Unity Tempo Manager Example

TempoManager.cs

/**
 * This is an example of how to make a class that fires off events to the BPM of a song.
 * I haven't tested it and it may require work to compile, this is based off a much more complex
 * manager from another project.
 * 
 * Copyright (c) 2015 Eliot Lash
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
using UnityEngine;
using System;

public class TempoManager
{
	public float BPM = 120;
	private float _lastSyncTime = 0;
	private uint _beatsSinceSync = 0;

	void Start() {
		syncBPM();
	}

	void Update() {
		//Check beat timer and trigger beat if neccessary
		if (Time.time > _lastSyncTime + (beatsPerMinuteToDelay(BPM) * _beatsSinceSync)) {
			beat();
		}
	}

	private static float beatsPerMinuteToDelay(float beatsPerMinute) {
		//beats per second = beatsPerMinute / 60
		return 1.0f / (beatsPerMinute / 60.0f);
	}

	private void beat() {
		_beatsSinceSync++;
		//TODO Fire your beat event off here to your listeners
		print("beat!");
	}

	/// <summary>
	/// Restart BPM timer
	/// </summary>
	public void syncBPM() {
		_lastSyncTime = Time.time;
		_beatsSinceSync = 0;
		beat(); //NB: beat is now synced immedately instead of after a 1 beat delay
	}
		
}