scale is : %f\n", self->viewScale);
    }
    
    return self;
}

- (void)dealloc
{
    [self deleteFramebuffer];
#if !__has_feature(objc_arc)
    [context release];
    
    [super dealloc];
#endif
}

- (EAGLContext *)context
{
    return context;
}

- (void)setContext:(EAGLContext *)newContext
{
    if (context != newContext)
    {
        [self deleteFramebuffer];
        
        context = newContext;
        
        [EAGLContext setCurrentContext:nil];
    }
}

- (void)createFramebuffer
{
    if (context && !defaultFramebuffer)
    {
        [EAGLContext setCurrentContext: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);
        BOOL success = [context renderbufferStorage:GL_RENDERBUFFER fromDrawable:(CAEAGLLayer *)self.layer];
        if (!success)
            NSLog(@"Failed to bind CAEAGLayer to renderbuffer object!\n");
        glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_WIDTH, &framebufferWidth);
        glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_HEIGHT, &framebufferHeight);
        
        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, colorRenderbuffer);

		//  Add depth buffer
        glGenRenderbuffers(1, &depthRenderbuffer);
        glBindRenderbuffer(GL_RENDERBUFFER, depthRenderbuffer);
        glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16 /*GL_DEPTH24_STENCIL8*/,
                              framebufferWidth, framebufferHeight);
		glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
                                  GL_RENDERBUFFER, depthRenderbuffer );
        
        // Doing stencil stuff isn't supported on iOS 4.1, and I can't see any reason to be using it to begin with
        /*glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT,
                                     GL_RENDERBUFFER, depthRenderbuffer );*/
        NSLog(@"Created framebuffer with size %d, %d\n", framebufferWidth, framebufferHeight);
		
        if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
            NSLog(@"Failed to make complete framebuffer object %x\n", glCheckFramebufferStatus(GL_FRAMEBUFFER));
    }
}

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

- (void)setFramebuffer
{
    if (context)
    {
        [EAGLContext setCurrentContext:context];
        
        if (!defaultFramebuffer)
            [self createFramebuffer];
        
        glBindFramebuffer(GL_FRAMEBUFFER, defaultFramebuffer);
        
        glViewport(0, 0, framebufferWidth, framebufferHeight);
    }
}

- (BOOL)presentFramebuffer
{
    BOOL success = FALSE;
    
    if (context)
    {
        [EAGLContext setCurrentContext:context];
        
        glBindRenderbuffer(GL_RENDERBUFFER, colorRenderbuffer);
        glBindFramebuffer(GL_FRAMEBUFFER, self->defaultFramebuffer);
        
#if __IPHONE_OS_VERSION_MIN_REQUIRED >= __IPHONE_4_0 && __IPHONE_OS_VERSION_MIN_REQUIRED <= __IPHONE_12_0
        GLenum discards[] = { GL_DEPTH_ATTACHMENT, GL_COLOR_ATTACHMENT0, GL_STENCIL_ATTACHMENT };
        glDiscardFramebufferEXT(GL_FRAMEBUFFER, 3, discards);
#endif
        
        success = [context presentRenderbuffer:GL_RENDERBUFFER];
    }
    
    return success;
}

- (void)layoutSubviews
{
    // The framebuffer will be re-created at the beginning of the next setFramebuffer method call.
    [self deleteFramebuffer];
}

@end