Shader "Erika/Common/Image/Blur" 
{
	Properties
	{
		_MainTex("Texture", 2D) = "white" {}
		_Angle("Angle", float) = 0
		_Distance("Distance", float) = 0
	}

	SubShader
	{
		Tags { "RenderType" = "Opaque" "Queue" = "Transparent-1"}
		LOD 100

		ZWrite Off
		ZTest LEqual

		Blend SrcAlpha OneMinusSrcAlpha

		Pass
		{
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag

			#include "UnityCG.cginc"

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

			struct v2f
			{
				float2 uv : TEXCOORD0;
				float4 vertex : SV_POSITION;
			};

			sampler2D _MainTex;
			float4 _MainTex_ST;

			float _Angle;

			float4 _TileOffset; // 角色的范围

			fixed _Distance;

			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
			{
				_Angle = 0; 
			    _Distance = 0;

				fixed2 uv = i.uv;
				fixed2 offset = fixed2(0.05, 0.05);
				const float sampleCount = 30;
				fixed4 color = fixed4(0,0,0,0);
				float radian = radians(_Angle);
				float distance = _Distance;
				for (int i = 0; i < sampleCount; i++)
				{
					float dx = distance * cos(radian) / sampleCount * i;
					float dy = distance * sin(radian) / sampleCount * i;
					color += tex2D(_MainTex,float2(uv.x + dx,uv.y + dy)) * (1 / sampleCount);
				}
				//color = tex2D(_MainTex, uv);
                if(uv.x > _TileOffset.z && uv.x < _TileOffset.x + _TileOffset.z 
                && uv.y > _TileOffset.w && uv.y < _TileOffset.w + _TileOffset.y) {
                    color = fixed4(1,0,0,0);
                }

				return color;
			}
			ENDCG
		}
	}

} // shader