spectogram-prototype/SpectogramPrototype/Ruler.m

//
//  Ruler.m
//  SpectogramPrototype
//
//  Created by Joshua Moerman on 25/02/14.
//  Copyright (c) 2014 Joshua Moerman. All rights reserved.
//

#import "Ruler.h"
#import "UIScreen+Util.h"


@implementation AbstractRuler
@synthesize visibleInterval;

- (void)setVisibleInterval:(Interval)visible_interval_{
    if (visibleInterval.begin != visible_interval_.begin || visibleInterval.end != visible_interval_.end) {
        [self setNeedsDisplay];
        visibleInterval = visible_interval_;
    }
}

@end


@implementation HorizontalRuler

- (void)drawRect:(CGRect) __unused rect{
    [[UIColor grayColor] setFill];
    UIRectFill(self.bounds);
    
    const Interval visibleInterval = self.visibleInterval;
    if(visibleInterval.end <= visibleInterval.begin) return;
    
    const CGFloat f = 60 * 44100.0 / 4096.0;
    const CGFloat start = f * ceil(visibleInterval.begin / f);
    const CGFloat d = visibleInterval.end - visibleInterval.begin;
    const int n = (int)floor(d / f) + 1;
    
    for(int i = 0; i < n; ++i){
        const CGFloat x = start + i * f;
        const CGFloat r = (x - visibleInterval.begin) / d;
        const CGFloat gx = r * self.bounds.size.width;
        
        [[UIColor blackColor] setFill];
        if([UIScreen isRetinaDisplay]){
            UIRectFill(CGRectMake(gx, 0, 0.5, self.bounds.size.height));
        } else {
            UIRectFill(CGRectMake(gx, 0, 1.0, self.bounds.size.height));
        }
        
        NSString* string = [NSString stringWithFormat:@"%.0f:00", x/f];
        NSMutableParagraphStyle* style = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
        style.alignment = NSTextAlignmentCenter;
        UIFont* font = [UIFont boldSystemFontOfSize:14];
        [string drawInRect:CGRectMake(gx-50, 20, 100, self.bounds.size.height-20)
            withAttributes:@{NSParagraphStyleAttributeName: style,
                             NSFontAttributeName: font}];
    }
}

@end


@implementation VerticalRuler
@synthesize tuning;

- (void)setTuning:(float)tuning_{
    tuning = tuning_;
    [self setNeedsDisplay];
}

- (UIColor*)colorForKey:(int)j{
    switch (j) {
        case 0:
            return [UIColor redColor];
        case 2:
        case 3:
        case 5:
        case 7:
        case 8:
        case 10:
            return [UIColor whiteColor];
            
        default:
            return [UIColor blackColor];
    }
}

- (void)drawRect:(CGRect) __unused rect{
    [[UIColor grayColor] setFill];
    UIRectFill(self.bounds);
    
    const Interval visibleInterval = self.visibleInterval;
    if(visibleInterval.end <= visibleInterval.begin) return;
    
    const CGFloat d = visibleInterval.end - visibleInterval.begin;
    const CGFloat f = 44100;
    const CGFloat N = 1 << 13;
    const CGFloat height = (1 << 13) >> 3;
    
    for(int i = 110; i < 44100/8; i *= 2){
        for(int j = 0; j < 12; ++j){
            const CGFloat k = (tuning/440.0) * i * pow(2, j/12.0);
            const CGFloat y = N*k/f;
            const CGFloat y2 = (height - y);
            const CGFloat gy = self.bounds.size.height * (y2 - visibleInterval.begin) / d;
            
            [[self colorForKey:j] setFill];
            
            if([UIScreen isRetinaDisplay]){
                UIRectFill(CGRectMake(0, gy, self.bounds.size.width, 0.5));
            } else {
                UIRectFill(CGRectMake(0, gy, self.bounds.size.width, 1.0));
            }
        }
    }
}

@end