TDCTRI - Cut triangles defined by a triangle list.

       To  use TDCTRI or c_tdctri, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c, preferably in
       that order.

       The C-binding argument descriptions are the same as the FORTRAN argument descriptions.

       #include <ncarg/ncargC.h>

       void c_tdctri(float *rtri, int mtri, int *ntri, int iaxs, float rcut)

       Copyright (C) 1987-2009
       University Corporation for Atmospheric Research

       The use of this Software is governed by a License Agreement.

UNIX                                                July 1997                                     TDCTRI(3NCARG)

       This routine, given a list of NTRI triangles in the array RTRI, an axis identifier IAXS (1 => U axis, 2
       => V axis, 3 => W axis), and a value RCUT along that axis, cuts all the triangles that intersect the
       plane perpendicular to the identified axis at the specified value into two pieces, one on either side of
       the plane.  This is useful when one is rendering the triangles in colors that depend on their position in
       U, V, or W.  (See the example "tdex04".)

       The arguments of TDCTRI are as follows:

       RTRI    (an  input/output  array,  of  type  REAL, dimensioned 10 x MTRI) - a list of triangles, probably
               created by means of calls to TDSTRI, TDITRI, and/or TDMTRI.  The number of triangles in the  list
               may increase as a result of calling TDCTRI.

       MTRI    (an  input expression of type INTEGER) - the second dimension of RTRI and thus the maximum number
               of triangles the triangle list will hold.

       NTRI    (an input/output variable of type INTEGER) - specifies the number of triangles currently  in  the
               list.   It  is  the  user's responsibility to zero this initially; its value is increased by each
               call to a triangle-generating routine like TDSTRI or TDITRI and may be increased  by  a  call  to
               TDCTRI.

       IAXS    (an  input variable of type INTEGER) - specifies the axis to which the cut plane is perpendicular
               (1 => U axis, 2 => V axis, 3 => W axis).

       RCUT    (an input variable of type REAL) - specifies that value of U, V, or W  at  which  the  cut  plane
               intersects the axis.

       TDCTRI - Cut triangles defined by a triangle list.

       Online: tdclrs, tddtri, tdgeti, tdgetr, tdgrds, tdgrid, tdgtrs, tdinit, tditri, tdlbla,  tdlbls,  tdline,
       tdlnpa,  tdmtri,  tdpack,  tdpack_params, tdpara, tdplch, tdprpa, tdprpi, tdprpt, tdseti, tdsetr, tdsort,
       tdstri, tdstrs

       CALL TDCTRI (RTRI, MTRI, NTRI, IAXS, RCUT)