function ng_bighalo(
\   clip clp,
\ string text,
\  float "x",
\  float "y",
\    int "first_frame",
\    int "last_frame",
\ string "font",
\  float "size",
\    int "text_color",
\    int "halo_color",
\    int "align",
\    int "spc",
\    int "lsp",
\  float "font_width",
\  float "font_angle",
\    int "halo_radius",
\ string "mode",
\ string "halo",
\ string "shadow"
\){

#Version 16-17 2012/12/1
# - added circle_12 as default
# - reworked math to avoid bitwise functions that are only
#   availible in experimental builds
#Version 15 2012/12/1
# - drop shadow added
# - halo_radius still works, but calculating the points of 
#   a hollow circle for halo is much faster
# - mode is depricated since memo-ing isn't as needed

    first_frame = default(first_frame, 0)
    last_frame  = default( last_frame, first_frame + 299)
    font        = default(       font, "Ariel")
    size        = default(       size, 112)
    x           = default(          x, -1)
    y           = default(          y, -1)
    text_color  = default( text_color, $00DDDDDD)
    halo_color  = default( halo_color, $80000000)
    align       = default(      align, 5)
    spc         = default(        spc, 0)
    lsp         = default(        lsp, 0)
    font_width  = default( font_width, 0)
    font_angle  = default( font_angle, 0)
    shadow      = default(     shadow, " -4 -8")
    w           = clp.width
    h           = clp.height
###
   ###
      ##
        #
         #
          #
          #
           #
           #
           #
            #
            #
#           #
circle_12="0 0 "+\
"12 0 0 12 -12 0 0 -12 "+\
"1 12 2 12 3 11 4 11 5 11 6 10 7 10 8 9 "+\
"12 1 12 2 11 3 11 4 11 5 10 6 10 7 9 8 "+\
"-1 12 -2 12 -3 11 -4 11 -5 11 -6 10 -7 10 -8 9 "+\
"-12 1 -12 2 -11 3 -11 4 -11 5 -10 6 -10 7 -9 8 "+\
"-1 -12 -2 -12 -3 -11 -4 -11 -5 -11 -6 -10 -7 -10 -8 -9 "+\
"-12 -1 -12 -2 -11 -3 -11 -4 -11 -5 -10 -6 -10 -7 -9 -8 "+\
"1 -12  2 -12 3 -11 4 -11 5 -11 6 -10 7 -10 8 -9 "+\
"12 -1  12 -2 11 -3 11 -4 11 -5 10 -6 10 -7 9 -8 "
    halo = (defined(halo_radius)) ? mt_circle(halo_radius) : circle_12

    invis = BlankClip(1, w, h, pixel_type="YV12")
    tm = Subtitle(invis, text, x, y, 0, 0, font, size, $00FFFFFF,\
        0, align, spc, lsp, font_width, font_angle)
    text_mask = tm.mt_expand(mode="0 0 "+shadow, chroma="-128")
    halo_mask = text_mask.mt_expand(mode=halo, chroma="-128")
    
    h0      = halo_color%$01000000
    h_color = (h0>=0) ? h0 : $01000000+h0
    t0      = text_color%$01000000
    t_color = (t0>=0) ? t0 : $01000000+t0
    h_alpha = (halo_color>=0) ? 255-(halo_color/$01000000) : (-halo_color-1)/$01000000
    t_alpha = (text_color>=0) ? 255-(text_color/$01000000) : (-text_color-1)/$01000000
    lut_str = string(h_alpha)+ " x * 255 / " +string(t_alpha)+\
              " " +string(h_alpha)+ " - y * 255 / +"

    alpha_mask = mt_lutxy(halo_mask, text_mask, lut_str)

    hc = BlankClip(1, w, h, color=h_color)
    tc = Subtitle(hc, text, x, y, 0, 0, font, size, t_color,\
        0, align, spc, lsp, font_width, font_angle)
    overlay = tc.Mask(alpha_mask.ConvertToRGB32())
    
    clp.ApplyRange(first_frame, last_frame, "Layer", overlay)
}