Audio meter for C4

C4WorkSpace.m

//
//  C4WorkSpace.m
//  audioMeter
//
//  Created by Travis Kirton on 12-05-17.
//  Copyright (c) 2012 POSTFL. All rights reserved.
//

#import "C4WorkSpace.h"
@interface C4WorkSpace ()
-(void)printMeters;
@end

@implementation C4WorkSpace {
    C4Sample *s;
    C4Shape *l1, *r1, *l2, *r2;
}

-(void)setup {
    s = [C4Sample sampleNamed:@"C4Loop.aif"];
    s.loops = YES;
    s.meteringEnabled = YES;
    [s prepareToPlay];
    [s play];
    
    C4Log(@"%d",s.player.numberOfChannels);
    
    CGPoint linePoints[2] = {CGPointMake(384/2, 1024),CGPointMake(384/2, 0)};
    l1 = [C4Shape line:linePoints];
    [self.canvas addShape:l1];
    
    linePoints[0].x += 20;
    linePoints[1].x += 20;
    l2 = [C4Shape line:linePoints];
    [self.canvas addShape:l2];
    
    linePoints[0].x += 364;
    linePoints[1].x += 364;
    r1 = [C4Shape line:linePoints];
    [self.canvas addShape:r1];
    
    linePoints[0].x += 20;
    linePoints[1].x += 20;
    r2 = [C4Shape line:linePoints];
    [self.canvas addShape:r2];
    
    l1.lineWidth = 20.0;
    l2.lineWidth = 20.0;
    r1.lineWidth = 20.0;
    r2.lineWidth = 20.0;
    
    l1.animationDuration = 0.0;
    r1.animationDuration = 0.0;
    l2.animationDuration = 0.0;
    r2.animationDuration = 0.0;
    
    NSTimer *t = [NSTimer timerWithTimeInterval:1.0/60.0f target:self selector:@selector(printMeters) userInfo:nil repeats:YES];
    [[NSRunLoop mainRunLoop] addTimer:t forMode:NSDefaultRunLoopMode];
}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    [self printMeters];
}

-(void)printMeters {
    [s.player updateMeters];
    
    l1.strokeEnd = pow (10, (0.05 *[s.player peakPowerForChannel:0]));
    l2.strokeEnd = pow (10, (0.05 *[s.player averagePowerForChannel:0]));
    
    r1.strokeEnd = pow (10, (0.05 *[s.player peakPowerForChannel:1]));
    r2.strokeEnd = pow (10, (0.05 *[s.player averagePowerForChannel:1]));
}
@end