common library
Common codes, constants, functions, presentation helpers and reference systems related to geospatial applications.
Features:
- Enums (codes): geospatial coordinate, geometry types, dimensionality, canvas origin, cardinal direction, DMS type, geo representation, axis order.
- Constants: epsilon, geodetic and screen related constants.
- Functions: conversions between radians and degrees, geographic coordinate helpers.
- Presentation: DMS (degree-minutes-seconds geographic representations).
- Reference: Coordinate and temporal reference systems. Reference ellipsoids.
This libary exports a subset of package:geobase/geobase.dart.
Usage: import package:geobase/common.dart
Classes
- CoordRefSys
- Metadata about a coordinate reference system (CRS) identified and specified by id.
- CoordRefSysResolver
- An abstract class for resolving coordinate reference system information.
- Dms
- A default implementation for DmsFormat abstract base class, that defines methods for parsing and formatting degrees/minutes/seconds on latitude, longitude and bearing values.
- DmsFormat
- A base class for formatters with methods for parsing and formatting degrees/minutes/seconds on latitude, longitude and bearing values.
- Ellipsoid
- A reference ellipsoid with ellipsoidal parameters (a, b and f).
- TemporalRefSys
- Metadata about a temporal coordinate reference system (TRS) identified and specified by id.
- TemporalRefSysResolver
- An abstract class for resolving temporal coordinate reference system information.
Enums
- AxisOrder
- The axis order of coordinate values in position and point representations.
- CanvasOrigin
- The position of the origin in a canvas or a grid.
- CardinalPrecision
- The precision for cardinal directions (compass point).
- Coords
- An enum for coordinate types (by spatial dimension and whether is measured).
- Dimensionality
- An enum for dimensionality or topological dimension in the context of geospatial applications.
- DmsType
- An enum for common representation of geographic positions by coordinates (using degrees, minutes and seconds as components).
- Geom
- An enum for geometry types.
- GeoRepresentation
- An enum for spatial representations that can be used to code logic when need to choose some options based on a representation.
Extensions
- DoubleAngleExtension on double
- An extension on double with basic degrees and radians utility methods.
- GeographicDoubleAngleExtension on double
- An extension on double with basic degrees and radians utility methods ( (for geographic coordinate reference systems).
Constants
- defaultEpsilon → const double
-
The default epsilon value
1.0e-9used as a tolerance inequals2D,equals3Dand similar methods in this package. - doublePrecisionEpsilon → const double
- The maximum relative precision of double numbers (IEEE 754).
- earthCircumferenceWgs84 → const double
- The earth circumference in meters (from earth equatorial radius by WGS 84).
- earthRadiusWgs84 → const double
- The earth equatorial radius in meters as specified by WGS 84.
- maxLatitude → const double
- The maximum value for the geographic latitude.
- maxLatitudeWebMercator → const double
- The maximum value for the geographic latitude inside the Web Mercator projection coverage.
- maxLongitude → const double
- The maximum value for the geographic longitude.
- minLatitude → const double
- The minimum value for the geographic latitude.
- minLatitudeWebMercator → const double
- The minimum value for the geographic latitude inside the Web Mercator projection coverage.
- minLongitude → const double
- The minimum value for the geographic longitude.
- screenPPIbyOGC → const double
- OGC defines a screen pixel of 0.28 mm that approximates to 90.7 ppi.