39 lines
1.2 KiB
Kotlin
39 lines
1.2 KiB
Kotlin
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package centre.sciprog.maps.compose
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/**
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* Observable position on the map
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*/
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data class MapViewPoint(
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val focus: GeodeticMapCoordinates,
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val zoom: Double,
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) {
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val scaleFactor by lazy { WebMercatorProjection.scaleFactor(zoom) }
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}
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fun MapViewPoint.move(deltaX: Float, deltaY: Float): MapViewPoint {
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val newCoordinates = GeodeticMapCoordinates.ofRadians(
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(focus.latitude + deltaY / scaleFactor).coerceIn(
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-MercatorProjection.MAXIMUM_LATITUDE,
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MercatorProjection.MAXIMUM_LATITUDE
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),
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focus.longitude + deltaX / scaleFactor
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)
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return MapViewPoint(newCoordinates, zoom)
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}
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fun MapViewPoint.move(delta: GeodeticMapCoordinates): MapViewPoint {
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val newCoordinates = GeodeticMapCoordinates.ofRadians(
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(focus.latitude + delta.latitude).coerceIn(
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-MercatorProjection.MAXIMUM_LATITUDE,
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MercatorProjection.MAXIMUM_LATITUDE
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),
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focus.longitude + delta.longitude
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)
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return MapViewPoint(newCoordinates, zoom)
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}
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fun MapViewPoint.zoom(zoomDelta: Double): MapViewPoint {
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return copy(zoom = (zoom + zoomDelta).coerceIn(1.0, 18.0))
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}
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fun MapViewPoint.toMercator() = WebMercatorProjection.toMercator(focus, zoom)
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