OpenGL-CMake-Config

A CMake configuration for Cross platform development.

Supports cross compiling for Linux and Windows- both x86 and x64.

Contains:

• SDL2 (cross platform library for hardware, and graphics via OpenGL and Direct3D)
• Bullet3 (3D Physics engine)
• GLM (Math library commonly used alongside OpenGL)
• glew (OpenGL extension loading library)
• GameNetworkSockets (Basic networking library for games)

Slightly based off of https://github.com/ArthurSonzogni/OpenGL_CMake_Skeleton

Building

Just a heads up: This is not an easy build process, but I added some scripts to make this process go as smooth as possible. Some of the CMake scripts and library linking could definitely be considered 'hacky' but I'm justifying it by saying it works, and it's mainly built for my own dev environment.

If you end up using this for your own project(s), hope you enjoy!

Windows 10 install for Visual Studio Cross Platform

• Git clone --recursive
• open root dir in Visual Studio
• Supply CMake settings
• install https://slproweb.com/products/Win32OpenSSL.html - both 86 and 64. These are used to build Google protobuf
• navigate to /lib/protobuf_build
• run populate_all.bat and supply your version of VsDevCmd.bat as an arg.

ex: populate_all.bat "C:\Program Files (x86)\Microsoft Visual Studio\2019\Preview\Common7\Tools\VsDevCmd.bat"

Protobuf should then be installed in C:\sdk\protobuf This WILL take awhile.

• navigate to /lib/gamenetworksockets_build
• run populate_all.bat and supply your version of VsDevCmd.bat as an arg.

ex: populate_all.bat "C:\Program Files (x86)\Microsoft Visual Studio\2019\Preview\Common7\Tools\VsDevCmd.bat"

GameNetworkSockets should then be installed in /lib/gamenetworksockets_build This shouldn't take as long as it took protobuf to build.

• Create a vm for linux. I used Ubuntu 16.04. This could also be a real machine you can ssh into.
• Configure ssh login for linux machine (not going to go into this, plenty of tutorials)
• Add machine ssh credentials to cmakesettings
• in launch.vs.json, your pipeArgs should look something like this:

"pipeArgs": [
          "/s",
          "${debugInfo.remoteMachineId}",
          "/p",
          "${debugInfo.parentProcessId}",
          "/c",
          "export DISPLAY=:0;${debuggerCommand}",
          "--tty=${debugInfo.tty}"
],

The export DISPLAY=:0; is a MUST or else you will get a segfault..

Configure linux machine for development

Install SDL2:

apt install libsdl2-dev  
apt install libsdl2-mixer-dev
apt install libsdl2-image-dev

Install libssl:

apt install libssl-dev

Now if you're unlucky like me, you probably need to update libssl and apt-get wont do the job. This awesome q/a will show you how to update libssl from it's source: https://askubuntu.com/questions/1102803/how-to-upgrade-openssl-1-1-0-to-1-1-1-in-ubuntu-18-04

Install protobuf:

apt install libprotobuf-dev protobuf-compiler

Install cmake:

apt install cmake

Install ninja:

apt install ninja-build

Install gamenetworkingsockets:

git clone 
cd GameNetworkingSockets
mkdir build
cd build
cmake -G Ninja ..
ninja

Optional but I move the output files into lib where sdl is

cd src
mv libGameNetworkingSockets_s.a /usr/lib/x86_64-linux-gnu
mv libGameNetworkingSockets.so /usr/lib/x86_64-linux-gnu

Debuging

• Double check CMakeSettings like SDL2_DIR and GNS_LIB_DIR, they should both point to their library directories.
• The populate_all scripts need to be supplied with VsDevCmd.bat. The path for VsDevCmd.bat differs on each version of visual studio.
• Lots of trial and error. Building this first try with no errors seems unlikely.