﻿Shader "NRSDK/AlphaBlend "
{
	Properties
	{
		_MainTex("_MainTex", 2D) = "white" {}
		_YTex("Y", 2D) = "white" {}
		_UTex("U", 2D) = "white" {}
		_VTex("V", 2D) = "white" {}
	}
		SubShader
	{
		Tags { "RenderType" = "Opaque" }
		LOD 100

		ZTest Always
		ZWrite Off

		Pass
		{
				CGPROGRAM
				#pragma vertex vert
				#pragma fragment frag

				#include "UnityCG.cginc"

				struct appdata
				{
					float4 vertex : POSITION;
					float2 uv : TEXCOORD0;
				};

				struct v2f
				{
					float2 uv : TEXCOORD0;
					UNITY_FOG_COORDS(1)
					float4 vertex : SV_POSITION;
				};

				sampler2D _MainTex;
				sampler2D _UTex;
				sampler2D _VTex;
				sampler2D _YTex;
				float4 _MainTex_ST;

				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
				{
					fixed2 uv = fixed2(i.uv.x, 1 - i.uv.y);
					fixed4 ycol = tex2D(_YTex, uv);
					fixed4 ucol = tex2D(_UTex, uv);
					fixed4 vcol = tex2D(_VTex, uv);
					float r = ycol.a + 1.4022 * vcol.a - 0.7011;
					float g = ycol.a - 0.3456 * ucol.a - 0.7145 * vcol.a + 0.53005;
					float b = ycol.a + 1.771 * ucol.a - 0.8855;
					fixed4 col_bg = fixed4(b, g, r, 1);
					col_bg.rgb = GammaToLinearSpace(col_bg.rgb);

					fixed4 col = tex2D(_MainTex, i.uv);
					fixed3 col_tex = lerp(col_bg.rgb, col.rgb, col.a);
					return fixed4(col_tex,1);
				}
			ENDCG
		}
	}
}
