A C++ Library for Planar Visibility Computations
See also https://karlobermeyer.github.io/VisiLibity1/.
To use VisiLibity in your C++ program, you simply need to place an
#include "visilibity.hpp" directive at the beginning of your program and link
with visilibity.cpp when compiling. For details on particular classes and
methods, refer to the source code documentation page to which there is a link on
the project page https://karlobermeyer.github.io/VisiLibity1/.
The files main.cpp and makefile (listed below) provide an elementary example
of a C++ program which uses VisiLibity. Once compiled (make main), this
program provides a text interface which will
- read an environment and guard locations from files given as command line arguments,
- check the geometric validity of these inputs (edges of the environment do not cross each other, guards are contained in the environment, etc.),
- display environment and guards' data and statistics, and
- compute and display the coordinates of a visibility polygon of a guard chosen by the user.
The environment representation and the guard locations can be read from any file
in the (human-readable) format demonstrated in
example1.environment,
example2.environment, and
example1.guards.
A Matlab MEX interface is provided in
visibility_polygon_demo.m,
shortest_path_demo.m,
visibility_graph_demo.m,
in_environment.cpp,
visibility_polygon.cpp,
shortest_path.cpp, and
visibility_graph.cpp.
First the files in_environment.cpp, visibility_polygon.cpp,
shortest_path.cpp, and visibility_graph.cpp should be compiled into MEX
files (see instructions at the heads of the files themselves). The scripts
visibility_polygon_demo.m and shortest_path_demo.m can be used to display a
graphical representation of the supplied environment files while the user
selects points with the mouse so that the visibility polygon of, resp. shortest
path between, points are displayed. The script visibility_graph_demo.m can be
used to display a graphical representation of an environment together with the
visibility graph of a set of points specified within the script.
For more details on the examples, see the file descriptions below and the comments in the files themselves.
File: ./COPYING
Description: a copy of the GNU General Public License.
File: ./COPYING.LESSER
Description: a copy of the GNU Lesser General Public License.
File: ./src/visilibity.hpp
Description: the VisiLibity header file.
File: ./src/visilibity.cpp
Description: the VisiLibity implementation file.
File: ./src/main.cpp
Description: an example program using VisiLibity. After compiling with the
provided makefile (just type make in the ./src/ directory), and run the
program with the command line ./main example1.environment example.guards.
File: ./src/makefile
Description: a makefile for compiling main.cpp using g++.
File: ./src/example1.environment
./src/example2.environment
Description: an example of the human-readable files that VisiLibity uses to
store polygonal environments with holes. You can use this as a template to
create your own *.environment files. To read and write Environment files, use
the Environment::read_from_file() and Environment::write_to_file() methods.
File: ./src/example1.guards
Description: an example of the human-readable files that VisiLibity uses to
store guard positions. You can use this as a template to create your own
*.guards files. To read and write Guards files, use the
Guards::read_from_file() and Guards::write_to_file() methods.
File: ./src/visibility_polygon.cpp
Description: MEX file source code to interface VisiLibity's visibility polygon
calculation with Matlab.
File: ./src/in_environment.cpp
Description: MEX file source code to interface VisiLibity's Point-in-Environment
calculation with Matlab.
File: ./src/shortest_path.cpp
Description: MEX file source code to interface VisiLibity's shortest path
through a polygon with holes calculation with Matlab.
File: ./src/visibility_graph.cpp
Description: MEX file source code to interface VisiLibity's visibility graph
calculation, for a set of points in a polygonal environment with holes, with
Matlab.
File: ./src/visibility_polygon_demo.m
Description: an example Matlab script which uses the the MEX files generated
from visibility_polygon.cpp an in_environment.cpp (these must be compiled
before running visibility_polygon_demo.m).
File: ./src/shortest_path_demo.m
Description: an example Matlab script which uses the MEX files generated from
shortest_path.cpp and in_environment.cpp (these must be compiled before
running shortest_path_demo.m).
File: ./src/visibility_graph_demo.m
Description: an example Matlab script which uses the MEX file generated from
visibility_graph.cpp (must be compiled before running
visibility_graph_demo.m).
File: ./src/read_vertices_from_file.m
Description: a subroutine of visibiity_polygon_demonstration.m and
shortest_path_demo.m used to read a VisiLibity style Environment file into a
Matlab cell array.
VisiLibity: A Floating-Point Visibility Algorithms Library Copyright (C) 2008 Karl J. Obermeyer (karl.obermeyer@gmail.com)
This file is part of VisiLibity.
VisiLibity is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
VisiLibity is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along with VisiLibity. If not, see http://www.gnu.org/licenses/.