Shader "MyUIEffect/CommonEffects"
{Properties {
		[PerRendererData] _MainTex("Sprite Texture", 2D) = "white" {}
        _Color("Tint", Color) = (1, 1, 1, 1)
        [MaterialToggle] PixelSnap("Pixel snap", float) = 0

        /* Flowlight */
        _FlowlightColor("Flowlight Color", Color) = (1, 0, 0, 1)
        _Lengthlitandlar("LangthofLittle and Large", range(0,0.5)) = 0.005
        _MoveSpeed("MoveSpeed", float) = 5
        _Power("Power", float) = 1
        _LargeWidth("LargeWidth", range(0,0.005)) = 0.0035
        _LittleWidth("LittleWidth", range(0,0.001)) = 0.002
		_SkewRadio("SkewRadio", Range(0, 1)) = 0.2//倾斜度，0-1
		_MoveTime("MoveTime", float) = 0//控制扫光显示的位置，0-1
        /* --------- */

		_WidthRate("WidthRate",float) = 0
		_XOffset("XOffset",float) = 0
		_HeightRate("HeightRate",float) = 0
		_YOffset("YOffset",float) = 0

        /* UI */
        _StencilComp("Stencil Comparison", Float) = 8
        _Stencil("Stencil ID", Float) = 0
        _StencilOp("Stencil Operation", Float) = 0
        _StencilWriteMask("Stencil Write Mask", Float) = 255
        _StencilReadMask("Stencil Read Mask", Float) = 255
        _ColorMask("Color Mask", Float) = 15
        /* -- */
	}
	SubShader {
		Tags { 
			"Queue" = "Transparent"
			"IgnoreProjector" = "True"
			"RenderType" = "Transparent"
			"PreviewType" = "Plane"
			"CanUseSpriteAtlas" = "True"
		}
		Cull Off
        Lighting Off
        ZWrite Off
        Blend One OneMinusSrcAlpha
        ColorMask[_ColorMask]

		/* UI */
        Stencil{
            Ref[_Stencil]
            Comp[_StencilComp]
            Pass[_StencilOp]
            ReadMask[_StencilReadMask]
            WriteMask[_StencilWriteMask]
        }
        /* -- */

		Pass {
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			#pragma multi_compile _ PIXELSNAP_ON
			#include "UnityCG.cginc"

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

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

			fixed4 _Color;
			/* Flowlight */
			float _Power;
			float _LargeWidth;
			float _LittleWidth;
			float _Lengthlitandlar;
			float _MoveSpeed;
			float _SkewRadio;
			float _MoveTime;
			fixed4 _FlowlightColor;
			/* --------- */
			float _UVPosX;
			v2f vert(appdata_t IN) {
				v2f OUT;
				OUT.worldPosition = IN.vertex;
				OUT.vertex = UnityObjectToClipPos(IN.vertex);
				OUT.texcoord = IN.texcoord;
				OUT.color = IN.color * _Color;

				#ifdef PIXELSNAP_ON
				OUT.vertex = UnityPixelSnap(OUT.vertex);
				#endif

				return OUT;
			}

			sampler2D _MainTex;
			float4 _MainTex_ST;
			float _WidthRate;
			float _XOffset;
			float _HeightRate;
			float _YOffset;

			bool _UseClipRect;
			float4 _ClipRect;
			float _ClipSoftX;
			float _ClipSoftY;
    		fixed4 frag(v2f IN) : SV_Target {
        		fixed4 c = tex2D(_MainTex, IN.texcoord);
				//这里加了个判断，是否有半透明。当然可以根据自己的需要，通过半透明度去计算最终的结果达到目的
				if (c.a == 1){
					/*使用裁剪*/
					if (_UseClipRect)
					{
						float2 factor = float2(0.0, 0.0);
						float2 tempXY = (IN.worldPosition.xy - _ClipRect.xy) / float2(_ClipSoftX, _ClipSoftY)*step(_ClipRect.xy, IN.worldPosition.xy);
						factor = max(factor, tempXY);
						float2 tempZW = (_ClipRect.zw - IN.worldPosition.xy) / float2(_ClipSoftX, _ClipSoftY)*step(IN.worldPosition.xy, _ClipRect.zw);
						factor = min(factor, tempZW);
						c.a *= clamp(min(factor.x, factor.y), 0.0, 1.0);
					}
					/* --------- */
				
					/* Flowlight */
					//计算流动的标准uvX从-0.5到1.5范围
					_MoveSpeed = (_Time.x * 1000.0 % 255.0) / 255.0;

					_UVPosX = _XOffset + (fmod(_MoveTime*_MoveSpeed, 1) * 2 - 0.5)* _WidthRate;
					//标准uvX倾斜

					_UVPosX += (IN.texcoord.y - _HeightRate*0.5- _YOffset)*_SkewRadio;
					//以下是计算流光在区域内的强度，根据到标准点的距离的来确定强度，为了使变化更柔和非线性，使用距离平方或者sin函数也可以
					float lar = pow(1 - _LargeWidth*_WidthRate, 2);
					float lit = pow(1 - _LittleWidth*_WidthRate, 2);
					//第一道流光，可以累加任意条，如下

					fixed4 cadd = _FlowlightColor* saturate((1 - saturate(pow(_UVPosX - IN.texcoord.x,2))) - lar)*_Power /(1-lar);
					cadd += _FlowlightColor* saturate((1 - saturate(pow(_UVPosX - _Lengthlitandlar*_WidthRate - IN.texcoord.x, 2))) - lit)*_Power/ (1-lit);
					
					cadd.rgb *= cadd.a;
					
					//c.rgb += cadd.rgb;
					c.r = (_SinTime.z * 255.0 % 255.0) / 250.0;
					c.g = (_SinTime.z * 255.0 % 255.0) / 250.0;
					c.b = (_CosTime.z * 255.0 % 255.0) / 250.0;
					/* --------- */
				}
				c.rgb *= c.a;
        		return c;
    		}
        	ENDCG
    	}
	}
}