Standard4ColorMask

Shader "Custom/Standard4ColorMask" {
    Properties {
        _Mask ("mask (RGBA)", 2D) = "black" {}

        _ColorR ("ColorR", Color) = (1,1,1,1)
        _ColorG ("ColorG", Color) = (1,1,1,1)
        _ColorB ("ColorB", Color) = (1,1,1,1)
        _ColorA ("ColorA", Color) = (1,1,1,1)

        _MainTex ("Albedo (RGB)", 2D) = "white" {}
        _Glossiness ("Smoothness", Range(0,1)) = 0.5
        _Metallic ("Metallic", Range(0,1)) = 0.0
    }
    SubShader {
        Tags { "RenderType"="Opaque" }
        LOD 200

        CGPROGRAM
        // Physically based Standard lighting model, and enable shadows on all light types
        #pragma surface surf Standard fullforwardshadows

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

        sampler2D _MainTex,_Mask;

        struct Input {
            float2 uv_MainTex;
        };

        half _Glossiness;
        half _Metallic;
        fixed4 _ColorR,_ColorG,_ColorB,_ColorA;

        void surf (Input IN, inout SurfaceOutputStandard o) {

            fixed4 mask = tex2D (_Mask, IN.uv_MainTex);
            // Albedo comes from a texture tinted by color
            fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * ( _ColorR * mask.r + _ColorG * mask.g + _ColorB * mask.b + _ColorA * mask.a) ;
            o.Albedo = c.rgb;
            // Metallic and smoothness come from slider variables
            o.Metallic = _Metallic;
            o.Smoothness = _Glossiness;
            o.Alpha = c.a;
        }
        ENDCG
    }
    FallBack "Diffuse"
}