Shader "3Blend" {
    Properties {
        _tex1 ("Texture 1", 2D) = "white" {}
        _tex2 ("Texture 2", 2D) = "white" {}
        _tex3 ("Texture 3", 2D) = "white" {}

    }
    SubShader
    {
        Tags { "RenderType"="Opaque"}
        pass
        {
            CGPROGRAM
            #pragma vertex VertexOutput
            #pragma fragment FragmentOutput
            #include "UnityCG.cginc"
            sampler2D _tex1;
            sampler2D _tex2;
            sampler2D _tex3;

            struct VertOut
            {
                float4 position : POSITION;
                float4 color : COLOR;
                float4 uv : TEXCOORD0;
            };

            struct VertIn
            {
                float4 vertex : POSITION;
                float4 color : COLOR;
                float4 texcoord : TEXCOORD0;
            };

            VertOut VertexOutput(VertIn input, float3 normal : NORMAL)
            {
                VertOut output;
                output.position = mul(UNITY_MATRIX_MVP,input.vertex);
                output.color = input.color;
                output.uv = float4(input.texcoord.xy,0,0);
                return output;
            }

            struct FragOut
            {
                float4 color : COLOR;
            };

            FragOut FragmentOutput(float4 color : COLOR, float4 uv : TEXCOORD0)
            {
                FragOut output;
                float4 vColor = color;
                float4 t1 = tex2D(_tex1,uv.xy);
                float4 t2 = tex2D(_tex2,uv.xy);
                float4 t3 = tex2D(_tex3,uv.xy);

                float4 final = t1*vColor.x + t2*vColor.y;
                final = t3*vColor.z + final*(1-vColor.z);
                output.color = final;

                return output;
            }
            ENDCG

        }
    }
    FallBack "Diffuse"
}