Shader "Zhanyou/BlindEffect" {
	Properties {
		_MainTex("Base (RGB)", 2D) = "white" {}
		LightNum("Light", Range(0.0, 1.0)) = 1.0
		RadiuRange("Radiu", Range(0.0, 0.5)) = 0.7
	}

	SubShader {
		Tags
		{
            "IgnoreProjector"="True"
            "Queue"="Overlay"
			// 防止Shader Replace渲染这个东西
	        "RenderType"="NoReplace"
		}
	
		Pass {
			Lighting Off
			CGPROGRAM
			#pragma vertex vert  
			#pragma fragment frag  

			#include "UnityCG.cginc"  
			
			sampler2D _MainTex;
			float LightNum;
			float RadiuRange;

			struct appdata_t
			{
				float4 vertex : POSITION;
				float2 texcoord : TEXCOORD0;
				fixed4 color : COLOR;
			};

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

			v2f vert(appdata_t v)
			{
				v2f o;
				o.vertex = UnityObjectToClipPos(v.vertex);
				o.texcoord = v.texcoord;
				o.color = v.color;
				return o;
			}

			fixed4 frag(v2f i) : COLOR
			{
				fixed4 renderTex = tex2D(_MainTex, i.texcoord);
				fixed4 finalColor = renderTex;
				float2 center = float2(0.5, 0.45);
				float dis = distance(i.texcoord, center);
				if (dis >= RadiuRange)
				{
					finalColor = renderTex * LightNum;
				}
				else
				{
					if (dis < RadiuRange )
					{
						finalColor = renderTex * (LightNum + 1 - dis/RadiuRange);
					}
				}
					
				return finalColor;
			}

			ENDCG
		}
	}
}