/*
--------------------------------- qhalf.c compute the intersection of halfspaces about a point see unix.c for full interface Copyright (c) 1993-2020, The Geometry Center */ #include "libqhull/libqhull.h" #include#include #include #include #include #if defined(_MSC_VER) #include #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 /*--------------------------------- qh_prompt long prompt for qhull notes: restricted version of libqhull.c same text as unix.c see concise prompt below limit maximum literal to 1800 characters */ /* duplicated in qhalf.htm */ char hidden_options[]=" d n v Qbb QbB Qf Qg Qm 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 Q10 Q11 Q15 "; 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\ Qc - keep coplanar halfspaces\n\ Qi - keep other redundant halfspaces\n\ QJ - joggled input instead of merged facets\n\ Qt - triangulated output\n\ \n\ Qhull control options:\n\ Qa - allow input with fewer or more points than coordinates\n\ Qbk:0Bk:0 - remove k-th coordinate from input\n\ QJn - randomly joggle input in range [-n,n]\n\ QRn - random rotation (n=seed, n=0 time, n=-1 time/no rotate)\n\ Qs - search all halfspaces for the initial simplex\n\ \n\ %s%s%s%s"; /* split up qh_prompt for Visual C++ */ char qh_promptb[]= "\ Qhull extra options:\n\ QGn - print intersection if visible to halfspace n, -n for not\n\ QVn - print intersections for halfspace n, -n if not\n\ Qw - allow option warnings\n\ Q12 - allow wide facets and wide dupridge\n\ Q14 - merge pinched vertices that create a dupridge\n\ \n\ T options:\n\ TFn - report summary when n or more facets created\n\ TI file - input file, may be enclosed in single quotes\n\ TO file - output file, may be enclosed in single quotes\n\ Ts - statistics\n\ Tv - verify result: structure, convexity, and in-circle test\n\ Tz - send all output to stdout\n\ \n\ "; char qh_promptc[]= "\ Trace options:\n\ T4 - trace at level n, 4=all, 5=mem/gauss, -1= events\n\ Ta - annotate output with message codes\n\ TAn - stop qhull after adding n vertices\n\ TCn - stop qhull after building cone for point n\n\ TVn - stop qhull after adding point n, -n for before\n\ Tc - check frequently during execution\n\ Tf - flush each qh_fprintf for debugging segfaults\n\ TPn - turn on tracing when point n added to hull\n\ TMn - turn on tracing at merge n\n\ TWn - trace merge facets when width > n\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 2-d or 3-d convex hull)\n\ Fn - count plus neighboring intersections for each intersection\n\ FN - count plus intersections for each 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\ 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\ Gc - centrums\n\ GDn - drop dimension n in 3-d and 4-d output\n\ Gh - hyperplane intersections\n\ Gi - inner planes (i.e., halfspace intersections) only\n\ Gn - no planes\n\ Go - outer planes only\n\ Gr - ridges\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\ PFn - keep facets whose area is at least n\n\ Pg - print good facets (needs 'QGn' or 'QVn')\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\ -? - help with examples\n\ -V - version\n\ "; /* for opts, don't assign 'e' or 'E' to a flag (already used for exponent) */ /*--------------------------------- qh_prompt2 synopsis for qhull */ char qh_prompt2[]= "\n\ qhalf -- halfspace intersection about a point. Qhull %s\n\ input (stdin): [dimension, 1, interior point]\n\ dimension+1, number of halfspaces, 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 each option\n\ -? - this message\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\ G - Geomview output (dual convex hull)\n\ m - Mathematica output (dual convex hull)\n\ o - OFF file format (dual convex hull)\n\ QVn - print intersections for halfspace n, -n if not\n\ TI file - input file, may be enclosed in single quotes\n\ TO file - output 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) */ /*--------------------------------- 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\ facet-dump Geomview H0,0-interior incidences mathematica\n\ off-format point-dual summary\n\ \n\ Fc-redundant Fd-cdd-in FF-dump-xridge FIDs Fmerges\n\ FMaple Fneighbors FN-intersect FOptions Fp-coordinates\n\ FP-nearest FQhalf Fsummary Fv-halfspace Fx-non-redundant\n\ \n\ Gall-points Gcentrums GDrop-dim Ghyperplanes Ginner\n\ Gno-planes Gouter Gpoints Gridges Gvertices\n\ \n\ PArea-keep Pdrop-d0:0D0 PFacet-area-keep Pgood PGood-neighbors\n\ PMerge-keep Poutput-forced Pprecision-not\n\ \n\ Qallow-short Qbk:0Bk:0-drop Qcoplanar QG-half-good Qi-redundant\n\ QJoggle QRotate Qsearch-all Qtriangulate QVertex-good\n\ Qwarn-allow Q12-allow-wide Q14-merge-pinched\n\ \n\ TFacet-log TInput-file TOutput-file Tstatistics Tverify\n\ Tz-stdout\n\ \n\ T4-trace Tannotate TAdd-stop Tcheck-often TCone-stop\n\ Tflush TMerge-trace TPoint-trace TVertex-stop TWide-trace\n\ \n\ Angle-max Centrum-size Random-dist Ucoplanar-max Wide-outside\n\ "; /*--------------------------------- 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) == '?' || *(argv[1] + 1) == '-')) { /* -? or --help */ 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); 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(7079, "qhull internal warning (main): did not free %d bytes of long memory(%d pieces)\n", totlong, curlong); #endif return exitcode; } /* main */