FPGA hexagon video game

gameplay video: https://www.youtube.com/watch?v=jnG2rAN-wWk

This is my submission for the 48-hour 2026 cambridge game jam. In previous years [1][2], I participated in the game jam and wrote my game in assembly. This year I wanted to go even "lower-level". So this submission is written in Verilog and runs on an Nexus A7 T100 development board equiped with an AMD Artix 7 FPGA. This is my first time properly using verilog, the idea was that I'd use the game jam as an oppotunity to learn a hardware description language.

Video output is generated with my custom graphics pipeline and sent to the VGA driver which was also written during the jam. There is no framebuffer, instead I generate pixels in a 36-stage pipeline clocked at 25MHz, the same frequency pixels are output on VGA. Pixels leaving the pipeline are sent directly to VGA in a kind of "just-in-time" rendering of individial pixels. The pipeline looks something like this:

1. Predict screen_coords that will need to be sent on VGA 36 cycles in the future.
2. Model,view,projection matrix applied.
3. 2 divisions convert from homogenous to non-homogenous plane xy coordinates.
4. Plane coordinates convert to 'cube' hexagonal coordinate system.
5. Hexagon coordinates converted to color by inspecting game state.

Keyboard input is read from a PS2 keyboard driver. I use a modified version of Digilent's keyboard demo [3].

Gemini 3.1 Pro with Opencode was used to write the cpp test benches and the game logic. So the technical achievement of the project is the 3d rendering pipeline.

In the game, you play a a hexagon. The objective is to visit all hexagons on the game board without visiting the same hexagon twice.

The theme of the game jam "set in stone" is met in two ways.

1. The game code is in some sense "set in stone" when flashed to the board.
2. After you visit a hexagon, it becomes "set in stone" and can not be re-visited.

[1] https://github.com/Chris-F5/2425_cambridge_game_jam [2] https://github.com/Chris-F5/lazer_recoil [3] https://github.com/Digilent/Nexys-A7-100T-Keyboard

Built With

• artix7
• nexusa7
• verilog