bb4-simulations

Interactive Scala/Swing simulations of physical, mathematical, and procedural systems — reaction–diffusion chemistry, Mandelbrot navigation, fluid flow, Conway’s Game of Life, spring-based snakes, stock trading strategies, wave-function collapse, and more. Each app shares a common simulator framework so you can tweak parameters and watch the system evolve in real time.

Screenshots

Reaction Diffusion	Henon Phase	Fractal Explorer	Cave Explorer
Dungeon Generator	Conway's Life	Snake	Dice
Stock Price	Stock Trading	Habitat	Verhulst
Voronoi Explorer	Predator Prey	Fluid	Liquid
Water	Trebuchet	Spirograph	Sierpinski
L-System Tree	Wave Function Collapse

Click a thumbnail to open the full-size image.

Simulations

Simulation	Gradle task	Description
Reaction Diffusion	runReactiondiffusion	Two-chemical reaction–diffusion patterns (Gray–Scott style).
Henon Phase Explorer	runHenonexplorer	Explore parameters of the Hénon strange attractor.
Fractal Explorer	runFractalexplorer	Zoom the Mandelbrot set; drag to zoom, undo with go-back.
Cave Explorer	runCave	Generate cave maps with cellular automata.
Dungeon Generator	runDungeon	Procedurally generate dungeon levels.
Conway’s Game of Life	runConway	Cellular automaton with alternate rule sets; color shows age.
Snake	runSnake	Spring-based snake locomotion (Gavin Miller, SIGGRAPH 1988).
Dice	runDice	Histogram of rolling N dice with M sides.
Stock Price	runStock	Expected outcomes for volatile stocks over many periods.
Stock Trading	runTrading	Compare trading strategies on simulated price paths.
Habitat	runHabitat	Multi-creature habitat with predator/prey dynamics.
Verhulst Population	runVerhulst	Discrete logistic (Verhulst) population growth / chaos.
Voronoi Explorer	runVoronoi	Poisson-disc sampling and Voronoi diagrams.
Predator Prey	runPredprey	Fox and rabbit population curves over time.
Fluid	runFluid	Deep-water fluid dynamics (Jos Stam); drag to stir.
Liquid	runLiquid	Particle-based liquid simulation (Foster et al.).
Water	runWater	2D deep-water waves (Kass & Miller); drag to reshape.
Trebuchet	runTrebuchet	Physically based trebuchet with tunable parameters.
Spirograph	runSpirograph	Parametric spirograph curves.
Sierpinski Triangle	runSierpinski	Classic self-similar triangular fractal.
L-System Tree	runLsystem	Fractal trees from L-system expressions.
Wave Function Collapse	runWaveFunctionCollapse	Procedural scenes from seed images or tile sets.

Developer / demo apps (not packaged as installers): runGraphing, runFuncinverse, runParameter, runComplexmapping.

Running it

Option 1 — installer (recommended): download the installer for your OS from the latest release (macOS .dmg, Windows .msi, Linux .deb — one installer per simulation).

Option 2 — from source:

git clone https://github.com/bb4/bb4-simulations.git
cd bb4-simulations
./gradlew runReactiondiffusion   # or runSnake, runFractalexplorer, runFluid, …
./gradlew tasks --group application   # list all runnable simulations

The default ./gradlew run launches the Dice simulator. Most apps share the SimulatorApp entry point with a -panel_class argument; Gradle creates a run<App> task for each entry in appMap.

Using it as a library

Published artifact (latest release 2.1):

implementation 'com.barrybecker4:bb4-simulation:2.1'

See the releases page if you need a different version.

What's inside

• com.barrybecker4.simulation.common — shared Swing simulator framework (Simulator, SimulatorApp, options dialogs, animation hooks)
• Per-simulation packages under com.barrybecker4.simulation.* — model and UI for each app in the table above (e.g. reactiondiffusion, fractalexplorer, snake, fluid, waveFunctionCollapse)
• Standalone launchers — Spirograph and SierpinskiApplet also ship as their own start scripts (bb4-spirograph, bb4-sierpinski)

Building from source

See the Building bb4 Projects wiki.

License

MIT — see LICENSE.