gon

Summary

gon is a pure Python library that provides support for planar geometry objects built from discrete points, finite number of straight line segments (e.g. polylines) and areas bound by closed polylines (e.g. polygons).

Main features are

• convenience: all geometric objects are immutable, hashable and implement set-like interface, i.e. support containment, equality, "is-subset" tests and boolean set operations (e.g. finding intersection).
• correctness: all calculations are robust for floating point numbers & precise for integral numbers (like int), each operation corresponds to its mathematical definition and property-based tested.
• efficiency: all operations are efficient in terms of both time & memory complexity, upper bound for expected time complexity is O(n * log n), for memory complexity is O(n).

---

In what follows python is an alias for python3.7 or pypy3.7 or any later version (python3.7, pypy3.8 and so on).

Installation

Install the latest pip & setuptools packages versions

python -m pip install --upgrade pip setuptools

User

Download and install the latest stable version from PyPI repository

python -m pip install --upgrade gon

Developer

Download the latest version from GitHub repository

git clone https://github.com/lycantropos/gon.git
cd gon

Install dependencies

python -m pip install -r requirements.txt

Install

python setup.py install

Usage

>>> from gon.base import EMPTY, Angle, Contour, Point, Polygon
>>> square = Polygon(Contour([Point(0, 0), Point(4, 0), Point(4, 4),
...                           Point(0, 4)]))
>>> square == square
True
>>> square >= square
True
>>> square <= square
True
>>> square < square
False
>>> square > square
False
>>> square & square == square
True
>>> square | square == square
True
>>> square - square is EMPTY
True
>>> square ^ square is EMPTY
True
>>> Point(0, 0) in square
True
>>> square.index()
>>> Point(0, 0) in square
True
>>> len(square.border.vertices) == 4
True
>>> len(square.holes) == 0
True
>>> square.is_convex
True
>>> square.convex_hull == square
True
>>> square.area == 16
True
>>> square.perimeter == 16
True
>>> square.centroid == Point(2, 2)
True
>>> square.distance_to(Point(2, 2)) == 0
True
>>> square.distance_to(Point(7, 8)) == 5
True
>>> (square.rotate(Angle(0, 1), Point(4, 4))
...  == Polygon(Contour([Point(8, 0), Point(8, 4), Point(4, 4), Point(4, 0)])))
True
>>> (square.scale(1, 2)
...  == Polygon(Contour([Point(0, 0), Point(4, 0), Point(4, 8), Point(0, 8)])))
True
>>> (square.translate(1, 2)
...  == Polygon(Contour([Point(1, 2), Point(5, 2), Point(5, 6), Point(1, 6)])))
True
>>> (square.triangulate().triangles()
...  == [Contour([Point(0, 4), Point(4, 0), Point(4, 4)]),
...      Contour([Point(0, 0), Point(4, 0), Point(0, 4)])])
True

Development

Bumping version

Preparation

Install bump2version.

Pre-release

Choose which version number category to bump following semver specification.

Test bumping version

bump2version --dry-run --verbose $CATEGORY

where $CATEGORY is the target version number category name, possible values are patch/minor/major.

Bump version

bump2version --verbose $CATEGORY

This will set version to major.minor.patch-alpha.

Release

Test bumping version

bump2version --dry-run --verbose release

Bump version

bump2version --verbose release

This will set version to major.minor.patch.

Running tests

Install dependencies

python -m pip install -r requirements-tests.txt

Plain

pytest

Inside Docker container:

• with CPython

  docker-compose --file docker-compose.cpython.yml up

• with PyPy

  docker-compose --file docker-compose.pypy.yml up

Bash script:

• with CPython

  ./run-tests.sh

  or

  ./run-tests.sh cpython

• with PyPy

  ./run-tests.sh pypy

PowerShell script:

• with CPython

  .\run-tests.ps1

  or

  .\run-tests.ps1 cpython

• with PyPy

  .\run-tests.ps1 pypy