2.15

This is the first release since a long time with a breaking change. The focus on this version was mainly performance/memory management. For a longer explanation, check out the discussion.
For more details refer to the new EntityRef wiki entry.

Changelog:

• NEW: new EntityRef to store a stable reference to an Entity in a component. Unlike a raw Entity, an EntityRef becomes invalid when the referenced entity is removed from the world, allowing safe detection of stale references. Added getRef to Entity as well as null-safe isValid and isNotValid helpers on EntityRef
• NEW: add sparse set implementation (SparseEntityBag) for better family performance
• UPDATE: make Entity a value class again and remove the version field; invalidation of removed entities is now handled via EntityRef instead
• UPDATE: add safety that the fixed time step of an IntervalSystem cannot be zero or negative
• UPDATE: use kotlinx-atomicfu to generate component ids atomically in a thread-safe way
• UPDATE: refactor build configuration from buildSrc to a separate build-logic and update to a minimum of JDK 17
• UPDATE: update following versions
  • Gradle 9.7.1
  • Kotlin 2.4.10
  • kotlinx-benchmark: 0.4.17
  • kotlinx-serialization: 1.11.0
  • Dokka: 2.2.0
  • kotlinx-atomicfu: 0.33.0