Sprites/Diffuse with Hue shift

Hi guys, i worked on a sprite shader which can accept lights like the sprites/diffuse but including hue shift too.
This is because i searched a lot for such a shader but never found exactly this specific effect. Its a very simple shader so you can extend it as you want.

Code (CSharp):

1.  
2. Shader "Sprites/DefaultSprite" {
3.     Properties{
4.         _MainTex("Texture", 2D) = "white" {}
5.         _HueShift("HueShift", Float) = 0
6.     }
7.         SubShader{
8.         Tags{ "Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent" }
9.         ZWrite Off
10.         Blend SrcAlpha OneMinusSrcAlpha
11.         Cull Off
12.         CGPROGRAM
13.  
14.         //#pragma surface surf Lambert
15. #pragma surface surf Lambert alpha
16. #pragma target 3.0
17.  
18.     float3 rgb_to_hsv_no_clip(float3 RGB)
19.     {
20.         float3 HSV;
21.  
22.         float minChannel, maxChannel;
23.         if (RGB.x > RGB.y) {
24.             maxChannel = RGB.x;
25.             minChannel = RGB.y;
26.         }
27.         else {
28.             maxChannel = RGB.y;
29.             minChannel = RGB.x;
30.         }
31.  
32.         if (RGB.z > maxChannel) maxChannel = RGB.z;
33.         if (RGB.z < minChannel) minChannel = RGB.z;
34.  
35.         HSV.xy = 0;
36.         HSV.z = maxChannel;
37.         float delta = maxChannel - minChannel;             //Delta RGB value
38.         if (delta != 0)
39.         {                    // If gray, leave H  S at zero
40.             HSV.y = delta / HSV.z;
41.             float3 delRGB;
42.             delRGB = (HSV.zzz - RGB + 3 * delta) / (6.0*delta);
43.             if (RGB.x == HSV.z) HSV.x = delRGB.z - delRGB.y;
44.             else if (RGB.y == HSV.z) HSV.x = (1.0 / 3.0) + delRGB.x - delRGB.z;
45.             else if (RGB.z == HSV.z) HSV.x = (2.0 / 3.0) + delRGB.y - delRGB.x;
46.         }
47.         return (HSV);
48.     }
49.  
50.     float3 hsv_to_rgb(float3 HSV)
51.     {
52.         float3 RGB = HSV.z;
53.  
54.         float var_h = HSV.x * 6;
55.         float var_i = floor(var_h);   // Or ... var_i = floor( var_h )
56.         float var_1 = HSV.z * (1.0 - HSV.y);
57.         float var_2 = HSV.z * (1.0 - HSV.y * (var_h - var_i));
58.         float var_3 = HSV.z * (1.0 - HSV.y * (1 - (var_h - var_i)));
59.         if (var_i == 0) { RGB = float3(HSV.z, var_3, var_1); }
60.         else if (var_i == 1) { RGB = float3(var_2, HSV.z, var_1); }
61.         else if (var_i == 2) { RGB = float3(var_1, HSV.z, var_3); }
62.         else if (var_i == 3) { RGB = float3(var_1, var_2, HSV.z); }
63.         else if (var_i == 4) { RGB = float3(var_3, var_1, HSV.z); }
64.         else { RGB = float3(HSV.z, var_1, var_2); }
65.  
66.         return (RGB);
67.     }
68.  
69.     struct Input {
70.         float2 uv_MainTex;
71.     };
72.  
73.     sampler2D _MainTex;
74.     float _HueShift;
75.  
76.     void surf(Input IN, inout SurfaceOutput o) {
77.         o.Albedo = tex2D(_MainTex, IN.uv_MainTex).rgb;
78.  
79.         float3 hsv = rgb_to_hsv_no_clip(o.Albedo.xyz);
80.         hsv.x += _HueShift;
81.      
82.         o.Albedo = half3(hsv_to_rgb(hsv));
83.         o.Alpha = tex2D(_MainTex, IN.uv_MainTex).a;
84.     }
85.  
86.     ENDCG
87.     }
88.         Fallback "Diffuse"
89. }

 

FYI, this blog has optimized version which remove if-else statement http://www.chilliant.com/rgb2hsv.html