ASM Funbox

This is the ASM Funbox. Giving you input and a framebuffer 60 times a second, write game logic in x64 assembly.

Explore writing 64-bit assembly by writing a game without all of the setup or shutdown calls, focusing on pure game logic.

Major Update

This is ASM Funbox 2.0, which removes SCons and makes other quality of life updates. For legacy projects, ASM Funbox 1.0 is still available at the tag asmfunbox_1 but is no longer supported.

Compiling

Dependencies

ASM Funbox runs on Linux. Any VM that can run a fixed function OpenGL pipeline should be sufficient, in lieu of dedicated hardware.

• Python for scons
• nasm for assembling
• SDL2 and OpenGL headers

apt-get install nasm libsdl2-dev libglu1-mesa-dev should do it.

Known Issues

None. Report bugs!

Controls

See sample_input_buttons in game.c

Building

After installing dependencies (see above):

./make.py

This produces executables in the bin subdirectory.

Writing Your Own Game

Each file in src/asm generates an exe with the same name under the bin directory. So, create src/asm/game.asm to generate bin/game.

The game must implement a function called asm_tick. See stub.asm for the simplest example.

The prototype of asm_tick is, effectively:

int asm_tick(u8 buttons, uint32 *pixels, uint32 elapsed_ms);

• If asm_tick returns 1, the program quits.

• buttons is a set of bitflags, akin to a NES controller. See BTN constants in game.c.

• pixels is a 160x90 32-bit RGBA image buffer. Write your pixels once per frame.

• elapsed_ms is the number of elapsed milliseconds since program start

Author

Michael Labbe