Just a simple fog to my simple vertex colour shader?

Here's a simple shader I got from the Unity Wiki. It's great because it applies the vertex colour in a way that lets me create my own lighting (which is necessary in a Minecraft game - normal lighting looks dark and ugly because of the angle of the block faces).

All I want to do is add a fog colour based on distance. What's the simplest way to do it for this shader?

Code (CSharp):

1. Shader "Custom/Vertex color unlit" {
2. Properties {
3.     _MainTex ("Texture", 2D) = "white" {}
4. }
5.  
6. Category {
7.     Tags { "Queue"="Geometry" }
8.     Lighting Off
9.     BindChannels {
10.         Bind "Color", color
11.         Bind "Vertex", vertex
12.         Bind "TexCoord", texcoord
13.     }
14.  
15.     SubShader {
16.         Pass {
17.             SetTexture [_MainTex] {
18.                 Combine texture * primary DOUBLE
19.             }
20.         }
21.     }
22. }
23. }

 

Fog On

 

Ah thanks - I tried that, it gave a code error, but it turns out the answer is really that I'm an idiot. The fog settings under lighting for the scene work just fine with this shader...