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Overview

Open Mobile Maps uses coordinate objects to represent positions, rectangles, and polygons in various coordinate systems. Understanding these types is essential for working with map positioning and geometry.

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Coord

Represents a single point in a specific coordinate system.

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Constructor

Coord(
    systemIdentifier: CoordinateSystemIdentifier,
    x: Double,
    y: Double,
    z: Double
)
​
systemIdentifier
CoordinateSystemIdentifier
required
The coordinate system identifier (e.g., EPSG 4326, EPSG 3857)
​
x
Double
required
The x-coordinate (longitude in geographic systems)
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y
Double
required
The y-coordinate (latitude in geographic systems)
​
z
Double
required
The z-coordinate (elevation/height, typically 0.0)

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Examples

EPSG 4326 (WGS84 - Latitude/Longitude): 
val coordinate = Coord(
    CoordinateSystemIdentifiers.EPSG4326(),
    8.378232525377973,  // longitude
    46.962592372639634, // latitude
    0.0                 // elevation
)
EPSG 3857 (Web Mercator): 
val coordinate = Coord(
    CoordinateSystemIdentifiers.EPSG3857(),
    932445.23,  // x in meters
    5879564.87, // y in meters
    0.0
)

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RectCoord

Represents a rectangular area defined by two corner coordinates.

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Constructor

RectCoord(
    topLeft: Coord,
    bottomRight: Coord
)
​
topLeft
Coord
required
The top-left corner coordinate
​
bottomRight
Coord
required
The bottom-right corner coordinate

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Example

val epsg3857Bounds = RectCoord(
    Coord(
        CoordinateSystemIdentifiers.EPSG3857(),
        -20037508.34,  // left
        20037508.34,   // top
        0.0
    ),
    Coord(
        CoordinateSystemIdentifiers.EPSG3857(),
        20037508.34,   // right
        -20037508.34,  // bottom
        0.0
    )
)
Both coordinates in a RectCoord must use the same coordinate system.

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PolygonCoord

Represents a polygon with an outer boundary and optional holes.

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Constructor

PolygonCoord(
    positions: List<Coord>,
    holes: List<List<Coord>>
)
​
positions
List<Coord>
required
List of coordinates defining the outer boundary of the polygon
​
holes
List<List<Coord>>
required
List of coordinate lists, each defining a hole in the polygon

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Example

Simple Polygon (No Holes): 
val polygonCoord = PolygonCoord(
    positions = listOf(
        Coord(CoordinateSystemIdentifiers.EPSG4326(), 8.0, 47.0, 0.0),
        Coord(CoordinateSystemIdentifiers.EPSG4326(), 9.0, 47.0, 0.0),
        Coord(CoordinateSystemIdentifiers.EPSG4326(), 9.0, 46.0, 0.0),
        Coord(CoordinateSystemIdentifiers.EPSG4326(), 8.0, 46.0, 0.0),
        Coord(CoordinateSystemIdentifiers.EPSG4326(), 8.0, 47.0, 0.0) // Close the polygon
    ),
    holes = emptyList()
)
Polygon with Hole: 
val polygonWithHole = PolygonCoord(
    positions = listOf(
        // Outer boundary
        Coord(CoordinateSystemIdentifiers.EPSG4326(), 8.0, 47.0, 0.0),
        Coord(CoordinateSystemIdentifiers.EPSG4326(), 9.0, 47.0, 0.0),
        Coord(CoordinateSystemIdentifiers.EPSG4326(), 9.0, 46.0, 0.0),
        Coord(CoordinateSystemIdentifiers.EPSG4326(), 8.0, 46.0, 0.0),
        Coord(CoordinateSystemIdentifiers.EPSG4326(), 8.0, 47.0, 0.0)
    ),
    holes = listOf(
        // Hole
        listOf(
            Coord(CoordinateSystemIdentifiers.EPSG4326(), 8.3, 46.7, 0.0),
            Coord(CoordinateSystemIdentifiers.EPSG4326(), 8.7, 46.7, 0.0),
            Coord(CoordinateSystemIdentifiers.EPSG4326(), 8.7, 46.3, 0.0),
            Coord(CoordinateSystemIdentifiers.EPSG4326(), 8.3, 46.3, 0.0),
            Coord(CoordinateSystemIdentifiers.EPSG4326(), 8.3, 46.7, 0.0)
        )
    )
)

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Coordinate System Identifiers

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CoordinateSystemIdentifiers

Provides standard coordinate system identifiers. EPSG 4326 (WGS84): 
CoordinateSystemIdentifiers.EPSG4326()
Standard latitude/longitude coordinates used by GPS. EPSG 3857 (Web Mercator): 
CoordinateSystemIdentifiers.EPSG3857()
Projected coordinate system used by most web mapping services (Google Maps, OpenStreetMap).

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CoordinateSystemFactory

Creates coordinate system objects for use in MapConfig. 
val coordinateSystem = CoordinateSystemFactory.getEpsg3857System()
Example in MapView setup: 
mapView.setupMap(MapConfig(CoordinateSystemFactory.getEpsg3857System()))

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Usage in Layers

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Icon Layer

val icon = IconFactory.createIcon(
    identifier = "marker",
    coordinate = Coord(
        CoordinateSystemIdentifiers.EPSG4326(),
        8.378232,
        46.962592,
        0.0
    ),
    texture = texture,
    iconSize = Vec2F(32.0f, 32.0f),
    scaleType = IconType.INVARIANT,
    blendMode = BlendMode.NORMAL
)

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Polygon Layer

val polygon = PolygonInfo(
    identifier = "area",
    coordinates = PolygonCoord(
        positions = listOf(/* coords */),
        holes = listOf(/* hole coords */)
    ),
    color = Color(1.0f, 0.0f, 0.0f, 0.5f),
    highlightColor = Color(1.0f, 0.4f, 0.4f, 0.7f)
)

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Line Layer

val line = LineFactory.createLine(
    identifier = "route",
    coordinates = listOf(
        Coord(CoordinateSystemIdentifiers.EPSG4326(), 8.0, 47.0, 0.0),
        Coord(CoordinateSystemIdentifiers.EPSG4326(), 9.0, 47.0, 0.0),
        Coord(CoordinateSystemIdentifiers.EPSG4326(), 9.0, 46.0, 0.0)
    ),
    style = lineStyle
)

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