// overridden from EditboxWindowRenderer base class.
public override int GetTextIndexFromPosition(Lunatics.Mathematics.Vector2 pt)
{
var w = (Editbox)Window;
// calculate final window position to be checked
var wndx = CoordConverter.ScreenToWindowX(w, pt.X);
wndx -= _lastTextOffset;
// Return the proper index
return(w.GetFont().GetCharAtPixel(w.IsTextMaskingEnabled()
? new string(w.GetTextMaskCodePoint(), w.GetTextVisual().Length)
: w.GetTextVisual(), wndx));
}