Page Menu
Home
c4science
Search
Configure Global Search
Log In
Files
F83664503
qhalf.c
No One
Temporary
Actions
Download File
Edit File
Delete File
View Transforms
Subscribe
Mute Notifications
Award Token
Subscribers
None
File Metadata
Details
File Info
Storage
Attached
Created
Wed, Sep 18, 09:22
Size
11 KB
Mime Type
text/x-c
Expires
Fri, Sep 20, 09:22 (1 d, 23 h)
Engine
blob
Format
Raw Data
Handle
20875297
Attached To
rCADDMESH CADD_mesher
qhalf.c
View Options
/*<html><pre> -<a href="../libqhull/qh-qhull.htm"
>-------------------------------</a><a name="TOP">-</a>
qhalf.c
compute the intersection of halfspaces about a point
see unix.c for full interface
Copyright (c) 1993-2015, The Geometry Center
*/
#include "libqhull/libqhull.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <math.h>
#if __cplusplus
extern "C" {
int isatty(int);
}
#elif _MSC_VER
#include <io.h>
#define isatty _isatty
/* int _isatty(int); */
#else
int isatty(int); /* returns 1 if stdin is a tty
if "Undefined symbol" this can be deleted along with call in main() */
#endif
/*-<a href="../libqhull/qh-qhull.htm#TOC"
>-------------------------------</a><a name="prompt">-</a>
qh_prompt
long prompt for qhull
notes:
restricted version of libqhull.c
see:
concise prompt below
*/
/* duplicated in qhalf.htm */
char hidden_options[]=" d n v Qbb QbB Qf Qg Qm Qr QR Qv Qx Qz TR E V Fa FA FC FD FS Ft FV Gt Q0 Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 ";
char qh_prompta[]= "\n\
qhalf- compute the intersection of halfspaces about a point\n\
http://www.qhull.org %s\n\
\n\
input (stdin):\n\
optional interior point: dimension, 1, coordinates\n\
first lines: dimension+1 and number of halfspaces\n\
other lines: halfspace coefficients followed by offset\n\
comments: start with a non-numeric character\n\
\n\
options:\n\
Hn,n - specify coordinates of interior point\n\
Qt - triangulated output\n\
QJ - joggled input instead of merged facets\n\
Qc - keep coplanar halfspaces\n\
Qi - keep other redundant halfspaces\n\
\n\
Qhull control options:\n\
QJn - randomly joggle input in range [-n,n]\n\
%s%s%s%s"; /* split up qh_prompt for Visual C++ */
char qh_promptb[]= "\
Qbk:0Bk:0 - remove k-th coordinate from input\n\
Qs - search all halfspaces for the initial simplex\n\
QGn - print intersection if visible to halfspace n, -n for not\n\
QVn - print intersections for halfspace n, -n if not\n\
\n\
";
char qh_promptc[]= "\
Trace options:\n\
T4 - trace at level n, 4=all, 5=mem/gauss, -1= events\n\
Tc - check frequently during execution\n\
Ts - print statistics\n\
Tv - verify result: structure, convexity, and redundancy\n\
Tz - send all output to stdout\n\
TFn - report summary when n or more facets created\n\
TI file - input data from file, no spaces or single quotes\n\
TO file - output results to file, may be enclosed in single quotes\n\
TPn - turn on tracing when halfspace n added to intersection\n\
TMn - turn on tracing at merge n\n\
TWn - trace merge facets when width > n\n\
TVn - stop qhull after adding halfspace n, -n for before (see TCn)\n\
TCn - stop qhull after building cone for halfspace n (see TVn)\n\
\n\
Precision options:\n\
Cn - radius of centrum (roundoff added). Merge facets if non-convex\n\
An - cosine of maximum angle. Merge facets if cosine > n or non-convex\n\
C-0 roundoff, A-0.99/C-0.01 pre-merge, A0.99/C0.01 post-merge\n\
Rn - randomly perturb computations by a factor of [1-n,1+n]\n\
Un - max distance below plane for a new, coplanar halfspace\n\
Wn - min facet width for outside halfspace (before roundoff)\n\
\n\
Output formats (may be combined; if none, produces a summary to stdout):\n\
f - facet dump\n\
G - Geomview output (dual convex hull)\n\
i - non-redundant halfspaces incident to each intersection\n\
m - Mathematica output (dual convex hull)\n\
o - OFF format (dual convex hull: dimension, points, and facets)\n\
p - vertex coordinates of dual convex hull (coplanars if 'Qc' or 'Qi')\n\
s - summary (stderr)\n\
\n\
";
char qh_promptd[]= "\
More formats:\n\
Fc - count plus redundant halfspaces for each intersection\n\
- Qc (default) for coplanar and Qi for other redundant\n\
Fd - use cdd format for input (homogeneous with offset first)\n\
FF - facet dump without ridges\n\
FI - ID of each intersection\n\
Fm - merge count for each intersection (511 max)\n\
FM - Maple output (dual convex hull)\n\
Fn - count plus neighboring intersections for each intersection\n\
FN - count plus intersections for each non-redundant halfspace\n\
FO - options and precision constants\n\
Fp - dim, count, and intersection coordinates\n\
FP - nearest halfspace and distance for each redundant halfspace\n\
FQ - command used for qhalf\n\
Fs - summary: #int (8), dim, #halfspaces, #non-redundant, #intersections\n\
for output: #non-redundant, #intersections, #coplanar\n\
halfspaces, #non-simplicial intersections\n\
#real (2), max outer plane, min vertex\n\
Fv - count plus non-redundant halfspaces for each intersection\n\
Fx - non-redundant halfspaces\n\
\n\
";
char qh_prompte[]= "\
Geomview output (2-d, 3-d and 4-d; dual convex hull)\n\
Ga - all points (i.e., transformed halfspaces) as dots\n\
Gp - coplanar points and vertices as radii\n\
Gv - vertices (i.e., non-redundant halfspaces) as spheres\n\
Gi - inner planes (i.e., halfspace intersections) only\n\
Gn - no planes\n\
Go - outer planes only\n\
Gc - centrums\n\
Gh - hyperplane intersections\n\
Gr - ridges\n\
GDn - drop dimension n in 3-d and 4-d output\n\
\n\
Print options:\n\
PAn - keep n largest facets (i.e., intersections) by area\n\
Pdk:n- drop facet if normal[k] <= n (default 0.0)\n\
PDk:n- drop facet if normal[k] >= n\n\
Pg - print good facets (needs 'QGn' or 'QVn')\n\
PFn - keep facets whose area is at least n\n\
PG - print neighbors of good facets\n\
PMn - keep n facets with most merges\n\
Po - force output. If error, output neighborhood of facet\n\
Pp - do not report precision problems\n\
\n\
. - list of all options\n\
- - one line descriptions of all options\n\
-V - version\n\
";
/* for opts, don't assign 'e' or 'E' to a flag (already used for exponent) */
/*-<a href="../libqhull/qh-qhull.htm#TOC"
>-------------------------------</a><a name="prompt2">-</a>
qh_prompt2
synopsis for qhull
*/
char qh_prompt2[]= "\n\
qhalf- halfspace intersection about a point. Qhull %s\n\
input (stdin): [dim, 1, interior point], dim+1, n, coefficients+offset\n\
comments start with a non-numeric character\n\
\n\
options (qhalf.htm):\n\
Hn,n - specify coordinates of interior point\n\
Qt - triangulated output\n\
QJ - joggled input instead of merged facets\n\
Tv - verify result: structure, convexity, and redundancy\n\
. - concise list of all options\n\
- - one-line description of all options\n\
-V - version\n\
\n\
output options (subset):\n\
s - summary of results (default)\n\
Fp - intersection coordinates\n\
Fv - non-redundant halfspaces incident to each intersection\n\
Fx - non-redundant halfspaces\n\
o - OFF file format (dual convex hull)\n\
G - Geomview output (dual convex hull)\n\
m - Mathematica output (dual convex hull)\n\
QVn - print intersections for halfspace n, -n if not\n\
TO file - output results to file, may be enclosed in single quotes\n\
\n\
examples:\n\
rbox d | qconvex FQ n | qhalf s H0,0,0 Fp\n\
rbox c | qconvex FQ FV n | qhalf s i\n\
rbox c | qconvex FQ FV n | qhalf s o\n\
\n\
";
/* for opts, don't assign 'e' or 'E' to a flag (already used for exponent) */
/*-<a href="../libqhull/qh-qhull.htm#TOC"
>-------------------------------</a><a name="prompt3">-</a>
qh_prompt3
concise prompt for qhull
*/
char qh_prompt3[]= "\n\
Qhull %s.\n\
Except for 'F.' and 'PG', upper_case options take an argument.\n\
\n\
incidences Geomview mathematica OFF_format point_dual\n\
summary facet_dump\n\
\n\
Fc_redundant Fd_cdd_in FF_dump_xridge FIDs Fmerges\n\
Fneighbors FN_intersect FOptions Fp_coordinates FP_nearest\n\
FQhalf Fsummary Fv_halfspace FMaple Fx_non_redundant\n\
\n\
Gvertices Gpoints Gall_points Gno_planes Ginner\n\
Gcentrums Ghyperplanes Gridges Gouter GDrop_dim\n\
\n\
PArea_keep Pdrop d0:0D0 Pgood PFacet_area_keep\n\
PGood_neighbors PMerge_keep Poutput_forced Pprecision_not\n\
\n\
Qbk:0Bk:0_drop Qcoplanar QG_half_good Qi_redundant QJoggle\n\
Qsearch_1st Qtriangulate QVertex_good\n\
\n\
T4_trace Tcheck_often Tstatistics Tverify Tz_stdout\n\
TFacet_log TInput_file TPoint_trace TMerge_trace TOutput_file\n\
TWide_trace TVertex_stop TCone_stop\n\
\n\
Angle_max Centrum_size Random_dist Ucoplanar_max Wide_outside\n\
";
/*-<a href="../libqhull/qh-qhull.htm#TOC"
>-------------------------------</a><a name="main">-</a>
main( argc, argv )
processes the command line, calls qhull() to do the work, and exits
design:
initializes data structures
reads points
finishes initialization
computes convex hull and other structures
checks the result
writes the output
frees memory
*/
int main(int argc, char *argv[]) {
int curlong, totlong; /* used !qh_NOmem */
int exitcode, numpoints, dim;
coordT *points;
boolT ismalloc;
QHULL_LIB_CHECK /* Check for compatible library */
if ((argc == 1) && isatty( 0 /*stdin*/)) {
fprintf(stdout, qh_prompt2, qh_version);
exit(qh_ERRnone);
}
if (argc > 1 && *argv[1] == '-' && !*(argv[1]+1)) {
fprintf(stdout, qh_prompta, qh_version,
qh_promptb, qh_promptc, qh_promptd, qh_prompte);
exit(qh_ERRnone);
}
if (argc > 1 && *argv[1] == '.' && !*(argv[1]+1)) {
fprintf(stdout, qh_prompt3, qh_version);
exit(qh_ERRnone);
}
if (argc > 1 && *argv[1] == '-' && *(argv[1]+1)=='V') {
fprintf(stdout, "%s\n", qh_version2);
exit(qh_ERRnone);
}
qh_init_A(stdin, stdout, stderr, argc, argv); /* sets qh qhull_command */
exitcode= setjmp(qh errexit); /* simple statement for CRAY J916 */
if (!exitcode) {
qh NOerrexit = False;
qh_option("Halfspace", NULL, NULL);
qh HALFspace= True; /* 'H' */
qh_checkflags(qh qhull_command, hidden_options);
qh_initflags(qh qhull_command);
if (qh SCALEinput) {
fprintf(qh ferr, "\
qhull error: options 'Qbk:n' and 'QBk:n' are not used with qhalf.\n\
Use 'Qbk:0Bk:0 to drop dimension k.\n");
qh_errexit(qh_ERRinput, NULL, NULL);
}
points= qh_readpoints(&numpoints, &dim, &ismalloc);
if (dim >= 5) {
qh_option("Qxact_merge", NULL, NULL);
qh MERGEexact= True; /* 'Qx' always */
}
qh_init_B(points, numpoints, dim, ismalloc);
qh_qhull();
qh_check_output();
qh_produce_output();
if (qh VERIFYoutput && !qh FORCEoutput && !qh STOPpoint && !qh STOPcone)
qh_check_points();
exitcode= qh_ERRnone;
}
qh NOerrexit= True; /* no more setjmp */
#ifdef qh_NOmem
qh_freeqhull(qh_ALL);
#else
qh_freeqhull(!qh_ALL);
qh_memfreeshort(&curlong, &totlong);
if (curlong || totlong)
qh_fprintf_stderr(6263, "qhull internal warning (main): did not free %d bytes of long memory(%d pieces)\n",
totlong, curlong);
#endif
return exitcode;
} /* main */
Event Timeline
Log In to Comment