ShaderLab 枚举常量

1.     public enum ZTest
2.     {
3.         Always = 0,
4.         Less = 2,
5.         Equal = 3,
6.         LEqual = 4,
7.         GEqual = 5,
8.     }

// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

Shader "NexgenDragon/FX/Particle" {
   Properties {
      [Enum(Additive,1,AlphaBlend,10)] _DstBlend("Desination Blend Options", Int) = 1
      [Enum(Always,0,Less,2)] _ZTest("Z Test Options", Int) = 2
      _MainTex ("Base (RGB)", 2D) = "white" {}
      _TintColor ("Tint Color", Color) = (0.5,0.5,0.5,1)
      _AlphaFactor ("Alpha Factor", Range(0, 2)) = 2
      _Brightness ("Brightness", Float) = 2
   }

   Category {
      Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent" }
      Blend SrcAlpha [_DstBlend]
      Cull Off
      ZWrite Off
      ZTest [_ZTest]
      Lighting Off
      SubShader {
         Pass {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma fragmentoption ARB_precision_hint_fastest

            #include "UnityCG.cginc"

            uniform sampler2D _MainTex;
            uniform fixed4 _TintColor;
            uniform fixed _AlphaFactor;
            uniform half _Brightness;

            struct appdata_t {
               float4 vertex : POSITION;
               fixed4 color : COLOR;
               half2 texcoord : TEXCOORD0;
            };

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

            half4 _MainTex_ST;

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

            fixed4 frag (v2f i) : COLOR
            {
               fixed4 c = i.color * _TintColor * tex2D(_MainTex, i.texcoord);
               fixed3 rgb = c.rgb;
               fixed a = c.a * _AlphaFactor;
               rgb = rgb * _Brightness;
               return fixed4(rgb.r, rgb.g, rgb.b, a);
            }
            ENDCG
         }
      } 
      FallBack "Diffuse"
   }
}