GlobalGameJam-2021/Assets/Shaders/Border.shader

// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

Shader "Outlined/Silhouette Only" {
	Properties{
		_OutlineColor("Outline Color", Color) = (0,0,0,1)
		_Outline("Outline width", Range(0.0, 10.0)) = .005
	}

		CGINCLUDE
#include "UnityCG.cginc"

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

	struct v2f {
		float4 pos : POSITION;
		float4 color : COLOR;
	};

	uniform float _Outline;
	uniform float4 _OutlineColor;

	v2f vert(appdata v) {
		// just make a copy of incoming vertex data but scaled according to normal direction
		v2f o;
		o.pos = UnityObjectToClipPos(v.vertex);

		float3 norm = mul((float3x3)UNITY_MATRIX_IT_MV, v.normal);
		float2 offset = TransformViewToProjection(norm.xy);

		o.pos.xy += offset * o.pos.z * _Outline;
		o.color = _OutlineColor;
		return o;
	}
	ENDCG

		SubShader{
			Tags { "Queue" = "Transparent" }

			Pass {
				Name "BASE"
				Cull Back
				Blend Zero One

		// uncomment this to hide inner details:
		//Offset -8, -8

		SetTexture[_OutlineColor] {
			ConstantColor(0,0,0,0)
			Combine constant
		}
	}

		// note that a vertex shader is specified here but its using the one above
		Pass {
			Name "OUTLINE"
			Tags { "LightMode" = "Always" }
			Cull Off
			Offset 5,5


		// you can choose what kind of blending mode you want for the outline
		//Blend SrcAlpha OneMinusSrcAlpha // Normal
		//Blend One One // Additive
		Blend One OneMinusDstColor // Soft Additive
		//Blend DstColor Zero // Multiplicative
		//Blend DstColor SrcColor // 2x Multiplicative

CGPROGRAM
#pragma vertex vert
#pragma fragment frag

half4 frag(v2f i) :COLOR {
	return i.color;
}
ENDCG
		}


	}

		Fallback "Diffuse"
}