UGUI里可用的Shader+流光效果

U3D抠脚菜鸡的第一篇Blog

这是一篇超级无脑的copy。。。不过帮我实现了甲方爸爸的需求。所以写下来方便更多萌新使用。
首先感谢以下两个链接博主的贡献。（因为就是参考~~copy~~这两位大牛的代码。。。）
流光效果(http://www.mamicode.com/info-detail-1111952.htm）
缺少_Stencil和_ColorMask的解决办法（UGUI里可用的Shader+流光效果

需求

UGUI设计的图片，背景是个边框，一开始交上去的稿件有点单调，需要让边框里有光影的效果。于是想到了遮罩+UV贴图。做出来的效果老板略满意，但是希望效果更好一些。所以把UV流动改成了流光效果。

接下来就是~~copy~~实现过程了：

新建一个Shader，具体什么类型无所谓。因为你终将会替代掉它。。。

双击打开，可以愉快的~~copy~~编辑了：

Shader "Sprites/FlowLight"
 {
    Properties
    {
	[PerRendererData]
		_MainTex("Sprite Texture", 2D) = "white" {}
		_Color("Tint", Color) = (1, 1, 1, 1)
	[MaterialToggle] 
		PixelSnap("Pixel snap", float) = 0
		_FlowlightTex("Flowlight Texture", 2D) = "white" {}
        _Power("Power", float) = 1
        _SpeedX("SpeedX", float) = 1
        _SpeedY("SpeedY", float) = 0
        //以下代码块可以有效防止Editor报缺失参数的错误（笔者踩过的坑）
		_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"
		}
		  //以下代码块可以有效防止Editor报缺失参数的错误（笔者踩过的坑）
		Stencil{
			Ref[_Stencil]
			Comp[_StencilComp]
			Pass[_StencilOp]
			ReadMask[_StencilReadMask]
			WriteMask[_StencilWriteMask]
		}
		//----
		Cull Off
	         Lighting Off
	         ZWrite Off
	         Blend One OneMinusSrcAlpha
			
        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;
                 half2 texflow : TEXCOORD1;
            };
	    fixed4 _Color;
	    sampler2D _FlowlightTex;
            fixed4 _FlowlightTex_ST;
            fixed _SpeedX;
            fixed _SpeedY;
	
             v2f vert(appdata_t IN)
             {
                 v2f OUT;
                 OUT.vertex = UnityObjectToClipPos(IN.vertex);
                 OUT.texcoord = IN.texcoord;
                 OUT.texflow = TRANSFORM_TEX(IN.texcoord, _FlowlightTex);
                 OUT.texflow.x += _Time * _SpeedX;
                 OUT.texflow.y += _Time * _SpeedY;
                 OUT.color = IN.color * _Color;
             #ifdef PIXELSNAP_ON
                 OUT.vertex = UnityPixelSnap(OUT.vertex);
             #endif
					
                 return OUT;
             }
			
             sampler2D _MainTex;
             float _Power;
			
             fixed4 frag(v2f IN) : SV_Target
             {
                 fixed4 c = tex2D(_MainTex, IN.texcoord);
                 fixed4 cadd = tex2D(_FlowlightTex, IN.texflow) * _Power;
                 cadd.rgb *= c.rgb;
                 c.rgb += cadd.rgb;
                 c.rgb *= c.a;
                 return c;
             }
        ENDCG
       }
   }
}