第四代ipod Touch上的openGL ES 1.0不兼容

Question

刚刚发现我的应用只是在第4代ipod touch上显示黑屏。它已经在我测试的大多数其他苹果设备上工作，例如iphone 3gs，它工作正常。这是我的样板代码生成我的GLView，任何人都知道可能是什么问题？还是用于操作1.0的更现代的样板？

GLView.m：

//
//  GLView.m
//  Part6Project
//
//  Created by jeff on 5/31/09.
//  Copyright Jeff LaMarche 2009. All rights reserved.
//

#import <QuartzCore/QuartzCore.h>
#import <OpenGLES/EAGLDrawable.h>
#import "GLView.h"
#import "GLViewController.h"

@interface GLView (private)

- (id)initGLES;
- (BOOL)createFramebuffer;
- (void)destroyFramebuffer;

@end

@implementation GLView

@synthesize animationInterval;
+ (Class) layerClass
{
    return [CAEAGLLayer class];
}
-(id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if(self != nil)
    {
        self = [self initGLES];
    }
    return self;
}

- (id)initWithCoder:(NSCoder*)coder
{
    if((self = [super initWithCoder:coder]))
    {
        self = [self initGLES];
    }   
    return self;
}

-(id)initGLES
{
    NSLog(@"created");
    CAEAGLLayer *eaglLayer = (CAEAGLLayer*) self.layer;

    if ([self respondsToSelector:@selector(contentScaleFactor)])
    {
        self.contentScaleFactor = [[UIScreen mainScreen] scale]; 
        // scale value should be 1.0 on 3G and 3GS, and 2.0 on iPhone 4.
        self.contentMode = UIViewContentModeScaleToFill;
    }

    // Configure it so that it is opaque, does not retain the contents of the backbuffer when displayed, and uses RGBA8888 color.
    eaglLayer.opaque = YES;
    eaglLayer.drawableProperties = [NSDictionary dictionaryWithObjectsAndKeys:
                                    [NSNumber numberWithBool:FALSE], kEAGLDrawablePropertyRetainedBacking,
                                    kEAGLColorFormatRGBA8, kEAGLDrawablePropertyColorFormat,
                                    nil];

    // Create our EAGLContext, and if successful make it current and create our framebuffer.
    context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES1];
    if(!context || ![EAGLContext setCurrentContext:context] || ![self createFramebuffer])
    {
//      [self release];
        return nil;
    }

    // Default the animation interval to 1/60th of a second.
    animationInterval = 1.0 / kRenderingFrequency;
    return self;
}

-(GLViewController *)controller
{
    return controller;
}

-(void)setController:(GLViewController *)d
{
    controller = d;
    controllerSetup = ![controller respondsToSelector:@selector(setupView:)];
}

// If our view is resized, we'll be asked to layout subviews.
// This is the perfect opportunity to also update the framebuffer so that it is
// the same size as our display area.
-(void)layoutSubviews
{

    [EAGLContext setCurrentContext:context];
    [self destroyFramebuffer];
    [self createFramebuffer];
    [self drawView];
}

- (BOOL)createFramebuffer
{
        // Generate IDs for a framebuffer object and a color renderbuffer
    glGenFramebuffersOES(1, &viewFramebuffer);
    glGenRenderbuffersOES(1, &viewRenderbuffer);

    glBindFramebufferOES(GL_FRAMEBUFFER_OES, viewFramebuffer);
    glBindRenderbufferOES(GL_RENDERBUFFER_OES, viewRenderbuffer);
    // This call associates the storage for the current render buffer with the EAGLDrawable (our CAEAGLLayer)
    // allowing us to draw into a buffer that will later be rendered to screen whereever the layer is (which corresponds with our view).
    [context renderbufferStorage:GL_RENDERBUFFER_OES fromDrawable:(id<EAGLDrawable>)self.layer];
    glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_COLOR_ATTACHMENT0_OES, GL_RENDERBUFFER_OES, viewRenderbuffer);

    glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_WIDTH_OES, &backingWidth);
    glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_HEIGHT_OES, &backingHeight);

    // For this sample, we also need a depth buffer, so we'll create and attach one via another renderbuffer.
    glGenRenderbuffersOES(1, &depthRenderbuffer);
    glBindRenderbufferOES(GL_RENDERBUFFER_OES, depthRenderbuffer);
    glRenderbufferStorageOES(GL_RENDERBUFFER_OES, GL_DEPTH_COMPONENT16_OES, backingWidth, backingHeight);
    glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_DEPTH_ATTACHMENT_OES, GL_RENDERBUFFER_OES, depthRenderbuffer);

    if(glCheckFramebufferStatusOES(GL_FRAMEBUFFER_OES) != GL_FRAMEBUFFER_COMPLETE_OES)
    {
        NSLog(@"failed to make complete framebuffer object %x", glCheckFramebufferStatusOES(GL_FRAMEBUFFER_OES));
        return NO;
    }

    return YES;
}

// Clean up any buffers we have allocated.
- (void)destroyFramebuffer
{
    glDeleteFramebuffersOES(1, &viewFramebuffer);
    viewFramebuffer = 0;
    glDeleteRenderbuffersOES(1, &viewRenderbuffer);
    viewRenderbuffer = 0;

    if(depthRenderbuffer)
    {
        glDeleteRenderbuffersOES(1, &depthRenderbuffer);
        depthRenderbuffer = 0;
    }
}

- (void)startAnimation
{
    animationTimer = [NSTimer scheduledTimerWithTimeInterval:animationInterval target:self selector:@selector(drawView) userInfo:nil repeats:YES];
}

- (void)stopAnimation
{
    [animationTimer invalidate];
    animationTimer = nil;
}

- (void)setAnimationInterval:(NSTimeInterval)interval
{
    animationInterval = interval;

    if(animationTimer)
    {
        [self stopAnimation];
        [self startAnimation];
    }
}

// Updates the OpenGL view when the timer fires
- (void)drawView
{
    // Make sure that you are drawing to the current context
    [EAGLContext setCurrentContext:context];

    // If our drawing delegate needs to have the view setup, then call -setupView: and flag that it won't need to be called again.
    if(!controllerSetup)
    {
        [controller setupView:self];
        controllerSetup = YES;
    }

    glBindFramebufferOES(GL_FRAMEBUFFER_OES, viewFramebuffer);

    [controller drawView:self];

    glBindRenderbufferOES(GL_RENDERBUFFER_OES, viewRenderbuffer);
    [context presentRenderbuffer:GL_RENDERBUFFER_OES];

    GLenum err = glGetError();
    if(err)
        NSLog(@"%x error", err);
}

// Stop animating and release resources when they are no longer needed.
- (void)dealloc
{
    [self stopAnimation];

    if([EAGLContext currentContext] == context)
    {
        [EAGLContext setCurrentContext:nil];
    }

    context = nil;

}

@end

GLView.h：

//
//  GLView.h
//  Part6Project
//
//  Created by jeff on 5/31/09.
//  Copyright Jeff LaMarche 2009. All rights reserved.
//

#import <UIKit/UIKit.h>
#import <OpenGLES/EAGL.h>
#import <OpenGLES/ES1/gl.h>
#import <OpenGLES/ES1/glext.h>
#import "ConstantsAndMacros.h"
#import "OpenGLCommon.h"
@class GLViewController;
@interface GLView : UIView
{
@private
    // The pixel dimensions of the backbuffer
    GLint backingWidth;
    GLint backingHeight;

    EAGLContext *context;
    GLuint viewRenderbuffer, viewFramebuffer;
    GLuint depthRenderbuffer;
    NSTimer *animationTimer;
    NSTimeInterval animationInterval;

    GLViewController *controller;
    BOOL controllerSetup;
}

@property(nonatomic, weak) GLViewController *controller;
@property NSTimeInterval animationInterval;

-(void)startAnimation;
-(void)stopAnimation;
-(void)drawView;

@end