Skip to main content

Cython wrapper for the C++ translation of the Angus Johnson's Clipper library (ver. 6.2.1)

Project description

About

Pyclipper is a Cython wrapper exposing public functions and classes of the C++ translation of the Angus Johnson’s Clipper library (ver. 6.2.1).

Pyclipper releases were tested with Python 2.7 and 3.4 on Linux (Ubuntu 14.04, x64) and Windows (8.1, x64).

Source code is available on GitHub.

About Clipper

Clipper - an open source freeware library for clipping and offsetting lines and polygons.

The Clipper library performs line & polygon clipping - intersection, union, difference & exclusive-or, and line & polygon offsetting. The library is based on Vatti’s clipping algorithm.

Angus Johnson’s Clipper library

Install

Dependencies

Cython dependency is optional. Cpp sources generated with Cython are available in releases.

Note on using the setup.py:

setup.py operates in 2 modes that are based on the presence of the dev file in the root of the project.

  • When dev is present, Cython will be used to compile the .pyx sources. This is the development mode (as you get it in the git repository).

  • When dev is absent, C/C++ compiler will be used to compile the .cpp sources (that were prepared in in the development mode). This is the distribution mode (as you get it on PyPI).

This way the package can be used without or with an incompatible version of Cython.

The idea comes from Matt Shannon’s bandmat library.

From PyPI

Cython not required.

pip install pyclipper

From source

Cython required.

Clone the repository:

git clone git@github.com:greginvm/pyclipper.git

Install:

python setup.py install

After every modification of .pyx files compile with Cython:

python setup.py build_ext --inplace

How to use

This wrapper library tries to follow naming conventions of the original library.

  • ClipperLib namespace is represented by the pyclipper module,

  • classes Clipper and ClipperOffset -> Pyclipper and Pyclipper and PyclipperOffset,

  • when Clipper is overloading functions with different number of parameters or different types (eg. Clipper.Execute, one function fills a list of paths the other PolyTree) that becomes Pyclipper.Execute and Pyclipper.Execute2.

Basic example (based on Angus Johnson’s Clipper library):

import pyclipper

subj = (
    ((180, 200), (260, 200), (260, 150), (180, 150)),
    ((215, 160), (230, 190), (200, 190))
)
clip = ((190, 210), (240, 210), (240, 130), (190, 130))

pc = pyclipper.Pyclipper()
pc.AddPath(clip, pyclipper.PT_CLIP, True)
pc.AddPaths(subj, pyclipper.PT_SUBJ, True)

solution = pc.Execute(pyclipper.CT_INTERSECTION, pyclipper.PFT_EVENODD, pyclipper.PFT_EVENODD)

The Clipper library uses integers instead of floating point values to preserve numerical robustness. You can use pyclipper.SCALING_FACTOR to scale your values to preserve the desired presision. The default value is 1, which disables scaling. This setting only scales coordinates of polygon vertices, properties like miterLimit, roundPrecision etc. are not scaled.

For more examples of use see tests/test_pyclipper.py and Clipper documentation.

Authors

License

  • Pyclipper is available under MIT license.

  • The core Clipper library is available under Boost Software License. Freeware for both open source and commercial applications.

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

pyclipper-0.9.1b0.tar.gz (93.2 kB view details)

Uploaded Source

File details

Details for the file pyclipper-0.9.1b0.tar.gz.

File metadata

  • Download URL: pyclipper-0.9.1b0.tar.gz
  • Upload date:
  • Size: 93.2 kB
  • Tags: Source
  • Uploaded using Trusted Publishing? No

File hashes

Hashes for pyclipper-0.9.1b0.tar.gz
Algorithm Hash digest
SHA256 6ef099b0cfefc22e09d61a694af30462feb6c3c410983c28c8e672221c239dc5
MD5 1b89ee015c789a086fa26e90ae418668
BLAKE2b-256 7665d5458029f9abc2e4f9a587a290691928a3374ddac3fae45c220bd7a2604f

See more details on using hashes here.

Provenance

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page