/*
--------------------------------- user_eg.c sample code for calling qhull() from an application call with: user_eg "cube/diamond options" "delaunay options" "halfspace options" for example: user_eg # return summaries user_eg "n" "o" "Fp" # return normals, OFF, points user_eg "n Qt" "o" "Fp" # triangulated cube user_eg "QR0 p" "QR0 v p" "QR0 Fp" # rotate input and return points # 'v' returns Voronoi # transform is rotated for halfspaces main() makes three runs of qhull. 1) compute the convex hull of a cube 2a) compute the Delaunay triangulation of random points 2b) find the Delaunay triangle closest to a point. 3) compute the halfspace intersection of a diamond notes: For another example, see main() in unix.c and user_eg2.c. These examples, call qh_qhull() directly. They allow tighter control on the code loaded with Qhull. For a simple C++ example, see qhull_interface.cpp Summaries are sent to stderr if other output formats are used compiled by 'make user_eg' see qhull.h for data structures, macros, and user-callable functions. */ #include "qhull_a.h" /*------------------------------------------------- -internal function prototypes */ void print_summary (void); void makecube (coordT *points, int numpoints, int dim); void makeDelaunay (coordT *points, int numpoints, int dim, int seed); void findDelaunay (int dim); void makehalf (coordT *points, int numpoints, int dim); /*------------------------------------------------- -print_summary() */ void print_summary (void) { facetT *facet; int k; printf ("\n%d vertices and %d facets with normals:\n", qh num_vertices, qh num_facets); FORALLfacets { for (k=0; k < qh hull_dim; k++) printf ("%6.2g ", facet->normal[k]); printf ("\n"); } } /*-------------------------------------------------- -makecube- set points to vertices of cube points is numpoints X dim */ void makecube (coordT *points, int numpoints, int dim) { int j,k; coordT *point; for (j=0; jvertices) { for (k=0; k < dim; k++) printf ("%5.2f ", vertex->point[k]); printf ("\n"); } } /*.findDelaunay.*/ /*-------------------------------------------------- -makehalf- set points to halfspaces for a (dim)-dimensional diamond points is numpoints X dim+1 each halfspace consists of dim coefficients followed by an offset */ void makehalf (coordT *points, int numpoints, int dim) { int j,k; coordT *point; for (j=0; j = 2 ? argv[1] : ""); numpoints= SIZEcube; makecube (points, numpoints, DIM); for (i=numpoints; i--; ) rows[i]= points+dim*i; qh_printmatrix (outfile, "input", rows, numpoints, dim); exitcode= qh_new_qhull (dim, numpoints, points, ismalloc, flags, outfile, errfile); if (!exitcode) { /* if no error */ /* 'qh facet_list' contains the convex hull */ print_summary(); FORALLfacets { /* ... your code ... */ } } qh_freeqhull(!qh_ALL); /* free long memory */ qh_memfreeshort (&curlong, &totlong); /* free short memory and memory allocator */ if (curlong || totlong) fprintf (errfile, "qhull internal warning (user_eg, #1): did not free %d bytes of long memory (%d pieces)\n", totlong, curlong); /* Run 2: Delaunay triangulation */ printf( "\ncompute 3-d Delaunay triangulation\n"); sprintf (flags, "qhull s d Tcv %s", argc >= 3 ? argv[2] : ""); numpoints= SIZEcube; makeDelaunay (points, numpoints, dim, time(NULL)); for (i=numpoints; i--; ) rows[i]= points+dim*i; qh_printmatrix (outfile, "input", rows, numpoints, dim); exitcode= qh_new_qhull (dim, numpoints, points, ismalloc, flags, outfile, errfile); if (!exitcode) { /* if no error */ /* 'qh facet_list' contains the convex hull */ /* If you want a Voronoi diagram ('v') and do not request output (i.e., outfile=NULL), call qh_setvoronoi_all() after qh_new_qhull(). */ print_summary(); FORALLfacets { /* ... your code ... */ } printf( "\nfind 3-d Delaunay triangle closest to [0.5, 0.5, ...]\n"); exitcode= setjmp (qh errexit); if (!exitcode) { /* Trap Qhull errors in findDelaunay(). Without the setjmp(), Qhull will exit() after reporting an error */ qh NOerrexit= False; findDelaunay (DIM); } qh NOerrexit= True; } #if qh_QHpointer /* see user.h */ { qhT *oldqhA, *oldqhB; coordT pointsB[DIM*TOTpoints]; /* array of coordinates for each point */ printf( "\nsave first triangulation and compute a new triangulation\n"); oldqhA= qh_save_qhull(); sprintf (flags, "qhull s d Tcv %s", argc >= 3 ? argv[2] : ""); numpoints= SIZEcube; makeDelaunay (pointsB, numpoints, dim, time(NULL)+1); for (i=numpoints; i--; ) rows[i]= pointsB+dim*i; qh_printmatrix (outfile, "input", rows, numpoints, dim); exitcode= qh_new_qhull (dim, numpoints, pointsB, ismalloc, flags, outfile, errfile); if (!exitcode) print_summary(); printf( "\nsave second triangulation and restore first one\n"); oldqhB= qh_save_qhull(); qh_restore_qhull (&oldqhA); print_summary(); printf( "\nfree first triangulation and restore second one.\n"); qh_freeqhull (qh_ALL); /* free short and long memory used by first call */ /* do not use qh_memfreeshort */ qh_restore_qhull (&oldqhB); print_summary(); } #endif qh_freeqhull(!qh_ALL); /* free long memory */ qh_memfreeshort (&curlong, &totlong); /* free short memory and memory allocator */ if (curlong || totlong) fprintf (errfile, "qhull internal warning (user_eg, #2): did not free %d bytes of long memory (%d pieces)\n", totlong, curlong); /* Run 3: halfspace intersection about the origin */ printf( "\ncompute halfspace intersection about the origin for a diamond\n"); sprintf (flags, "qhull H0 s Tcv %s", argc >= 4 ? argv[3] : "Fp"); numpoints= SIZEcube; makehalf (points, numpoints, dim); for (i=numpoints; i--; ) rows[i]= points+(dim+1)*i; qh_printmatrix (outfile, "input as halfspace coefficients + offsets", rows, numpoints, dim+1); /* use qh_sethalfspace_all to transform the halfspaces yourself. If so, set 'qh feasible_point and do not use option 'Hn,...' [it would retransform the halfspaces] */ exitcode= qh_new_qhull (dim+1, numpoints, points, ismalloc, flags, outfile, errfile); if (!exitcode) print_summary(); qh_freeqhull (!qh_ALL); qh_memfreeshort (&curlong, &totlong); if (curlong || totlong) /* could also check previous runs */ fprintf (stderr, "qhull internal warning (user_eg, #3): did not free %d bytes of long memory (%d pieces)\n", totlong, curlong); return exitcode; } /* main */