Cog/Visualization/SpectrumView.m

//
//  SpectrumView.m
//  Cog
//
//  Created by Christopher Snowhill on 2/12/22.
//

#import "SpectrumView.h"

#import "analyzer.h"

#define LOWER_BOUND -80

extern NSString *CogPlaybackDidBeginNotficiation;
extern NSString *CogPlaybackDidPauseNotficiation;
extern NSString *CogPlaybackDidResumeNotficiation;
extern NSString *CogPlaybackDidStopNotficiation;

@interface SpectrumView () {
	VisualizationController *visController;
	NSTimer *timer;
	BOOL paused;
	BOOL stopped;
	BOOL isListening;

	NSColor *baseColor;
	NSColor *peakColor;
	NSColor *backgroundColor;
	NSColor *borderColor;
	ddb_analyzer_t _analyzer;
	ddb_analyzer_draw_data_t _draw_data;
}
@end

@implementation SpectrumView

@synthesize isListening;

- (id)initWithFrame:(NSRect)frame {
	self = [super initWithFrame:frame];
	if(self) {
		[self setup];
	}
	return self;
}

- (void)updateVisListening {
	if(self.isListening && (paused || stopped)) {
		[self stopTimer];
		self.isListening = NO;
	} else if(!self.isListening && (!stopped && !paused)) {
		[self startTimer];
		self.isListening = YES;
	}
}

- (void)setup {
	visController = [NSClassFromString(@"VisualizationController") sharedController];
	timer = nil;
	stopped = YES;
	paused = NO;
	isListening = NO;

	[self colorsDidChange:nil];

	ddb_analyzer_init(&_analyzer);
	_analyzer.db_lower_bound = LOWER_BOUND;
	_analyzer.peak_hold = 10;
	_analyzer.view_width = 64;
	_analyzer.fractional_bars = 1;
	_analyzer.octave_bars_step = 2;
	_analyzer.max_of_stereo_data = 1;
	_analyzer.mode = DDB_ANALYZER_MODE_OCTAVE_NOTE_BANDS;

	[[NSNotificationCenter defaultCenter] addObserver:self
	                                         selector:@selector(colorsDidChange:)
	                                             name:NSSystemColorsDidChangeNotification
	                                           object:nil];
	[[NSNotificationCenter defaultCenter] addObserver:self
	                                         selector:@selector(playbackDidBegin:)
	                                             name:CogPlaybackDidBeginNotficiation
	                                           object:nil];
	[[NSNotificationCenter defaultCenter] addObserver:self
	                                         selector:@selector(playbackDidPause:)
	                                             name:CogPlaybackDidPauseNotficiation
	                                           object:nil];
	[[NSNotificationCenter defaultCenter] addObserver:self
	                                         selector:@selector(playbackDidResume:)
	                                             name:CogPlaybackDidResumeNotficiation
	                                           object:nil];
	[[NSNotificationCenter defaultCenter] addObserver:self
	                                         selector:@selector(playbackDidStop:)
	                                             name:CogPlaybackDidStopNotficiation
	                                           object:nil];
}

- (void)dealloc {
	ddb_analyzer_dealloc(&_analyzer);
	ddb_analyzer_draw_data_dealloc(&_draw_data);

	[[NSNotificationCenter defaultCenter] removeObserver:self
	                                                name:NSSystemColorsDidChangeNotification
	                                              object:nil];
	[[NSNotificationCenter defaultCenter] removeObserver:self
	                                                name:CogPlaybackDidBeginNotficiation
	                                              object:nil];
	[[NSNotificationCenter defaultCenter] removeObserver:self
	                                                name:CogPlaybackDidPauseNotficiation
	                                              object:nil];
	[[NSNotificationCenter defaultCenter] removeObserver:self
	                                                name:CogPlaybackDidResumeNotficiation
	                                              object:nil];
	[[NSNotificationCenter defaultCenter] removeObserver:self
	                                                name:CogPlaybackDidStopNotficiation
	                                              object:nil];
}

- (void)repaint {
	self.needsDisplay = YES;
}

- (void)startTimer {
	[self stopTimer];
	timer = [NSTimer timerWithTimeInterval:1.0 / 60.0
	                                target:self
	                              selector:@selector(timerRun:)
	                              userInfo:nil
	                               repeats:YES];
	[[NSRunLoop currentRunLoop] addTimer:timer forMode:NSRunLoopCommonModes];
}

- (void)stopTimer {
	[timer invalidate];
	timer = nil;
}

- (void)timerRun:(NSTimer *)timer {
	[self repaint];
}

- (void)colorsDidChange:(NSNotification *)notification {
	backgroundColor = [NSColor textBackgroundColor];
	backgroundColor = [backgroundColor colorWithAlphaComponent:0.0];
	borderColor = [NSColor systemGrayColor];

	if(@available(macOS 10.14, *)) {
		baseColor = [NSColor textColor];
		peakColor = [NSColor controlAccentColor];
		peakColor = [peakColor colorWithAlphaComponent:0.7];
	} else {
		peakColor = [NSColor textColor];
		baseColor = [peakColor colorWithAlphaComponent:0.6];
	}

	[self repaint];
}

- (void)playbackDidBegin:(NSNotification *)notification {
	stopped = NO;
	paused = NO;
	[self updateVisListening];
}

- (void)playbackDidPause:(NSNotification *)notification {
	stopped = NO;
	paused = YES;
	[self updateVisListening];
}

- (void)playbackDidResume:(NSNotification *)notification {
	stopped = NO;
	paused = NO;
	[self updateVisListening];
}

- (void)playbackDidStop:(NSNotification *)notification {
	stopped = YES;
	paused = NO;
	[self updateVisListening];
	[self repaint];
}

- (void)drawAnalyzerDescreteFrequencies {
	CGContextRef context = NSGraphicsContext.currentContext.CGContext;
	ddb_analyzer_draw_bar_t *bar = _draw_data.bars;
	for(int i = 0; i < _draw_data.bar_count; i++, bar++) {
		CGContextMoveToPoint(context, bar->xpos, 0);
		CGContextAddLineToPoint(context, bar->xpos, bar->bar_height);
	}
	CGContextSetStrokeColorWithColor(context, baseColor.CGColor);
	CGContextStrokePath(context);

	bar = _draw_data.bars;
	for(int i = 0; i < _draw_data.bar_count; i++, bar++) {
		CGContextMoveToPoint(context, bar->xpos - 0.5, bar->peak_ypos);
		CGContextAddLineToPoint(context, bar->xpos + 0.5, bar->peak_ypos);
	}
	CGContextSetStrokeColorWithColor(context, peakColor.CGColor);
	CGContextStrokePath(context);
}

- (void)drawAnalyzerOctaveBands {
	CGContextRef context = NSGraphicsContext.currentContext.CGContext;
	ddb_analyzer_draw_bar_t *bar = _draw_data.bars;
	for(int i = 0; i < _draw_data.bar_count; i++, bar++) {
		CGContextAddRect(context, CGRectMake(bar->xpos, 0, _draw_data.bar_width, bar->bar_height));
	}
	CGContextSetFillColorWithColor(context, baseColor.CGColor);
	CGContextFillPath(context);

	bar = _draw_data.bars;
	for(int i = 0; i < _draw_data.bar_count; i++, bar++) {
		CGContextAddRect(context, CGRectMake(bar->xpos, bar->peak_ypos, _draw_data.bar_width, 1.0));
	}
	CGContextSetFillColorWithColor(context, peakColor.CGColor);
	CGContextFillPath(context);
}

- (void)drawAnalyzer {
	if(_analyzer.mode == DDB_ANALYZER_MODE_FREQUENCIES) {
		[self drawAnalyzerDescreteFrequencies];
	} else {
		[self drawAnalyzerOctaveBands];
	}
}

- (void)drawRect:(NSRect)dirtyRect {
	[super drawRect:dirtyRect];

	[self updateVisListening];

	[backgroundColor setFill];
	NSRectFill(dirtyRect);

	CGContextRef context = NSGraphicsContext.currentContext.CGContext;
	CGContextMoveToPoint(context, 0.0, 0.0);
	CGContextAddLineToPoint(context, 64.0, 0.0);
	CGContextAddLineToPoint(context, 64.0, 26.0);
	CGContextAddLineToPoint(context, 0.0, 26.0);
	CGContextAddLineToPoint(context, 0.0, 0.0);
	CGContextSetStrokeColorWithColor(context, borderColor.CGColor);
	CGContextStrokePath(context);

	if(stopped) return;

	float visAudio[8192], visFFT[4096];

	[self->visController copyVisPCM:&visAudio[0] visFFT:&visFFT[0]];

	ddb_analyzer_process(&_analyzer, [self->visController readSampleRate] / 2.0, 1, visFFT, 4096);
	ddb_analyzer_tick(&_analyzer);
	ddb_analyzer_get_draw_data(&_analyzer, self.bounds.size.width, self.bounds.size.height, &_draw_data);

	[self drawAnalyzer];
}

@end