Expo Spatial Layer Showcase 🌍⚡

A professional-grade demonstration of the Expo Spatial Layer Engine, a high-performance native library for rendering and interacting with massive geospatial datasets in React Native.

🚀 The Mission

Visualizing millions of points on a mobile map without lag or synchronization issues is a major challenge. This project showcases a solution that combines a C++ QuadTree Engine with Google Maps Native Tiles to achieve desktop-class performance on mobile devices.

✨ Key Features

• 1,000,000+ Points: Smoothly handle massive datasets with sub-millisecond query times.
• QuadTree Spatial Indexing: $O(\log n)$ performance for rendering and picking.
• Zero-Latency Interaction: Instant point selection through JSI-bridged C++ logic.
• Agnostic Styling: Configure point colors and categories dynamically from JavaScript.
• Binary Zero-Copy: Direct Float32Array transfer to native memory for instant loading.

🏗️ Repository Structure

• modules/expo-spatial-layer/: The core high-performance engine.
• app/spatial-test.tsx: Industrial-grade demo showing picking, memory monitoring, and dynamic styles.
• convert_csv.py: Utility to transform raw CSV/Parquet data into efficient binary format.

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📦 Getting Started

1. Prerequisites

• Node.js & npm/yarn
• Android Studio/SDK (for Android builds)
• Python 3 (for data conversion)

2. Prepare Data

The app uses a binary format for extreme speed. Convert the sample taxi data:

python3 convert_csv.py

This generates taxi-data.bin in the assets/ folder.

3. Run the Showcase (coming soon to NPM)

npm install
npx expo run:android

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📖 In-Depth Documentation

For advanced technical details, check the internal module docs:

• Technical Architecture - How JSI and QuadTree work.
• API Reference - Props and methods for the engine.

🗺️ Roadmap

Check our ROADMAP.md for future plans including iOS support, clustering, and heatmaps.

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Built with ❤️ by the Geospatial Community.