SpriteKit sound player singleton for iOS8 and iOS9.
While developing Heavy Metal Saumrai I ran into some issues while trying to get the sound right. I ended up using quite a few effects from Free Sounds, but of course they we're all at different volumes. I was a little disappointed to see that the SpriteKit framework didn't have any methods for allowing me to set the volume on my samples. Loading them into a audio workstation and normalizing everything was going to be a pain in the ass, so I set out to write a class with built in volume adjustment. Matter of fact, for future reference, it looked a little like this.
This led me to AVAudioPlayer. So I went about creating a class that made use of it. Problem is, AVAudioPlayer wasn't really designed to play sounds in rapid succession. If a player was mashing buttons and triggering the slash sound effect, it wouldn't start playing it till the first had finished. This left the game feeling choppy and unsynced.
So I went about doing it the old fashioned way. Loading all my game sounds into Ableton Live and adjusting the volume there (I ended up putting the voice over in there as well).
So that's that. I load the sounds into the game, and start playing them the spriteKit way, by using an SKAction.
self.runAction(SKAction.playSoundFileNamed("slash1.m4a", waitForCompletion: false))
Things seemed all well and good until I started testing the app in iOS 8. Repeatedly hitting the attack button, like the game was designed for, would occationally cause a system crash with a message like this...
NSInvalidArgumentException Resource can not be loaded
Oops, turns out (at least in iOS 8 it seems) that the playSoundFileNamed method loads the sound from the disk each time it's played. Doing that rapidly would eventually cause the crash. ***Sigh...
Ok, time to implement caching for these effects. When the game loads up I'll create a singleton that loads all these playable sounds in memory and has them ready to go for the user. That's exactly what I did and you can check out the example code here.
| // | |
| // SoundLoader.swift | |
| // Heavy Metal Samurais | |
| // | |
| // Created by john on 1/11/16. | |
| // Copyright © 2016 Large Pixels. All rights reserved. | |
| // | |
| import Foundation | |
| import AVFoundation | |
| import SpriteKit | |
| //Global variable available to all objects | |
| let SharedLPSoundLoader = LPSoundLoader.sharedInstance | |
| /** | |
| This object can be used to preload sounds and rapidly play them | |
| */ | |
| class LPSoundLoader { | |
| static let sharedInstance = LPSoundLoader() | |
| private init() { | |
| soundDictionary.setValue(SKAction.playSoundFileNamed("slash1.m4a", waitForCompletion: false), forKey: "slash1.m4a") | |
| soundDictionary.setValue(SKAction.playSoundFileNamed("slash2.m4a", waitForCompletion: false), forKey: "slash2.m4a") | |
| soundDictionary.setValue(SKAction.playSoundFileNamed("slash3.m4a", waitForCompletion: false), forKey: "slash3.m4a") | |
| soundDictionary.setValue(SKAction.playSoundFileNamed("slash4.m4a", waitForCompletion: false), forKey: "slash4.m4a") | |
| soundDictionary.setValue(SKAction.playSoundFileNamed("swoosh1.m4a", waitForCompletion: false), forKey: "swoosh1.m4a") | |
| soundDictionary.setValue(SKAction.playSoundFileNamed("swoosh2.m4a", waitForCompletion: false), forKey: "swoosh2.m4a") | |
| soundDictionary.setValue(SKAction.playSoundFileNamed("swoosh3.m4a", waitForCompletion: false), forKey: "swoosh3.m4a") | |
| soundDictionary.setValue(SKAction.playSoundFileNamed("swoosh4.m4a", waitForCompletion: false), forKey: "swoosh4.m4a") | |
| //soundDictionary.setValue(SKAction.playSoundFileNamed("land1.m4a", waitForCompletion: false), forKey: "land1.m4a") | |
| //soundDictionary.setValue(SKAction.playSoundFileNamed("land2.m4a", waitForCompletion: false), forKey: "land2.m4a") | |
| //soundDictionary.setValue(SKAction.playSoundFileNamed("ouch1.m4a", waitForCompletion: false), forKey: "ouch1.m4a") | |
| //soundDictionary.setValue(SKAction.playSoundFileNamed("ouch2.m4a", waitForCompletion: false), forKey: "ouch2.m4a") | |
| //soundDictionary.setValue(SKAction.playSoundFileNamed("ouch3.m4a", waitForCompletion: false), forKey: "ouch3.m4a") | |
| //soundDictionary.setValue(SKAction.playSoundFileNamed("ouch4.m4a", waitForCompletion: false), forKey: "ouch4.m4a") | |
| //soundDictionary.setValue(SKAction.playSoundFileNamed("ouch5.m4a", waitForCompletion: false), forKey: "ouch5.m4a") | |
| //soundDictionary.setValue(SKAction.playSoundFileNamed("death_groan1.m4a", waitForCompletion: false), forKey: "death_groan1.m4a") | |
| //soundDictionary.setValue(SKAction.playSoundFileNamed("death_groan2.m4a", waitForCompletion: false), forKey: "death_groan2.m4a") | |
| //soundDictionary.setValue(SKAction.playSoundFileNamed("death_groan3.m4a", waitForCompletion: false), forKey: "death_groan3.m4a") | |
| //soundDictionary.setValue(SKAction.playSoundFileNamed("death_groan4.m4a", waitForCompletion: false), forKey: "death_groan4.m4a") | |
| //soundDictionary.setValue(SKAction.playSoundFileNamed("death_groan5.m4a", waitForCompletion: false), forKey: "death_groan5.m4a") | |
| //soundDictionary.setValue(SKAction.playSoundFileNamed("death_groan6.m4a", waitForCompletion: false), forKey: "death_groan6.m4a") | |
| //soundDictionary.setValue(SKAction.playSoundFileNamed("power_up.m4a", waitForCompletion: false), forKey: "power_up.m4a") | |
| } | |
| //MARK: Sfx Player | |
| let soundDictionary = NSMutableDictionary() | |
| //should always use this so we don't play sounds it it's disabled | |
| func playRandomSfx(sfxPrefix: String, onWhat: SKNode) { | |
| if (!SharedLPOptionsLoader.playSfx) { | |
| return | |
| } | |
| switch sfxPrefix { | |
| case "slash": | |
| onWhat.runAction(getRandomSlashSoundAction()) | |
| case "land": | |
| onWhat.runAction(getRandomLandSoundAction()) | |
| case "swoosh": | |
| onWhat.runAction(getRandomSwooshSoundAction()) | |
| case "ouch": | |
| onWhat.runAction(getRandomOuchSoundAction()) | |
| case "death_groan": | |
| onWhat.runAction(getRandomDeathGroanSoundAction()) | |
| default: | |
| print("tried playing a sound type we don't have") | |
| } | |
| } | |
| //play sounds not part of a collection | |
| func playSfx(sfxName: String, onWhat: SKNode) { | |
| if (!SharedLPOptionsLoader.playSfx) { | |
| return | |
| } | |
| onWhat.runAction(soundDictionary.objectForKey(sfxName) as! SKAction) | |
| } | |
| private func getRandomSlashSoundAction() -> SKAction { | |
| let randomInt = Int.random(1, max: 4) | |
| return soundDictionary.objectForKey("slash\(randomInt).m4a") as! SKAction | |
| } | |
| private func getRandomLandSoundAction() -> SKAction { | |
| let randomInt = Int.random(1, max: 2) | |
| return soundDictionary.objectForKey("land\(randomInt).m4a") as! SKAction | |
| } | |
| private func getRandomSwooshSoundAction() -> SKAction { | |
| let randomInt = Int.random(1, max: 4) | |
| return soundDictionary.objectForKey("swoosh\(randomInt).m4a") as! SKAction | |
| } | |
| private func getRandomOuchSoundAction() -> SKAction { | |
| let randomInt = Int.random(1, max: 5) | |
| return soundDictionary.objectForKey("ouch\(randomInt).m4a") as! SKAction | |
| } | |
| private func getRandomDeathGroanSoundAction() -> SKAction { | |
| let randomInt = Int.random(1, max: 6) | |
| return soundDictionary.objectForKey("death_groan\(randomInt).m4a") as! SKAction | |
| } | |
| //MARK: Background Music | |
| var backgroundMusicPlayer: AVAudioPlayer? | |
| var lastSetVolume = Float(0.0) | |
| func playBackgroundMusic(filename: String) { | |
| playBackgroundMusic(filename, loops: -1) | |
| } | |
| func playBackgroundMusic(filename: String, loops: Int) { | |
| playBackgroundMusic(filename, loops: loops, volume: 1.0) | |
| } | |
| func playBackgroundMusic(filename: String, loops: Int, volume: Float) { | |
| lastSetVolume = volume | |
| let url = NSBundle.mainBundle().URLForResource(filename, withExtension: nil) | |
| if (url == nil) { | |
| print("Could not find file: \(filename)") | |
| return | |
| } | |
| do { | |
| backgroundMusicPlayer = try AVAudioPlayer(contentsOfURL: url!) | |
| if let player = backgroundMusicPlayer { | |
| player.volume = SharedLPOptionsLoader.playMusic ? lastSetVolume : 0.0 | |
| player.numberOfLoops = loops | |
| player.prepareToPlay() | |
| player.play() | |
| } | |
| } | |
| catch { | |
| print("Could not create audio player") | |
| } | |
| } | |
| func setVolumeBackToLastSet() { | |
| backgroundMusicPlayer?.volume = lastSetVolume | |
| } | |
| func setVolumeToZero() { | |
| backgroundMusicPlayer?.volume = 0.0 | |
| } | |
| func pauseBackgroundMusic() { | |
| if let player = backgroundMusicPlayer { | |
| if player.playing { | |
| player.pause() | |
| } | |
| } | |
| } | |
| func resumeBackgroundMusic() { | |
| if let player = backgroundMusicPlayer { | |
| if !player.playing { | |
| player.play() | |
| } | |
| } | |
| } | |
| } |
An example project is available on LargePixels GitHub.