// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

Shader "Custom/GrayScale"
{
     Properties
     {
         [PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
         _Color ("Tint", Color) = (1,1,1,1)
         [MaterialToggle] PixelSnap ("Pixel snap", Float) = 0
         _EffectAmount ("Effect Amount", Range (0, 1)) = 1.0
     }

     SubShader
     {
         Tags
         {
             "Queue"="Transparent"
             "IgnoreProjector"="True"
             "RenderType"="Transparent"
             "PreviewType"="Plane"
             "CanUseSpriteAtlas"="True"
         }

         Cull Off
         Lighting Off
         ZWrite Off
         Fog { Mode Off }
         Blend SrcAlpha OneMinusSrcAlpha

         Pass
         {
         CGPROGRAM
             #pragma vertex vert
             #pragma fragment frag
             #pragma multi_compile DUMMY PIXELSNAP_ON
             #include "UnityCG.cginc"

             struct appdata_t
             {
                 float4 vertex   : POSITION;
                 float4 color    : COLOR;
                 float2 texcoord : TEXCOORD0;
             };

             struct v2f
             {
                 float4 vertex   : SV_POSITION;
                 fixed4 color    : COLOR;
                 half2 texcoord  : TEXCOORD0;
             };

             fixed4 _Color;

             v2f vert(appdata_t IN)
             {
                 v2f OUT;
                 OUT.vertex = UnityObjectToClipPos(IN.vertex);
                 OUT.texcoord = IN.texcoord;
                 OUT.color = IN.color * _Color;
                 #ifdef PIXELSNAP_ON
                 OUT.vertex = UnityPixelSnap (OUT.vertex);
                 #endif

                 return OUT;
             }

             sampler2D _MainTex;
             uniform float _EffectAmount;

             fixed4 frag(v2f IN) : COLOR
             {
                 half4 texcol = tex2D (_MainTex, IN.texcoord);
                 texcol.rgb = lerp(texcol.rgb, dot(texcol.rgb, float3(0.3, 0.59, 0.11)), _EffectAmount);
                 texcol = texcol * IN.color;
                 return texcol;
             }
         ENDCG
         }
     }
     Fallback "Sprites/Default"
}