EAGLView.m

//
//  EAGLView.m
//  gambit-iphone
//
//  Created by James on 4/22/09.
//  Copyright Coptix, Inc 2009. All rights reserved.
//



#import <QuartzCore/QuartzCore.h>
#import <OpenGLES/EAGLDrawable.h>

#import "EAGLView.h"

#define USE_DEPTH_BUFFER 0

// A class extension to declare private methods
@interface EAGLView ()

@property (nonatomic, retain) EAGLContext *context;
@property (nonatomic, assign) NSTimer *animationTimer;

- (BOOL) createFramebuffer;
- (void) destroyFramebuffer;

@end


@implementation EAGLView

@synthesize context;
@synthesize animationTimer;
@synthesize animationInterval;
@synthesize label;


// 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:NO], kEAGLDrawablePropertyRetainedBacking, kEAGLColorFormatRGBA8, kEAGLDrawablePropertyColorFormat, nil];
		
		context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES1];
		
		if (!context || ![EAGLContext setCurrentContext:context]) {
			[self release];
			return nil;
		}
		
		animationInterval = 1.0 / 60.0;

        register_view(self);
        init();
        [self initAccelerometer];
	}
	return self;
}

//// Accelerometer

- (void)initAccelerometer {
	UIAccelerometer* theAccelerometer = [UIAccelerometer sharedAccelerometer];
	theAccelerometer.updateInterval = 1/50.0;
	theAccelerometer.delegate = self;
}

- (void)accelerometer:(UIAccelerometer *)accelerometer
		didAccelerate:(UIAcceleration *)acceleration {
	did_accelerate(accelerometer, acceleration);
}
                       

//// Touches

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    touches_began(touches, event);
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    touches_moved(touches, event);
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    touches_ended(touches, event);
}

- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event {
    touches_cancelled(touches, event);
}

//// Rendering

- (void)drawView {
    NSString *labelText = [[NSString alloc] initWithCString:(char*)get_title()
                                            encoding: NSASCIIStringEncoding];
    [self.label setText:labelText];
		
	[EAGLContext setCurrentContext:context];
	
	glBindFramebufferOES(GL_FRAMEBUFFER_OES, viewFramebuffer);
	glViewport(0, 0, backingWidth, backingHeight);
	
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrthof(0.0f, 1.0f, 1.0f, 0.0f, -1.0f, 1.0f);
	glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    
	glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
	glClear(GL_COLOR_BUFFER_BIT);

    render();

    glBindRenderbufferOES(GL_RENDERBUFFER_OES, viewRenderbuffer);
	[context presentRenderbuffer:GL_RENDERBUFFER_OES];
}


- (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:(CAEAGLLayer*)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 {
	self.animationTimer = [NSTimer scheduledTimerWithTimeInterval:animationInterval target:self selector:@selector(drawView) userInfo:nil repeats:YES];
}


- (void)stopAnimation {
	self.animationTimer = nil;
}


- (void)setAnimationTimer:(NSTimer *)newTimer {
	[animationTimer invalidate];
	animationTimer = newTimer;
}


- (void)setAnimationInterval:(NSTimeInterval)interval {
	
	animationInterval = interval;
	if (animationTimer) {
		[self stopAnimation];
		[self startAnimation];
	}
}


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

@end