Shader "Unlit/FakeLighth"
{
    Properties
    {
        _Color ("Color", Color) = (1,1,1,1)
    }
    SubShader
    {
        Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent" "PreviewType"="Plane" }
        Blend One One
        ZWrite Off Fog { Mode Off }
	    Lighting Off 
        ZTest On

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "UnityCG.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
            };

            float4 _Color;


            float2 Unity_PolarCoordinates_float(float2 UV, float2 Center, float RadialScale, float LengthScale)
            {
                float2 delta = UV - Center;
                float radius = length(delta) * 2 * RadialScale;
                float angle = atan2(delta.x, delta.y) * 1.0/6.28 * LengthScale;
                return float2(radius, angle);
            }


            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = v.uv;
                return o;
            }

            fixed4 frag (v2f i) : SV_Target
            {
                return _Color * (1.0 - Unity_PolarCoordinates_float(i.uv, float2(0.5, 0.5), 1, 1).r);
            }
            ENDCG
        }
    }
}