無法使用glGenFramebuffers生成幀緩衝區

Question

glGenFramebuffers不分配幀緩衝區對象！我無法得到這個小程序的工作。

代碼：

/* ----- AppDelegate.h ----- */ 
#import <UIKit/UIKit.h> 

#import "GLView.h" 

@interface AppDelegate : NSObject <UIApplicationDelegate>{ 
@private 
    UIWindow *window; 
    GLView *view; 
} 

@end 

---

/* ----- AppDelegate.h ----- */ 

#import "AppDelegate.h" 

@implementation AppDelegate 

- (void)dealloc 
{ 
    [view release]; 
    [window release]; 
    [super dealloc]; 
} 

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 
{ 
    CGRect frame = [[UIScreen mainScreen] bounds]; 

    window = [[UIWindow alloc] initWithFrame:frame]; 
    view = [[GLView alloc] initWithFrame:frame]; 

    [window addSubview:view]; 
    [window makeKeyAndVisible]; 
    return YES; 
} 

@end 

---

/* ----- GLView.h ----- */ 

#import <UIKit/UIKit.h> 
#import <QuartzCore/QuartzCore.h> 
#import <OpenGLES/EAGL.h> 
#import <OpenGLES/ES2/gl.h> 
#import <OpenGLES/ES2/glext.h> 

@interface GLView : UIView{ 
@private 
    EAGLContext* context; 
    GLuint color_render_buffer; 
    GLuint depth_render_buffer; 
    GLuint frame_buffer; 
} 

-(void)render:(CADisplayLink*)displayLink; 

@end 

---

/* ----- GLView.mm ----- */ 

#import "GLView.h" 

@implementation GLView 

- (id)initWithFrame:(CGRect)frame 
{ 
    self = [super initWithFrame:frame]; 
    if (self) { 
     CAEAGLLayer* eaglLayer = (CAEAGLLayer*)self.layer; 
     eaglLayer.opaque = YES; 

     context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2]; 
     if(!context && ![EAGLContext setCurrentContext:context]){ 
      [self release]; 
      return nil; 
     } 

     int width = (int)frame.size.width; 
     int height = (int)frame.size.height; 

     glGenFramebuffers(1, &frame_buffer); 
     glBindFramebuffer(GL_FRAMEBUFFER, frame_buffer); 
     if(glIsFramebuffer(frame_buffer) == GL_FALSE){ 
      //NSLog(@"%i", frame_buffer); 
      NSLog(@"frame_buffer is GL_FALSE!"); 
     } 

     glGenRenderbuffers(1, &color_render_buffer); 
     glBindRenderbuffer(GL_RENDERBUFFER, color_render_buffer); 
     [context renderbufferStorage:GL_RENDERBUFFER fromDrawable:eaglLayer]; 

     if(glIsRenderbuffer(color_render_buffer) == GL_FALSE){ 
      NSLog(@"%i", color_render_buffer); 
      NSLog(@"color_render_buffer is GL_FALSE"); 
     } 

     glGenRenderbuffers(1, &depth_render_buffer); 
     glBindRenderbuffer(GL_RENDERBUFFER, depth_render_buffer); 
     glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, width, height); 

     if(glIsRenderbuffer(depth_render_buffer) == GL_FALSE){ 
      NSLog(@"depth_render_buffer is GL_FALSE"); 
     } 


     glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, color_render_buffer); 
     glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depth_render_buffer); 

     if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE){ 
#ifdef DEBUG_LOG 
      NSLog(@"Framebuffer is not complete!"); 
      exit(1); 
#endif 
     } 

     [[CADisplayLink displayLinkWithTarget:self selector:@selector(render:)] addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; 
    } 
    return self; 
} 

+(Class)layerClass{ 
    return [CAEAGLLayer class]; 
} 

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

    [context release]; 
    [super dealloc]; 
} 

-(void)render:(CADisplayLink*)displayLink{ 
    /* Rendering */ 

    [context presentRenderbuffer:GL_RENDERBUFFER]; 
} 

@end 

我總是得到 「frame_buffer是GL_FALSE！」打印到控制檯... frame_buffer始終爲0（窗口系統默認幀緩衝區） 是否需要將任何設置添加到plist？或者我錯過了什麼？

請幫忙。

Answer 1

你永遠不會調用setCurrentContext：當context！= nil。
變化：

if(!context && ![EAGLContext setCurrentContext:context]){ 

要：

if(!context || ![EAGLContext setCurrentContext:context]){