8# Modular C++ Application & Library (using Qt6)

The concepts-directory contains projects used to proof if what is needed is feasible. C++ concepts for proofing for me needed concepts using the Qt framework. Common basic libraries are not Qt dependent. This makes building non Gui application modules without Qt possible.

Before building some packages need to be installed:

• cmake (Linux) (Required)
• libopengl0 (Linux) (Required)
• libgl1-mesa-dev (Linux) (Stops cmake warnings)
• libxkbcommon-dev (Linux) (Stops cmake warnings)
• libxkbfile-dev (Linux) _(Stops cmake warnings)
• libvulkan-dev (Linux) (Stops cmake warnings)
• libssl-dev (Linux) (Required)
• gcc or gcc-12(Linux) (Required)
• g++ or g++-12 (Linux) (Required)
• doxygen (Linux, Cygwin) (Required)
• graphviz (Linux, Cygwin) (Required)

sudo apt install libopengl0 libgl1-mesa-dev libxkbcommon-dev libxkbfile-dev libvulkan-dev doxygen graphviz

To cross compile for Windows-64bit the MinGW 64bit c++ compiler must be installed.

sudo apt install g++-mingw-w64-x86-64

For some reason WineHQ-staging (stable not present yet) references to directory /usr/lib/gcc/x86_64-w64-mingw32/9.3-posix which is not it is not available but /usr/lib/gcc/x86_64-w64-mingw32/10-posix is.

To fix this a symbolic link need to be created for the 9.3-posix directory pointing to 10-posix for now.

sudo ln -s  10-posix  /usr/lib/gcc/x86_64-w64-mingw32/9.3-posix

To access the needed Windows build DLL's and binaries for compiling the next directory is only copied to a Linux directory (~/lib/QtWin/<qtversion>/mingw_64).

The script cross-windows-fix.sh which creates links to the needed executable binaries required by the CMake files. It also appends some to Cmake files to allow them to compile.

Running the application from wine using the wine-exec.sh script a Wine version 7 or later is required. For this run the next line to accomplish that.

wget -q https://dl.winehq.org/wine-builds/winehq.key -O- | apt-key add -
apt-add-repository "deb https://dl.winehq.org/wine-builds/$(lsb_release -is | tr '[:upper:]' '[:lower:]')/ $(lsb_release -cs) main"
apt install --install-recommends winehq-stable

apt-cyg install doxygen graphviz

For Cygwin a script apt-cyg it there to install packages from the command line.

Use the build.sh to call the cmake command having the needed options. All projects are configured to drop the result into the ./bin directory.

The usage is ./build.sh <directory>.
Where the directory is any with a CMakelists.txt project file in it.

On Ubuntu 20.04 LTS in order to use the GCC 10 compiler the next packages need to be installed.

sudo apt install gcc-10 gcc-10-base gcc-10-doc g++-10 libstdc++-10-dev libstdc++-10-doc

Check with this command the C++20 GNU defined values.

g++-10 -x c++ -std=c++2a -dM -E - </dev/null | grep -i GNU

Install Cygwin to build this project the same way as for Linux using the same bash script.

For installing Cygwin see the git repository Cygwin Bash Scripts This allows to call the bash build.sh to be called in side Windows.