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Qhull functions, macros, and data structures

The following sections provide an overview and index to Qhull's functions, macros, and data structures.

Each section starts with an introduction.

Qhull uses the following conventions:

in code, global variables start with "qh "
in documentation, global variables start with 'qh.'
constants start with an upper case word
important globals include an '_'
functions, macros, and constants start with "qh_"

data types end in "T"

macros with arguments end in "_"

iterators are macros that use local variables

iterators for sets start with "FOREACH"

iterators for lists start with "FORALL"

qhull options are in single quotes (e.g., 'Pdn')

lists are sorted alphabetically

preprocessor directives on left margin for older compilers

When reading the code, please note that the global data structure, 'qh', is a macro. It either expands to "qh_qh." or to "qh_qh->". The later is used for applications which run concurrent calls to qh_qhull().
When reading code with an editor, a search for "procedure will locate the header of qh_procedure. A search for * procedure will locate the tail of qh_procedure.
A useful starting point is qhull.h. It defines most of Qhull data structures and top-level functions. Search for 'PFn' to determine the corresponding constant in Qhull. Search for 'Fp' to determine the corresponding qh_PRINT... constant. Search io.c to learn how the print function is implemented.

If your web browser loads .c and .h files with an external application, change the MIME type of .c and .h files to "text/html". Opera does not always work since it treats '<' characters as HTML tags.
Please report documentation and link errors to qhull-bug@geom.umn.edu.
Brad Barber, Cambridge MA, October 4, 2001

»Qhull files

This sections lists the .c and .h files for Qhull. Please refer to these files for detailed information.

qhull.h

Include file for the Qhull library, qhull.a. Data structures are documented under Poly. Global variables are documented under Global. Other data structures and variables are documented under Qhull or Geom.

Geom, geom.h, geom.c, geom2.c

Geometric routines. These routines implement mathematical functions such as Gaussian elimination and geometric routines needed for Qhull. Frequently used routines are in geom.c while infrequent ones are in geom2.c.

Global, global.c, qhull.h

Global routines. Qhull uses a global data structure, qh, to store globally defined constants, lists, sets, and variables. global.c initializes and frees these structures.

Io, io.h, io.c

Input and output routines. Qhull provides a wide range of input and output options.

Mem, mem.h, mem.c

Memory routines. Qhull provides memory allocation and deallocation. It uses quick-fit allocation.

Merge, merge.h, merge.c

Merge routines. Qhull handles precision problems by merged facets or joggled input. These routines merge simplicial facets, merge non-simplicial facets, merge cycles of facets, and rename redundant vertices.

Poly, poly.h, poly.c, poly2.c, qhull.h

Polyhedral routines. Qhull produces a polyhedron as a list of facets with vertices, neighbors, ridges, and geometric information. Qhull.h defines the main data structures. Frequently used routines are in poly.c while infrequent ones are in poly2.c.

Qhull, qhull.c, qhull.h, qhull_a.h, unix.c , qconvex.c , qdelaun.c , qhalf.c , qvoronoi.c

Top-level routines. The Quickhull algorithm is implemented by qhull.c. qhull_a.h includes all header files.

Set, qset.h, qset.c

Set routines. Qhull implements its data structures as sets. A set is an array of pointers that is expanded as needed. This is a separate package that may be used in other applications.

Stat, stat.h, stat.c

Statistical routines. Qhull maintains statistics about its implementation.

User, user.h, user.c, user_eg.c, qhull_interface.cpp

User-defined routines. Qhull allows the user to configure the code with defined constants and specialized routines.

Up: Home page for Qhull
Up: Qhull manual: Table of Contents
Up: Programs • Options • Output • Formats • Geomview • Print • Qhull • Precision • Trace
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To: Qhull files
To: Geom • Global • Io • Mem • Merge • Poly • Qhull • Set • Stat • User

The Geometry Center Home Page

Comments to: qhull@geom.umn.edu
Created: May 2, 1997 --- Last modified: see top