Pluggable Software Modules

Some users of Geogram may be interested only in a subset of Geogram functionalities. Following the principle that Geogram should be as easy to use/compile as possible, some subsets of functionalities are alternatively available as a standalone pair of (header,implementation) files, automatically extracted/assembled from Geogram sourcetree. This makes the functionality usable with 0 dependency: client code that uses a PSM just need to insert the header and the implementation file into the project (rather than linking with the entire Geogram library).

Geogram PSMs are available in the Geogram distribution

They can be also automatically generated from the Geogram sourcetree, by using:

tools/extract_psm.sh filename.psm

on a Linux box or under Cygwin (the latter is untested).

Most PSMs come with an example file. To compile, use:

g++ MultiPrecision_example.cpp MultiPrecision_psm.cpp -o MultiPrecision_example

(where MultiPrecision can be replaced with the PSM name)

List of PSMs

OpenNL

(src/lib/geogram/NL/OpenNL.psm): solvers for sparse linear systems / least squares regression

To compile, it needs the math library:

gcc OpenNL_example.c OpenNL_psm.c -o OpenNL_example -lm

To enable support for SuperLU dynamic linking (Linux only), use:

gcc -DGEO_DYNAMIC_LIBS OpenNL_example.c OpenNL_psm.c -o OpenNL_example -lm -ldl

To enable OpenMP parallel mode, use:

gcc -fopenmp OpenNL_example.c OpenNL_psm.c -o OpenNL_example -lm

MultiPrecision

(src/lib/geogram/numerics/MultiPrecision.psm): an easy-to-use number type for computing the exact sign of a polynom

To compile, use:

g++ MultiPrecision_example.cpp MultiPrecision_psm.cpp -o MultiPrecision_example

Predicates

(src/lib/geogram/numerics/Predicates.psm): exact geometric predicates with symbolic perturbation (SOS)

To compile, use:

g++ -c Predicates_psm.cpp

(no example program for now)

Delaunay

(src/lib/geogram/delaunay/Delaunay.psm): Sequential and parallel Delaunay triangulation and power diagrams in 2D and 3D.

To compile, use:

gcc -O3 -fopenmp -frounding-math -ffp-contract=off Delaunay_example.cpp Delaunay_psm.cpp -o Delaunay_example -lm

Syntax of a PSM file

A PSM file specifies a list of header files and a list of source files that will be assembled into a single header file (respectively a single source file). All file paths are relative to where the PSM file is located:

HEADERS="header_1.h header_2.h ... header_n.h"

Sources can be either C++ or C files. If sources are only C files, then the generated source is a C file, else it is a C++ file:

SOURCES="source_1.cpp source_2.cpp ... source_n.cpp"

To avoid including too many Geogram classes in a PSM, there is a drop-in replacement of some Geogram mechanisms (Logger, etc...) in basic/psm.h.

There is also a link to a documentation page, that is inserted in the generated header:

DOC="https://brunolevy.github.io/geogram/predicates_8h.html"

Optionally, there can be an example file, that will be also extracted. It can be a C++ or a C program. The specified path is relative to where the PSM file is located:

EXAMPLE="path to example.cpp"