Shader "BF/PostEffect/RadialBlur"
{
    Properties
    {
        _MainTex("MainTex", 2D) = "white"{}
        _BlurRadius("BlurRadius", Float)=0
        _RadialCenter("RadialCenter", Vector)=(0,0,0,0)
    }
    SubShader
    {
        Cull Off
        ZWrite Off
        ZTest Always

        CGINCLUDE
        #include "UnityCG.cginc"

        sampler2D _MainTex;
        float _BlurRadius;
	    float2 _RadialCenter;

        struct a2v
        {
            float4 vertex : POSITION;
            float2 texcoord : TEXCOORD0;
        };

        struct v2f
        {
            float4 vertex : SV_POSITION;
            half2 texcoord : TEXCOORD0;
        };

        v2f vert(a2v v)
        {
            v2f o;
            o.vertex = UnityObjectToClipPos(v.vertex);
            o.texcoord = v.texcoord;
            return o;
        }

        // fixed4 frag(v2f i) : SV_TARGET
        // {
        //     float2 uv = i.texcoord - _RadialCenter;

        //     half scale = 1;
        //     half4 color = tex2D(_MainTex, uv * scale + _RadialCenter);

        //     scale = _BlurRadius + 1;
        //     color += tex2D(_MainTex, uv * scale + _RadialCenter);

        //     scale = 2 * _BlurRadius + 1;
        //     color += tex2D(_MainTex, uv * scale + _RadialCenter);

        //     scale = 3 * _BlurRadius + 1;
        //     color += tex2D(_MainTex, uv * scale + _RadialCenter);

        //     color *= 0.25f;
        //     return  color;
        // }

        half4 frag(v2f i): SV_Target
        {
            float2 uv = i.texcoord - _RadialCenter;

            half scale = 1;
            half4 color = tex2D(_MainTex, uv * scale + _RadialCenter); //1 MAD

            scale = _BlurRadius + 1;  //1 MAD
            color += tex2D(_MainTex, uv * scale + _RadialCenter); //1 MAD

            scale = 2 * _BlurRadius + 1; //1 MAD
            color += tex2D(_MainTex, uv * scale + _RadialCenter); //1 MAD

            scale = 3 * _BlurRadius + 1; //1 MAD
            color += tex2D(_MainTex, uv * scale + _RadialCenter); //1 MAD

            scale = 4 * _BlurRadius + 1; //1 MAD
            color += tex2D(_MainTex, uv * scale + _RadialCenter); //1 MAD

            scale = 5 * _BlurRadius + 1; //1 MAD
            color += tex2D(_MainTex, uv * scale + _RadialCenter); //1 MAD


            color *= 0.1667f; // 1/6

            return  color;
        }
        ENDCG

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            ENDCG
        }
    }
}