Triangle: -u switch

The -u switch

Imposes a user-defined constraint on triangle size, somewhat like the -a switch, but you write C code that examines a triangle's coordinates and area, and decides whether to refine the triangle or not.
There are two ways to use this feature. The first is to edit the triunsuitable() procedure in triangle.c to encode any constraint you like, then recompile Triangle.
The second way to use this feature is to compile triangle.c with the EXTERNAL_TEST symbol set (compiler switch -DEXTERNAL_TEST), then link Triangle against a separate object file that implements triunsuitable().
In either case, the -u switch causes the user-defined test to be applied to every triangle.
Read the comments and sample code for triunsuitable() in triangle.c to learn how to write your own version of the procedure.

jrs@cs.berkeley.edu