cuts two alpha holes in a texture.

secretshader.shader

Shader "Expiremental/CircleCutout"
{
	Properties
	{
		[PerRendererData] x1 ("1.x", Float) = 0
		[PerRendererData] y1 ("1.y", Float) = 0
		
		[PerRendererData] x2 ("2.x", Float) = 0
		[PerRendererData] y2 ("2.y", Float) = 0
		
		
		[PerRendererData] size1 ("Size1", float) = 2
		[PerRendererData] size2 ("Size2", float) = 2
		[PerRendererData] falloffMult ("Falloff", float) = 3
	}

	SubShader
	{
		Tags
		{ 

		}

		Cull Off
		Lighting Off
		ZWrite Off
		Blend One OneMinusSrcAlpha

		Pass
		{
		CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			#include "UnityCG.cginc"
			
			struct appdata_t
			{
				float4 vertex   : POSITION;
			};

			struct v2f
			{
				float4 vertex   : SV_POSITION;
		 		float3 wpos : TEXCOORD1;
			};

			v2f vert(appdata_t IN)
			{
				v2f OUT;
				OUT.vertex = mul(UNITY_MATRIX_MVP, IN.vertex);
				
				float3 worldPos = mul (_Object2World, IN.vertex).xyz;
				OUT.wpos = worldPos;

				return OUT;
			}

			float x1;
			float x2;
			
			float y1;
			float y2;
			
			float size1;
			float size2;
			float falloffMult;

			fixed4 frag(v2f IN) : SV_Target
			{
				fixed4 c = fixed4(0.0, 0.0, 0.0, 1.0);
			
				c.a *= pow(min(size1, distance(IN.wpos.xy, fixed2(x1, y1))) / size1, falloffMult);
				c.a *= pow(min(size2, distance(IN.wpos.xy, fixed2(x2, y2))) / size2, falloffMult);
	
				return c;
			}
		
		ENDCG
		}
	}
}

secretshader_rgba.shader

Shader "Expiremental/CircleCutout2/RGBA"
{
	Properties
	{
		[PerRendererData] x1 ("1.x", Float) = 0
		[PerRendererData] y1 ("1.y", Float) = 0
		
		[PerRendererData] x2 ("2.x", Float) = 0
		[PerRendererData] y2 ("2.y", Float) = 0
		
		[PerRendererData] size1 ("Size1", float) = 2
		[PerRendererData] size2 ("Size2", float) = 2
		[PerRendererData] falloffMult ("Falloff", float) = 3
		
		_MainTex ("Base (RGBA)", 2D) = "white" {}
	}

	SubShader
	{
		Tags
		{ 

		}

		Cull Off
		Lighting Off
		ZWrite Off
		Blend One OneMinusSrcAlpha

		Pass
		{
		CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			#include "UnityCG.cginc"
			
			struct appdata_t
			{
				float4 vertex : POSITION;
				float2 texcoord : TEXCOORD0;
			};

			struct v2f
			{
				float4 vertex : SV_POSITION;
		 		float3 wpos : TEXCOORD1;
				half2 texcoord  : TEXCOORD0;
			};

			v2f vert(appdata_t IN)
			{
				v2f OUT;
				OUT.vertex = mul(UNITY_MATRIX_MVP, IN.vertex);

				OUT.wpos = mul (_Object2World, IN.vertex).xyz;
				
				OUT.texcoord = IN.texcoord;

				return OUT;
			}

			float x1;
			float x2;
			
			float y1;
			float y2;
			
			float size1;
			float size2;
			float falloffMult;
			
			uniform sampler2D _MainTex;

			fixed4 frag(v2f IN) : SV_Target
			{
				fixed4 c = tex2D(_MainTex, IN.texcoord);
							
				c.a *= pow(min(size1, distance(IN.wpos.xy, fixed2(x1, y1))) / size1, falloffMult);
				c.a *= pow(min(size2, distance(IN.wpos.xy, fixed2(x2, y2))) / size2, falloffMult);
	
				return c;
			}
		
		ENDCG
		}
	}
}