Shader "Custom/ArmorShader" {
	Properties {
		_Color ("Color", Color) = (1,1,1,1)
		_SpeColor ("Specular Color", Color) = (1,1,1,1)
		_MainTex ("Albedo (RGB)", 2D) = "white" {}
		//_SpecInt ("Specular intensity", Range(0,2) ) = 0.5
		//_SpecSat ("Specular saturation", Range(0,1) ) = 1.0
		_Glossiness ("Smoothness", Range(0,1)) = 0.5
		////_Shift ("shift", float) = 0.05
		_Offset ("Offset", Range(0,0.5)) = 0.0
		_Contrast ("Contrast", float) = 0.5
		
		[MaterialToggle] _showSpecMap("show spec map", Float) = 0
		
		//_SpecuColor ("Specular Color", Color) = (0,1,0,1)
	}
	SubShader {
		Tags { "RenderType"="Opaque" }
		LOD 200
		
		CGPROGRAM
		// Physically based Standard lighting model, and enable shadows on all light types
		#pragma surface surf StandardSpecular fullforwardshadows

		// Use shader model 3.0 target, to get nicer looking lighting
		#pragma target 3.0

		sampler2D _MainTex;

		struct Input {
			float2 uv_MainTex;
		};

		half _Glossiness;
		//float4 _SpecuColor;
		float _SpecInt;
		fixed4 _Color;
		fixed4 _SpeColor;
		float _Offset;
		float _Contrast;
		float _Shift;
		float _SpecSat;
		float _showSpecMap;
		
		//fixed3 Albedo;      // diffuse color
    //fixed3 Specular;    // specular color
    //fixed3 Normal;      // tangent space normal, if written
    //half3 Emission;
    //half Smoothness;    // 0=rough, 1=smooth
    //half Occlusion;     // occlusion (default 1)
   // fixed Alpha;        // alpha for transparencies
   
   float3 rgbTohsv(float3 RGB)
        {
             float3 HSV;
	           
	         float minChannel, maxChannel;
	         if (RGB.x > RGB.y) {
	          maxChannel = RGB.x;
	          minChannel = RGB.y;
	         }
	         else {
	          maxChannel = RGB.y;
	          minChannel = RGB.x;
	         }
         
	         if (RGB.z > maxChannel) maxChannel = RGB.z;
	         if (RGB.z < minChannel) minChannel = RGB.z;
           
             HSV.xy = 0;
             HSV.z = maxChannel;
             float delta = maxChannel - minChannel;             //Delta RGB value
             if (delta != 0) {                    // If gray, leave H  S at zero
                   HSV.y = delta / HSV.z;
                   float3 delRGB;
                   delRGB = (HSV.zzz - RGB + 3*delta) / (6.0*delta);
                   if      ( RGB.x == HSV.z ) HSV.x = delRGB.z - delRGB.y;
                   else if ( RGB.y == HSV.z ) HSV.x = ( 1.0/3.0) + delRGB.x - delRGB.z;
                   else if ( RGB.z == HSV.z ) HSV.x = ( 2.0/3.0) + delRGB.y - delRGB.x;
             }
             return (HSV);
        }
 
        float3 hsvTorgb(float3 HSV)
        {
                float3 RGB = HSV.z;
           
                   float var_h = HSV.x * 6;
                   float var_i = floor(var_h);   // Or ... var_i = floor( var_h )
                   float var_1 = HSV.z * (1.0 - HSV.y);
                   float var_2 = HSV.z * (1.0 - HSV.y * (var_h-var_i));
                   float var_3 = HSV.z * (1.0 - HSV.y * (1-(var_h-var_i)));
                   if      (var_i == 0) { RGB = float3(HSV.z, var_3, var_1); }
                   else if (var_i == 1) { RGB = float3(var_2, HSV.z, var_1); }
                   else if (var_i == 2) { RGB = float3(var_1, HSV.z, var_3); }
                   else if (var_i == 3) { RGB = float3(var_1, var_2, HSV.z); }
                   else if (var_i == 4) { RGB = float3(var_3, var_1, HSV.z); }
                   else                 { RGB = float3(HSV.z, var_1, var_2); }
           
           return (RGB);
        }

		void surf (Input IN, inout SurfaceOutputStandardSpecular o) {
			// Albedo comes from a texture tinted by color
			fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
			
			
			float lum = Luminance(c.rgb) + _Offset;
			
			//contrast
			lum = clamp( ((lum - 0.5f) * max(_Contrast, 0)) + 0.5f , 0.0, 1.0 );
			
			float3 scolHSV = rgbTohsv(_SpeColor.rgb);
			float3 colHSV = rgbTohsv(c.rgb);
			//scolHSV.z = _SpecInt;
			//scolHSV.x += _Shift;
			scolHSV.y = colHSV.y;
			
			
			if( _showSpecMap == 1 )
			{			
				o.Albedo = float4(lum, lum, lum, c.a);
				o.Specular = float3(0,0,0);
				o.Smoothness = 0;
			}
			else
			{		
				o.Albedo = c.rgb;
				o.Specular = hsvTorgb(scolHSV);
				o.Specular *= lum;			
				o.Smoothness = _Glossiness;
			}
			
			o.Alpha = c.a;
		}
		ENDCG
	} 
	FallBack "Diffuse"
}