Outline3.shader

Shader "Screw/Silhouetted Diffuse" {
	Properties {
		_Color ("Main Color", Color) = (.5,.5,.5,1)
		_FrontColor ("Front Color", Color) = (.5,.5,.5,1)
		_OutlineColor ("Outline Color", Color) = (0,0,0,1)
		_Outline ("Outline width", Range (0.0, 0.1)) = .005
		_MainTex ("Base (RGB)", 2D) = "white" { }
		_Alpha ("Alpha", Range(0, 1)) = 1
	}
 
	CGINCLUDE
		#include "UnityCG.cginc"
		 
		struct appdata {
			half4 vertex : POSITION;
			half3 normal : NORMAL;
			half2 texcoord : TEXCOORD0;
			half4 color : COLOR;
		};
		 
		struct v2f {
			half4 pos : POSITION;
			half4 color : COLOR;
			half2 uv : TEXCOORD0;
			half3 normalDir : NORMAL;
		};
		 
		uniform float _Outline;
		uniform float4 _OutlineColor;
		 
		v2f vert(appdata v) {
			v2f o;
			
//			half3 vertex = v.vertex.xyz;
//			vertex += _Outline * v.color;
//			o.pos = mul(UNITY_MATRIX_MVP, half4(vertex, v.vertex.w));

			o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
			half3 norm   = normalize(mul ((float3x3)UNITY_MATRIX_IT_MV, v.color.xyz));
			o.pos.xyz += _Outline * norm;
			
			o.color = _OutlineColor;
			return o;
		}
	ENDCG
 
	SubShader {
		Tags { "Queue" = "Transparent" }
 
		Pass {
			Name "OUTLINE"
			Cull Off
			ZWrite Off
			ZTest Always
			ColorMask RGB 
 
			Blend SrcAlpha OneMinusSrcAlpha
 
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			
			half _Alpha; 
			half4 frag(v2f i) :COLOR {
				return half4(i.color.rgb, _Alpha);
			}
			ENDCG
		}
 
		Pass {
			Name "BASE"
			ZWrite On
			ZTest LEqual
			Blend SrcAlpha OneMinusSrcAlpha
			
			CGPROGRAM

			#pragma vertex vert2
			#pragma fragment frag
						
			v2f vert2 (appdata v)
			{
				v2f o;
				o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
				o.uv = v.texcoord;
				o.normalDir = normalize(mul(half4(v.normal, 0), _World2Object).xyz);
								
				return o;
			}
			
			uniform sampler2D _MainTex;
			half4 _Color;
			half4 _FrontColor;
			half _Alpha;
			
			half4 frag (v2f i) : COLOR
			{
				half4 color = _Color;
				if (dot(i.normalDir, half3(0, 0, -1)) > 1/sqrt(2) || dot(i.normalDir, half3(0, 0, 1)) > 1/sqrt(2)) {
					color = _FrontColor;
				}
				
				color.a = _Alpha;
				return color;				
			}
			
			ENDCG
			

		}
	}
  
	Fallback "Diffuse"
}