Outline shader for Unity

outlineshader.shader

Shader "squidzoo/Outline"
{
	Properties
	{
		_MainTex ("Texture", 2D) = "white" {}
		_OutlineColor("Outline color", Color) = (0,0,0,1)
		_OutlineWidth("Outline width", Range(1.0,5.0)) = 1.05
	}

	CGINCLUDE
	#include "UnityCG.cginc"

	struct appdata
	{
		float4 vertex : POSITION;
		float3 normal : NORMAL;
	};

	struct v2f
	{
		float4 pos : POSITION;
		float3 normal : NORMAL;
	};

	float _OutlineWidth;
	float4 _OutlineColor;

	ENDCG

	SubShader
	{

		Pass
		{
			Zwrite Off

			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag

			v2f vert(appdata v)
			{
				v.vertex.xyz *= _OutlineWidth;
				v2f o;
				o.pos = UnityObjectToClipPos(v.vertex);
				return o;
			}

			half4 frag(v2f i) : COLOR
			{
				return _OutlineColor;
			}

			ENDCG
		}

		Pass
		{
			CGPROGRAM
			#pragma vertex vertPassTwo
			#pragma fragment fragPassTwo
			#pragma multi_compile_fog
			
			#include "UnityCG.cginc"

			struct appdataPassTwo
			{
				float4 vertex : POSITION;
				float2 uv : TEXCOORD0;
			};

			struct v2fPassTwo
			{
				float2 uv : TEXCOORD0;
				UNITY_FOG_COORDS(1)
				float4 vertex : SV_POSITION;
			};

			sampler2D _MainTex;
			float4 _MainTex_ST;
			
			v2fPassTwo vertPassTwo (appdataPassTwo v)
			{
				v2fPassTwo o;
				o.vertex = UnityObjectToClipPos(v.vertex);
				o.uv = TRANSFORM_TEX(v.uv, _MainTex);
				UNITY_TRANSFER_FOG(o,o.vertex);
				return o;
			}
			
			fixed4 fragPassTwo (v2fPassTwo i) : SV_Target
			{
				fixed4 col = tex2D(_MainTex, i.uv);
				UNITY_APPLY_FOG(i.fogCoord, col);
				return col;
			}
			ENDCG
		}
	}
}