Shader "Carmen/Crook Portrait"
{
    Properties
    {
        _MainTex ("Portrait", 2D) = "white" {}
        _Text ("Portrait Text", 2D) = "white" {}
        _TextAlpha ("Portrait Text Alpha", 2D) = "white" {}
    }
    SubShader
    {
        Tags { "RenderType" = "Opaque" }
        LOD 200

        CGPROGRAM
            #pragma surface surf Standard
            //#pragma vertex vert
            //#pragma fragment frag
        
            UNITY_DECLARE_TEX2D(_MainTex);
            UNITY_DECLARE_TEX2D(_Text);
            UNITY_DECLARE_TEX2D(_TextAlpha);
  

            // struct Data
            // {
            //     float4 vertex : POSITION;
            //     float2 uv : TEXCOORD0;
            // };

            // struct Vert2Frag
            // {
            //     float4 position : SV_POSITION;
            //     float2 uv : TEXCOORD0;
            // };

            struct Input
            {
                float2 uv_MainTex;
                float2 uv_Text;
                float2 uv_TextAlpha;
            };
            

            // Vert2Frag vert(inout Data v)
            // {
            //     Vert2Frag o;
            //     o.position = UnityObjectToClipPos(v.vertex);
            //     o.uv = v.uv;
            //     return o;
            // }

            // fixed4 frag(Vert2Frag i) : SV_TARGET
            // {
            //     return UNITY_SAMPLE_TEX2D(_MainTex, i.uv);
            // }
        
            void surf (Input IN, inout SurfaceOutputStandard o)
            {
                float3 MainColour = UNITY_SAMPLE_TEX2D(_MainTex, IN.uv_MainTex);
                float Text = UNITY_SAMPLE_TEX2D(_Text, IN.uv_MainTex).r;
                float TextAlpha = UNITY_SAMPLE_TEX2D(_TextAlpha, IN.uv_MainTex).r;

                float3 TextColourMix = lerp(float3(1.0, 1.0, 1.0), float3(0.0, 0.0, 0.0), TextAlpha - Text);
                float3 ImageMix = lerp(MainColour, TextColourMix, TextAlpha);

                o.Albedo = ImageMix;//lerp(MainColour, float3(0.0, 0.0, 0.0), TextAlpha - Text);
                //o.Albedo = UNITY_SAMPLE_TEX2D(_Text, IN.uv_MainTex).r;
            }
        ENDCG
    }
    Fallback "Diffuse"
}