﻿Shader "Nostalgia/Tiles/Canvas"
{
	Properties
	{
		_MainTex ("Tiles Texture", 2D) = "white" {}
		_Color ("Tint", Color) = (1,1,1,1)

		_StencilComp ("Stencil Comparison", Float) = 8
		_Stencil ("Stencil ID", Range(0.0, 255.0)) = 0
		_StencilOp ("Stencil Operation",Float) = 0
		_StencilWriteMask ("Stencil Write Mask",Range(0.0, 255.0)) = 255
		_StencilReadMask ("Stencil Read Mask",Range(0.0, 255.0)) = 255

		_ColorMask("Color Mask",Float) = 15
		
		[MaterialToggle] PixelSnap ("Pixel snap", Float) = 0
	}

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

		Stencil
		{
			Ref [_Stencil]
			Comp [_StencilComp]
			Pass [_StencilPass]
			ReadMask [_StencilReadMask]
			WriteMask [_StencilWriteMask]
		}

		Cull Off
		Lighting Off
		ZWrite Off
		Blend SrcAlpha OneMinusSrcAlpha
		ColorMask [_ColorMask]		

		Pass
		{
		CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag

			#pragma multi_compile_local _ PIXELSNAP_ON
			#pragma multi_compile_local __ UNITY_UI_ALPHACLIP

			#include "UnityCG.cginc"
			#include "UnityUI.cginc"
			#include "./TileCG.cginc"
			
			struct appdata_t
			{
				float4 vertex   : POSITION;
				float4 color    : COLOR;
				float4 texcoord : TEXCOORD0;
				float4 animation : TEXCOORD1;
			};

			struct v2f
			{
				float4 vertex   : SV_POSITION;
				fixed4 color	: COLOR;
				half2 texcoord  : TEXCOORD0;
				float4 worldPosition : TEXCOORD1;
			};
			
			fixed4 _Color;
			fixed4 _TextureSampleAdd;
			float4 _ClipRect;

			v2f vert(appdata_t IN)
			{
				v2f OUT;
				OUT.worldPosition = IN.vertex;
				OUT.vertex = UnityObjectToClipPos(OUT.worldPosition);

				float4 animation = float4(IN.animation.xy, 10, 0);
				OUT.texcoord = AnimateUV(IN.texcoord, animation);

				#ifdef UNITY_HALF_TEXEL_OFFSET
				OUT.vertex.xy += (_ScreenParams.zw-1.0)*float2(-1,2);
				#endif

				OUT.color = IN.color * _Color;
				
				return OUT;
			}

			sampler2D _MainTex;
			
			fixed4 frag(v2f IN) : SV_Target
			{
				half4 color = (tex2D(_MainTex, IN.texcoord) + _TextureSampleAdd) * IN.color;

				color.a *= UnityGet2DClipping(IN.worldPosition.xy,_ClipRect);

				#ifdef UNITY_UI_ALPHACLIIP
				clip (color.a - 0.0001);
				#endif

				return color;
			}
		ENDCG
		}
	}

	Fallback "UI/Default"
}
