FadeObjectInOut

/*
	FadeObjectInOut.cs
 	Hayden Scott-Baron (Dock) - http://starfruitgames.com
 	6 Dec 2012 
 
	This allows you to easily fade an object and its children. 
	If an object is already partially faded it will continue from there. 
	If you choose a different speed, it will use the new speed. 
 
	NOTE: Requires materials with a shader that allows transparency through color.  
*/
 
using UnityEngine;
using System.Collections;
 
public class FadeObjectInOut : MonoBehaviour
{
	// publically editable speed
	public float fadeTime = 0.5f; 
	public bool fadeInOnStart = false; 
	public bool fadeOutOnStart = false; 
 
	// store colours
	private Color[] colors; 
 
	// allow automatic fading on the start of the scene
	IEnumerator Start ()
	{
		yield return null; 
		if (fadeInOnStart)
			FadeIn(fadeTime); 
		if (fadeOutOnStart)
			FadeOut(fadeTime); 
	}
 
	// check the alpha value of most opaque object
	float MaxAlpha()
	{
		float maxAlpha = 0.0f; 
		Renderer[] rendererObjects = GetComponentsInChildren<Renderer>(); 
		foreach (Renderer item in rendererObjects)
		{
			maxAlpha = Mathf.Max (maxAlpha, item.material.color.a); 
		}
		return maxAlpha; 
	}
 
	// fade sequence
	IEnumerator FadeSequence (float fadingOutTime)
	{
		// log fading direction, then precalculate fading speed as a multiplier
		bool fadingOut = (fadingOutTime < 0.0f);
		float fadingOutSpeed = 1.0f / fadingOutTime; 
 
		// grab all child objects
		Renderer[] rendererObjects = GetComponentsInChildren<Renderer>(); 
		if (colors == null)
		{
			//create a cache of colors if necessary
			colors = new Color[rendererObjects.Length]; 
 
			// store the original colours for all child objects
			for (int i = 0; i < rendererObjects.Length; i++)
			{
				colors[i] = rendererObjects[i].material.color; 
			}
		}
 
		// make all objects visible
		for (int i = 0; i < rendererObjects.Length; i++)
		{
			rendererObjects[i].enabled = true;
		}
 
		// get current max alpha
		float alphaValue = MaxAlpha();  
 
		// iterate to change alpha value 
		while ( (alphaValue >= 0.0f && fadingOut) || (alphaValue <= 1.0f && !fadingOut)) 
		{
			alphaValue += Time.deltaTime * fadingOutSpeed; 
 
			for (int i = 0; i < rendererObjects.Length; i++)
			{
				Color newColor = (colors != null ? colors[i] : rendererObjects[i].material.color);
				newColor.a = Mathf.Min ( newColor.a, alphaValue ); 
				newColor.a = Mathf.Clamp (newColor.a, 0.0f, 1.0f); 				
				rendererObjects[i].material.SetColor("_Color", newColor) ; 
			}
 
			yield return null; 
		}
 
		// turn objects off after fading out
		if (fadingOut)
		{
			for (int i = 0; i < rendererObjects.Length; i++)
			{
				rendererObjects[i].enabled = false; 
			}
		}
	}
 
 
	void FadeIn ()
	{
		FadeIn (fadeTime); 
	}
 
	void FadeOut ()
	{
		FadeOut (fadeTime); 		
	}
 
	void FadeIn (float newFadeTime)
	{
		StopAllCoroutines(); 
		StartCoroutine("FadeSequence", newFadeTime); 
	}
 
	void FadeOut (float newFadeTime)
	{
		StopAllCoroutines(); 
		StartCoroutine("FadeSequence", -newFadeTime); 
	}
 
 
	// These are for testing only. Comment out to try fading in and out! 
//	void Update()
//	{
//		if (Input.GetKeyDown (KeyCode.Alpha0) )
//		{
//			FadeIn();
//		}
//		if (Input.GetKeyDown (KeyCode.Alpha9) )
//		{
//			FadeOut(); 
//		}
//	}
 
}