Changes.txt

.............This file lists all changes to qhull and rbox.....................


qhull 2002.1  2002/8/20

Changes to distribution:
 - Set up savannah.gnu.org/projects/qhull/ [R. Laboissiere]
 - Set up www.thesa.com/software/qhull as a backup
 - Added qh-get.htm, a local copy of the download page
 - Added Visual C++ interface to Qhull, qhull_interface.cpp [K. Erleben]
 - Use HTTP instead of FTP for downloading Qhull
 - Renamed qhull-1.0.sit.hqx

Bug fixes:
 - Fixed sign of coefficients for cdd halfspaces ('FD','Fd')  [T. Abraham]

Changes to code:
 - Replace qh_version with qh_VERSION in qhull.h.
   Allows shared libraries and single point of definition

Changes to build
 - Makefile.txt works under cygwin
 - Added Make-config.sh to create a Debian build [R. Laboissiere]
 - Added .exe to Makefile.txt#clean.  
 - In README, use -fno-strict-aliasing with gcc-2.95.1 [Karas, Krishnaswami]
 - Fixed chmod in Makefile.txt [B. Karas]

Documentation updates
 - Documented input options for each program [A. Montesinos]
 - FAQ: "How to get the radii of the empty spheres for Voronoi vertices"

URL updates:
 - Changed official URL from locate/qhull to software/qhull
 - Changed URLs from relative to absolute in qh-home.htm and qh-get.htm
 - Added URL for Newsgroup: comp.soft-sys.matlab
 - Added URL for GNU Octave
 - Added URLs for Google and Google Groups
 - Replaced qhull_mail.html and qhull_bug.html with mailto links.
 - Removed URL for Computational Geometry Tribune
 - Changed URL for locate/cglist to software/cglist
 - Used site relative links for qh-home.htm

qhull 3.1 2001/10/04

New features
 - Added option 'Qt' to triangulate non-simplicial facets
 - Added option 'TI file' to input data from file
 - Added option 'Q10' to prevent special processing for narrow distributions
        e.g., RBOX 1000 L100000 s G1e-6 t1001803691 | QHULL Tv Q10
 - Tried to compute Voronoi volumes ('Pv'). Requires dual face graph--not easy
        See Clarkson's hull program for code.

Changes to options
 - Added numtricoplanars to 'Fs'. Number of good, triangulated facets for 'Qt'
 - Added Zdelvertextot to 'Fs'.  If non-zero and Delaunay, input is degenerate
 - Qhull command ('FQ') may be repeated.
 - If 'TPn' and 'TWn' defined, trace the addition of point 'n'
     otherwise continue tracing (previously it stopped in 4-d)
 - Removed 'Ft' from qdelaunay.  Use 'Qt o' or 'qhull d QJ Qt' instead.
     For non-simplicial regions, 'Ft' does not satisify the Delaunay property.
 - If 'Po' or 'TVn', qhull checks outer planes.  Use 'Q5' to turn off.
 - If 'T4', print facet lists and check polygon after adding each point
 
Corrections to code
 - rbox: allow 'c' and 'd' with 's r', meshes, etc.
 - qh_findbest: redesigned as directed search. qh_findbesthorizon for coplanar
      qh_findbest is faster for many distributions
 - qh_findbestnew: redesigned to search horizon of coplanar best newfacets
      needed for distributions with a sharp edge, 
	  e.g., rbox 1000 s Z1 G1e-13 | qhull Tv
 - qh_findbest/qh_findbestnew: search neighbors of better horizon facets
      was needed for RBOX 1000 s Z1 G1e-13 t996564279 | qhull Tv  
      and RBOX 1000 s W1e-13 P0 t996547055 | QHULL d Qbb Qc Tv
 - qh_findbest with noupper: could return an upperdelaunay facet if dist>qh.MINoutside.
 - qh_findbestnew: allow facet->upperdelaunay if dist > qh.MINoutside
 - qh_partitioncoplanar: call qh_partitionpoint if outside and perpendicular
      for distributions with a sharp edge
 - qh_partitionvisible: report precision error if all newfacets degenerate.
      was needed for RBOX 1000 s W1e-13 t995138628 | QHULL d
 - qh_createsimplex: clears qh.num_visible, may be non-zero with 'TRn QJ'

Changes to prompts, warnings, and statistics
 - For Delaunay & Voronoi, 's' reports deleted vertices due to facet merging.
   They were incorrectly reported as nearly incident points.
 - Warn if recompute centrum after constructing hull
 - Simplified narrow hull warning and print all digits of cosine.  
     A narrow hull may lead to a point outside of the hull.
 - Print total vertices deleted instead of ave. per iteration (Zdelvertextot)
 - Improved tracing for qh_partitionpoint and qh_partitioncoplanar
 - Added number of distance tests for checking outer planes (qh_check_maxout)
 - Simplified "qhull precision error: Only n facets remain."
 - Included 'TRn' in the causes of a premature exit

Changes to documentation
 - README.txt: Added quickstart instructions for Visual C++
 - rbox: Added example of edge of narrow lens, rbox 1000 L100000 s G1e-6
 - Added cross references between options 'o' and 'p'.
 - qh-eg.html: added examples comparing 'Qt', 'QJ', and neither 'Qt' nor 'QJ' 
	eg.15a.surface, eg.15b.triangle, eg.17a.delaunay.2, etc.
 - Reorganized and enhanced discussion of precision problems in qh_impre.htm
 - Fixed spelling errors [K. Briggs]
 - Fixed link errors, validated HTML, and spell checked [HomeSite]
 - Removed unnecessary #TOP links
 - Added source links to the qh-quick.htm's header and footer
 - qh-geom.htm, qh-poly.htm: add links to Voronoi functions in io.c
 - src/index.htm: Added how to search qhull.h for qhull options
 - qvoronoi.htm/qdelaun.htm: 'Fc' and 'FN' includes deleted vertices

Changes to URLs
 - Added http://www.voronoi.com and http://www.magic-software.com

Changes to code
 - qh_qhull: if 'TVn' or 'TCn' do not call qh_check_maxout and qh_nearcoplanar
 - reviewed time profile.  Qhull is slower.  Optimized qh_findbestnew()
 - qh_addpoint: Added warning note about avoiding a local minimum
 - qh_checkpolygon: report qh.facet_next error if NARROWhull & dist>MINoutside
 - qh_findbest: renamed "newfacets" parameter to "isnewfacets" since it is boolT
 - qh_findbest/qh_findbestnew: testhorizon even if !MERGING
        Otherwise qhull c D6 | qhull Q0 Tv assigns coplanar points 
 - qh_resetlists: add qh_RESETvisible for qh_triangulate
 - qh_findbest: search better facets first.  Rewritten.
 - qh_findbest: increased minminsearch, always check coplanar facets.  
        See: RBOX 1000 s Z1 G1e-13 t996564279 | QHULL Tv
 - qh_findbestnew: report precision error for deleted cones [rare event]
        e.g.:  RBOX 1000 s W1e-13 P0 t1001034076 | QHULL d Qbb Qc Tv
 - qh_findbesthorizon: search horizon of qh.coplanarset.  New.
 - qh_findbestsharp: replaced with qh_sharpnewfacets followed by qh_findbestnew
 - qh_partitionpoint, Delaunay sites can not be inside.  Otherwise points may
       be outside upperDelaunay facets yet not near-inside Delaunay facets
       See: RBOX s 1000 t993602376 | QHULL C-1e-3 d  Qbb FA Tv
 - qh_partitioncoplanar: call qh_findbest/qh_findbestnew with qh DELAUNAY 
 - qh_printlists: format long lines 
 - qh_printvertex: format long lines
 - user.h: tightened qh_WARNnarrow and qh_MAXnarrow.  Do not see problems 
       until they are -1.0.
 - user.h: defined qh_DISToutside, qh_SEARCHdist, and qh_USEfindbestnew 
 - qh_checkfacet: in 3-d, allow #ridges > #vertices.  Can get a vertex twice
   in a ridge list, e.g,  RBOX 1000 s W1e-13 t995849315 D2 | QHULL d Tc Tv 

Changes to FAQ
 - Recommended use of triangulated output ('Qt')

Changes to distribution
 - Recompiled in Visual C++ 5.0 with optimization (as was version 2.6)
 - q_test: Added bad cases for Qhull and tests for new features

Changes to Qhull library
 - Added qh_triangulate() to poly2.c.  It triangulates the output.
 - Added option 'Q11' to copy normals and recompute centrums for tricoplanar facets 
        'FP' may not print the nearest vertex for coplanar points
        Use option 'Q11' when adding points after qh_triangulate()

qhull 3.0 2001/02/11

Changes to distribution
 - added qconvex, qdelaunay, qhalf, and qvoronoi
 - added qhull-interface.cpp on calling Qhull from C++ [K. Erleben]
 - renamed to qhull3.0/.   
 - added eg/, html/, and src/ directories 

Changes to URLs
 - MathLab6 qhull: convhulln, delaunayn, griddatan, tsearchn, vororoin [Z. You]
 - Wolfram Research wrote a Mathematica interface for qdelaunay [Hinton]
 - Geomview moved from www.geom.umn.edu to www.geomview.org [M. Phillips}
 - added URLs for tcsh and cygwin to README.txt

Changes to documentation
 - reorganized table of contents and renamed qh-man.htm to index.htm
 - wrote program documentation, dropped qh-opt.htm and qh-optv.htm
 - added quick reference, qh-quick.htm
 - reorganized qh-rbox.htm and renamed it to rbox.htm
 - split up qh-c.htm for quick navigation

Corrections to code
 - fixed type of arg for error message in qh_initqhull_globals [N. Max]
 - fixed incorrect initialization of qh MINdenom_1 for scalepoints
 - fixed drop dim for 'H Qbk:0Bk:0'.  Added qh.feasible_point to qh_projectinput 
 - qh_WARNnarrow is angle between facet normals.  Negate for warning message.
 -   statistics for Wangle/etc. concerns facet normals.  Reworded [E. Voth]
 - fixed error message for 'FC v'
 - report cospherical points if Delaunay and error in qh_scalelast()

Changes to code
 - turn on Pg if (QVn or QGn) and not (Qg or PG)
 - turn on Qc if format option 'Fc', 'FP', or 'Gp' (removes warning)
 - removed last good facet unless ONLYgood ('Qg').
 - added count of non-simplicial or merged facets to 'FS'
 - added count of non-simplicial facets to 's' (OK if #vertices==dim)
 - added Znonsimplicial and Znowsimplicial to 'Ts'
 - allow Mathematica output of dual polytope for halfspace intersection
 - added qh_checkflags to globals.c for multiple front ends
 - qh_initqhull_globals sets qh.MERGING if qh.MERGEexact
 - removed hashentryT.  It is no longer used.

Changes to prompts and warnings
 - reorganized prompts
 - reorganized synopsis for rbox.c
 - print warning if 'Fc' or 'FP' with 'd QJ'.  Coincident points are unlikely.
 - ignore warning if options 'v i Pp'.  qvoronoi users may need Delaunay tri.
 - reworded warning if 'Pg' and 'QVn' is not a vertex.
 - reworded warning for 'Qx Tv', qh_check_points() in poly2.c
 - if 'Pp', turn off warning for 'Qbb' without 'd' or 'v' 
 - in qh_printsummary() of Voronoi and Delaunay, distinguish QVn, QGn, Pdn, PDn 

Changes to FAQ
 - added FAQ item for nearly flat Delaunay triangles [Z. You]
 - added FAQ item for area and volume [R. Konatham]
 - added FAQ item for Voronoi diagram of a square [J. Yong]
 - edited FAQ item on point location in Delaunay triangles [Z. You]
 - added FAQ item on nearly flat Delaunay triangles [Dehghani]
 - added FAQ item about halfspace intersection [V. Tyberghein]
 - added FAQ item for missing ridges [M. Schmidt]
 - added FAQ item about qh_call_qhull [R. Snyder]
 - added FAQ item about memory statistics [Masi]
 - added FAQ item on meshing non-convex objects
 - added FAQ item on MATLAB and Mathematica interface

qhull 2.6 1999/04/19
 - fixed memory overwrite (no effect) in qh_initstatistics() [K. Ford]
 - added zdoc11 to qh-stat.h#ZZdef for !qh_KEEPstatistics [K. Ford]
 - enhanced qh_initqhull_globals() test of qh_RANDOMint and qh_RANDOMmax
 - added debugging option to always return qh_RANDOMmax from qh_rand()
 - fixed option 'Qr', qh_initialvertices(), to allow a broken qh_rand() 
   fixed option 'Qr', qh_nextfurthest(), to allow narrow hulls  
     Option 'Qr' simulates the random incremental algorithm for convex hulls
 - added note that qh.num_outside includes coplanar points for narrow hulls
 - added FAQ items for triangles/ridges of 3-d Delaunay triangulation[P. Kumar]
 - added FAQ item about on-line processing with the Qhull library [O. Skare]
 - changed name of option 'Error-roundoff' to 'Distance-roundoff'

qhull 2.6 1998/12/30
 - for the unbounded rays of the Voronoi diagram, use a large box [Schmidt]
     e.g., 'rbox P4,4,4 P4,2,4 P2,4,4 P4,4,2 10 | qhull v Fv' fails for point 0
     while 'rbox P4,4,4 P4,2,4 P2,4,4 P4,4,2 10 c G5 | qhull v Fv' is OK.
 - fixed qh_new_qhull() to use outfile/errfile instead of stdout/stderr [Ford]
 - clarified COPYING.txt for use in other programs [Archer]
 - improved qh_readpoints() error message for incorrect point count.
 - added FAQ item for closest triangle to a point [Sminchisescu & Heijting]
 - added FAQ item for is a point outside of a facet [Beardsley]
 - added FAQ item for visiting facets of the Delaunay triangulation [Heijting]
 - added link to Erickson's Computational Geometry Software
 - added link to Sharman's HTML version of the comp.graphics.algorithms FAQ
 - added link to Owen's Meshing Research Corner
 - added note to 'd' about quadratic size of 'rbox 100 l | qhull d' [Kumar]
 - added 'about a point' to mentions of halfspace intersection
 - added request to qh-in.htm to compute largest empty circle [Hase]
 - the DOS window in Windows NT is better than the DOS window in Windows 95
 - removed obsolete qh_findfacet() from qh-c.htm [Sminchisescu]

qhull 2.6 1998/8/12
 new and modified features
 - rbox: added option Mn,m,r to generate a rotated lattice or mesh
 - rbox: report error if more than one of 'l', 'x', 'L', 's', or 'M'

 Qhull library changes
 - added qh_new_qhull() to user.c for calling qhull() from a program [D. Zwick]
   rewrote user_eg.c to use qh_new_qhull().  Added qh_QHpointer example.
 - added qh_CLOCKtype 2 in user.h to call times() for CPU time [B. Hemkemeier]
 - renamed set.c/set.h to avoid conflict with STL's set.h [G. van den Bergen] 
   can also use '#include <qhull/qhull_a.h>' for Qhull library

 fixed errors
 - fixed qh_init_B() to call qh_initqhull_mem() once only [D. Zwick]
   This only effects Qhull library users of qh_QHpointer.
 - fixed qh_mergecycle_all() to check for redundant vertices [J. Nagle]
   e.g., 'rbox M3,4 64 | qhull Qc' should report 8 vertices & 48 coplanars
 - fixed gmcoord initialization in qh_setfacetplane() for qh.RANDOMdist
 - turn off qh.RANDOMdist during qh_printfacetheader()
 - fixed error messages for unknown option flags

 documentation changes
 - added note to FAQ on the Voronoi diagram of cospherical points [H. Hase]
 - added note to 'Qu' on furthest-site Delaunay triangulation via convex hull
 - added note to 'QJ' about coplanar points on the convex hull of the input
 - added note that 'o' and 'FN' list Voronoi regions in site id order [Arvind]
 - added links to Fukuda's introduction to convex hulls, etc. [H. Hase]
 - added .c and .h source files to web distribution and qh-c.htm [J. Sands]
 - documented qh_ZEROdelaunay.  Delaunay and Voronoi diagrams do not include
   facets that are coplanar with the convex hull of the input sites.
  
 modified code
 - replaced computed minnorm in qh_sethyperplane_det with distance test
 - removed 'qh rand_seed' since random number generator is independent of qhull
 - dropt 'qhull-PPC.sit.bin' from the distribution (out-of-date) [M. Harris]

qhull 2.5 1998/5/4

 fixed errors
 - removed zero-area Delaunay triangles and furthest-site triangles [I. Beichl]
   Zero-area triangles occur for points coplanar with the input's convex hull.
 - replaced qh.MINnorm with computed minnorm in qh_sethyperplane_det [J. Nagle]
   qh.MINnorm was incorrect for the convex hull of the "teapot" example.
   Qhull runs 0-20% slower in 3-d and 4-d.
 - allow 'Qg' with furthest-site Delaunay triangulation (may be faster)
 - removed extra space in definition of FOREACHmerge_() for Alpha cc [R. LeRoy]
 - fixed innerouter type in qh_printvdiagram2 [does not effect code, R. Adams]

 documentation changes
 - to browse qh-c.htm, set MIME type of .c and .h files to text/html
 - added example of 3-d Delaunay triangulation to q-faq.htm
 - added Delaunay and Voronoi examples to qh-optv.htm
 
qhull 2.5 1998/2/4
 - added option 'v Fi' for separating hyperplanes of bounded Voronoi regions
 - added option 'v Fo' for separating hyperplanes of unbounded Voronoi regions
 - option 'Pp' turns off the warning, "initial hull is narrow"
 - fixed partial, 3-d Voronoi diagrams (i.e., 'v Fv QVn Tc')
 - fixed missing statistics in qh_allstat* [T. Johnson]
 - rearranged qh_printvdiagram.  Use qh_eachvoronoi to iterate Voronoi ridges.
 - added qh_check_points to qh-math.c
 
qhull 2.5 1998/1/28
 - added option 'Fv' to print the Voronoi diagram
 - added rbox option 'x' to generate random points in a simplex
 - added rbox option 'y' to generate a simplex and random points
 - added rbox option 'On' to offset the output 
 - add unpacking instructions to README.txt
 - updated discussion of forced output, 'Po'
 - sorted the options alphabetically
 - removed __STDC__ check from qhull.h for VisualC++
 - moved qh_markvoronoi from qh_printvoronoi and cleared facet->seen flags
 - added facet->seen2 flag for 'Fv'

qhull 2.5 1998/1/16
 - fixed initialization of qh.last_low on restart of 'd QJ' 
 - renamed qh_JOGGLEmax to qh_JOGGLEmaxincrease
 - updated URL for Fukuda's cdd program
  
qhull 2.5 1998/1/12

New or modified features
 - added option 'Fx' to print vertices by point id [G. Harris, T. McClendon]
     in 2-d, the vertices are printed in counter-clockwise order
     for Delaunay triangl., 'Fx' lists the extreme points of the input sites
 - added option 'QJ' to randomly joggle input instead of merging facets
 - added option 'TO file' to output results to a file.  Needed for Windows95.
 - added option 'TRn' to rerun Qhull n times. Use to collect joggle statistics

Corrections
 - fixed 2-d facet orientation for 'i' and 'o' outputs
 - for Mathematica 2.2 ('m') changed %10.8g to %16.8f [A. Zhaxybayev]
 - fixed incorrect warning for 'QV0 Qg' in qh_initbuild [B. Wythoff]
 - fixed unaccessible statistic if !qh_KEEPstatistics for Wnewvertexmax
 - fixed overestimate of qh ONEmerge for point sets outside of 
     first quadrant and far from the origin
 - fixed overestimate of 'Qbb' for point sets far from the origin
 - fixed potential overestimate of qh DISTround under 'Qbb'
 - fixed 'p' printing coplanar points of unselected facets
 - fixed 'Ft' printing centrums unnecessarily in 2-d
  
Changes to documentation 
 - wrote internal design documentation (qh-c.htm)
 - started frequently asked questions (qh-faq.htm)
 - added a section on joggled input to qh-impre.htm
 -   added joggle example to qh-eg.htm (eg.15.joggle)
 -   changed q_eg to use 'QJ' instead of 'Q0' were appropriate
 - added an example to each of the main options
 - added examples to rbox.htm
 - added examples to the synopsis
 - added a reference to Mucke, et al ['96], Fast randomized point location ...
 - added code for printing Delaunay triangles to qh-in.htm [A. Tsui]
 - options 'Pdk' and 'PDk' do not drop on equality

Improvements to the code 
 - reviewed warning messages for Qhull options in qh_initflags
 - added warning to 's' if premature exit from 'TCn' or 'TVn'
 - 's' prints max distance above/below only if qh.MERGING
 - reduced maxoutside in qh_check_bestdist/qh_check_points for 'Rn'
 - in post-merging, rebuild centrums of large facets that become small
 - lowered cutoff for coplanar facets for ischeckmax/qh_findbest
 - removed qh_check_maxout for 'Wn Q0'
 - reset tracing after 'TPn' adds point in 4-d and higher

Changes for the Qhull library 
 - changed qh_setdelaunay to call qh_scalelast if used with 'Qbb' or 'QJ'
     Delaunay callers to qh_findbestfacet, qh_addpoint, or qh_findfacet_all
     should always use qh_setdelaunay as in user_eg.c
 - defined qh.outside_err to check points against a given epsilon [E. Voth]
 - added header to user_eg.c to avoid its incorporation into qhull [C. Begnis]
 - added qh_nearcoplanar() calls to user_eg.c
     only needed if use 'QJ'
 - expanded __STDC__ warning message in qhull.h [C. Begnis]
 - renamed qh maxmaxcoord to qh MAXabs_coord
 - replaced qh MAXlowcoord with qh MAXabs_coord
 - random seed ('QR-n') is reset in qh_initqhull_globals after testing
 - replaced 'FO' options "_max-coord/_min-coord" with "_max-width"/qh.MAXwidth

Other changes to Qhull functions
 - report error for !bestfacet in qh_findbest (it shouldn't happen) [H. Meuret]
 - set newbest in qh_findbest only if bestfacet updated 
 - renamed facet parameter for qh_findbest
 - added maxdist argument to qh_checkpoint
 - moved 'FO' output after qh_partitionall
 - separated qh_initbuild from qh_qhull
 -   reinitialize globals modified by qh_buildhull
 -   moved initialization of qh.GOODvertexp & qh.GOODpointp to qh_initbuild
 - separated qh_nearcoplanar from qh_check_maxout
 - separated qh_geomplanes from qh_printfacet2geom, etc.
 - separated qh_freebuild from qh_freeqhull
 - separated qh_outerinner from io.c to return outer and inner planes
 - separated qh_distround and qh_detroundoff from qh_maxmin


qhull 2.4 97/4/2

New or modified features
 - made 'C-0' and 'Qx' default options.  Use 'Q0' to not handle roundoff errors
 - removed point-at-infinity from Delaunay/Voronoi.  
     you no longer need to use 'Qu PDk'
 - added 'Qz' to add a point-at-infinity to Delaunay and Voronoi constructions
 - added published version of qhull article in ACM Trans Math Software
 - ported qhull to Windows95 under Visual C++ and Borland C++
 - added 'Ft' for triangulation by adding the centrums of non-simplicial facets
 - added 'Gt' to display 3-d Delaunay triangulations with a transparent hull
 - changed definition of coplanar point in output to qh min_vertex (see 'Qc')
     it was qh MAXcoplanar ('Un') [could make vertices non-coplanar]
 - automatically set 'Qi' for options 'd Qc' and 'v Qc'.
 - reworded summary ('s') for Delaunay/Voronoi/halfspace.  
     use 'Fs' and 'FS' for summary statistics.
 - for summary 's' of Delaunay/Voronoi, display number of coplanars for facets
     if none, display total number of coplanars (i.e., non-vertices)
 - input comment is first non-numeric text (previously limited to header)
 - added input warning if use 'Qbb' without 'd' or 'v'
 - 'Q3' can not be followed with a numeric option

Corrections
 - fixed qh_partitioncoplanar() to not drop interior points if 'Qi' is used
 - fixed 'FP d' to report distance in point set instead of paraboloid
 - fixed qh_findbest() to search all coplanar facets for qh_check_maxout()
  
Changes to documentation 
 - added example eg.17f.delaunay.3 to show a triangulation of cospherical sites
 - split up qh-opt.htm into multiple pieces
 - split off qh-in.htm for Qhull internals
 - renamed .html files to .htm for Windows95
 - rewrote qh-optv.htm on Delaunay triangulation and Voronoi vertices
 - added 'man' pages qhull.txt and rbox.txt.  These list all the options
 - removed 'txt' versions of html files
 - added note to 'PDk' about avoiding a 'd' option immediately after a float
 - under option 'd', display the triangulation with 'GrD3', not 'GnrD3'
 
Changes to the Qhull library
 - added 'format' argument to qh_printfacetNvertex_nonsimplicial() in io.c
 - removed C++ type errors [J. Stern, S. Marino]
 -  created SETelemt, SETfirstt, etc. for specifying data types.  
 -  use SETelem,etc. for assignments. 
 -  changed setT.maxsize to 'int' to prevent type conversion warnings
 -  changed FOREACH.. to a comma expression for better code and less warning
 -  changed qh.vertex_visit and .visit_id to unsigned int to prevent warnings
 - changed clock() to qh_CPUclock (user.h)
 - qh_init_B() and qh_readpoints() do not set qh.ATinfinity for Delaunay tri.
 - qh_setvoronoi_all() sets upper Delaunay facets if qh.UPPERdelaunay is set
 - qh_nearvertex() returns distance in dim-1 for qh.DELAUNAY
 - removed MSDOS path from qhull_command.  Spaces in Win95 tripped qh_setflags
 - removed memory.h from qhull_a.h.  memset,etc. should be in strings.h
 - split qh_prompt into pieces for Visual C++
 - added note to qh_addpoint that coordinates can not be deallocated
 - added Baker '89 to constrained Delaunay diagrams under Enhancements
    please let me know if you try this
 - added request for unbounded Voronoi rays to Enhancements
    please let me know if you try this

qhull V2.3 96/6/5
 - fixed total area of Delaunay triangulation. [A. Enge]  
      It should ignore facets on the upper-envelope.
 - if 'd Qu FA', the total area is summed over the upper-Delaunay triangles
 - fixed sign of area for Delaunay triangulations. 
 - fixed cdd input format for Delaunay triangulation. [A. Enge]
 - for cdd input, allow feasible point for halfspaces.
 - warning if cdd output format for centrums, halfspace intersections, or OFF.
 - print '0' for area ('Fa') if area is not computed for a facet
 - option 'QR-n' sets random number seed to n without rotating input
 - fixed qh_findbest() to retest coplanar and flipped facets after a restart
 - for 'd Qu Ts' collects angle statistics for upper Delaunay facets
 
 Changes to the Qhull library
 - expanded user_eg.c for incremental constructions and Delaunay triangulation
 - added discussion of incremental construction to qh_man.html#library
 - WARNING: The default value of qh ATinfinity was changed from True to False.
            A new flag, qh UPPERdelaunay, was defined for 'Qu'.
         Please set qh ATinfinity if you explicitly add the point "at-infinity"
         Please set qh ATinfinity if you explicitly call qh_projectinput.
         Please set qh UPPERdelaunay if you explicitly cleared qh ATinfinity.
	 Other users do not need to change their code.         
   Now you can build a Delaunay triangulation without creating a point 
   "at-infinity".  This removes a potential, hard-to-understand error.  
   qh_readpoints sets qh ATinfinity for options 'd' or 'v' without 'Qu'.
   qh_initB sets qh ATinfinity for qh PROJECTdelaunay w/o qh UPPERdelaunay.
   qh_projectinput adds a point "at-infinity" only if qh ATinfinity is set.
 - added qh_setdelaunay to geom2.c to project points to paraboloid
 - added qh_findbestfacet() to poly2.c to replace qh_findfacet()
 - removed procedure qh_findfacet().  It does not always work.
 - removed NULL option for facet in qh_addpoint().  It does not always work.
 - added noupper parameter to qh_findbest.
 - added search of upperdelaunay facets to qh_findbest()
 - allowed qh_findbest() to start with a flipped or upperdelaunay facet
 - removed qh_nonupper() -- it is no longer needed
 - allow space at end of options
 - fixed qh_projectinput for furthest-site Delaunay (qh PROJECTdelaunay 'd Qu')
 - added voids to procedure declarations with empty parameter lists

qhull V2.3 96/3/25
 - fixed missing qh_check_maxout when coplanar points and no merged facets.
 - fixed qh_freeqhull/allmem (e.g., if qh_NOmem) [only custom code] [E. Voth]
 - fixed qh_freeqhull to free qh interior_point [E. Voth]
 - fixed main() to free all of memory if qh_NOmem.  Include "mem.h" [E. Voth]
 - reset f.newcycle link in qh_mergecycle_all [E. Voth]
 - fixed false error if 'Tc', coplanar points, and a narrow hull
 - turn off 'Rn' when computing statistics, checking code, or tracing code
 - removed ={0} from global.c and stat.c to reduce compiler warnings
 - changed Makefile dependences to $(HFILES) for all but unix.o, set.o, mem.o
 - pulled out qh_printpointid and reordered qh_pointid [E. Voth]
 - removed some compiler warnings
 - moved 'FO' print of options to just before qh_buildhull
 - changed 'FO' to list difference from -1 for _narrow-hull

qhull V2.2 96/2/15
 - detect narrow initial hulls (cosine of min angle < qh_MAXnarrow in user.h).
   Write warning if cosine < qh_WARNnarrow in user.h.  If narrow (qh NARROWhull), 
   partition coplanar points as outside points and delay coplanar test to end.
   Needed for  RBOX 1000 L100000 s G1e-6 t995127886 | QHULL Tv
   See 'limitations' in qh-impre.html for further discussion.
 - corrected some confusions between 'FV' and 'Fv' in qh-opt.html
 - fixed initialization error for small Voronoi diagrams (e.g., [0,0], [1,0], [0,1]) [J. Velez]
  - fixed bad return from qh_mindiff in geom2.c
 - for initial hull, first process facet with furthest outside point (qh_furthestnext)
 - added facet->notfurthest flag for recomputing furthest point
 - added check for __STDC__ (needs ANSI C) [E. Voth]
 - reduced warning messages from [E. Voth].  e[1] in setT still reports a warning.
 - added a cube to the discussion of option 'v' (Voronoi) in qh-opt.html [J. Velez]
 - added notes about adjacent vertices to "Calling Qhull" in qh-man.html [R. Lewis & J. Velez]
 - added note about 'lines closer' when viewing 3-d Delaunay triangulations [P. Kallberg]
 - added option 'Q9' to always process furthest of furthest outside points.
 - removed option 'Pp' from q_eg and qh-eg.html.

qhull V2.2 95/12/28
 - added option 'Qbb' to scale the last coordinate to [0,m] (max prev coord).
   This reduces roundoff errors for Delaunay triangulations with integer coordinates.
 - changed option 'Qu d' to print out the furthest-site Delaunay triangulation
   Use options 'Qu d PD2' to compute the normal 2-d Delaunay triangulation without
   the point at infinity. 
 - added notes to the documentation of option 'd'
 - added notes to limitations of how Qhull handles imprecision
 - added warning if options 'FP', 'Fc', or 'Gp' without option 'Qc' or 'Qi'
 - added note to options 'PDk:n' and 'Pdk:n' that closest facet is returned if none match
 - added check that 'Qbk' and 'QBk' does not invert paraboloid for 'd'
 - added notes that qh_findfacet and qh_addpoint require lifted points for Delaunay triangulations
 - fixed 'rbox s 5000 W1e-13 D2 | qhull d Qcu C-0 Qbb'
 - fixed option 'QbB' (qh SCALEpoints was not set)
 - fixed minor confusion between 'Gc' (print centrums) and 'Gp' (print points)
 - rewrote qh_findbestnew for upper convex hull, Delaunay facets
 - changed option name for 'Gp' from 'Gcoplanar' to 'Gpoints' 
 - changed "nearest" facet for 'Pdk' to threshold - normal
 - reworked qh GOODclosest for 'Qg'
 - added note that 'Qg' does not always work
 - recorded option 'C-0' as "_zero-merge" in option 'FO'
 - refined qh DISTround in qh_maxmin/geom2.c for Delaunay triangulations

qhull V2.2 95/12/4
 - Version 2.2 fixes an important bug in computing Delaunay triangulations 
   and convex hulls with edges sharper than ninety degrees.  The problem 
   occurs when processing a point at a sharp edge.  A directed search can 
   not be used for partitioning because one side may hide facets from the 
   other side.  The new lens-shaped distribution for rbox demonstrates the 
   problem.  For example, 'rbox 100 L3 G0.5 s | qhull Tv' fails for Version 2.1.
   O. Schramm found the bug when computing the Delaunay triangulation of points
   near an outside edge.  

   I rewrote qh_findbest and related functions.  Qh_findbest 
   uses an exhaustive test for sharp edges (qh_findbest_sharp).  
   Qh_findbest avoids the upper convex hull of Delaunay triangulations.

   Options 'd' and 'v' no longer assign coplanar points to the upper convex hull.
    
   Qh_check_maxout tests near-inside points.  It ignores fully inside points.
   When done, it removes near-inside points from the coplanar sets.

   If you use qh_addpoint or qh_findbest, please review the function headers.  
   They do not work for lens-shaped hulls for arbitrary facets.  They do work for 
   Delaunay triangulations.

 Changes to options for V2.2
 - added 'Qu' for computing the furthest-site Delaunay triangulation (upper hull)
   and furthest-site Voronoi vertices.
 - added 'FP' to print nearest vertex for coplanar points
 - added coplanar count to 'Fs' and 's'
 - added number of similar points to summary for Delaunay/Voronoi
 - Option 'Qc' is no longer necessary when merging.  
 - 'o' format for Voronoi vertices ('v') generates "0" lines for similar points
 - 'QRn' for Delaunay ('d' or 'v') now rotates about the Z axis (see qh_init_B).
   Otherwise Qhull does not identify the upper hull
 - removed option 'Qa' for "all points outside".  In V2.1 it was automatically
   set for 'd'.  Even though it was a bad idea, it revealed the above bug.
 - for option list ('FO'), added version, values for one-merge, maxpos, maxneg,
   and near-inside, and flags for zero-centrum
 - optimized 'C-0' and 'Qx'.  These options ("zero-centrum") test vertices 
   instead of centrums for adjacent simplicial facets.
 - if 'Tv', report number of points that are not verified due to qh_findbest
 - Option 'Q8' ignores near-inside points.

 rbox 95/12/3
 - added lens distribution ('Ln')  It may be used with 's', 'r', 'Wn', and 'Gn'
 - removed default point count except for the test case, 'Dn'
 - divided main() of rbox.c into sections

 Documentation changes for V2.2
 - added examples for lens distribution and furthest-site Delaunay triangulation
   and renumbered the examples for q_eg
 - described facet orientation in 'data structure' section [P. Soikkonen]
 - added notes to qh-man.html/"What to do if something goes wrong"
 - added note about using 'Tv' to verify the results [O. Schramm] 
 - expanded definition of f_r in Performance section [S. Grundmann]
 - noted that Geomview display of a Voronoi diagram adds extra edges 
   for unbounded Voronoi cells
 - rewrote error "convexity constraints may be too strong" [D. Newland]
 - added limitations section to "Imprecision in Qhull"
 - added note about zero-area facets to 'Imprecise convex hulls' in qh-impre.html
 - added note to 'Qi' that it does not retain coplanar points
 - added note that option 'Q5' may be used if outer planes are not needed
 - added note to README.txt about Irix 5.1 [C. Goudeseune]
 - added code fragment for visiting Voronoi vertices to "Calling Qhull" [M. Downes]
 - added note about qh_addpoint() to "Calling Qhull" [M. Downes]

 Errors fixed for V2.2
 - use qh_sethyperplane_gauss if 3-d or 4-d norm is less than qh MINnorm
 - count Zcentrumtests if qh_NOstat
 - reversed sign convention for qh_sethyperplane_gauss
   it was opposite to qh_sethyperplane_det
   this effects qh_determinant and qh_detsimplex
 - fixed error in qh_findgood_all with multiple restrictions, e.g., 'QVn Pdk'
 - fixed call to qh_clearcenters for qh_produce_output
 - in qh_errexit, report p0 if last furthest point

 Changes for users of the Qhull library
 - user code needs to define qh_version (see user_eg.c)
 - merged initialization code into qh_init_A and qh_init_B [M. Mazzario] 
   old code works as before.
   qh_initflags also sets qh qhull_command for qh_initthresholds
   redid initialization for user_eg.c
 - simplified user_eg.c.  It computes the convex hull of a cube.
 - added qh_setvoronoi_all in poly2.c to compute Voronoi centers
   added related note to call_qhull
 - added qh_findfacet to use in place of qh_findbest
 - added qh_nearvertex to return nearest vertex in facet to point
 - redid notes on multiple, concurrent calls in call_qhull/user.c
 - changed BoolT to unsigned int (prevent implicit enum conversion warnings)
 - added upperdelaunay to facetT.  It indicates a facet of the upper convex hull.
 - converted qhull-PPC.sit for CodeWarrior 7

 Code changes for V2.2
 - simplified calls to setjmp() for Cray J916 [Salazar & Velez]
 - replaced fprintf(fp,string) with fputs in io.c
 - 'qh num_coplanar' removed (too expensive and not used).
 - added numcoplanars to qh_countfacets()
 - added min norm to qh_normalize2().  qh_normalize() wasn't changed
 - removed type casts from qh_point and qh_pointid [Salazar & Velez]
 - account for roundoff error in detecting upper convex hull (qh ANGLEround).
 - post merging uses qh_findbestnew for partitioning
 - qh_findbestnew for qh_partitioncoplanar goes to best facet
 - 'Qm' always processes points above the upper hull of a Delaunay triangulation
 - GOODvertex initialized with qh_findbestnew instead of qh_findbest
 - for 'v', qh_facetcenter returns furthest-neighbor vertex if 'Qu'
 - added test for qh feasible_point if use 'Fp' and qh_sethalfspace_all
 - reviewed Sugihara's algorithm for topologically robust beneath-beyond
 - on error, report if qhull in post-merging or has completed
 - if tracing, option 'FO' and qhull command always printed
 - added current furthest point ("during p%d") to 'T-1' events
 - added 'TWn' tracing for vertices of new facets (qh_setfacetplane)
 - added 'TWn' tracing for vertices in an output facet (qh_check_maxout)
 - reorganized split between poly/poly2.c and geom/geom2.c
 - reordered object files in Makefile

qhull V2.1 95/9/25
 - converted qhull.man to html format, many edits
 - referenced Shewchuk's triangle program and Schneiders' Mesh Generation page
 - added option 'Qa' to force all points outside 
     automatically set for "precise" Delaunay or Voronoi [Salazar & Velez]
     it is turned off by merging, 'Wn', 'Qc' or 'Qi'
 - added coplanar points to option 'FN'
 - moved option 'FO' to include default precision options
 - changed default random number generator to qh_rand in geom2.c (user.h)

 other code changes
 - fixed option comment Pdrop-facets-dim-less, Qbound-dim-low, QbBound-unit-box
 - defined ptr_intT for converting 64-bit ptrs to 'unsigned long' [D. Bremner]
 - defined setelemT to distinguish actual size from pointers [D. Bremner]
     use either e[...].p or e[...].i (user-level code should use set.h macros)
 - changed %x to %p in format statements for pointers [D. Bremner]
 - added test of REALmax,etc. to qh_maxmin [H. Poulard]
 - added type parameter to qh_memalloc_() macro for type conversion
 - added type conversion to qh_memalloc() calls where missing
 - added type conversion to calls into set.c that return void*

 other documentation changes:
 - new URLs for graphics images
 - fixed comment for facetT.neighbors in qhull.h [P. Soikkonen]
 - changed recommendations for precision errors in qh_printhelp_degenerate()
 -  added recommendation for 'V0' (facet is visible if distance >= 0)
 - added note about 'long double' to user.h [S. Grundmann]
 - added note about zero area Delaunay triangles for the 'v' option
 - added note about locating Delaunay triangles to option 'd' [A. Curtis]
 - added note that coplanar vertices correspond to duplicate points for 'd'
 - added note about option 'd' automatically setting 'PDk' (lower convex hull)
 - added note about precision errors to option 'd' [many users] 
 - added note about qh_findbest() to the Qhull library section [L. Lai]
 - 'make install' renames qhull.man to qhull.1 for Unix [M. Phillips]
 - renamed README, etc. to *.txt to match WWW conventions [D. Cervone]

qhull V2.1 7/10/95
  - in 2-d, 'v o' lists the vertex at infinity in order [R. Critchlow]
  -   it used to always list the vertex at infinity ("0") first
  - rewrote description of 'v' option (Voronoi vertices and 2-d diagrams)
  - added 'PFn' for printing facets whose area is at least 'n' [D. Holland]
  - prefixed 'Q',etc. to the 'Q',etc. options in the long help prompt
  - fixed references to 'Fv' and 'FV' options under option 'Hn,n,n'
  - updated reference to cdd, <ftp://ifor13.ethz.ch/pub/fukuda/cdd/>
  - in set.c, added some missing type coercions for qhmem.tempstack

qhull V2.1 6/12/95
  - replaced qhull.ps with qhull-2.ps (paper submitted to ACM TOMS)
  - use BUFSIZ for setvbuf for Power Macintosh
  - number of good facets printed if QVn, QGn, Pd, or PD
  - added Makefile for Borland C++ 4.02 with Win32 [D. Zwick]
  - added note to Enhancements section of qhull.1 about constrained
       Delaunay triangulations [T. Rasanen]

qhull V2.1 6/7/95
  - fixed qh_facetarea_simplex() for non-simplicial facets [L. Schramm]
  - fixed cast in qh_point and qh_pointid for 64-bit architectures
  - fixed URL for Amenta's list of computational geometry software
  - fixed cast in qh_meminitbuffers for qhmem.freelists
  - added test for !qh half_space in qh readpoints 
  - clarified options for qh_printhelp_singular()
  - discussed non-simplicial facet area under option 'Fa' in qhull.1

qhull V2.1 6/3/95
  - home page for Qhull and new descriptions for the Qhull examples
      http://www.geom.umn.edu/software/qhull
  - changed SIOUX buffering for Power Macintosh.   It runs fast now.
      added a project file for Metrowerk's C
  - note in README about compiling qhull on the PC

qhull V2.1 beta 5/15/95

		======= main changes ========
  - added halfspace intersection ('Hn,n,n')
  - facet merging is better, especially for high dimensions 
  -   added 'Qx' for exact merges of coplanar points and precision faults
  - facet merging is faster, especially for high dimensions.
      e.g., convex hull of the 8-d hypercube is seven times faster
  - added 'F' output formats for printing each aspect of the convex hull
  - format 'Fa' computes facet areas, total area, and total volume
  - format 'FO' writes a descriptive list of selected options to stderr
  - moved all customization options to user.h
  - changed the default precision to 'double' since it's needed for Delaunay.
      using 'float' is faster and takes less space (REALfloat in user.h)
  - option 'Qm' is no longer important for facet merging
  - removed need for 'Qs' by selecting initial simplex with pos. determinants
  - renamed 'Qv' to 'Q7' since virtual memory does not work well for qhull
  - Qhull is available for the Power Mac (no graphical output)

                 ====== other new and modified options ===========
  - changed default MINvisible ('Vn') to a multiple of premerge_centrum ('C-n')
  - added 'Un' option to set width of facet for coplanar points.
       This replaces the previous rules for determining coplanar points.
  - changed default MINoutside ('Wn') to twice MINvisible ('Vn')
  - Geomview output adjusts point radii for MINvisible 'Vn' 
  - the input format allows the number of points to precede the dimension
  - options 'v' 'd' 'FAn' and 'FMn' record good facets ('Pg')
  - added 'Fd' and 'FD' options for homogeneous coordinates in cdd format
  -   in rbox, added 'h' flag to generate homogeneous coordinates in cdd format
  - option 'PAn' prints out the n facets with the largest area 
  - option 'PMn' prints out the n facets with the most merges
  - option 'Po' under tracing ('Tn') no longer tries to write erroneous facets
  - option 'TCn' only prints the old 'visible' facets for 'f'
  - 'TFn' reports intermediate results when post-merging
  -   option 'Ts' with option 'TFn' prints intermediate statistics
  - the message for 'Tv' reports if it is checking outer planes
  - 'Tz' sends stderr output to stdout
  - added 'Q1' to ignore angle when sorting merges (merges are worse)
  - added 'Q2' to not perform merges in independent sets (merges are worse)
  - added 'Q3' to not remove redundant vertices (faster)
  - added 'Q4' to avoid merges of old facets into new facets (does worse)
  - added 'Q5' to skip qh_check_maxout (faster, but less accurate)
  - added 'Q6' to skip pre-merge of concave and coplanar facets
  - added 'Qv' for testing vertex neighbors for convexity (needs merge option) 
  - added warning if mix Geomview output with other outputs ('Po' turns off)
  - options 'o v' for 3-d and higher sort the Voronoi vertices by index

		======= documentation =======
  - rewrote the introduction and precision sections 
  - added a section on performance
  - added an example on halfspace intersection
  - installed examples of Qhull in
    <http://www.geom.umn.edu/pix/archive/subjects/computational_geometry.html>

		======= Makefile, user.h, and messages =======
  - Makefile calls ./qhull, ./rbox, and prints short prompt for qhull
  - added new statistics, e.g., for buildhull
  - changed default qh_RANDOMtype to RAND_MAX with rand()
  - added comment about numeric overflow to printhelp_singular
  - reorganized the code to improve locality of reference
  - option in mem.h (qh_NOmem) to turn off memory management in qhull
  - option in user.h (qh_NOtrace) to turn off tracing in qhull
  - option in user.h (qh_NOmerge) to turn off merging in qhull.
  -   use this instead of redefining qh_merge_nonconvex in user.c
  - simplified user_eg.c.  See qh_call_qhull() in user.c for the full version
  
		======== bug fixes ============
  - fixed error in number of points for 'rbox 100 r' (odd distribution)
  - fixed performance error in qh_degen_redundant_neighbors
  - qh_partitionpoint now sets facet->maxoutside for first outside point
  - fixed performance error in partitioning when merging a large, regular cone
  - removed memory leak in qh_appendmergeset
  - removed double free of qh line under errors in qh_readinput()
  - forcing output on error ('Po') fixed for options 'n' 'o' 'i' 's'
  - fixed optimization error on HP machines [fprintf(... *p++)]

                ======== changes to qhull.h for user code =======
  - qh_collectstatistics and qh_printstatistics removed from qhull.h.
      should use qh_printallstatistics instead
  - qh_findbest uses boolT for newfacets
  - added qh_findbestnew for non-simplicial facets.  qh_findbest is
    too slow in this case since it needs to look at many nearly coplanar
    facets.
  - renamed qh_voronoi/qh_centrum to qh_ASvoronoi, qh_AScentrum
  - changed facet->id to 32-bits, added new flags for merging
  - added facet->f for facet pointers while merging and for facet area
  - added dfacet/dvertex for printing facets/vertices while debugging
  - added qh_produce_output and qh_printsummary
   
		======== changes to code ==========
  - moved qh_setfacetplane from qh_makenewfacets to qh_makenewplanes
  - added qh_setfree2, qh_setcompact, and qh_setduplicate to set.c
  - qh_findgooddist returns list of visible facets instead of setting global
  - in qh_check_maxout, inside points may be added to coplanar list.
  - qh_findbestnew used for qh_partitionall.  It is faster.
  - in qh_findbest, changed searchdist to MINvisible+max_outside+DISTround.
      MINvisible is the default MAXcoplanar.
  - cleaned up list management via qh_resetlists
  - uses facet->dupridge to indicate duplicated ridges instead of ->seen
  - qh_buildtracing records CPU time relative to qh hulltime instead of 0

		========== changes to merging =======
  - many performance improvements, especially in high-d.
  - when merging, qh_findbest and qh_findbestnew stops search at qh_DISToutside
  - vertex neighbors delayed until first merge
  - post merges reported every TFn/2 merges
  - vertex merging turned off in 7-d and higher (lots of work, no benefit).
      vertex merging moved to qh_qhull_postmerging in 6-d.
  - replaced qh min_vertex with MAXcoplanar for determining coplanarity
  - pick closest facets to merge in duplicate ridge instead of flip/flip
      (see qh_matchduplicates in poly2.c)
  - optimize merge of simplex into a facet
  - optimize merge of a "samecycle" of facets into a coplanar horizon facet
  - cleaned up qh_forcedmerges/qh_flippedmerges and removed facet->newmerge
  - rewrote qh_merge_degenredundant with separate queue
  - qh_facetdegen replaced by facet->degenredun
  - flipped neighbors no longer merged in preference to flip/non-flip pairs
  - removed angle argument from qh_merge_degenredundant and qh_mergefacet
       only used for tracing
  - getmergeset_initial had extra test of neighbor->simplicial
  - ridge->nonconvex is now set on only one ridge between non-convex facets 
  - moved centrum deletion to qh_updatetested
  - qh_isnewmerge(facet) changed to facet->newmerge (removed NEWmerges)
  - qh_findbestneighbor reports correct distance even if testcentrum
  - added hull_dim factor to qh_BESTcentrum
  - removed horizon preference in qh_merge_nonconvex (qh AVOIDold)
  - facet->keepcentrum if qh WIDEfacet or qh_MAXnewcentrum extra vertices

qhull V2.02 1/25/95
  - rbox 'z' prints integer coordinates, use 'Bn' to change range
  - fixed rare bug in qh_check_maxout when qh_bestfacet returns NULL
  - fixed performance bug in findbestneighbor, should be + BESTnonconvex
  - renamed 'notgood' flag in 'f' option to 'notG' flag (caused confusion)
  - changed qh.hulltime to (unsigned) to prevent negative CPU times
  - added random perturbations to qh_getangle under the 'Rn' option
  - reviewed the documentation and enhancement list
  - added discussion of how to intersect halfspaces using qhull
  - replaced expression that caused incorrect code under an old version of gcc
  - added buffer after qh.errexit in case 'jmp_buf' has the wrong size
  - rewrote qh_printhelp_singular for lower-dimensional inputs
  - rewrote qh_printhelp_degenerate
  - added options for qh_RANDOMint in qhull_a.h
  - changed time format for 'TFn' to %02d

qhull V2.01 6/20/94
  - fixed bug in qh_matchnewfacets that occured when memory alignment makes
    facet->neighbors larger than necessary.
  - fixed bug in computing worst-case simplicial merge of angle coplanar
    facets (ONEmerge).  This decreases (...x) in printsummary.

qhull V2.01 6/17/94
  - added recommendation for 'Qcm' to documentation and help prompts
  - added an input warning to qh_check_points ('Tv') if coplanars and no 'Qc'
  - qh_partitionpoint: always counts coplanar partitions (Zcoplanarpart)
  - rewrote qh_printhelp_degenerate to emphasize option 'C-0'
  - For Geomview output, roundoff is not needed when printing the inner and 
    outer planes.  This improves Geomview output for the 'Rn' option.
  - For Geomview output without coplanar points or vertices, qh_GEOMepislon 
    is not needed.  This removes the edge gap when displaying a Voronoi cell.
  - For Geomview output 'Gp', direct vertices to the interior point 
    instead of the arithmetic center of the displayed vertices.
    
qhull V2.01 6/11/94
  - if pre-merge, 'Qf' is automatically set.  Otherwise an outside point may 
        be dropt by qh_findbest().  This slows down partitioning.
  - always use 'Qc' if merging and all facet->maxoutside's must be right.
        Otherwise distributions with many coplanar points may occassionally
	miss a coplanar point for a facet.  This is because qh_findbest, when 
	called by qh_check_maxout, can become stuck at a local maximum if 
	the search is started at an arbitrary facet.  With 'Qc', the search 
	is started from a coplanar facet.  For example,
		rbox 1000 W8e-6 t | qhull C-0 Tv
	will (rarely) report that a facet->minoutside is incorrect
  - option 'Pp' turns off "Verifying" message for 'Tv'
  - added qh_copynonconvex to qh_renameridgevertex (fixes rare error)
  - 'rbox tn' sets random seed to n
  - 'rbox t' reports random seed in comment line
  - qh_errexit reports rbox_command | qhull_command and 'QR' random seed
  - added additional tracing to bestdist and setfacetplane
  - in qh_checkconvex, need to test coplanar against 0 instead of -DISTround 
  - in qh_checkconvex, always test centrums if merging.  The opposite
    vertex of a simplicial facet may be coplanar since a vertex of
    a simplicial facet may be above the facet's hyperplane.
  - fixed error handling in qh_checkconvex when merging
  - in qh_printsummary, one merge ratio not printed if less than 'Wn'
  - documented that 'Tv' verifies all facet->maxoutside

qhull V2.01 6/2/94
  - 's' prints summary to stderr
  - multiple output formats printed in order to stdout
  - added statistic for worst-case distance for merging simplicial facets 
       	can not hope for a better "max distance above/below facet"
        print factor for "max distance.."/"merge simplicial" in printsummary
  - fixed error in scaling input with min/max reversed ('Qb0:1B0:-1')
  - fixed error in scaling if project & Delaunay & scale ('d Qb0:0B1:0b2:0')
  - user_eg.c: qh_delpoint removed since it does not always work
  - user_eg.c now works for either convex hull or Delaunay triangulation
  - added PROJECTdelaunay for Delaunay triangulations and Voronoi diagrams
	with libqhull.a and user_eg.c
  - user_eg.c: if project or scale input, need to copy points
  - user_eg.c: default just defines main, added fprintf's for qh_errprint etc.
  - qh_gausselim: a 0 pivot no longer zeros the rest of the array,
	  need the remaining elements for area computation
  - qh_qhull: restore cos_max, centrum_radius at end of POSTmerging
  - qh_checkflipped with !allerror is >=0.0 instead of >0.0
  - removed -Wall from gcc due to unnecesssary "warning: implicit declaration"
  - renamed 'new' variables and fields to allow compilation by g++
  - added README notes on C++, and "size isn't known"
  - updated manual on 'Qg' with coplanar facets and no merging ('rbox c D7')
      'Qg Pg' and 'Pg' produce different results because of precision problems

Converting from qhull 1.01 to qhull 2.00
  - 'qhull An' is now 'qhull Wn'
	option 'Wn Po' is faster but it doesn't check coplanars
  - 'qhull g' is now 'qhull G', and the output formats are different
  - 'qhull c' is now 'qhull Tc'
  - 'qhull f' is now 'qhull Qf'
  - 'qhull o' is now 'qhull Po'
  - 'qhull b' is now always done
  - qhull and rbox now use floats, change REALfloat in qhull.h for doubles
  - qhull 2.00 fixes several initialization errors and performanace errors
	e.g., "singular input" on data with lots of 0 coordinates
  - 'rbox b' is now 'rbox c G0.48'
  - all rbox distributions are now scaled to a 0.5 box (use 'Bn' to change)
  - rbox now adds a comment line.  This may be removed by 'rbox n'
  - 'rbox r s Z G' no longer includes the positive pole
  - no changes to the Macintosh version 

qhull V2.00 5/23/94
  - if force output ('Po'), facet->maxoutside= 'Wn' since coplanars not updated
        convexity checked if precision problems or verify ('Tv')
  - if merging, new facets always checked for flipped orientation
  - a facet is visible (findhorizon) under 'Qm' if distance > max_vertex
  - if using 'Qm' then min. outside is max_vertex instead of max_outside
  - default is random()/srandom() in qhull_a.h, checked in initqhull_globals
  - created internal strtod since strtod may skip spacing after number
  - removed lower bound (1.0) for qh maxmaxcoord
  - divzero needs to handle 0/0 and large/small
  - decreased size of precise vertices
  - need to initialize qh MINdenom_1 for scalepoints
  - added factor of qh maxmaxcoord into DISTround (needed for offset)
  - 'Rn' perturbs distance computations by random +/-n
  - check_points needs an extra DISTround to get from precise point to computed
  - rewrote some of the IMPRECISION section in qhull.man
  - added the input format to the qhull prompt
  - moved include files to qhull_a.h since some compilers do not use float.h
  - added qhull.1 and rbox.1 since SGI does not ship nroff
  - reduced cutoff for printpointvect
  - use time for qhull random seed only if QR0 or QR-1
  - radius of vertices and coplanar points determined by pre-merge values

qhull V2.00 5/12/94
  - facet2point (io.c) used vertex0 instead of vertex1
  - can't print visible facets after cone is attached
  - shouldn't check output after STOPcone (TCn)
  - statistic 'Wminvertex' and 'Wmaxoutside' only if MERGING or APPROXhull
  - 'make doc' uses lineprinter format for paging
  - warning if Gpv in 4-d

qhull V2.b05 5/9/94
  - decreased size of precise vertices
  - precise facets in 2-d print hyperplanes
  - accounted for GOODpoint in printsummary
  - added IMPRECISION section to qhull.man
  - 'Qg' does work in 7-d unless there's many coplanar facets