ColorHSV.cs

using UnityEngine;

/**
* A color in HSV space
*/

public class ColorHSV : MonoBehaviour
{
	static private float lastTime;

	void FixedUpdate ()
	{
		if (Time.time > lastTime + 1)
		{
			Color newColor = ColorHSV.GetRandomColor(Random.Range(0.0f, 360f), Random.Range(0.0f, 360f), Random.Range(0.0f, 360f));
			GetComponent<Renderer>().material.color = newColor;
			lastTime = Time.time;
		}
	}


	private float h;
	private float s;
	private float v;
	private float a;
	
	/**
    * Construct without alpha (which defaults to 1)
    */
	
	public ColorHSV (float h ,float s ,float v){
		this.h = h;
		this.s = s;
		this.v = v;
		this.a = 1.0f;
	}
	
	/**
    * Construct with alpha
    */
	
	public ColorHSV (float h , float s, float v,float a){
		this.h = h;
		this.s = s;
		this.v = v;
		this.a = a;
	}
	
	/**
    * Create from an RGBA color object
    */
	
	public ColorHSV ( Color color  ){
		float min = Mathf.Min(Mathf.Min(color.r, color.g), color.b);
		float max = Mathf.Max(Mathf.Max(color.r, color.g), color.b);
		float delta = max - min;
		// value is our max color
		this.v = max;
		// saturation is percent of max
		
		if(!Mathf.Approximately(max, 0)){
			this.s = delta / max;
		}else{
			// all colors are zero, no saturation and hue is undefined
			this.s = 0;
			this.h = -1;
			return;
		}
		
		// grayscale image if min and max are the same
		if(Mathf.Approximately(min, max)){
			this.v = max;
			this.s = 0;
			this.h = -1;
			return;
		}
		// hue depends which color is max (this creates a rainbow effect)
		if( color.r == max ){
			this.h = ( color.g - color.b ) / delta;         // between yellow  magenta
		}else if( color.g == max ){
			this.h = 2 + ( color.b - color.r ) / delta; // between cyan  yellow
		}else{
			this.h = 4 + ( color.r - color.g ) / delta; // between magenta  cyan
		}
		
		// turn hue into 0-360 degrees
		this.h *= 60;
		if(this.h < 0 ){
			this.h += 360;
		}
	}
	
	/**
    * Return an RGBA color object
    */
	
	public Color ToColor (){
		// no saturation, we can return the value across the board (grayscale)
		if(this.s == 0 ){
			return new Color(this.v, this.v, this.v, this.a);
		}
		// which chunk of the rainbow are we in?
		float sector = this.h / 60;
		// split across the decimal (ie 3.87f into 3 and 0.87f)
		int i;
		i = (int)Mathf.Floor(sector);
		float f = sector - i;
		float v = this.v;
		float p = v * ( 1 - s );
		float q = v * ( 1 - s * f );
		float t = v * ( 1 - s * ( 1 - f ) );
		// build our rgb color
		Color color = new Color(0, 0, 0, this.a);
		switch(i){
		case 0:
			color.r = v;
			color.g = t;
			color.b = p;
			break;
		case 1:
			color.r = q;
			color.g = v;
			color.b = p;
			break;
		case 2:
			color.r  = p;
			color.g  = v;
			color.b  = t;
			break;
		case 3:
			color.r  = p;
			color.g  = q;
			color.b  = v;
			break;
		case 4:
			color.r  = t;
			color.g  = p;
			color.b  = v;
			break;
		default:
			color.r  = v;
			color.g  = p;
			color.b  = q;
			break;
		}
		return color;
	}
	
	public static Color GetRandomColor(float h ,float s ,float v){
		ColorHSV col = new ColorHSV(h,s,v);
		return col.ToColor();
	}
}