user redefinable function -- qh_fprintf

  see README.txt  see COPYING.txt for copyright information.

  If you recompile and load this file, then userprintf_r.o will not be loaded
  from qhull_r.a or qhull_r.lib

  See libqhull_r.h for data structures, macros, and user-callable functions.
  See user_r.c for qhull-related, redefinable functions
  see user_r.h for user-definable constants
  See usermem_r.c for qh_exit(), qh_free(), and qh_malloc()
  see Qhull.cpp and RboxPoints.cpp for examples.

  qh_printf is a good location for debugging traps, checked on each log line

  Please report any errors that you fix to qhull@qhull.org

#include "libqhull_r.h"
#include "poly_r.h" /* for qh.tracefacet */



  qh_fprintf(qh, fp, msgcode, format, list of args )
    print arguments to *fp according to format
    Use qh_fprintf_rbox() for rboxlib_r.c

    sets qh.last_errcode if msgcode is error 6000..6999
    same as fprintf()
    fgets() is not trapped like fprintf()
    exit qh_fprintf via qh_errexit()
    may be called for errors in qh_initstatistics and qh_meminit

void qh_fprintf(qhT *qh, FILE *fp, int msgcode, const char *fmt, ... ) {
  va_list args;
  facetT *neighbor, **neighborp;

  if (!fp) {
      qh_fprintf_stderr(6241, "qhull internal error (userprintf_r.c): fp and qh not defined for qh_fprintf '%s'\n", fmt);
      qh->last_errcode= 6241;
      qh_exit(qh_ERRqhull);  /* can not use qh_errexit() */
    /* could use qh->qhmem.ferr, but probably better to be cautious */
    qh_fprintf_stderr(6028, "qhull internal error (userprintf_r.c): fp is 0.  Wrong qh_fprintf was called.\n");
    qh->last_errcode= 6028;
    qh_errexit(qh, qh_ERRqhull, NULL, NULL);
  if ((qh && qh->ANNOTATEoutput) || msgcode < MSG_TRACE4) {
    fprintf(fp, "[QH%.4d]", msgcode);
  }else if (msgcode >= MSG_ERROR && msgcode < MSG_STDERR ) {
    fprintf(fp, "QH%.4d ", msgcode);
  va_start(args, fmt);
  vfprintf(fp, fmt, args);
  if (qh) {
    if (msgcode >= MSG_ERROR && msgcode < MSG_WARNING)
      qh->last_errcode= msgcode;
    /* Place debugging traps here. Use with trace option 'Tn' 
       Set qh.tracefacet_id, qh.traceridge_id, and/or qh.tracevertex_id in global_r.c
    if (False) { /* in production skip test for debugging traps */
      if (qh->tracefacet && qh->tracefacet->tested) {
        if (qh_setsize(qh, qh->tracefacet->neighbors) < qh->hull_dim)
          qh_errexit(qh, qh_ERRdebug, qh->tracefacet, qh->traceridge);
        FOREACHneighbor_(qh->tracefacet) {
          if (neighbor != qh_DUPLICATEridge && neighbor != qh_MERGEridge && neighbor->visible)
            qh_errexit2(qh, qh_ERRdebug, qh->tracefacet, neighbor);
      if (qh->traceridge && qh->traceridge->top->id == 234342223) {
        qh_errexit(qh, qh_ERRdebug, qh->tracefacet, qh->traceridge);
      if (qh->tracevertex && qh_setsize(qh, qh->tracevertex->neighbors)>3434334) {
        qh_errexit(qh, qh_ERRdebug, qh->tracefacet, qh->traceridge);
    if (qh->FLUSHprint)
} /* qh_fprintf */