ok, I got it. This works. Thanks
def gegl_custom_bevel(image, layer, opacity, blendmode, azimuth, elevation, depth, size, alphapercentile, gaus, box, mcb):
if blendmode==0:
blend_mode= "Hardlight"
if blendmode==1:
blend_mode= "Multiply"
if blendmode==2:
blend_mode= "ColorDodge"
if blendmode==3:
blend_mode= "Plus"
if blendmode==4:
blend_mode= "Darken"
if blendmode==5:
blend_mode= "Lighten"
gegl_graph_string="lb:script-custom-bevel opacity=%f blendmode=%s azimuth=%f elevation=%f depth=%f size=%f alphapercentile=%f gaus=%f box=%f mcb=%f" % (opacity, blend_mode, azimuth, elevation, depth, size, alphapercentile, gaus, box, mcb)
pdb.python_fu_gegl_graph(image, layer, gegl_graph_string)
register(
"python_fu_gegl_custom_bevel",
"GEGL to Python. Works on the active layer",
"Custom Bevel GEGL Text Styling Plugin In Python",
"Auto Author",
"Auto Author",
"Auto Generated Dated",
"<Image>/GEGL as Python/gegl-custom-bevel...", #Menu path
"*",
[
(PF_FLOAT, "opacity","opacity (default:1.0, 3.5 10.0):", 3.5),
(PF_OPTION, "blend_mode", "blendmode:", 0, ["Hardlight","Multiply","ColorDodge","Plus","Darken","Lighten"]),
(PF_FLOAT, "azimuth","azimuth (default:67, 30 90.0):", 67),
(PF_FLOAT, "elevation","elevation (default:25, 7 90):", 25),
(PF_FLOAT, "depth","depth (default:24, 1 100):", 24),
(PF_FLOAT, "size","size (default:1, 0 15):", 1),
(PF_FLOAT, "alphapercentile","alphapercentile (default:68, 0 100):", 68),
(PF_FLOAT, "gaus","Internal Gaussian Blur (default:2, 0 9):", 2),
(PF_FLOAT, "box","Internal Box Blur (default:0, 0 6):", 0),
(PF_FLOAT, "mcb","Smooth (default:0, 0 6):", 1),
],
[],
gegl_custom_bevel)