Start work on dependencies info

Signed-off-by: Matthew J. Milner <[email protected]>

source/conf.py

@@ -50,6 +50,7 @@
  'sphinx.ext.viewcode',
  'sphinx_design',
  'sphinx_copybutton',
+ 'sphinx_togglebutton',
  'breathe',
  'myst_parser',
 ]

source/develop/build.md

@@ -2,21 +2,145 @@
 
 # Building Source Code
 
-The Open Chemistry project uses Git for version control, and CMake to
-direct the build process. The [openchemistry
-repository](https://github.com/OpenChemistry/openchemistry) contains
-git submodules with other actively developed projects such as Avogadro and
-MoleQueue. It will also automatically download and build third party dependencies, with variables named USE_SYSTEM_LIBRARY to attempt to find and build against system versions.
-
-This page goes through the steps of building the Open Chemistry projects
-using the openchemistry git repository. It is entirely possible to build
-each project individually without using the "superbuild" approach, but
-you will need to ensure all dependencies are built and can be found by
-the project.
-
-Once successfully built you will be left with several build
-directories which you can treat as normal build directories, developing
-and compiling from inside them largely ignoring the outer build tree.
+This guide has been updated to include detailed instructions for compiling Avogadro on each major operating system and has been verified to work for the 2.0 release on all of them.
+
+However, Avogadro is a large project with many pieces, resulting in a somewhat complex build process that also varies from platform to platform.
+If you encounter difficulties you are encouraged to reach out on the [forum](https://discuss.avogadro.cc) for help.
+
+The Avogadro desktop application brings together several of the Open Chemistry subprojects (see [Project Structure](develop-structure)).
+The easiest way to build Avogadro is to use the [openchemistry
+repository](https://github.com/OpenChemistry/openchemistry) as a basis, as it will automatically download and build many of the dependencies (including third-party ones) for you.
+
+It is also entirely possible to build each project individually without using the "superbuild" approach, but you will need to ensure all dependencies are built and can be found by the project.
+
+For simplicity, this guide will focus on the first approach.
+
+:::{tip}
+Platform-specific instructions, guidance, and information is provided in expandable callouts marked by the respective icons {fab}`windows` {fab}`apple` {fab}`linux`.
+:::
+
+
+## System
+
+Only 64-bit operated systems are supported.
+
+The primary supported operating systems are those for which binaries are distributed:
+
+- Windows 10+ (`x64` only)
+- macOS (Intel and Apple Silicon)
+- Linux (`x64` only)
+
+Others may work, but this guide will not cover them.
+
+:::{admonition} Windows {fab}`windows`
+:class: dropdown
+Windows on ARM will be fully supported by Qt from around Qt 6.8 onwards, so it is likely that Avogadro will likewise support ARM once the port to Qt6 is complete.
+:::
+
+## Dependencies and prerequisites
+
+:::{admonition} Windows {fab}`windows`
+:class: dropdown
+All the software can of course be obtained by downloading from the respective websites, which are generally linked, and running an installer.
+
+Alternatively, much of it can these days be obtained from the Windows Package Manager using [`winget`](https://learn.microsoft.com/en-us/windows/package-manager/winget/).
+
+The third-party [winget.run](https://winget.run/) can be a helpful site to see whether a package is available in this way.
+:::
+
+:::{admonition} macOS {fab}`apple`
+:class: dropdown
+The [Homebrew](https://brew.sh/) package manager works well for getting development software on macOS.
+:::
+
+:::{admonition} Linux {fab}`linux`
+:class: dropdown
+On Linux, all of the necessary (non-Open-Chemistry) software is almost certainly available via your distribution's package manager.
+
+A notable exception to this is Open Babel, which as of the time of writing (September 2024) is generally only available from distro repos as version 3.3.1, whereas Avogadro requires a patched version incorporating many CJSON-related changes over the past few years.
+
+The easiest thing is just to let the build process automatically download and compile Open Babel for you (the default behavior).
+If you particularly wish to use Open Babel from your system, you will have to have compiled it from [source](https://github.com/openbabel/openbabel) yourself.
+:::
+
+### Development tools
+
+The Open Chemistry project uses [Git](https://git-scm.com/) for version control, and [CMake](cmake.org) to direct the build process, so the first step is to ensure that you have both of these installed and set up on your system.
+
+
+### Compiler
+
+Broadly, you will need a C/C++ compiler that supports C++17.
+
+:::{admonition} Windows {fab}`windows`
+:class: dropdown
+On Windows, [Visual Studio](https://visualstudio.microsoft.com/) is best supported, and it includes the MSVC compiler.
+:::
+
+:::{admonition} macOS {fab}`apple`
+:class: dropdown
+We recommend to use [Clang 17](https://clang.llvm.org/) on a Mac.
+:::
+
+:::{admonition} Linux {fab}`linux`
+:class: dropdown
+Both `gcc`/`g++` and `clang`/`clang++` generally work fine, as do both Unix Makefiles and Ninja for generating the Make files.
+
+If in doubt, stick to the combination of **gcc with Ninja**; this is what the automatic preparation of Avogadro binaries with GitHub actions uses, so if it is working successfully there, it should also work for you.
+:::
+
+
+### Python and Perl
+
+To compile Avogadro you will need to have both Python and Perl on your system.
+
+It is important that Python is in the PATH so that Avogadro can find it.
+
+:::{admonition} Windows {fab}`windows`
+:class: dropdown
+A Python interpreter can be downloaded and installed from [python.org](https://www.python.org/downloads/windows/).
+The option to add to the PATH is offered at install time, so make sure to check this.
+
+The best way to get Perl on Windows is the [Strawberry Perl](https://strawberryperl.com/) distribution.
+:::
+
+
+### Libraries
+
+#### Qt
+
+Avogadro is built using the open-source [Qt framework](https://www.qt.io/download-open-source).
+
+Avogadro is in the process of moving to Qt6, which will be hopefully complete by the release of Avogadro 2.0 – see [the forum tracking thread](https://discuss.avogadro.cc/t/qt6-tracking-thread/5592) for progress.
+For now though, you will probably need to obtain Qt5.
+
+:::{admonition} Windows {fab}`windows`
+:class: dropdown
+Be sure to make a note of the install directory of Qt (e.g. `C:/Qt/5.15.2/msvc2019_64/lib/cmake/Qt5`) as it will be of importance later.
+:::
+
+:::{admonition} Linux {fab}`linux`
+:class: dropdown
+Qt is large, so on Linux distributions it is often broken up into its modules.
+
+You should make sure the following Qt modules are installed:
+
+- `QtCore`
+- `QtWidgets`
+- `QtGui`
+- `QtOpenGL`
+- `QtConcurrent`
+- `QtNetwork`
+- `QtSvg`
+
+If building with Qt6, you will also need:
+
+- `QtOpenGLWidgets`
+- `QtCore5Compat`
+
+There are often separate `-devel` versions of each module as well, in which case, you will need those.
+:::
+
 
 (cloning-repositories)=
 

source/develop/index.md

@@ -8,7 +8,19 @@ The code is intended to be modular and extensible, so in many cases
 you can add features without needing to understand the entire C++
 codebase.
 
-## Script Plugins
+## Working on the Avogadro codebase
+
+Do you want to fix a bug in Avogadro, or integrate a new feature directly into the main code?
+
+In order to start contributing code, you will need to first familiarize yourself with the [structure of the project](develop-structure) and make sure you can successfully [build Avogadro](develop-build).
+See the respective pages for guides on this.
+
+Avogadro welcomes pull requests via GitHub.
+For guidance on how the project is managed, the coding style, and how to go about contributing in a constructive manner, see [Contribute](contrib).
+
+## Interfacing to and extending Avogadro
+
+### Script plugins
 
 Many features in Avogadro can be extended with Python scripts, including:
 
@@ -22,20 +34,20 @@ These scripts can be installed by drag-and-drop into the main Avogadro window or
 
 For more details, see the [script plugin](develop-scripts) documentation.
 
-## External Scripting
+### External scripting
 
 Avogadro supports sending messages from external scripts, through
 remote procedure call (RPC) JSON. This can be very helpful for rendering
 images of molecules, generating orbitals, etc.
 
 For more details, see the [RPC](develop-rpc) documentation.
 
-## Libraries
+### Libraries
 
 The Avogadro libraries are developed to support the Avogadro2 application, and
 provide liberally BSD-licensed, open-source reusable components for both C++ and Python. At its core it is a platform for developing molecular visualization, editing and interactive simulation applications. This is achieved using a collection of libraries, along with a plugin interface allowing the platform to be easily extended and used in a variety of environments.
 
-## Main Classes
+#### Main classes
 
 The Avogadro libraries are implemented as a set of libraries, where all classes
 are implemented in the Avogadro `namespace`, and each library uses a namespace
@@ -72,6 +84,7 @@ maxdepth: 2
 hidden: true
 ---
 Introduction <self>
+structure
 build
 scripts/index
 rpc

source/develop/structure.md

@@ -0,0 +1,13 @@
+(develop-structure)=
+
+# Project Structure
+
+## What is Open Chemistry?
+
+[Open Chemistry](https://www.openchemistry.org/) is an umbrella for the development of several open-source chemical tools.
+Avogadro is its primary subproject, but it also oversees the [Chemical JSON](https://github.com/OpenChemistry/chemicaljson) file format as well as [a bunch of other cool stuff](https://github.com/orgs/OpenChemistry/repositories).
+
+The Avogadro desktop application is made up primarily of the `avogadrolibs` module, which does all the behind-the-scenes work, and the `avogadroapp` module, which provides a GUI on top.
+In practice,
+
+ relies on various other Open Chemistry modules to function.