Recently I have been working on creating a game using Visual C++ 2017 and SDL2. I want to make my game accessible to users on all different kinds of systems, not just Windows. I tried starting with making my game also usable on Mac OS, but I cannot figure out any ways of doing this. I figured the best method would be to get Visual Studio to compile my code into a file type like ".APP" rather than ".EXE" since I don't own any form of Mac or Apple computer that can use software made to create apps for Mac. However, I cannot figure out how to change the options in Visual Studio to compile the code into a different file type or even if doing so is possible.
I've searched all over the internet for methods of converting ".EXE" to other file types, using different C++ compilers for compiling into Mac-compatible files, etc. but I haven't been able to find anything that works without requiring a virtual machine or having a physical Mac computer (neither of which I've tried yet since it would take a lot of effort and I'd like an easier solution).
If anybody could tell me how to change the type of file that Visual Studio compiles your code into or if they could suggest a different compiler that works on Windows, is compatible with SDL2, and can compile C++ code into file types that work on Mac computers like ".APP", that would solve my problem. Thank you in advance!
You need to compile your code on all the different platforms you want to support. Using a compiler supported on each of those platforms. Code compiled on one platform can not run on another (except cross compiling, see below, but that's painful).
Cross compiling is an option on some platforms and with some compilers, but it's usually more pain than gain if you can in any way set up a local tool chain. Cross compilers generate code for a different platform than you are currently running, but getting that working can be hard. And you then also have no way to test your code on the target platform (unless you have one, in which case native compiling would just be easier in the first place).
You should automate the building of your code on different systems with different compilers in your Continuous Integration systen (CI) btw. So you always know after you push a commit, on what platforms it fails and why.
Easiest way forward (IMHO): Buy a cheap Mac. Buy a cheap PC and install Linux on it. Setup a CI system to build all code you commit to your code repository on all your systems (Windows, Mac, Linux) and make it scream at you when the build fails. Also use that system to build installable packages for each platform and again, scream when that fails.
Do the same for all your unit tests.
That's the only serious way to go forward supporting multiple platforms.