Unity5.0内置Shader解析

Shader "Mobile/Bumped Specular" {
Properties {
_Shininess ("Shininess", Range (0.03, 1)) = 0.078125
_MainTex ("Base (RGB) Gloss (A)", 2D) = "white" {}
_BumpMap ("Normalmap", 2D) = "bump" {}
}
SubShader { 
Tags { "RenderType"="Opaque" }
LOD 250

CGPROGRAM
#pragma surface surf MobileBlinnPhong exclude_path:prepass nolightmap noforwardadd halfasview interpolateview


inline fixed4 LightingMobileBlinnPhong (SurfaceOutput s, fixed3 lightDir, fixed3 halfDir, fixed atten)
{
fixed diff = max (0, dot (s.Normal, lightDir));
fixed nh = max (0, dot (s.Normal, halfDir));
fixed spec = pow (nh, s.Specular*128) * s.Gloss;

fixed4 c;
c.rgb = (s.Albedo * _LightColor0.rgb * diff + _LightColor0.rgb * spec) * atten;

UNITY_OPAQUE_ALPHA(c.a);

/*此函数定义在UnityCG.cginc文件中，

具体定义为：#define UNITY_OPAQUE_ALPHA(outputAlpha) outputAlpha = 1.0

看函数名称和用法我想此函数的作用为：由于此Shader是不透明的，所以保证最终输出颜色其a通道为1。*/

return c;
}


sampler2D _MainTex;
sampler2D _BumpMap;
half _Shininess;


struct Input {
float2 uv_MainTex;
};


void surf (Input IN, inout SurfaceOutput o) {
fixed4 tex = tex2D(_MainTex, IN.uv_MainTex);
o.Albedo = tex.rgb;
o.Gloss = tex.a;
o.Alpha = tex.a;
o.Specular = _Shininess;
o.Normal = UnpackNormal (tex2D(_BumpMap, IN.uv_MainTex));
}
ENDCG
}


FallBack "Mobile/VertexLit"
}