Getting pydecenttree to work on Windows 10.

1. Had to add zlib and build/zlib folders to the include paths in pydecenttree/setup.py
(to avoid errors about not finding zlib.h).

2. Had to recognize _WIN32
and _WIN64 to avoid Python's
preferred compiler (I wonder, is it 32 bit?!)
trying to include <unistd.h>

Author: JamesBarbetti

doco/Compilation_on_Windows.md

@@ -25,5 +25,7 @@ At present (October 2022), the version of CMake that MS Code uses (3.23 or 3.24)
 Builds may fail outright (with no error messages), due to missing DLLs (libisl-23.dll, for example) (the version number might vary). If you are installing GCC using MSYS2 and pacman you may find it necessary to copy files from c:\msys64\user\bin (where pacman puts them!) into c:\msys64\mingw64\bin (which is where pacman probably should put them, but might not).
 <br><br>
 <h4>Compiling with Microsoft Code and the Visual Studio Compiler</h4>
-[todo: this bit not written yet]
+On Windows 10 (and 11) workstations, decenttree will compile with Visual Studio 2017 through Visual Studio 2022.
+It's recommended that you compile 64 bit versions (using the - x86_amd64 rather than the - amd64_x86 compiler toolkit, if both choices are available).
+
 

doco/pydecenttree.md

@@ -54,3 +54,42 @@ rm -r dist
 pip install -e . 
 python3.11 test_pydecenttree.py
 ```
+
+<h3>With Python 3.11, on Windows 10 (or 11)</h3>
+<i>These instructions are probably not the best (and are as yet incomplete).
+I've got as far as installing python and numpy, but I haven't figured out how
+to get pip to build (let alone install) the pydecenttree module itself</i> -James.
+
+Download Python via the Windows download page
+
+[https://www.python.org/downloads/windows](https://www.python.org/downloads/windows).
+
+Run the Python 3.11 app, and execute the commands
+```
+import ensurepip
+ensurepip.bootstrap()
+```
+
+Open the command prompt and navigate to the folder where you installed python (for me this was c:\Users\james\AppData\Local\Programs\Python\Python311). Execute the command (alernatively you could add your Python install directory to your %PATH% and then you could execute the following command from any folder - I didn't):
+
+```
+python -m pip install numpy
+```
+
+Navigate to the pydecenttree folder (for me this was c:\Users\james\Source\repos\decenttree\pydecenttree).
+Run a command <i>like</i> this (replace C:\Users\james\AppData\Local\Programs\Python\Python311 with the directory 
+to which you installed Python):
+
+```
+C:\Users\james\AppData\Local\Programs\Python\Python311\Scripts\pip install -e .
+```
+
+(if you get an error message about it not being able to find zconf.h, you may need
+to run CMake in the build subfolder of the decenttree project folder, either 
+directly, or via VS Code or Microsoft VIsual Studio, to create a
+build\zconf.h header file)
+
+(this is building for me but I am getting a disturbing number of warnings)
+
+
+

pydecenttree/setup.py

@@ -7,7 +7,7 @@
 #python_include = get_paths() 
 #(but this doesn't seem necessary, so I've commented it out)
 
-dirs   = [numpy_include, "..", "../build"]
+dirs   = [numpy_include, "..", "../build", "../zlib-1.2.7", "../build/zlib-1.2.7"]
 flags  = ['-std=c++11']
 link_flags = []
 

utils/operatingsystem.cpp

@@ -8,7 +8,7 @@
 #include "operatingsystem.h"
 #include <string>
 #include <sstream>
-#if defined(WIN32) || defined(WIN64)
+#if defined(WIN32) || defined(WIN64) || defined(_WIN32) || defined(_WIN64)
     #include <io.h> //for _isatty
     #include <stdio.h> //for _fileno (explicit include needed for GCC 9.2 builds)
 #else