// 1:09 https://www.youtube.com/watch?v=LhqI_yj3zO0 
Shader "Erika/Unit/Effect/unit_effect_blur"
{
    Properties
    {
		_MainTex("Texture", 2D) = "white" {}
		_BlurTex("Texture", 2D) = "black" {}
		_MaskColor ("Mask Color", Color) = (1,1,1,1)
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" "Queue" = "Transparent"}
        LOD 100

		Blend SrcAlpha OneMinusSrcAlpha

        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;
            };

            sampler2D _MainTex;
            float4 _MainTex_ST;

			sampler2D _BlurTex;
			float4 _BlurTex_ST;

			fixed4 _MaskColor;

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

            fixed4 frag (v2f i) : SV_Target
            {
				float2 uv = i.uv;
				fixed4 blur = tex2D(_BlurTex, uv).r;
				//uv.x += blur.r;
				//uv.y += blur.r;
				fixed4 col = tex2D(_MainTex, uv);
				col *= blur;
				
				return col;
            }
            ENDCG
        }
    }
}