Minimalist 2D Java game engine. Result of covid lockdown.

About

ScrewBox is a small pure Java 2D game engine. I started developing ScrewBox in february 2021 right during too much time at hand because of covid lockdown. I use it to learn about Java and have some fun. If you want to get something startet in a few minutes ScrewBox might be a fun choice.

▶ Watch trailer on Youtube

Features

• Entity Component System Add and remove game objects and behaviour. Save and load the game state.
• Render Engine Fast rendering of shapes, animated graphics and text. Enhance graphics with dynamic light and shadow effects. Use split screen mode to create local multiplayer games.
• Physics System Move objects and resolve collisions. Detect obstacles via raycasting and use pathfinding to move around.
• Asset Management Load game assets without interrupting the game flow.
• Particle Effects Add particle effects to create some nice visuals.
• Basic UI Create an animated interactive game ui in an instant.
• Input Support Receive player interactions via keyboard and mouse.
• Scene Management Use scenes to structure different game situations. Add animated transitions to smoothly switch between the scenes.
• Audio Support Play wav and midi sounds. Control the volume and pan manually or automatically based on the position of the sound source. Get information on whats currently playing.
• Archivements Add archivements to challange players with custom goals.
• Support for Tiled Editor Import your game map and tilesets in Json format from the Tiled Editor

Getting started

1. Create a new Maven project using Java 21+ and add the screwbox-core dependency:

   <dependency>
       <groupId>io.github.srcimon</groupId>
       <artifactId>screwbox-core</artifactId>
       <version>2.12.0</version>
   </dependency>

2. Create a minimal application using example code:

   import io.github.srcimon.screwbox.core.Engine;
   import io.github.srcimon.screwbox.core.ScrewBox;
   import io.github.srcimon.screwbox.core.graphics.drawoptions.TextDrawOptions;
   
   import static io.github.srcimon.screwbox.core.assets.FontBundle.BOLDZILLA;
   
   public class HelloWorldApp {
   
   public static void main(String[] args) {
       Engine screwBox = ScrewBox.createEngine();
   
       screwBox.environment().addSystem(engine -> engine.graphics().canvas().drawText(
               engine.mouse().offset(),
               "current fps is: " + engine.loop().fps(),
               TextDrawOptions.font(BOLDZILLA).scale(3).alignCenter()));
   
       screwBox.start();
   }

3. Run main method (it's recommended to use JVM option -Dsun.java2d.opengl=true for much better performance)

Modules

Here is a quick overview over all modules contained in this project:

screwbox

BOM to manage all project dependencies.

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>io.github.srcimon</groupId>
            <artifactId>screwbox</artifactId>
            <version>2.12.0</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

screwbox-core

Adds the core functionality of the ScrewBox engine. Nothing more needed to make game.

<dependency>
    <groupId>io.github.srcimon</groupId>
    <artifactId>screwbox-core</artifactId>
</dependency>

// creating a fancy black window
ScrewBox.createEngine().start();

screwbox-tiled

Adds support for tilesets and maps made with Tiled Editor. For real code have a look at the pathfinding example.

<dependency>
    <groupId>io.github.srcimon</groupId>
    <artifactId>screwbox-tiled</artifactId>
</dependency>

// loading a map made with Tiled Editor
Map map = Map.fromJson("underworld_map.json");

Documentation

ScrewBox packs some examples. You can inspect these examples to learn how to use the engine. If you have any questions please let me know by creating an Issue.

Example	Description
hello-world	Hello world application with some interactive particle effects.
pathfinding	Example application showing how to use pathfinding and importing maps from Tiled Editor
game-of-life	An interactive game of life implementation.
platformer	A much more complex example showing how to make a platformer.
vacuum-outlaw	Example for a top down game.
playground	Just a playground, containing whatever is currently in focus of development.

Libraries used

• JUnit Eclipse Public License 2.0
• FasterXML Jackson Core Apache License 2.0
• AssertJ Apache License 2.0
• Mockito MIT License

Acknowledgments

The project idea was inspired by Gurkenlabs Litiengine.