Shader "UnityEffects/ShadowProject" {
	Properties{
		_ShadowTex("ShadowTex", 2D) = "gray" {}
		_bulerWidth("BulerWidth", float) = 1
		_shadowfactor("Shadowfactor", Range(0,1)) = 0.5
		_ShadowMask("ShadowMask",2D) = "white"{}
	}
		SubShader{
			Tags { "Queue" = "AlphaTest+1" }
			Pass {
				ZWrite Off
				ColorMask RGB
				Blend DstColor Zero
				Offset -1, -1

				CGPROGRAM
				#pragma vertex vert
				#pragma fragment frag
				#include "UnityCG.cginc"

				struct v2f {
					float4 pos:POSITION;
					float4 sproj:TEXCOORD0;
				};

				float4x4 unity_Projector;
				sampler2D _ShadowTex;
				sampler2D _ShadowMask;
				//half4 _ShadowTex_TexelSize;
				//float _bulerWidth;
				float _shadowfactor;

				v2f vert(float4 vertex:POSITION) {
					v2f o;
					o.pos = UnityObjectToClipPos(vertex);
					o.sproj = mul(unity_Projector, vertex);
					return o;
				}

				half4 frag(v2f i) :COLOR{

					half4 uv4 = UNITY_PROJ_COORD(i.sproj);
					half shadowColR = tex2Dproj(_ShadowTex, uv4).r;
					half maskColA = tex2Dproj(_ShadowMask, uv4).r;
					half a = (shadowColR * maskColA);

					//blur来柔化边缘
					//a += tex2D(_ShadowTex, uv + _ShadowTex_TexelSize.xy * _bulerWidth * float2(1,0)).a;
					//a += tex2D(_ShadowTex, uv + _ShadowTex_TexelSize.xy * _bulerWidth * float2(0,1)).a;
					//a += tex2D(_ShadowTex, uv + _ShadowTex_TexelSize.xy * _bulerWidth * float2(-1,0)).a;
					//a += tex2D(_ShadowTex, uv + _ShadowTex_TexelSize.xy * _bulerWidth * float2(0,-1)).a;

					//a = a/5;
					if (a > 0)
					{
						return  half4(1,1,1,1) * (1 - _shadowfactor * a);
					}
					else
					{
						return half4(1,1,1,1);
					}
				}

				ENDCG
			}
	}
		FallBack "Diffuse"
}