libmkb - Super Monkey Ball Simulation Library

This project extracts and refines the gameplay logic of Super Monkey Ball into a portable C/C++ library. It no longer attempts to build the original GameCube executable; all effort is directed at maintaining libmkb as a clean simulation library.

Building

Requirements

• gcc or clang
• make
• Emscripten (optional for WebAssembly builds)

Building libmkb

Running make (or explicitly make libmkb.a) will compile the standalone simulation library libmkb.a using the host compiler. This library contains the stage loading, ball, camera, world, stage object, item and animation simulation code and can be linked into custom frontends. The full list of available functions is documented in include/libmkb.h.

Example usage:

#include <libmkb.h>

int main(void) {
    struct Ball ball;
    struct Camera camera;

    load_stage_collision(1);       // Load STAGE001
    world_sim_init();
    stobj_sim_init();
    item_sim_init();
    stage_anim_init();
    ball_sim_init(&ball);
    camera_sim_init(&camera, &ball);

    while (1) {
        world_sim_step();
        stobj_sim_step();
        item_sim_step();
        stage_anim_step();
        ball_sim_step(&ball);
        camera_sim_step(&camera, &ball);
        // render here
    }

    stage_anim_destroy();
    item_sim_destroy();
    stobj_sim_destroy();
    world_sim_destroy();
    free_stage_collision();
    return 0;
}

Building libmkb for WebAssembly

The library can also be compiled with Emscripten to produce a WebAssembly build suitable for the browser. A helper script is provided to build the WebAssembly version and export all functions used by the simulation:

tools/build_wasm.sh

This script configures the project with emcmake, builds the static library and then links it with emcc, exporting all of the simulation entry points and placing libmkb.js and libmkb.wasm in the webdemo directory.

Alternatively you can invoke emcc directly on the source files if you prefer a custom build system.

Web Frontend Demo

A simple three.js based demo is provided in the webdemo directory. After building libmkb.js and libmkb.wasm with Emscripten copy both files into the webdemo folder. The demo script will automatically instantiate the WebAssembly module when the page loads. You can then serve the directory with any static file server:

cd webdemo
python3 -m http.server

Navigate to http://localhost:8000 to see the simulation running in your browser.