Shader "Custom/AutoTileTriplanarShader"
{
    Properties
    {
        _MainTexX ("Texture X", 2D) = "white" {}
        _MainTexY ("Texture Y", 2D) = "white" {}
        _MainTexZ ("Texture Z", 2D) = "white" {}
        _TileFactor ("Tile Factor", Range(1, 10)) = 1.0
    }

    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 200

        CGPROGRAM
        #pragma surface surf Lambert

        sampler2D _MainTexX;
        sampler2D _MainTexY;
        sampler2D _MainTexZ;
        float _TileFactor;

        struct Input
        {
            float2 uv_MainTex;
            float3 worldNormal;
        };

        void surf (Input IN, inout SurfaceOutput o)
        {
            // Calculate the tiling factor based on the model scale
            float modelScale = max(max(UNITY_MATRIX_M[0].x, UNITY_MATRIX_M[1].y), UNITY_MATRIX_M[2].z);
            float tilingFactor = _TileFactor / modelScale;

            // Calculate the UV coordinates for each axis using the worldNormal
            float2 uvX = IN.worldNormal.yz * tilingFactor;
            float2 uvY = IN.worldNormal.xz * tilingFactor;
            float2 uvZ = IN.worldNormal.xy * tilingFactor;

            // Sample the textures using the calculated UV coordinates
            fixed4 cX = tex2D(_MainTexX, IN.uv_MainTex + uvX);
            fixed4 cY = tex2D(_MainTexY, IN.uv_MainTex + uvY);
            fixed4 cZ = tex2D(_MainTexZ, IN.uv_MainTex + uvZ);

            // Blend the sampled colors based on the absolute value of the worldNormal
            fixed4 finalColor = cX * abs(IN.worldNormal.x) + cY * abs(IN.worldNormal.y) + cZ * abs(IN.worldNormal.z);

            // Output the color
            o.Albedo = finalColor.rgb;
            o.Alpha = finalColor.a;
        }
        ENDCG
    }
    FallBack "Diffuse"
}