pyblocks: what it carries that was made by others
==================================================

tools/build_dist.py copies this file beside pyblocks.exe.


The stars
---------

The Bright Star Catalogue, 5th Revised Edition. Hoffleit D., Warren Jr W.H.,
1991, Astronomical Data Center, NSSDC/ADC. From the Centre de Donnees
astronomiques de Strasbourg, catalogue V/50. The app carries the position,
magnitude and colour of its 5,080 stars of magnitude 6.0 and brighter.


The constellation lines, and where their names are written
----------------------------------------------------------

From d3-celestial, https://github.com/ofrohn/d3-celestial, whose licence is:

Copyright (c) 2015, Olaf Frohn
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice,
   this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its
   contributors may be used to endorse or promote products derived from this
   software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


The planets
-----------

The orbits of Mercury, Venus, the Earth, Mars, Jupiter and Saturn are from
E.M. Standish and J.G. Williams, "Approximate Positions of the Planets", as
published by the Solar System Dynamics group of the Jet Propulsion Laboratory,
https://ssd.jpl.nasa.gov/planets/approx_pos.html (Table 2a and 2b, 3000 BC to
3000 AD).


Pillow
------

The app bundles Pillow, the Python imaging library, so that a program can
read a picture (https://python-pillow.github.io). Its licence:

The Python Imaging Library (PIL) is Copyright (c) 1997-2011 by Secret Labs AB
and Copyright (c) 1995-2011 by Fredrik Lundh and contributors. Pillow is the
friendly PIL fork, Copyright (c) 2010 by Jeffrey A. Clark and contributors.
Like PIL, Pillow is licensed under the open source MIT-CMU License:

By obtaining, using, and/or copying this software and/or its associated
documentation, you agree that you have read, understood, and will comply
with the following terms and conditions:

Permission to use, copy, modify and distribute this software and its
documentation for any purpose and without fee is hereby granted, provided
that the above copyright notice appears in all copies, and that both that
copyright notice and this permission notice appear in supporting
documentation, and that the name of Secret Labs AB or the author not be used
in advertising or publicity pertaining to distribution of the software
without specific, written prior permission.

SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR BE LIABLE FOR ANY SPECIAL,
INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.


The mathematics of the sky
--------------------------

The formulas in godot/scripts/sky_math.gd are from Jean Meeus, Astronomical
Algorithms, second edition (Willmann-Bell, 1998), and are checked against the
book's worked examples.
