Scala Days 2014 - Experiment: A Reactive 3D Game Engine in Scala - Alexandar Prokopec

Most modern 3D game engines are written close to the metal in C++ to achieve smooth performance and stunning. Managed languages and runtimes are usually avoided for this task since they incur garbage collection lags and other performance penalties.

We decided to put this conventional wisdom to test with an experiment - we used an Rx-style reactive programming framework enriched with reactive collections and isolates in unison with a high-level OpenGL framework to build a modern 3D engine.

Game engines are traditionally written in low-level imperative style to achieve optimal performance. Such code can be hard to understand and maintain - the uprising reactive programming is much more natural for writing games, since game engines are in essence discrete event simulations. However, reactive programming comes with performance penalties that we overcome using Scala Specialization, inlining and efficient reactive data containers. Similarly, the OpenGL API exposes a plethora of low-level routines unfit for large scale development - a more structured approach to graphics programming with higher level programming abstractions is desired, but yields a higher performance cost. Through the use of Scala Macros we eliminate these inefficiencies while in the same time retaining the advantages of a structured graphics programming framework.

Result? A high-throughput reactive 3D real-time game engine achieving smooth 60FPS on modern hardware with high polygon counts, texture blending, GPU-based object instancing, and effects like ambient occlusion, shadow mapping and image filtering.

No need to spread Fear, Uncertainty and Doubt about performance anymore - Scala is ready for modern real-time game engines, delivering great performance with the convenience of the modern managed language.

To view the video visit www.parleys.com.