Shader "DashGame/GrayMesh"
{
	Properties
	{
		[PerRendererData] _MainTex("Sprite Texture", 2D) = "white" {}
	_Color("Tint", Color) = (1,1,1,1)
		[MaterialToggle] PixelSnap("Pixel snap", Float) = 0

		[PerRendererData] _GrayScaleX("GrayScaleX", range(0,1)) = 0.299
		[PerRendererData] _GrayScaleY("GrayScaleY", range(0,1)) = 0.587
		[PerRendererData] _GrayScaleZ("GrayScaleZ", range(0,1)) = 0.114
	}

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

		Cull Off
		Lighting Off
		ZWrite Off
		Blend One OneMinusSrcAlpha

		Pass
	{
		CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma target 2.0
#pragma multi_compile _ PIXELSNAP_ON
#pragma multi_compile _ ETC1_EXTERNAL_ALPHA
#include "UnityCG.cginc"

		struct appdata_t
	{
		float4 vertex   : POSITION;
		float4 color    : COLOR;
		float2 texcoord : TEXCOORD0;
		float2 grayScale : TEXCOORD1;
		UNITY_VERTEX_INPUT_INSTANCE_ID
	};

	struct v2f
	{
		float grayScale : COLOR1;
		float4 vertex   : SV_POSITION;
		fixed4 color : COLOR;
		float2 texcoord  : TEXCOORD0;
		UNITY_VERTEX_OUTPUT_STEREO
	};

	fixed4 _Color;

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

		return OUT;
	}

	float _GrayScaleX;
	float _GrayScaleY;
	float _GrayScaleZ;
	sampler2D _MainTex;
	sampler2D _AlphaTex;

	fixed4 SampleSpriteTexture(float2 uv)
	{
		fixed4 color = tex2D(_MainTex, uv);

#if ETC1_EXTERNAL_ALPHA
		// get the color from an external texture (usecase: Alpha support for ETC1 on android)
		color.a = tex2D(_AlphaTex, uv).r;
#endif //ETC1_EXTERNAL_ALPHA

		return color;
	}

	fixed4 frag(v2f IN) : SV_Target
	{
		fixed4 c = SampleSpriteTexture(IN.texcoord)*IN.color;
	c.rgb *= c.a;

	fixed gray = dot(c.rgb, fixed3(_GrayScaleX, _GrayScaleY, _GrayScaleZ));

	fixed newR = lerp(c.r, gray, IN.grayScale);
	fixed newG = lerp(c.g, gray, IN.grayScale);
	fixed newB = lerp(c.b, gray, IN.grayScale);

	c.rgb = fixed3(newR, newG, newB);

	return c;
	}
		ENDCG
	}
	}
}