GEOK

Small geometry library for Java and Kotlin. Contains useful basic utilities that require on most application. Designed to support data exchange between client (such as Android) and Restful api server with GeoJSON Spec

Download

def geokVersion = '1.2.0' //see download badge or latest released tag

repositories {
  mavenCentral()
}

// For multiplatform projects
kotlin {
  sourceSets {
    commonMain {
      dependencies {
        implementation "io.github.piruin:geok:$geokVersion"
      }
    }
  }
}

dependencies {
  // For JVM or JS
  implementation "io.github.piruin:geok:$geokVersion"
  // For JVM only
  implementation "io.github.piruin:geok-gson:$geokVersion" // for work with `gson` library
}

def geokVersion = '1.2.0' //see download badge or latest released tag

repositories {
  maven { url 'https://jitpack.io' }
}

// For multiplatform projects
kotlin {
  sourceSets {
    commonMain {
      dependencies {
        implementation "com.github.piruin.geok:geok:$geokVersion"
      }
    }
  }
}

dependencies {
  // For JVM or JS
  implementation "com.github.piruin.geok:geok:$geokVersion"
  // For JVM only
  implementation "com.github.piruin.geok:geok-gson:$geokVersion" // for work with `gson` library
}

Usage

LatLng

LatLng is base class of this library to build up any Geometry you want. It come with utilities such as

• toUtm() -- convert to Utm type that widely use on GPS handheld system (also support create Latlng form Utm)
• distanceTo(latlng: LatLng) -- calculate distance between 2 Latlng in meter

Geometry

List of Supported Geometry type

• Point
• LineString
• Polygon
• MultiPoint
• MultiLineString
• MultiPolygon

Point

  val point = Point(100.0 to 0.0)

• distanceTo(latlng: Point) -- calculate distance between 2 Point in meter
• insideOf(polygon: Polygon) -- Determines whether this LatLng are inside of given Polygon.

LineString

  val lineString = LineString(
      100.0 to 0.0,
      101.0 to 1.0
  )

LineString come with

• distance -- calculate distance of LineString in meter

Polygon

    val polygon = Polygon(
            LatLng(16.4268129901041, 102.8380009059),
            LatLng(16.4266819930293, 102.8379568936),
            LatLng(16.4267047695460, 102.8378494011),
            LatLng(16.4268502721458, 102.8378330329),
            LatLng(16.4268937418855, 102.8378020293),
            LatLng(16.4268129901041, 102.8380009059)
    )

Polygon come with utilities such as

• area -- calculate area of polygon in sq.meter
• centroid -- calculate centroid point of Polygon
• perimeter -- calculate perimeter of Polygon's boundary in meter
• contains(latlng: LatLng) -- check whether latlng is in bound of polygon
• intersactionWith(other: Polygon) -- get intersection with other polygon

Object creation support both LatLng styles and pair of X, Y value

BBox

Every geometry except Point automatically generate BBox on create instance. You can also create your BBox's instance with

  val bbox = BBox.from(listOf<LatLng>())

GeoJson

All Geometry of GEOK is designed to fully support GeoJSON, You can easily use Gson to serialize/deserialize them with geok-gson module

  private val gson: Gson = GsonBuilder()
            .registerGeokTypeAdapter() // call this
            .create()

Feature

Follow GeoJSON specification, You can use Feature to contain extra properties along with Geometry data.

 val feature = Feature(Polygon(
                100.0 to 0.0,
                101.0 to 0.0,
                101.0 to 1.0,
                100.0 to 1.0,
                100.0 to 0.0), Properties())

And you may pack many Feature together with FeatureCollection

License

Copyright (c) 2018-2021 Piruin Panichphol

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

Notice

• Convert Between Geographic and UTM Coordinates by Professor Steven Dutch
• Intersection of Convex Polygons Algorithm by Sinan Oz