Spine Runtimes is a 2D skeletal animation runtime library that loads and plays back animations created with the Spine design tool. It manages a skeleton hierarchy of bones, slots, and attachments, applying keyframe-driven animations with configurable easing curves. The runtime renders animated characters using textured meshes from a packed atlas, supporting GPU-accelerated display across multiple platforms.
The library provides animation blending and crossfading for smooth pose transitions between animations, and it allows switching a character’s appearance on the fly by applying different skins without requiring re‑export of assets. Each skin remaps attachment references per slot, enabling fast visual variations for game characters. The renderer is designed to work across platforms, consuming data exported from Spine and drawing the animated skeleton in real time.
Core data loading handles both binary and JSON formats, decoupling authoring from runtime use. The bone hierarchy updates transforms recursively, and the slot‑layered attachment system stacks region or mesh drawables for complex visuals. Animation playback supports starting, stopping, and blending between multiple poses. Documentation for each platform is included directly in the repository, covering data loading, animation control, and rendering integration.
