ios – 使用GLKit绘图

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];

    if (!self.context) {
        NSLog(@"Failed to create ES context");
    }

    if(!renderer)
        renderer = [RenderManager sharedManager];
    tiles = [[TileSet alloc]init];

    GLKView *view = (GLKView *)self.view;
    view.context = self.context;
    view.drawableDepthFormat = GLKViewDrawableDepthFormat24;

    [self setupGL];
}

- (void)setupGL
{
    int width = [[self view] bounds].size.width;
    int height = [[self view] bounds].size.height;

    [EAGLContext setCurrentContext:self.context];

    self.effect = [[GLKBaseEffect alloc] init];
    self.effect.light0.enabled = GL_TRUE;
    self.effect.light0.diffuseColor = GLKVector4Make(0.4f,0.4f,1.0f);

    //Configure Buffers
    glGenFramebuffers(1,&framebuffer);
    glBindFramebuffer(GL_FRAMEBUFFER,framebuffer);

    glGenRenderbuffers(2,&colourRenderBuffer);
    glBindRenderbuffer(GL_RENDERBUFFER,colourRenderBuffer);
    glRenderbufferStorage(GL_RENDERBUFFER,GL_RGBA8_OES,width,height);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER,GL_COLOR_ATTACHMENT0,GL_RENDERBUFFER,colourRenderBuffer);

    glGenRenderbuffers(3,&depthRenderBuffer);
    glBindRenderbuffer(GL_RENDERBUFFER,depthRenderBuffer);
    glRenderbufferStorage(GL_RENDERBUFFER,GL_DEPTH_COMPONENT16,GL_DEPTH_ATTACHMENT,depthRenderBuffer);

    //Confirm everything happened awesomely
    GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER) ;
    if(status != GL_FRAMEBUFFER_COMPLETE) {
        NSLog(@"failed to make complete framebuffer object %x",status);
    }

    glEnable(GL_DEPTH_TEST);

    // Enable the OpenGL states we are going to be using when rendering
    glEnableClientState(GL_VERTEX_ARRAY);

}

- (void)glkView:(GLKView *)view drawInRect:(CGRect)rect
{
    glClearColor(0.4f,1.0f);


    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glBindFramebuffer(GL_FRAMEBUFFER,framebuffer);


    float iva[] = {
        0.0,0.0,1.0,};

    glVertexPointer(3,GL_FLOAT,sizeof(float) * 3,iva);

    glDrawArrays(GL_POINTS,4);

}
@end

使用此缓冲区清除(为灰色),但顶点数组没有任何渲染.我不知道该怎么做,由于技术的时代,没有太多关于如何正确使用glkit的信息.