/*

     File: EAGLView.m

 Abstract: This class wraps the CAEAGLLayer from CoreAnimation into a convenient UIView subclass. The view content is basically an EAGL surface you render your OpenGL scene into.  Note that setting the view non-opaque will only work if the EAGL surface has an alpha channel.

  Version: 1.0

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#import <QuartzCore/QuartzCore.h>

#import <OpenGLES/EAGLDrawable.h>

#import "EAGLView.h"

#define USE_DEPTH_BUFFER 1

@interface EAGLView (EAGLViewPrivate)

- (BOOL)createFramebuffer;

- (void)destroyFramebuffer;

@end

@interface EAGLView (EAGLViewSprite)

- (void)setupView;

@end

@implementation EAGLView

@synthesize applicationResignedActive;

// You must implement this

+ (Class) layerClass

{

    return [CAEAGLLayer class];

}

//The GL view is stored in the nib file. When it's unarchived it's sent -initWithCoder:

- (id)initWithCoder:(NSCoder*)coder

{

    if((self = [super initWithCoder:coder])) {

        // Get the layer

        CAEAGLLayer *eaglLayer = (CAEAGLLayer*) self.layer;

        eaglLayer.opaque = YES;

        eaglLayer.drawableProperties = [NSDictionary dictionaryWithObjectsAndKeys:

                                        [NSNumber numberWithBool:FALSE], kEAGLDrawablePropertyRetainedBacking, kEAGLColorFormatRGBA8, kEAGLDrawablePropertyColorFormat, nil];

        context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES1];

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

            [self release];

            return nil;

        }

        animationInterval = 1.0 / 60.0;

        [self setupView];

        [self drawView];

    }

    return self;

}

- (void)layoutSubviews

{

    [EAGLContext setCurrentContext:context];

    [self destroyFramebuffer];

    [self createFramebuffer];

    [self drawView];

}

- (BOOL)createFramebuffer

{

    glGenFramebuffersOES(1, &viewFramebuffer);

    glGenRenderbuffersOES(1, &viewRenderbuffer);

    glBindFramebufferOES(GL_FRAMEBUFFER_OES, viewFramebuffer);

    glBindRenderbufferOES(GL_RENDERBUFFER_OES, viewRenderbuffer);

    [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);

    if(USE_DEPTH_BUFFER) {

        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;

}

- (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];

    animationStarted = [NSDate timeIntervalSinceReferenceDate];

}

- (void)stopAnimation

{

    [animationTimer invalidate];

    animationTimer = nil;

}

- (void)setAnimationInterval:(NSTimeInterval)interval

{

    animationInterval = interval;

    if(animationTimer) {

        [self stopAnimation];

        [self startAnimation];

    }

}

- (void)setupView

{

    // Sets up matrices and transforms for OpenGL ES

    glViewport(0, 0, backingWidth, backingHeight);

    glMatrixMode(GL_PROJECTION);

    glLoadIdentity();

    glOrthof(0, backingWidth, 0, backingHeight, -1.0f, 1.0f);

    glMatrixMode(GL_MODELVIEW);

    // Clears the view with black

    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);

    glEnableClientState(GL_VERTEX_ARRAY);

    ///glEnableClientState(GL_TEXTURE_COORD_ARRAY);

}

// Updates the OpenGL view when the timer fires

- (void)drawView

{

    // the NSTimer seems to fire one final time even though it's been invalidated

    // so just make sure and not draw if we're resigning active

    if (self.applicationResignedActive) return;

    // Make sure that you are drawing to the current context

    [EAGLContext setCurrentContext:context];

    glBindFramebufferOES(GL_FRAMEBUFFER_OES, viewFramebuffer);

    [delegate drawView:self forTime:([NSDate timeIntervalSinceReferenceDate] - animationStarted)];

    /*

     glRotatef(3.0f, 0.0f, 0.0f, 1.0f);

     glClear(GL_COLOR_BUFFER_BIT);

     glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

     */

    glBindRenderbufferOES(GL_RENDERBUFFER_OES, viewRenderbuffer);

    [context presentRenderbuffer:GL_RENDERBUFFER_OES];

}

// Stop animating and release resources when they are no longer needed.

- (void)dealloc

{

    [self stopAnimation];

    if([EAGLContext currentContext] == context) {

        [EAGLContext setCurrentContext:nil];

    }

    [context release];

    context = nil;

    [super dealloc];

}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

{

    if ([(id)delegate respondsToSelector:@selector(touchesBegan:withEvent:)])

        [delegate touchesBegan:touches withEvent:event];

}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event

{

    if ([(id)delegate respondsToSelector:@selector(touchesMoved:withEvent:)])

        [delegate touchesMoved:touches withEvent:event];

}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event

{

    if ([(id)delegate respondsToSelector:@selector(touchesEnded:withEvent:)])

        [delegate touchesEnded:touches withEvent:event];

}

- (id <EAGLViewDelegate>)delegate { return delegate; }

- (void)setDelegate:(id <EAGLViewDelegate>)v

{

    delegate = v;

}

@end