Shader "Custom/outline"
{
    Properties
    {
		_OutlineWidth("Outline Width",Float) = 7.0
		_OutlineZbias("Outline Zbias",Float) = -10
		_OutlineColor("Outline Color",Color) = (1,1,1,1)
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 200

				Pass
		{
			Cull Front
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			#include "UnityCG.cginc"
			#include "AutoLight.cginc"


			struct appdata
			{
				float4 vertex : POSITION;
				float2 texcoord0 : TEXCOORD0;
				float3 normal : NORMAL;
				float4 color : COLOR;
			};

			struct v2f
			{
				float4 pos : SV_POSITION;
				float2 uv : TEXCOORD0;
				float4 vertex_color : TEXCOORD3;
			};

			float _OutlineWidth;
			float _OutlineZbias;
			float4 _OutlineColor;

			v2f vert(appdata v)
			{
				v2f o;
				float3 pos_view = UnityObjectToViewPos(v.vertex);
				float3 normal_world = UnityObjectToWorldNormal(v.normal);
				float3 outline_dir = normalize(mul((float3x3)UNITY_MATRIX_V, normal_world));
				outline_dir.z = _OutlineZbias * (1.0 - v.color.b);
				pos_view += outline_dir * _OutlineWidth * 0.001 * v.color.a;
				o.pos = mul(UNITY_MATRIX_P, float4(pos_view, 1.0));
				o.uv = v.texcoord0;
				o.vertex_color = v.color;
				return o;
			}

			half4 frag(v2f i) : SV_Target
			{
				half3 outlineColor = _OutlineColor.xyz;
				return float4(outlineColor, 1.0);
			}
			ENDCG
		}
    }
    FallBack "Diffuse"
}