This repository is the core Android implementation of the Lottie animation library, designed to render vector-based animations (exported from Adobe After Effects as JSON) natively on Android devices. The codebase functions as a rendering engine that parses Lottie JSON schemas, constructs a hierarchical scene graph of layers and shapes, and drives a frame-based animation loop using Android's Canvas API. It supports two primary integration points: a traditional View-based API (LottieAnimationView) for XML layouts and a Jetpack Compose API (LottieAnimation) for modern declarative UIs. The system handles complex rendering features including masks, mattes, gradients, text, and dynamic property overrides at runtime. Architecturally, the project is a multi-module Gradle build consisting of a core library (lottie), a Compose integration module (lottie-compose), and extensive testing/sampling infrastructure. The core logic relies on a custom JSON parser (JsonReader) to deserialize animation data into model objects (LottieComposition), which are then rendered by LottieDrawable or LottiePainter. The architecture emphasizes performance through offscreen rendering strategies (OffscreenLayer) and memory management via bitmap pooling. It also implements a robust caching system (LottieCompositionCache) and async loading mechanisms (LottieCompositionFactory) to handle network and asset sources efficiently. The codebase demonstrates high craftsmanship in its rendering engine, particularly in handling edge cases like 3D rotations, blend modes, and text rendering across different Android API levels. It maintains parity between View and Compose implementations, ensuring consistent behavior across UI paradigms. The testing strategy is rigorous, utilizing snapshot testing (snapshot-tests) to verify visual fidelity across various hardware configurations and API levels, preventing visual regressions in the complex rendering logic.

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