/*

     File: EAGLView.m

 Abstract: n/a

  Version: 1.3

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 */

#import <QuartzCore/QuartzCore.h>

#import <OpenGLES/EAGLDrawable.h>

#import "EAGLView.h"

#import "Imaging.h"

// A class extension to declare private methods

@interface EAGLView ()

@property (nonatomic, retain) EAGLContext *context;

@end

@implementation EAGLView

@synthesize context;

@synthesize slider;

@synthesize tabBar;

// You must implement this method

+ (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:NO], kEAGLDrawablePropertyRetainedBacking,

            kEAGLColorFormatRGBA8, kEAGLDrawablePropertyColorFormat,

            nil];

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

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

        {

            [self release];

            return nil;

        }

        // Create system framebuffer object. The backing will be allocated in -reshapeFramebuffer

        glGenFramebuffersOES(1, &viewFramebuffer);

        glGenRenderbuffersOES(1, &viewRenderbuffer);

        glBindFramebufferOES(GL_FRAMEBUFFER_OES, viewFramebuffer);

        glBindRenderbufferOES(GL_RENDERBUFFER_OES, viewRenderbuffer);

        glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_COLOR_ATTACHMENT0_OES, GL_RENDERBUFFER_OES, viewRenderbuffer);

        // Perform additional one-time GL initialization

        initGL();

    }

    return self;

}

- (void)drawView

{

    int mode = (int)self.tabBar.selectedItem.tag;

    float value = self.slider.value;

    // This application only creates a single GL context, so it is already current here.

    // If there are multiple contexts, ensure the correct one is current before drawing.

    drawGL(backingWidth, backingHeight, value, mode);

    // This application only creates a single (color) renderbuffer, so it is already bound here.

    // If there are multiple renderbuffers (for example color and depth), ensure the correct one is bound here.

    [context presentRenderbuffer:GL_RENDERBUFFER_OES];

}

- (void)reshapeFramebuffer

{

    // Allocate GL color buffer backing, matching the current layer size

    [context renderbufferStorage:GL_RENDERBUFFER_OES fromDrawable:(CAEAGLLayer*)self.layer];

    glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_WIDTH_OES, &backingWidth);

    glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_HEIGHT_OES, &backingHeight);

    // This application only needs color. If depth and/or stencil are needed, ensure they are also resized here.

    rt_assert(GL_FRAMEBUFFER_COMPLETE_OES == glCheckFramebufferStatusOES(GL_FRAMEBUFFER_OES));

    glCheckError();

}

- (void)layoutSubviews

{

    [self reshapeFramebuffer];

    [self drawView];

}

- (void)dealloc

{        

    if ([EAGLContext currentContext] == context)

        [EAGLContext setCurrentContext:nil];

    self.context = nil;

    self.slider = nil;

    self.tabBar = nil;

    [super dealloc];

}

@end