🌍 Geokit

Geokit is a powerful, type-safe geospatial toolkit for Kotlin Multiplatform. It brings a "Turf-like" experience to the Kotlin ecosystem, providing comprehensive utilities for coordinate math, GeoJSON handling, GML/WFS parsing, and WKT-CRS transformations.

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🚀 Key Features

• 📐 Turf-like Math: Geometric calculations, distance measurements, and vector operations.
• 🔥 Fire Weather Index: Hourly FWI calculations (FFMC, DMC, DC, ISI, BUI, FWI) with strict parity to NRCan/CFS reference implementation.
• 🌐 Multi-module Design: Only use what you need (calculation, geojson, ogc, coordinates, fwi).
• 🛠️ CRS Transformations: Parse WKT-CRS and perform coordinate conversions (e.g., EPSG:4326 to EPSG:25832).
• 📦 GeoJSON & GML: First-class support for industry-standard formats via kotlinx.serialization.
• 🏗️ Kotlin Multiplatform: Targets JVM, Android, JS, WasmJS, iOS, and Linux.

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📦 Modules

1. calculation

Core vector-based coordinate math. Uses a type-safe units library for measurements.

val point1 = Vertex(50.96, 10.99)
val point2 = Vertex(51.00, 11.05)

// Type-safe distance and bearing
val dist: Measure<Length> = point1 distanceTo point2
val bearing: Measure<Angle> = point1 angleTo point2

// Point-in-polygon check
val isInside = vertex inside shape

2. coordinates

WKT-CRS parser and transformation pipeline. Supports complex coordinate operations.

val registry = CrsRegistry()
registry.ingest(BuiltInCoordinateReferenceSystems.EPSG4326)
registry.ingest(BuiltInCoordinateReferenceSystems.EPSG25832)

val pipeline = registry.compose(
    source = LocalCoordinate(50.963841, 10.998273),
    fromEPSG = "EPSG:4326",
    toEPSG = "EPSG:25832"
)

val result = pipeline.execute() // Northing/Easting

3. geojson

GeoJSON implementation based on kotlinx.serialization. Provides interop with MapLibre SpatialK.

val position = Position(longitude = 10.99, latitude = 50.96)
val vertex = position.toVertex() // Convert to Geokit Vertex for math

4. ogc

GML and WFS (Web Feature Service) implementation. Handles XML parsing and generation for OGC services.

5. interop

The "glue" module that maps between GeoJSON models and OGC/GML types.

6. fwi

Hourly Fire Weather Index (FWI) system. A strict Kotlin Multiplatform port of the NRCan/CFS Python reference (NG_FWI.py).

val weatherStream = listOf(
    WeatherRow.Input(
        id = "STATION1",
        date = LocalDate(2023, 7, 1),
        hr = 12,
        temp = 25.5,
        rh = 40.0,
        ws = 15.0,
        prec = 0.0,
        lat = 45.0,
        long = -75.0,
        timezone = -5.0
    )
)

val processed = FireWeatherIndex(weatherStream)
val result = processed.first()

println("FWI: ${result.fwi}")
println("FFMC: ${result.ffmc}")

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🛠 Installation

Add the following to your build.gradle.kts:

repositories {
    mavenCentral()
    // Add your registry if needed
}

dependencies {
    implementation("cloud.mallne.geokit:calculation:1.0.0-SNAPSHOT")
    implementation("cloud.mallne.geokit:geojson:1.0.0-SNAPSHOT")
    implementation("cloud.mallne.geokit:fwi:1.0.0-SNAPSHOT")
    // ... other modules
}

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🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request or open an issue.

📄 License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.