//
//  EAGLView.m
//  Particles
//




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

#import "EAGLView.h"
#import "GL.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;



// 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;
        }
        
        animationInterval = 1.0 / 60.0;
    }
    return self;
}



-(void)inicializar
{
	particles = [Particles alloc];
	[particles inicializar];

	touching = false;
	
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	
	glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
	glEnable(GL_BLEND);	

}


- (void)setupView
{	
	glViewport(0, 0, backingWidth, backingHeight);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrthof(-160.0f, 160.0f, 
			 240.0f,-240.0f, 
			 -1.0f,   1.0f); // center <0,0,0> on screen
	glMatrixMode(GL_MODELVIEW);
	
	// Clears the view with black
	glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
	
}


-(void)clearBuffer
{
	[EAGLContext setCurrentContext:context];
	glBindFramebufferOES(GL_FRAMEBUFFER_OES, viewFramebuffer);
	glClear(GL_COLOR_BUFFER_BIT);		
}

-(void)swapBuffer
{
	glBindRenderbufferOES(GL_RENDERBUFFER_OES, viewRenderbuffer);
	[context presentRenderbuffer:GL_RENDERBUFFER_OES];
}

// Updates the OpenGL view when the timer fires
- (void)drawView
{
	[self clearBuffer];

	if(touching)
		[particles setTouch:touchx y:touchy];

	[particles draw];
	[self swapBuffer];
}


- (void)layoutSubviews {
    [EAGLContext setCurrentContext:context];
    [self destroyFramebuffer];
    [self createFramebuffer];
	[self inicializar];
	[self setupView];
    [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];
}


#pragma mark -
#pragma mark === Touch handling  ===
#pragma mark

// Handles the start of a touch
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
	UITouch *touch = [[event allTouches] anyObject];
	CGPoint location = [touch locationInView:touch.view];
	
    touching = true;
	touchx = location.x - 160;
	touchy = location.y - 240;
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{  
	UITouch *touch = [[event allTouches] anyObject];
	CGPoint location = [touch locationInView:touch.view];
	
    touching = true;
	touchx = location.x - 160;
	touchy = location.y - 240;
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    touching = false;
}

- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
    touching = false;
}


@end


@end