Posts Tagged ‘JavaSwing’
[DevoxxBE2024] Let’s Use IntelliJ as a Game Engine, Just Because We Can by Alexander Chatzizacharias
At Devoxx Belgium 2024, Alexander Chatzizacharias delivered a, lighthearted yet insightful talk on the whimsical idea of using IntelliJ IDEA as a game engine. As a Java enthusiast and self-proclaimed gamer, Alexander explored the absurdity and fun of leveraging IntelliJ’s plugin platform to create games within a codebase. His session, filled with humor and technical creativity, demonstrated how curiosity-driven projects can spark innovation while entertaining developers. From rendering Pong to battling mutable state in a Space Invaders-inspired game, Alexander’s talk was a testament to the joy of experimentation.
The Origin Story: Productivity Through Play
Alexander’s journey began with a reaction to Unity 3D’s controversial per-install pricing model in 2023, prompting him to explore alternative game engines. Inspired by a prior Devoxx talk on productivity through fun, he decided to transform IntelliJ IDEA, a powerful IDE, into a game engine using its plugin platform. Built with Kotlin and Java Swing, his approach avoided external frameworks like JavaFX or Chromium Embedded Framework to maintain authenticity. The goal was to render games within IntelliJ’s existing window, interact with code, and maximize performance, all while embracing the chaos of a developer’s curiosity. Alexander’s mantra—“productivity is messing around and having fun”—set the tone for a session that balanced technical depth with playfulness.
Pong: Proving the Concept
The first milestone was recreating Pong, the 1972 game that launched the video game industry, within IntelliJ. Using intentions (Alt+Enter context menus), Alexander rendered paddles and a ball over a code editor, leveraging Java Swing for graphics and a custom Kotlin Vector2 class inspired by Unity 3D for position and direction calculations. Collision detection was implemented by iterating through code lines, wrapping each character in a rectangle, and checking for overlaps—faking physics with simple direction reversals. This “fake it till you make it” approach ensured a functional game without complex physics, proving that IntelliJ could handle basic game logic and rendering. The demo, complete with a multiplayer jest, highlighted the feasibility of embedding games in an IDE.
State Invaders: Battling Mutable Variables
Next, Alexander tackled a backend developer’s “cardinal sin”: mutable state. He created State Invaders, a Space Invaders-inspired game where players eliminate mutable variables (var keywords) from the codebase. Using IntelliJ’s PSI (Program Structure Interface), the plugin scans for mutable fields, rendering them as enemy sprites. Players shoot these “invaders,” removing the variables from the code, humorously reducing the “chance of production crashing” from 100% to 80%. A nostalgic cutscene referencing the internet meme “All your base are belong to us” added flair. The game demonstrated how plugins can interact with code structure, offering a playful way to enforce coding best practices while maintaining a functional codebase.
Packag-Man: Navigating Dependency Mazes
Addressing another developer pain point—over-reliance on packages—Alexander built Packag-Man, a Pac-Man variant. The game generates a maze from Gradle or Maven dependency names, with each letter forming a cell. Ghosts represent past dependency mistakes, and consuming them removes the corresponding package from the build file. Sound effects, including a looped clip of a presenter saying “Java,” enhanced the experience. IntelliJ’s abstractions for dependency parsing ensured compatibility with both Gradle and Maven, showcasing the platform’s flexibility. The game’s random ghost placement added challenge, reflecting the unpredictable nature of dependency management, while reinforcing the theme of cleaning up technical debt through play.
Sonic the Test Dog and Code Hero: Unit Tests and Copy-Paste Challenges
Alexander continued with Sonic the Test Dog, a Sonic-inspired game addressing inadequate unit testing. Players navigate a vertical codebase to collect unit tests (represented as coins), with a boss battle against “Velocity Nick” in a Person.java file. Removing coins deletes tests, humorously highlighting testing pitfalls. Finally, Code Hero, inspired by Guitar Hero and OSU, tackles copy-pasting from Stack Overflow. Players type pasted code letter-by-letter to a rhythm, using open-source beat maps for timing. A live demo with an audience member showcased the game’s difficulty, proving developers must “earn” their code. These games underscored IntelliJ’s potential for creative, code-integrated interactions.
Lessons and Future Hopes
Alexander concluded with reflections on IntelliJ’s plugin platform limitations, including poor documentation, lack of MP3 and PNG support, and cumbersome APIs for color and write actions. He urged JetBrains to improve these for better game development support, humorously suggesting GIF support for explosions. Emphasizing coding as a “superpower,” he encouraged developers to experiment without fear of “bad ideas,” as the dopamine hit of a working prototype is unmatched. A final demo hinted at running Doom in IntelliJ, leaving the audience to ponder its feasibility. Alexander’s talk, blending technical ingenuity with fun, inspired attendees to explore unconventional uses of their tools.