📄 user.h
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/*<html><pre> -<a href="qh-c.htm#user"
>-------------------------------</a><a name="TOP">-</a>
user.h
user redefinable constants
see qh-c.htm. see COPYING for copyright information.
before reading any code, review qhull.h for data structure definitions and
the "qh" macro.
*/
#ifndef qhDEFuser
#define qhDEFuser 1
/*============= data types and configuration macros ==========*/
/*-<a href="qh-c.htm#user"
>--------------------------------</a><a name="realT">-</a>
realT
set the size of floating point numbers
qh_REALdigits
maximimum number of significant digits
qh_REAL_1, qh_REAL_2n, qh_REAL_3n
format strings for printf
qh_REALmax, qh_REALmin
maximum and minimum (near zero) values
qh_REALepsilon
machine roundoff. Maximum roundoff error for addition and multiplication.
notes:
Select whether to store floating point numbers in single precision (float)
or double precision (double).
Use 'float' to save about 8% in time and 25% in space. This is particularly
help if high-d where convex hulls are space limited. Using 'float' also
reduces the printed size of Qhull's output since numbers have 8 digits of
precision.
Use 'double' when greater arithmetic precision is needed. This is needed
for Delaunay triangulations and Voronoi diagrams when you are not merging
facets.
If 'double' gives insufficient precision, your data probably includes
degeneracies. If so you should use facet merging (done by default)
or exact arithmetic (see imprecision section of manual, qh-impre.htm).
You may also use option 'Po' to force output despite precision errors.
You may use 'long double', but many format statements need to be changed
and you may need a 'long double' square root routine. S. Grundmann
(sg@eeiwzb.et.tu-dresden.de) has done this. He reports that the code runs
much slower with little gain in precision.
WARNING: on some machines, int f(){realT a= REALmax;return (a == REALmax);}
returns False. Use (a > REALmax/2) instead of (a == REALmax).
REALfloat = 1 all numbers are 'float' type
= 0 all numbers are 'double' type
*/
#define REALfloat 0
#if (REALfloat == 1)
#define realT float
#define REALmax FLT_MAX
#define REALmin FLT_MIN
#define REALepsilon FLT_EPSILON
#define qh_REALdigits 8 /* maximum number of significant digits */
#define qh_REAL_1 "%6.8g "
#define qh_REAL_2n "%6.8g %6.8g\n"
#define qh_REAL_3n "%6.8g %6.8g %6.8g\n"
#elif (REALfloat == 0)
#define realT double
#define REALmax DBL_MAX
#define REALmin DBL_MIN
#define REALepsilon DBL_EPSILON
#define qh_REALdigits 16 /* maximum number of significant digits */
#define qh_REAL_1 "%6.16g "
#define qh_REAL_2n "%6.16g %6.16g\n"
#define qh_REAL_3n "%6.16g %6.16g %6.16g\n"
#else
#error unknown float option
#endif
/*-<a href="qh-c.htm#user"
>--------------------------------</a><a name="CPUclock">-</a>
qh_CPUclock
define the clock() function for reporting the total time spent by Qhull
returns CPU ticks as a 'long int'
qh_CPUclock is only used for reporting the total time spent by Qhull
qh_SECticks
the number of clock ticks per second
notes:
looks for CLOCKS_PER_SEC, CLOCKS_PER_SECOND, or assumes microseconds
to define a custom clock, set qh_CLOCKtype to 0
if your system does not use clock() to return CPU ticks, replace
qh_CPUclock with the corresponding function. It is converted
to unsigned long to prevent wrap-around during long runs.
Set qh_CLOCKtype to
1 for CLOCKS_PER_SEC, CLOCKS_PER_SECOND, or microsecond
Note: may fail if more than 1 hour elapsed time
2 use qh_clock() with POSIX times() (see global.c)
*/
#define qh_CLOCKtype 1 /* change to the desired number */
#if (qh_CLOCKtype == 1)
#if defined (CLOCKS_PER_SECOND)
#define qh_CPUclock ((unsigned long)clock()) /* return CPU clock */
#define qh_SECticks CLOCKS_PER_SECOND
#elif defined (CLOCKS_PER_SEC)
#define qh_CPUclock ((unsigned long)clock()) /* return CPU clock */
#define qh_SECticks CLOCKS_PER_SEC
#elif defined (CLK_TCK)
#define qh_CPUclock ((unsigned long)clock()) /* return CPU clock */
#define qh_SECticks CLK_TCK
#else
#define qh_CPUclock ((unsigned long)clock()) /* return CPU clock */
#define qh_SECticks 1E6
#endif
#elif (qh_CLOCKtype == 2)
#define qh_CPUclock qh_clock() /* return CPU clock */
#define qh_SECticks 100
#else /* qh_CLOCKtype == ? */
#error unknown clock option
#endif
/*-<a href="qh-c.htm#user"
>--------------------------------</a><a name="RANDOM">-</a>
qh_RANDOMtype, qh_RANDOMmax, qh_RANDOMseed
define random number generator
qh_RANDOMint generates a random integer between 0 and qh_RANDOMmax.
qh_RANDOMseed sets the random number seed for qh_RANDOMint
Set qh_RANDOMtype (default 5) to:
1 for random() with 31 bits (UCB)
2 for rand() with RAND_MAX or 15 bits (system 5)
3 for rand() with 31 bits (Sun)
4 for lrand48() with 31 bits (Solaris)
5 for qh_rand() with 31 bits (included with Qhull)
notes:
Random numbers are used by rbox to generate point sets. Random
numbers are used by Qhull to rotate the input ('QRn' option),
simulate a randomized algorithm ('Qr' option), and to simulate
roundoff errors ('Rn' option).
Random number generators differ between systems. Most systems provide
rand() but the period varies. The period of rand() is not critical
since qhull does not normally use random numbers.
The default generator is Park & Miller's minimal standard random
number generator [CACM 31:1195 '88]. It is included with Qhull.
If qh_RANDOMmax is wrong, qhull will report a warning and Geomview
output will likely be invisible.
*/
#define qh_RANDOMtype 5 /* *** change to the desired number *** */
#if (qh_RANDOMtype == 1)
#define qh_RANDOMmax ((realT)0x7fffffffUL) /* 31 bits, random()/MAX */
#define qh_RANDOMint random()
#define qh_RANDOMseed_(seed) srandom(seed);
#elif (qh_RANDOMtype == 2)
#ifdef RAND_MAX
#define qh_RANDOMmax ((realT)RAND_MAX)
#else
#define qh_RANDOMmax ((realT)32767) /* 15 bits (System 5) */
#endif
#define qh_RANDOMint rand()
#define qh_RANDOMseed_(seed) srand((unsigned)seed);
#elif (qh_RANDOMtype == 3)
#define qh_RANDOMmax ((realT)0x7fffffffUL) /* 31 bits, Sun */
#define qh_RANDOMint rand()
#define qh_RANDOMseed_(seed) srand((unsigned)seed);
#elif (qh_RANDOMtype == 4)
#define qh_RANDOMmax ((realT)0x7fffffffUL) /* 31 bits, lrand38()/MAX */
#define qh_RANDOMint lrand48()
#define qh_RANDOMseed_(seed) srand48(seed);
#elif (qh_RANDOMtype == 5)
#define qh_RANDOMmax ((realT)2147483646UL) /* 31 bits, qh_rand/MAX */
#define qh_RANDOMint qh_rand()
#define qh_RANDOMseed_(seed) qh_srand(seed);
/* unlike rand(), never returns 0 */
#else
#error: unknown random option
#endif
/*-<a href="qh-c.htm#user"
>--------------------------------</a><a name="ORIENTclock">-</a>
qh_ORIENTclock
0 for inward pointing normals by Geomview convention
*/
#define qh_ORIENTclock 0
/*========= performance related constants =========*/
/*-<a href="qh-c.htm#user"
>--------------------------------</a><a name="HASHfactor">-</a>
qh_HASHfactor
total hash slots / used hash slots. Must be at least 1.1.
notes:
=2 for at worst 50% occupancy for qh hash_table and normally 25% occupancy
*/
#define qh_HASHfactor 2
/*-<a href="qh-c.htm#user"
>--------------------------------</a><a name="VERIFYdirect">-</a>
qh_VERIFYdirect
with 'Tv' verify all points against all facets if op count is smaller
notes:
if greater, calls qh_check_bestdist() instead
*/
#define qh_VERIFYdirect 1000000
/*-<a href="qh-c.htm#user"
>--------------------------------</a><a name="INITIALsearch">-</a>
qh_INITIALsearch
if qh_INITIALmax, search points up to this dimension
*/
#define qh_INITIALsearch 6
/*-<a href="qh-c.htm#user"
>--------------------------------</a><a name="INITIALmax">-</a>
qh_INITIALmax
if dim >= qh_INITIALmax, use min/max coordinate points for initial simplex
notes:
from points with non-zero determinants
use option 'Qs' to override (much slower)
*/
#define qh_INITIALmax 8
/*-<a href="qh-c.htm#user"
>--------------------------------</a><a name="JOGGLEdefault">-</a>
qh_JOGGLEdefault
default qh.JOGGLEmax is qh.DISTround * qh_JOGGLEdefault
notes:
rbox s r 100 | qhull QJ1e-15 QR0 generates 90% faults at distround 7e-16
rbox s r 100 | qhull QJ1e-14 QR0 generates 70% faults
rbox s r 100 | qhull QJ1e-13 QR0 generates 35% faults
rbox s r 100 | qhull QJ1e-12 QR0 generates 8% faults
rbox s r 100 | qhull QJ1e-11 QR0 generates 1% faults
rbox s r 100 | qhull QJ1e-10 QR0 generates 0% faults
rbox 1000 W0 | qhull QJ1e-12 QR0 generates 86% faults
rbox 1000 W0 | qhull QJ1e-11 QR0 generates 20% faults
rbox 1000 W0 | qhull QJ1e-10 QR0 generates 2% faults
the later have about 20 points per facet, each of which may interfere
pick a value large enough to avoid retries on most inputs
*/
#define qh_JOGGLEdefault 30000.0
/*-<a href="qh-c.htm#user"
>--------------------------------</a><a name="JOGGLEincrease">-</a>
qh_JOGGLEincrease
factor to increase qh.JOGGLEmax on qh_JOGGLEretry or qh_JOGGLEagain
*/
#define qh_JOGGLEincrease 10.0
/*-<a href="qh-c.htm#user"
>--------------------------------</a><a name="JOGGLEretry">-</a>
qh_JOGGLEretry
if ZZretry = qh_JOGGLEretry, increase qh.JOGGLEmax
notes:
try twice at the original value in case of bad luck the first time
*/
#define qh_JOGGLEretry 2
/*-<a href="qh-c.htm#user"
>--------------------------------</a><a name="JOGGLEagain">-</a>
qh_JOGGLEagain
every following qh_JOGGLEagain, increase qh.JOGGLEmax
notes:
1 is OK since it's already failed qh_JOGGLEretry times
*/
#define qh_JOGGLEagain 1
/*-<a href="qh-c.htm#user"
>--------------------------------</a><a name="JOGGLEmaxincrease">-</a>
qh_JOGGLEmaxincrease
maximum qh.JOGGLEmax due to qh_JOGGLEincrease
relative to qh.MAXwidth
notes:
qh.joggleinput will retry at this value until qh_JOGGLEmaxretry
*/
#define qh_JOGGLEmaxincrease 1e-2
/*-<a href="qh-c.htm#user"
>--------------------------------</a><a name="JOGGLEmaxretry">-</a>
qh_JOGGLEmaxretry
stop after qh_JOGGLEmaxretry attempts
*/
#define qh_JOGGLEmaxretry 100
/*========= memory constants =========*/
/*-<a href="qh-c.htm#user"
>--------------------------------</a><a name="MEMalign">-</a>
qh_MEMalign
memory alignment for qh_meminitbuffers() in global.c
notes:
to avoid bus errors, memory allocation must consider alignment requirements.
malloc() automatically takes care of alignment. Since mem.c manages
its own memory, we need to explicitly specify alignment in
qh_meminitbuffers().
A safe choice is sizeof(double). sizeof(float) may be used if doubles
do not occur in data structures and pointers are the same size. Be careful
of machines (e.g., DEC Alpha) with large pointers.
If using gcc, best alignment is
#define qh_MEMalign fmax_(__alignof__(realT),__alignof__(void *))
*/
#define qh_MEMalign fmax_(sizeof(realT), sizeof(void *))
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