LD39/game/Assets/Scripts/DayTimeManager.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public enum RotationAxis
{
	X, Y
}

public class DayTimeManager : MonoBehaviour {

	public Light sunlight;
	public float secondsPerDay; 

	public RotationAxis rotAxis = RotationAxis.X; 

	public float maxAngle = 50.0f;

	private float _elapsedTime;

	public float timeFactor {
		get {
			return _elapsedTime / secondsPerDay;
		}
	}

	public DayTimeLabel dayTimeLabel {
		get {
			if (timeFactor >= 6.0f / 24.0f && timeFactor < 11.0f / 24.0f)
			{
				return DayTimeLabel.Morning;
			}

			if (timeFactor >= 11.0f / 24.0f && timeFactor < 17.0f / 24.0f)
			{
				return DayTimeLabel.Noon;
			}

			if (timeFactor >= 17.0f / 24.0f && timeFactor < 22.0f / 24.0f)
			{
				return DayTimeLabel.Evening;
			}

			if (timeFactor >= 23.0f / 24.0f && timeFactor < 24.0f / 24.0f)
			{
				return DayTimeLabel.Night;
			}

			if (timeFactor >= 0.0f / 24.0f && timeFactor < 6.0f / 24.0f)
			{
				return DayTimeLabel.Night;
			}

			return DayTimeLabel.Morning;
		}
	}

	private float _timeDirection = 1.0f;

	private Vector3 _position;
	private Vector3 _rotation;

	void Awake () {

	}

	// Use this for initialization
	void Start () {
		_position = sunlight.gameObject.transform.position;
		_rotation = sunlight.gameObject.transform.rotation.ToEulerAngles();
	}
	
	// Update is called once per frame
	void Update () {
		
		_elapsedTime += Time.deltaTime;
		if (_elapsedTime >= secondsPerDay)
		{
			_elapsedTime = 0;
		}

		float intensityAngle = this.timeFactor * Mathf.PI;
		sunlight.intensity = Mathf.Sin(intensityAngle);

		float rotationDirection = Mathf.Sign(this.timeFactor - 0.5f);

		switch (rotAxis)
		{
			case RotationAxis.X:
			{
				sunlight.gameObject.transform.rotation.SetEulerAngles(_rotation.x + rotationDirection * maxAngle, _rotation.y, _rotation.z);
			} break;

			case RotationAxis.Y:
			{
				sunlight.gameObject.transform.rotation.SetEulerAngles(_rotation.x, _rotation.y + rotationDirection * maxAngle, _rotation.z);
			} break;
		}

	}

	float FactorToDayTime(float factor)
	{
		return factor * 24.0f;
	}

	float DayTimeToFactor(float dayTime)
	{
		return dayTime / 24.0f;
	}

}