/*

    File: oalSpatialView.m

Abstract: A visual representation of our sound stage

 Version: 1.9

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*/

#import "oalSpatialView.h"

#import "oalPlayback.h"

CGPathRef CreateRoundedRectPath(CGRect RECT, CGFloat cornerRadius)

{

    CGMutablePathRef        path;

    path = CGPathCreateMutable();

    double      maxRad = MAX(CGRectGetHeight(RECT) / 2., CGRectGetWidth(RECT) / 2.);

    if (cornerRadius > maxRad) cornerRadius = maxRad;

    CGPoint     bl, tl, tr, br;

    bl = tl = tr = br = RECT.origin;

    tl.y += RECT.size.height;

    tr.y += RECT.size.height;

    tr.x += RECT.size.width;

    br.x += RECT.size.width;

    CGPathMoveToPoint(path, NULL, bl.x + cornerRadius, bl.y);

    CGPathAddArcToPoint(path, NULL, bl.x, bl.y, bl.x, bl.y + cornerRadius, cornerRadius);

    CGPathAddLineToPoint(path, NULL, tl.x, tl.y - cornerRadius);

    CGPathAddArcToPoint(path, NULL, tl.x, tl.y, tl.x + cornerRadius, tl.y, cornerRadius);

    CGPathAddLineToPoint(path, NULL, tr.x - cornerRadius, tr.y);

    CGPathAddArcToPoint(path, NULL, tr.x, tr.y, tr.x, tr.y - cornerRadius, cornerRadius);

    CGPathAddLineToPoint(path, NULL, br.x, br.y + cornerRadius);

    CGPathAddArcToPoint(path, NULL, br.x, br.y, br.x - cornerRadius, br.y, cornerRadius);

    CGPathCloseSubpath(path);

    CGPathRef               ret;

    ret = CGPathCreateCopy(path);

    CGPathRelease(path);

    return ret;

}

@implementation oalSpatialView

#pragma mark Object Init / Maintenance

- (id)initWithCoder:(NSCoder *)coder

{

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

        [self initializeContents];

    }

    return self;

}

- (void)dealloc

{

    [playback removeObserver:self forKeyPath:@"sourcePos"];

    [playback removeObserver:self forKeyPath:@"isPlaying"];

    [playback removeObserver:self forKeyPath:@"listenerPos"];

    [playback removeObserver:self forKeyPath:@"listenerRotation"];

    CGImageRelease(_speaker_off);

    CGImageRelease(_speaker_on);

    [super dealloc];

}

- (void)awakeFromNib

{   

    // We want to register as an observer for the oalPlayback environment, so we'll get notified when things 

    // change, i.e. source position, listener position.

    [playback addObserver:self forKeyPath:@"sourcePos" options:NSKeyValueObservingOptionNew context:NULL];

    [playback addObserver:self forKeyPath:@"isPlaying" options:NSKeyValueObservingOptionNew context:NULL];

    [playback addObserver:self forKeyPath:@"listenerPos" options:NSKeyValueObservingOptionNew context:NULL];

    [playback addObserver:self forKeyPath:@"listenerRotation" options:NSKeyValueObservingOptionNew context:NULL];

    [playback checkForMusic];

    [self layoutContents];

}

#pragma mark KVO

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context

{

    // Generally, we just call [self layoutContents] whenever something changes in the oalPlayback environment. 

    // When the sound sound source is turned on or off, we also change the image for the speaker to either show 

    // or hide the sound waves.

    if ( (object == playback) && ([keyPath isEqualToString:@"sourcePos"]) ) {

        [self layoutContents];

    } 

    else if ( (object == playback) && [keyPath isEqualToString:@"isPlaying"] ) {

        [self layoutContents];

        if (playback.isPlaying)

            _speakerLayer.contents = (id)_speaker_on;

        else 

            _speakerLayer.contents = (id)_speaker_off;

    } 

    else if ( (object == playback) && ([keyPath isEqualToString:@"listenerPos"]) ) {

        [self layoutContents];

    } else if ( (object == playback) && ([keyPath isEqualToString:@"listenerRotation"]) ) {

        [self layoutContents];

    } else {

        [NSException raise:@"Error" format:@"%@ observing unexpected keypath %@ for object %@", self, keyPath, object];

    }

}

#pragma mark View contents

- (void)initializeContents

{

    // Load images for the two speaker states and retain them, because we'll be switching between them

    _speaker_off = [[UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"speaker_off" ofType:@"png"]] CGImage];

    CGImageRetain(_speaker_off);

    _speaker_on = [[UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"speaker_on" ofType:@"png"]] CGImage];

    CGImageRetain(_speaker_on);

    CGImageRef listenerImg = [[UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"listener" ofType:@"png"]] CGImage];

    CGImageRef instructionsImg = [[UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"instructions" ofType:@"png"]] CGImage];

    // Set up the CALayer which shows the speaker

    _speakerLayer = [CALayer layer];

    _speakerLayer.frame = CGRectMake(0., 0., CGImageGetWidth(_speaker_off), CGImageGetHeight(_speaker_off));

    _speakerLayer.contents = (id)_speaker_off;

    // Set up the CALayer which shows the listener

    _listenerLayer = [CALayer layer];

    _listenerLayer.frame = CGRectMake(0., 0., CGImageGetWidth(listenerImg), CGImageGetHeight(listenerImg));

    _listenerLayer.contents = (id)listenerImg;

    _listenerLayer.anchorPoint = CGPointMake(0.5, 0.57);

    // Set up the CALayer which shows the instructions

    _instructionsLayer = [CALayer layer];

    _instructionsLayer.frame = CGRectMake(0., 0., CGImageGetWidth(instructionsImg), CGImageGetHeight(instructionsImg));

    _instructionsLayer.position = CGPointMake(0., -140.);

    _instructionsLayer.contents = (id)instructionsImg;

    // Set a sublayerTransform on our view's layer. This causes (0,0) to be in the center of the view. This transform 

    // is useful because now our view's coordinates map precisely to our oalPlayback sound environment's coordinates.

    CATransform3D trans = CATransform3DMakeTranslation([self frame].size.width / 2., [self frame].size.height / 2., 0.);

    self.layer.sublayerTransform = trans;

    // Set the background image for the sound stage

    CGImageRef bgImg = [[UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"stagebg" ofType:@"png"]] CGImage];

    self.layer.contents = (id)bgImg;

    // Add our sublayers

    [self.layer insertSublayer:_speakerLayer above:self.layer];

    [self.layer insertSublayer:_listenerLayer above:self.layer];

    [self.layer insertSublayer:_instructionsLayer above:self.layer];

    // Prevent things from drawing outside our layer bounds

    self.layer.masksToBounds = YES; 

}

- (void)layoutContents

{

    // layoutContents gets called via KVO whenever properties within our oalPlayback object change

    // Wrap these layer changes in a transaction and set the animation duration to 0 so we don't get implicit animation

    [CATransaction begin];

    [CATransaction setValue:[NSNumber numberWithDouble:0.] forKey:kCATransactionAnimationDuration];

    // Position and rotate the listener

    _listenerLayer.position = playback.listenerPos;

    _listenerLayer.transform = CATransform3DMakeRotation(playback.listenerRotation, 0., 0., 1.);

    // The speaker gets rotated so that it's always facing the listener

    CGFloat rot = atan2(-(playback.sourcePos.x - playback.listenerPos.x), playback.sourcePos.y - playback.listenerPos.y);

    // Rotate and position the speaker

    _speakerLayer.position = playback.sourcePos;

    _speakerLayer.transform = CATransform3DMakeRotation(rot, 0., 0., 1.);

    [CATransaction commit];

}

#pragma mark Events

- (void)touchPoint:(CGPoint)pt

{

    if (!(_instructionsLayer.hidden)) _instructionsLayer.hidden = YES;

    if (_draggingLayer == _speakerLayer) playback.sourcePos = pt;

    else if (_draggingLayer == _listenerLayer) playback.listenerPos = pt;

}

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

{

    CGPoint pointInView = [[touches anyObject] locationInView:self];

    // Clip our pointInView to within 5 pixels of any edge, so we can't position objects near or beyond 

    // the edge of the sound stage

    pointInView = CGPointWithinBounds(pointInView, CGRectInset([self bounds], 5., 5.));

    // Convert the view point to our layer / sound stage coordinate system, which is centered at (0,0)

    CGPoint pointInLayer = CGPointMake(pointInView.x - [self frame].size.width / 2., pointInView.y - [self frame].size.height / 2.);

    // Find out if the distance between the touch is within the tolerance threshhold for moving

    // the source object or the listener object

    if (hypot(playback.sourcePos.x - pointInLayer.x, playback.sourcePos.y - pointInLayer.y) < kTouchDistanceThreshhold)

    {

        _draggingLayer = _speakerLayer;

    }

    else if (hypot(playback.listenerPos.x - pointInLayer.x, playback.listenerPos.y - pointInLayer.y) < kTouchDistanceThreshhold)

    {

        _draggingLayer = _listenerLayer;

    }

    else

    {

        _draggingLayer = nil;

    }

    // Handle the touch

    [self touchPoint:pointInLayer];

}

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

{

    // Called repeatedly as the touch moves

    CGPoint pointInView = [[touches anyObject] locationInView:self];

    pointInView = CGPointWithinBounds(pointInView, CGRectInset([self bounds], 5., 5.));

    CGPoint pointInLayer = CGPointMake(pointInView.x - [self frame].size.width / 2., pointInView.y - [self frame].size.height / 2.);

    [self touchPoint:pointInLayer];

}

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

{

    _draggingLayer = nil;

}

@end