#pragma strict
#pragma implicit
#pragma downcast

// When attached to a camera, will clear alpha channel
// of camera's render texture to pure white.
// Useful if you have camera rendering into a texture and later
// want to display it in GUI.
private var 	mat : Material;

// customised map image variables to use within the GUI
var				mapRT : RenderTexture;
var				alpha : Texture2D;

function Awake() {

	if (!mat) {
		mat = new Material (
			"Shader \"\" {" +
			"   Properties {" +
			"		_MainTex (\"Base (RGB) Trans (A)\", 2D) = \"white\" {}" +
			"		_RadarMask (\"Mix Mask (A)\", 2D) = \"gray\" {}" +
			"   }" +
			"   SubShader {" +
			"		Lighting On " +
			"		Cull Off " +
			"		ZTest Always " +
			"		ZWrite Off " +
			"		Fog { Mode Off } " +
			"       Pass {" +
			"			SetTexture [_MainTex] { combine texture }" +
			"			SetTexture [_RadarMask] { combine previous - texture }" +
			"       }" +
			"   }" +
			"}"
		);
	}
	// make sure this material isn't saved or displayed in the editor
	mat.shader.hideFlags = HideFlags.HideAndDontSave;
	mat.hideFlags = HideFlags.HideAndDontSave;
}

function OnPostRender () {

	GL.PushMatrix ();
    GL.LoadOrtho ();
    for (var i = 0; i < mat.passCount; ++i) {
    	mat.SetTexture ("_MainTex", mapRT);
   		mat.SetTexture ("_RadarMask", alpha);
        mat.SetPass (i);
        GL.Begin (GL.QUADS);
        GL.Vertex3 (0, 0, 0.1);
        GL.Vertex3 (1, 0, 0.1);
        GL.Vertex3 (1, 1, 0.1);
        GL.Vertex3 (0, 1, 0.1);
        GL.End ();
    }
    GL.PopMatrix ();

}