In Chapter 4, Installing the Required Dependencies, you wrote and compiled a simple three-line program to ensure your Emscripten installation was valid. We passed several flags to the emcc command that were required to only output a single .wasm file. By passing other flags to the emcc command, we can output JavaScript glue code alongside the .wasm file as well as an HTML file to handle the loading process. In this section, we're going to write a more complex C program and compile it with the output options that Emscripten offers.
We didn't include any header files or pass in any functions in the example we covered in Chapter 4, Installing the Required Dependencies. Since the intention of the code was solely to test if the compiler installation was valid, there wasn't much need. Emscripten offers a lot of extra functionality that enables us to interact with our C and C++ code with JavaScript and vice versa. Some of these capabilities...