Shader "UI/GreyscaleShader"

{

  Properties

  {

    [PerRendererData] _MainTex("Sprite Texture", 2D) = "white" {}

    _Color("Tint", Color) = (1, 1,1 , 1)

    _Greyscale("Greyscale", Range(0, 1)) = 1

    [HideInInspector] _RendererColor("RendererColor", Color) = (1,1,1,1)

    [HideInInspector] _Flip("Flip", Vector) = (1,1,1,1)

    [PerRendererData] _AlphaTex("External Alpha", 2D) = "white" {}

    [PerRendererData] _EnableExternalAlpha("Enable External Alpha", Float) = 0

  }

  SubShader

  {

    Tags

    {

      "Queue" = "Transparent"

      "IgnoreProjector" = "True"

      "RenderType" = "Transparent"

      "PreviewType" = "Plane"

      "CanUseSpriteAtlas" = "True"

    }

    Cull Off

    Lighting Off

    ZWrite Off

    Blend SrcAlpha OneMinusSrcAlpha

    Pass

    {

      CGPROGRAM

      #pragma vertex SpriteVert

      #pragma fragment frag

      #pragma target 2.0

      #pragma multi_compile_instancing

      #pragma multi_compile _ ETC1_EXTERNAL_ALPHA

      #include "UnitySprites.cginc"

      half _Greyscale;

      fixed4 frag(v2f IN) : SV_Target

      {

        fixed4 c = SampleSpriteTexture(IN.texcoord) * IN.color;

        c.rgb = lerp(c.rgb, dot(c.rgb, float3(0.3, 0.59, 0.11)), _Greyscale);

        c.rgb *= c.a;

        return c;

      }

      ENDCG

    }

  }

  Fallback "Sprites/Default"

}