Twinpin is a minimalistic top-down twin-stick shooter. Each player controls a circle with their gamepad. Only Sony DualShock 4 V2 are supported so far but other gamepads have been reported to work as well. I develop this game to satisfy my functional programming itch. To play, either download the latest release, or build from source by following the instructions below.
Stack is used to build the project. Stack will download most of the other build dependencies but there are some manual steps required to get SDL2 working.
To set up SDL2 for Windows, follow step 1-4 in this Reddit post.
install SDL2 with sudo dnf install SDL2 SDL2-devel
stack build to build
stack exec twinpin-exe to play twinpin, or
stack run to both build and execute
stack test to run the tests
stack deploy.hs to make a twinpin distribuion for the current operating system
and processor architecture
To develop twinpin, I use Visual Studio Code with the following extensions:
The Twinpin tests uses hspec-discover. It needs to be installed globally with the command below. See this issue for more information.
stack install hspec-discover
Cabal may be needed for Haskell IDE Engine to work properly. To install and update cabal, run the commands below. See this issue for more information.
stack install cabal-install
cabal update
The entry point is found in Main. Main contains all the IO, in fact all side effects of twinpin are limited to Main only. Main communicates with Game, which is responsible for updating the game state given some user input. Below is the complete module dependency graph. Edges implied by transitivity are not shown, the image would be too cluttered if they were.
Below Game in the graph are:
- Match, which manages interactions between all objects in a match.
- Menu, which can draw a pause menu that can be used to quit the game.
- Player, which updates a player's state. A player is represented by a circle visually. Given the trigger input a player will fire a bullet.
- Bullet, which updates a bullet's state. A bullet is represented by a circle visually.
- Circle, which contains most of the physics. It updates a circle's position given a velocity.
- Visual, which contains convenience functions for moving from memory representations to drawable images.
- Space, which contains the basic data types and geometric functions.
The graph was generated with graphmod. Install it with:
stack build --copy-compiler-tool graphmod
and generate module-dependencies.svg with:
stack exec graphmod | tred | dot -Tsvg > doc/module-dependencies.svg