Synopsis
(macro) int gdx_IsSurface(DDF_TF tf)
Purpose
Determine if a GDX type form is a surface type.
Description
This macros provides a simple way to determine if a GDX entity is a surface.
Input
tf
The GDX entity type form.
Return
Result of comparison, 0 - tf is not a surface type 1 - tf is a surface type