xLights Linux build instructions
------------------------------------------------------------------------------

xLights can be built and run on Linux, Mac OS/X, or Windows. This
document describes how **developers** should set up their tool chain to build
xLights on Linux.
Ubuntu packages are provided for users at https://code.launchpad.net/~chris-debenham/+archive/ubuntu/xlights

xLights is written in C++ and uses the wxWidgets library as a
compatibility layer across operating systems.  The minimum required version
of wxWidgets for xLights is v3.1.5.  This can be compiled from
source or installed via packages if they are available for your distribution.
The provided makefile will download and build wxWidgets if needed - including
application of a small patch from the end of this file to fix the sizing of
bitmap buttons.
SDL2 needs to be 2.0.5 or later.
A precompiled libliquidfun.a.`uname -p` library and QM Vamp plugins are included for
i686, x86_64 and aarm64 - for other platforms it would need to be recompiled from
https://github.com/google/liquidfun

== Building for linux via docker container ==

If you wish to build for linux from other platforms or without having to touch your local install you can use Docker to test building
To setup the nessecary docker image you can checkout the build file from git and build directly via:

    docker build -t xlights-build https://github.com/xLightsSequencer/xlights-build-docker.git

This will leave you with a suitable base image
Once this is setup you can build xLights via:

    docker run --name buildvm xlights-build /bin/bash Recipe

If you want to build the appimage you can use:

    docker run --name buildvm xlights-build /bin/bash Recipe.appimage

If you want to create a fresh build then the container can be removed with:

    docker rm buildvm

== Building locally from source ==

These instructions have been tested on the following distributions:

  - Ubuntu 19.04
  - Fedora 31

Instructions for other Linux distributions will vary. 

  a) Using Software Manager (or apt-get or rpm), install the following packages.
     (Fedora packages will be named differently and have 'devel' instead of 'dev'
     in their name)

     build-essential
     libgtk-3-dev
     libgstreamer1.0-dev
     libgstreamer-plugins-base1.0-dev
     freeglut3-dev
     libavcodec-dev
     libavformat-dev
     libswscale-dev
     libsdl2-dev
     libportmidi-dev
     libzstd-dev
     libcurl4-openssl-dev
     libltc-dev
     liblua5.3-dev
     cbp2make (optional but recommended if compiling from git)

     Example command to install packages on Ubuntu

     sudo apt-get install g++ gcc build-essential libgtk-3-dev libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev freeglut3-dev libavcodec-dev libavformat-dev libswscale-dev libsdl2-dev libswresample-dev libavutil-dev libavresample-dev libportmidi-dev libzstd-dev libcurl4-openssl-dev libltc-dev liblua5.3-dev wget git cbp2make

     Example commands to install packages on Fedora 31

     sudo dnf install https://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm https://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm
     sudo dnf install gcc-c++ gtk3-devel gstreamer1-devel gstreamer1-plugins-base-devel freeglut-devel gstreamer1-plugins-bad-free-devel ffmpeg-devel SDL2-devel portmidi-devel libzstd-devel curl-devel liblua5.3-devel


  b) Get the xLights source code by opening a terminal window and
     typing the following:

     git clone --recurse-submodules https://github.com/smeighan/xLights.git xLights


xLights can be built 2 ways on Linux. First, you can use the
supplied makefile to build it. This is sufficient to get xLights
running, but you will be limited in what source code modifications you can
make.  Minor code changes or enhancements will be OK.  The second way to
build is to install the Code::Blocks IDE and compile xLights
within the IDE. If you plan on modifying xLights yourself, this
may be the easiest way to go.

To build xLights using the supplied makefile proceed to step 'c'.  To build
using Code::Blocks, proceed to step 'd'.:


  c) Build xLights using the supplied makefiles:

     Build using the simplified top-level Makefile in the main xLights
     directory.
     If wxWidgets 3.1 is not available then as part of this wxWidgets 3.1
     will be downloaded, compiled statically linked to xLights

           $ make

         Then install xLights to the default /usr/local/bin location as root:

           # make install

         To run the clean command:

           $ make clean

         To uninstall the xLights binary as root:

           # make uninstall

     You may get some compiler warnings, however, the executable 'xLights'
     should get built in the ./bin directory.  The proper dependencies are
     not currently setup in the makefile to trigger rebuilds when some
     files are modified, so you may have to run the clean command if your
     code does not build properly after making modifications to the source.

     If you want to build using Code::Blocks, proceed to step 'd'.

  d) Building xLights using Code::Blocks

     Install the Code::Blocks IDE using your distribution's package
     manager as long as it is version 16.01 or later.  Otherwise,
     you can try downloading it directly from the Code::Blocks web site:
        http://www.codeblocks.org/downloads
     Also, you may need to install libwxsmithlib0 to 
     enable visual layout.

     You will need to run 'make' from the command line once to build and
     patch wxwidgets.  Then ensure that the wx-config command is in your
     PATH so that codeblocks can find it. The simplest way to do this is
     to go into the wxWidgets-3.1.5 directory and run 'sudo make install'

     Now you are ready to use Code::Blocks to build xLights
     by double-clicking on the xLights.cbp file.
     In order for the double-click to work, you may need 
     to first right-click on the cbp file, select properties,
     and uncheck the box indicating that the file is runnable.
     Make sure you set the target to "Release Linux" before you build.

That should be all you need to build xLights.
If you get missing decoder messages related to gstreamer, a couple of things to try are:
- sudo apt-get install ubuntu-restricted-extras  (substitute as appropriate for other *nices)
- install "Play it slowly"  - this app includes some gstreamer dependencies


==============================================================================

If it is necessary to rebuild the xLights.cbp.mak makefile such as when new
source files are added to the project, the command used to run cbp2make is:

cbp2make -in xLights.cbp -cfg ../cbp2make.cfg -out xLights.cbp.mak --with-deps --keep-outdir --keep-objdir

This will be run automatically at compile time if cbp2make is installed.

==============================================================================

Troubleshooting:

With so few Linux users and a general lack of experience in the platform I think it is worthwhile
documenting some troubleshooting steps that can help determine issues.

Hangs & Pauses
--------------

To capture a log of systems calls

    strace -f -tt <executable> > strace.txt 2>&1
    
    you may also consider adding -y or -yy to capture socket and file descriptor information if 
    supported on your system
    
    These logs files are large and difficult to analyse but provide our best chance of debugging 
    these types of problems without an interactive debugger.

wxWidgets Bugginess (and possible xLights bugginess)

    There are some situations where limiting xLights to a single CPU can significantly minimise 
    issues at the expense of parallelism. So if you are getting random issues you may want to try
    
    taskset -c 0 <executable>