Hot-Reloading in C

This is a simple project to demonstrate how you can have a hot-reloading project in C.

I structure my program around SDL2 with a "game" concept, but the general idea should be transferrable.

Main Loop

The core portion of this project is located in main.c and driver/command.[h|c]. Main does general setup of SDL2 internals and handling the main loop. We load in our shared library and have a simple even handler for the 'r' key to hotreload. (This should be able to be implmented in different ways, we use this for simplicity.)

Driver

The rest of our application is behind a "driver" file. Ours is located in driver/driver.[h|c]. This is where we implement the expected functions defined in driver/command.h for our application.

We have a little setup at the beginning of most functions to handle if we are hotreloaded at any instance. Technically with our setup it only needs to be in the event function (as this is the next function that is called after hotreloading) but with different setups it could be setup to hotreload at any instance.

Running this Project

Steps to running this project:

• Run install_deps.sh file.
• Run make to build the project.
• Run ./bin/hotreload to run the executable.
• Make a change in objects/player.c in the render function.
• Run make shared to recompile the shared library.
• In the main application press the 'r' key to hot reload and your changes should show.

Demo

The demo is slightly older before I cleaned up the project, so ignore the old executable name.

simple_hotreload_in_c.mp4