似乎无法在模拟器上使用opengl es 1.1渲染

Question

我是OpenGL的完全noob，我一直试图让这个简单的代码在iphone模拟器上渲染，它启动正常，飞溅屏幕显示，然后...什么都没有...只是黑暗，我不能告诉我失踪，可以请一些人帮忙吗？ 我还没有做任何旋转，但等待，看看我先渲染了什么，然后继续旋转，然后......

我正在使用Xcode 4.2，如果有问题的话。

这里是我的代码：

IRenderEngine.cpp

#ifndef HelloArrow_IRenderingEngine_hpp 
#define HelloArrow_IRenderingEngine_hpp 

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

//Physical Orientation of a handheld device, equivalent to UIDeviceOrientation 
enum DeviceOrientation{ 
DeviceOrientationUnknown, 
DeviceOrientationPortrait, 
DeviceOrientationPortraitUpsideDown, 
DeviceOrientationLandscapeLeft, 
DeviceOrientationLandscapeRight, 
DeviceOrientationFaceUp, 
DeviceOrientationFaceDown 
}; 

//Creates an instance of a renderer and sets up various openGL state 
struct IRenderingEngine *CreateRenderer1(); 

//Interface to OpenGL ES renderer; consumed by GLView 
struct IRenderingEngine{ 
virtual void Initialize(int width, int height)=0; 
virtual void Render() = 0; 
virtual void UpdateAnimation(float timeStep) = 0; 
virtual void OnRotate(DeviceOrientation newOrientation) = 0; 
virtual ~IRenderingEngine(){}; 
}; 

RenderingEngine.cpp

#include <iostream> 

#include <OpenGLES/ES1/gl.h> 

#include <OpenGLES/ES1/glext.h> 

#include "IRenderingEngine.hpp" 


class RenderingEngine1 : public IRenderingEngine{ 
public: 
RenderingEngine1(); 
void Initialize(int width, int height); 
void Render(); 
void UpdateAnimation(float timeStep){} 
void OnRotate(DeviceOrientation newOrientation){} 
private: 
GLuint m_framebuffer; 
GLuint m_renderbuffer; 
}; 

IRenderingEngine * CreateRenderer1(){ 
return new RenderingEngine1; 
} 

struct Vertex { 
float Position[2]; 
float Color[4]; 
}; 

//Define the position and colors of the 2 triangles 
const struct Vertex Vertices[6] = { 
{{-0.5, -0.866},{1, 1, 0.5f, 1}}, 
{{0.5, -0.866},{1,1,0.5f,1}}, 
{{0,1},{1,1,0.5f,1}}, 
{{-0.5, -0.866},{0.5f,0.5f,0.5f}}, 
{{0.5, -0.866},{0.5f,0.5f,0.5f}}, 
{{0,-0.4f},{0.5f,0.5f,0.5f}} 
}; 
RenderingEngine1::RenderingEngine1(){ 
glGenRenderbuffersOES(1, &m_renderbuffer); 
glBindRenderbufferOES(GL_RENDERBUFFER_OES, m_renderbuffer); 
} 

void RenderingEngine1::Initialize(int width, int height){ 
//Create the framebuffer object and attache the renderbuffer  
glGenFramebuffersOES(1, &m_framebuffer); 
glBindFramebufferOES(GL_FRAMEBUFFER_OES, m_framebuffer); 

glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_COLOR_ATTACHMENT0_OES,  GL_RENDERBUFFER_OES, m_renderbuffer); 

glViewport(0, 0, width, height); 

glMatrixMode(GL_PROJECTION); 

glLoadIdentity(); 

const float maxX = 2; 
const float maxY = 3; 

glOrthof(-maxX,+maxX,-maxY,+maxY,-1,1); 


glMatrixMode(GL_MODELVIEW); 

glLoadIdentity(); 

} 

void RenderingEngine1::Render(){ 

glClearColor(0.5f, 0.5f, 0.5f, 1); 


glClear(GL_COLOR_BUFFER_BIT); 


glEnableClientState(GL_VERTEX_ARRAY); 


glEnableClientState(GL_COLOR_ARRAY); 
glVertexPointer(2,GL_FLOAT,4,&Vertices[0].Position); 


glColorPointer(4,GL_FLOAT,2,&Vertices[0].Color); 

GLsizei vertexcount = sizeof(Vertices)/sizeof(Vertex); 
glDrawArrays(GL_TRIANGLES, 0, vertexcount); 
glFlush(); 
glDisableClientState(GL_VERTEX_ARRAY); 
glDisableClientState(GL_COLOR_ARRAY); 
} 

GLView.h

#import "IRenderingEngine.hpp" 
#import <UIKit/UIKit.h> 
#import <OpenGLES/EAGL.h> 
#import <QuartzCore/QuartzCore.h> 


@interface GLView : UIView 
{ 
EAGLContext *m_context; 
struct IRenderingEngine *m_renderingEngine; 
float m_timestamp; 
} 

-(void) drawView:(CADisplayLink*) displayLink; 
-(void) didRotate: (NSNotification*) notification; 

@end 

GLView.mm

#import <OpenGLES/EAGLDrawable.h> 
#import <OpenGLES/ES1/gl.h> //<- for GL_RENDERBUFFER only 
#import "GLView.h" 
#import "mach/mach_time.h" 
#import "IRenderingEngine.hpp" 

@implementation GLView 

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

- (id)initWithFrame:(CGRect)frame 
{ 
self = [super initWithFrame:frame]; 
if (self) { 
    // Initialization code 
    CAEAGLLayer *eaglLayer = (CAEAGLLayer*) super.layer; 
    eaglLayer.opaque = YES; 
    m_context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES1]; 

    if(!m_context || ![EAGLContext setCurrentContext:m_context]){ 
     return nil; 
    } 

    m_renderingEngine = CreateRenderer1();  

    [m_context renderbufferStorage:GL_RENDERBUFFER fromDrawable:eaglLayer]; 

    m_renderingEngine->Initialize(CGRectGetWidth(frame), CGRectGetHeight(frame)); 
    [self drawView:nil]; 
    m_timestamp = CACurrentMediaTime(); 
    CADisplayLink *displayLink; 
    displayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(drawView:)]; 
    [displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; 
    [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications]; 
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(didRotate:) name:UIDeviceOrientationDidChangeNotification object:nil]; 

} 
return self; 
} 

/* 
// Only override drawRect: if you perform custom drawing. 
// An empty implementation adversely affects performance during animation. 
- (void)drawRect:(CGRect)rect 
{ 
// Drawing code 
} 
*/ 

-(void) drawView: (CADisplayLink *) displayLink{ 

if(displayLink != nil){ 
    float elapsedseconds = [displayLink timestamp] - m_timestamp; 
    m_timestamp = [displayLink timestamp]; 
    m_renderingEngine->UpdateAnimation(elapsedseconds); 
} 
m_renderingEngine->Render(); 

[m_context presentRenderbuffer:GL_RENDERBUFFER_OES]; 

} 

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

-(void) didRotate:(NSNotification *)notification{ 
UIDeviceOrientation orientation = [[UIDevice currentDevice] orientation]; 
m_renderingEngine->OnRotate((DeviceOrientation) orientation); 
[self drawView:nil]; 
} 

@end 

AppDelegate.h

#import <UIKit/UIKit.h> 
#import "GLView.h" 

@class ViewController; 

@interface AppDelegate : UIResponder <UIApplicationDelegate>{ 
UIWindow *m_window; 
GLView *m_view; 
} 

@property (strong, nonatomic) IBOutlet UIWindow *m_window; 

@end 

，最后，AppDelegate.mm

#import "AppDelegate.h" 
#import "OpenGLVC.h" 
#import <UIKit/UIKit.h> 

@implementation AppDelegate 

@synthesize m_window = _window; 

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 
{ 
CGRect screenBounds = [[UIScreen mainScreen] bounds]; 
self.m_window = [[UIWindow alloc] initWithFrame:screenBounds]; 
m_view = [[GLView alloc] initWithFrame:screenBounds]; 
[m_window addSubview:m_view]; 
[application setStatusBarHidden:YES withAnimation:UIStatusBarAnimationNone]; 
OpenGLVC *oglvc = [[OpenGLVC alloc] init]; 
self.m_window.rootViewController = oglvc; 
// Override point for customization after application launch. 
[self.m_window makeKeyAndVisible]; 
return YES; 
} 

- (void)applicationWillResignActive:(UIApplication *)application 
{ 
/* 
Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state. 
Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game. 
*/ 
} 

- (void)applicationDidEnterBackground:(UIApplication *)application 
{ 
/* 
Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later. 
If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits. 
*/ 
} 

- (void)applicationWillEnterForeground:(UIApplication *)application 
{ 
/* 
Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background. 
*/ 
} 

- (void)applicationDidBecomeActive:(UIApplication *)application 
{ 
/* 
Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface. 
*/ 
} 

- (void)applicationWillTerminate:(UIApplication *)application 
{ 
/* 
Called when the application is about to terminate. 
Save data if appropriate. 
See also applicationDidEnterBackground:. 
*/ 
} 

@end 

Answer 1

尝试改变

glVertexPointer(2,GL_FLOAT,4,&Vertices[0].Position); 
glColorPointer(4,GL_FLOAT,2,&Vertices[0].Color); 

到

glVertexPointer(2,GL_FLOAT,sizeof(Vertex),&Vertices[0].Position); 
glColorPointer(4,GL_FLOAT,sizeof(Vertex),&Vertices[0].Color); 

这两个函数中的第三个参数应该是跨度，即Vertices [0] .Position和Vertices [1] .Position之间的字节偏移量的差异。

换句话说，如果你站在Vertices [i] .Position并花了一个长的步幅，然后站在Vertices [i + 1] .Position，你的步幅必须以字节为单位要多长时间（不漂浮）。它是而不是你必须跳过从Vertices [i] .Position结束到Vertices [i + 1] .Position开始的间隙。

此外，步幅总是以字节表示，而不是浮点数或整数。

参见：

http://www.opengl.org/sdk/docs/man/xhtml/glVertexPointer.xml

http://www.opengl.org/sdk/docs/man/xhtml/glColorPointer.xml