Metadata-Version: 2.4
Name: pylineclip
Version: 1.0.0
Summary: Line clipping: Cohen-Sutherland
Home-page: https://github.com/scivision/lineclipping-python-fortran
Author: Michael Hirsch, Ph.D.
Author-email: scivision@users.noreply.github.com
Keywords: line clipping,cohen-sutherland
Classifier: Development Status :: 4 - Beta
Classifier: Environment :: Console
Classifier: Intended Audience :: Science/Research
Classifier: License :: OSI Approved :: MIT License
Classifier: Operating System :: OS Independent
Classifier: Programming Language :: Fortran
Classifier: Programming Language :: Python :: 3.5
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: 3.7
Classifier: Programming Language :: Python :: 3.8
Classifier: Programming Language :: Python :: 3.9
Classifier: Topic :: Scientific/Engineering :: Visualization
Requires-Python: >=3.5
Description-Content-Type: text/markdown
License-File: LICENSE.txt
Provides-Extra: tests
Requires-Dist: pytest; extra == "tests"
Provides-Extra: lint
Requires-Dist: flake8; extra == "lint"
Requires-Dist: mypy; extra == "lint"
Dynamic: license-file

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# Line clipping

-   `lineclipping.f90` Cohen-Sutherland line clipping algorithm for
    massively parallel coarray modern Fortran. Input scalars or arrays,
    output intersections or `NaN` if no intersection.
-   `lineClipping.py` Cohen-Sutherland line clipping algorithm for Python.
    Input scalars, output intersection length, or `None` if no intersection.


Julia line clipping is at https://github.com/scivision/lineclipping-julia

## Install

To install the latest release:

```sh
pip install pylineclip
```



### Fortran

If you want to use the Fortran Cohen-Sutherland line clipping modules
directly (optional):

```sh
meson build

meson test -C build
```

## Usage

The main difference with textbook implementations is that I return a
sentinel value (NaN, None, nothing) if there's no intersection of line
with box.

### Python

```python
import pylineclip.lineclipping as lc

x3,y3,x4,y4 = lc.cohensutherland((xmin, ymax, xmax, ymin, x1, y1, x2, y2)
```

If no intersection, `(None, None, None, None)` is returned.

### Fortran

lineclipping.f90 has two subroutines.
Pick Ccohensutherland if you're calling from C/C++/Python, which cannot tolerate assummed-shape arrays.
It's a slim wrapper to cohensutherland which is elemental (can handle scalar or any rank array).

Fortran programs will simply use

```fortran
use lineclipping
call cohensutherland(xmin,ymax,xmax,ymin,x1,y1,x2,y2)
```

The arguments are:

    INPUTS
    ------
    xmin,ymax,xmax,ymin:  upper left and lower right corners of box (pixel coordinates)

    INOUT
    -----
    x1,y1,x2,y2:
    in - endpoints of line
    out - intersection points with box. If no intersection, all NaN

