GroundImage

GroundImage places a UIImage over a geographic rectangle.

Use ground images for fixed geographic overlays such as floor plans, historical maps, diagrams, or custom raster annotations. The image is positioned by GeoRectBounds.

let bounds = GeoRectBounds(
    southWest: GeoPoint(latitude: 35.67, longitude: 139.74),
    northEast: GeoPoint(latitude: 35.69, longitude: 139.76)
)

GroundImage(
    bounds: bounds,
    image: UIImage(named: "overlay")!,
    opacity: 0.7,
    tileSize: 512,
    onClick: { event in
        print("Ground image clicked: \(String(describing: event.clicked))")
    }
)

Initializer

GroundImage(
    bounds: GeoRectBounds,
    image: UIImage,
    opacity: Double = 1.0,
    tileSize: Int = 512,
    id: String? = nil,
    extra: Any? = nil,
    onClick: OnGroundImageEventHandler? = nil
)

Updating State

let state = GroundImageState(bounds: bounds, image: image, opacity: 0.5)

GroundImage(state: state)

state.opacity = 1.0
state.bounds = updatedBounds

Opacity and Updates

GroundImageState exposes opacity, so you can fade an image in or out without replacing the overlay:

state.opacity = 0.35

When the underlying image changes, update state.image. When the geographic extent changes, update state.bounds.

Interaction

Use onClick when the overlay should be selectable:

GroundImage(
    bounds: bounds,
    image: image,
    onClick: { event in
        print("Clicked image: \(event.state.id)")
    }
)

Provider support for image overlays can differ. Test the provider modules you ship with the image sizes and opacity values your app will use.