Self Lit, Alpha channel (global), Texture mapped to UV, Overlay

Shader4SHUD.shader

Shader "Custom/Shader4SHUD" {
Properties {
    _MainTex ("Texture", 2D) = "white" { }
    _Alpha ("Alpha", Range(0.0,1.0)) = 1.0
}
SubShader {
    Tags { Queue = Overlay }
    ZWrite Off
    Blend SrcAlpha OneMinusSrcAlpha
    Pass {
        SetTexture[_MainTex] {
	        constantColor(0,0,0,[_Alpha])
	        combine texture, texture * constant
	    }
	    
    }
}
}