Revision as of 18:40, 27 August 2021

Compiling VCMI for Windows on Linux

Some developers may want to make Windows builds without dealing with dependencies as it may be headache when you're on Windows. It's possible to setup own cross-compiler toolkit that use MinGW, but that take time and skill. Fortunately there is project called MXE (M cross environment) that make cross compilation easy and work out of box for our engine.

Precompilled build from CI

In order to speed up MXE compilation time on CI we use precompiled MXE packages.

# Install nsis for cpack
sudo apt-get install nsis

#we might need this a bit outdated version of ssl
wget http://security.ubuntu.com/ubuntu/pool/main/o/openssl1.0/libssl1.0.0_1.0.2n-1ubuntu5.6_amd64.deb
sudo apt install ./libssl1.0.0_1.0.2n-1ubuntu5.6_amd64.deb

# Clone VCMI repository with submodules
git clone --depth 1 --recursive https://github.com/vcmi/vcmi.git

mkdir build
cd build

# MXE repository was too slow for Travis far too often
wget -nv https://github.com/vcmi/vcmi-deps-mxe/releases/download/2021-02-20/mxe-i686-w64-mingw32.shared-2021-01-22.tar
tar -xvf mxe-i686-w64-mingw32.shared-2021-01-22.tar
sudo dpkg -i mxe-*.deb
sudo apt-get install -f --yes

# build
sudo apt-get install ninja-build

/usr/lib/mxe/usr/bin/mxe-i686-w64-mingw32.shared-cmake -G Ninja ../vcmi -DCMAKE_BUILD_TYPE=Release -DENABLE_TEST=0
ninja

# pack an installer, on CI works with regular cmake's cpack.
cpack -C Release -D CPACK_NSIS_EXECUTABLE=`which makensis`

The full actual list of used MXE packages could be found here

Setting up a MXE cross compiler

Make sure cmake and git is installed on your system as well as all libraries and utils listed under requirements. MXE website have commands that will let install everything needed for almost every distribution.

Once it done clone MXE repository using git.

git clone https://github.com/mxe/mxe.git

Now just run make once to generate "settings.mk" file and then cancel build immediately with Ctrl+C:

make

Then you need to edit "settings.mk" file:

# "settings.mk" not exist by default
# You can create it by running "make" and then aborting it by Ctrl+C
#
# Uncomment "MXE_TARGETS" and make it look like that:
MXE_TARGETS := i686-w64-mingw32.shared

# You can add this line to plugins if you want MXE to use GCC6
# This is currently break NSIS though
#override MXE_PLUGIN_DIRS += plugins/gcc6

# And you can add following packages list
LOCAL_PKG_LIST := gcc boost zlib sdl2 sdl2_gfx sdl2_image sdl2_mixer sdl2_ttf ffmpeg minizip qtbase nsis
# Make sure to uncomment two lines under the list
.DEFAULT_GOAL  := local-pkg-list
local-pkg-list: $(LOCAL_PKG_LIST)

Then you can compile it:

make -j 9

Depend on your hardware that may take from 20 minutes to more than hour.

Compiling VCMI using MXE

First of all create two directories: one for CMake (vcmi-cmake) and other for result build (vcmi-build). Now build would looks like that:

# Clone VCMI repository with submodules
git clone --depth 1 --recursive https://github.com/vcmi/vcmi.git

# Create CMake directory and cd into it
mkdir vcmi-cmake && cd vcmi-cmake

# To configure build with launcher:
/home/test/mxe/usr/bin/i686-w64-mingw32.shared-cmake ../vcmi -DENABLE_TEST=0

# Compile
/home/test/mxe/usr/bin/i686-w64-mingw32.shared-cmake --build . -- -j 9

# To create installer
# MXE have own patched CPack that allow to pass path to makensis as option.
/home/test/mxe/usr/bin/i686-w64-mingw32.shared-cpack -D CPACK_NSIS_EXECUTABLE=/home/test/mxe/usr/bin/i686-w64-mingw32.shared-makensis

Script for automatic builds

If you want to have automatic build you can grab script that automatically compile and upload builds using MXE.

• Download it from Github Gist.