MapPackageDataSet Class
A dataset that reads data from an OGC GeoPackage, a Carmenta Engine Map Package or an MBTiles raster file.
NuGet/Assembly: Carmenta.Engine.5.16.2.nupkg (in the CEDataSets assembly)
Syntax
public class MapPackageDataSet : FileDataSet,
ISearchableRemarks
A MapPackageDataSet can read data from an OGC GeoPackage file.
GeoPackages are standalone files that contain one or more sets of data, prepared for specific coordinate reference systems, as well as the indexes that are necessary to quickly access the data. This makes them very easy to deploy, especially to devices where you want to avoid generating indexes due to performance reasons or battery drain.
OGC GeoPackage files use the .gpkg file extension. They can contain:
Tiled, multi-resolution image rasters - so called image pyramids.
Tiled vector data. Currently Mapbox Vector Tiles (MVT) is the only format of this kind that is supported.
Tiled coverage rasters, for example elevation data - so called coverage pyramids.
Vector features.
Mapbox Vector Tiles for geopackages is only supported at an experimental level because the extension has not yet been adopted by the OGC as of the time of writing.
Carmenta Engine can read both vector, image and coverage data that conform to the mandatory core capabilities defined in version 1.2.1 of the OGC GeoPackage Encoding Standard. Carmenta Engine will also automatically make use of spatial indexes that have been defined for vector data according to the gpkg_rtree_index extension as described in the OGC GeoPackage Encoding Standard. Other GeoPackage extensions used and supported by Carmenta Engine include the extensions WKT for Coordinate Reference Systems, Tiled Gridded Coverage Data and Zoom Other Intervals.
MapPackageDataSet can also read some other data formats similar to OGC GeoPackage:
Data in the legacy Carmenta Engine Map Package format, which predates the OGC GeoPackage specification. Such files use the .mpx file extension.
MBTiles raster files, using the .mbtiles file extension. Note that files with this file extension can also contain MVT data. While MapPackageDataSet has experimental support to read MVT data from files with the .gpkg file extension, such data in .mbtiles files can only be read by MvtDataSet.
Configuring a MapPackageDataSet
Configuring a MapPackageDataSet to read data from an OGC GeoPackage or Carmenta Engine Map Package is easy since the file format contains everything in one single file. You only need to specify which file and which set of data in that file to read, which is done through the TableName property. For an MBTiles raster file, no table needs to be specified.
Writing data to an OGC GeoPackage
You can use the MapPackage class to write data to a GeoPackage. The GeoPackage Tutorial describes how you can use Carmenta Studio and Carmenta Explorer to create a GeoPackage.
Inheritance Hierarchy
System.Object (not available in C#)
EngineObject
ResourceObject
DataSet
FileDataSet
MapPackageDataSet
Platforms
Windows, Linux, Android
MapPackageDataSet Members
The MapPackageDataSet type has the following members.
Constructors
| Name | Description |
|---|---|
| MapPackageDataSet | Initializes a new instance of the MapPackageDataSet class. |
Properties
| Name | Description |
|---|---|
| Continuous | Gets or sets a flag indicating whether rasters created by this dataset should be interpreted as being continuous or discrete. |
| Crs | Gets or sets the coordinate reference system of the MapPackageDataSet. Inherited from DataSet |
| Description | Gets or sets a short description of the dataset. Inherited from DataSet |
| DisplayName | Gets or sets a display name for the dataset. Inherited from DataSet |
| FileName | Gets or sets the name of the file to read from. Inherited from FileDataSet |
| ISearchable.HasSearchIndex | Gets a value that tells whether a dataset has a search index. Inherited from ISearchable |
| Id | Gets a unique identifier for this dataset instance. Inherited from DataSet |
| IndexFileName | Gets or sets an explicit index file name used for the generated index files in IndexPath. |
| IndexPath | Gets or sets the directory where the dataset index files are saved. |
| IsDisposed | Gets a value that tells whether the current MapPackageDataSet has been disposed. Inherited from EngineObject |
| IsoMetadataDocument | Gets or sets the path to an ISO 19139 metadata document for the dataset. Inherited from DataSet |
| Name | Gets or sets the name of the MapPackageDataSet. Inherited from ResourceObject |
| NativeHandle | Gets the native Carmenta Engine kernel object the current MapPackageDataSet represents. Inherited from EngineObject |
| Path | Gets or sets the path to the file or files to read from. Inherited from FileDataSet |
| RasterFilter | Gets or sets the filter that will be used by the RasterVisualizer attached to rasters created by the dataset. |
| SearchableAttributes | The attributes that will be used to create a search index for the dataset. |
| SearchableCondition | Gets or sets a condition that determines which features will be included in the search index for the dataset. |
| SuppressInitializationErrors | Gets or sets a flag indicating how errors during dataset initialization are handled. Inherited from DataSet |
| TableName | Gets or sets the name of the table in the GeoPackage or Map Package file that the dataset will read from. |
| IUserProperties.UserProperties | Gets the AttributeSet that contains the user properties. Inherited from IUserProperties |
Methods
| Name | Description |
|---|---|
| Clone | Creates a copy of an object. Inherited from EngineObject |
| Dispose | Releases the reference to the native Carmenta Engine kernel instance the EngineObject represents. Inherited from EngineObject |
| Equals | Determines whether this instance is equal to another. Inherited from EngineObject |
| FindChildObject | Overloaded. Finds the child object with the specified name. Inherited from DataSet |
| FlushCache | Frees any information the dataset may have cached, including all cached features. Inherited from DataSet |
| GetChildObjects | Overloaded. Gets the child objects of the current object. Inherited from DataSet |
| GetDataCoverage | Gets coverage information for this dataset in a given area. Inherited from DataSet |
 GetDataSetById | Looks up an existing dataset instance from a dataset identity. Inherited from DataSet |
| GetDataSetInfo | Returns a dataset info that describes the contents of this dataset. Inherited from DataSet |
| GetDataSetInfoAsync | Makes an asynchronous call to GetDataSetInfo. Inherited from DataSet |
| GetFeature | Gets the feature with the specified identity. Inherited from DataSet |
| GetFeatures | Overloaded. Gets features from the dataset. Inherited from DataSet |
| GetFloatValueAt | Overloaded. Gets the float raster value from a cell at the specified position. Inherited from DataSet |
| GetFloatValuesAt | Overloaded. Gets a number of float raster values. Inherited from DataSet |
| GetLocalizedDescription | Gets a localized version of the dataset description in a specific language. Inherited from DataSet |
| GetLocalizedDisplayName | Gets a localized version of the dataset display name in a specific language. Inherited from DataSet |
| GetLocalizedIsoMetadataDocument | Gets the path to an ISO 19139 metadata document for a specific language. Inherited from DataSet |
| GetMetadataDocuments | Gets the metadata documents associated with the OGC GeoPackage table. |
| GetNormalizedFloatValueAt | Overloaded. Gets the raster value from a cell at the specified position, normalized by Scale and Offset. Inherited from DataSet |
| GetNormalizedFloatValuesAt | Overloaded. Gets a number of raster values, normalized by Scale and Offset. Inherited from DataSet |
| GetValueAt | Overloaded. Gets the integer value from a raster cell at the specified position. Inherited from DataSet |
| GetValuesAt | Overloaded. Gets a number of raster values. Inherited from DataSet |
| HasLocalizedDescription | Checks if a localized version of the dataset description is available in a specific language. Inherited from DataSet |
| HasLocalizedDisplayName | Checks if a localized version of the dataset display name is available in a specific language. Inherited from DataSet |
| HasLocalizedIsoMetadataDocument | Checks if an ISO 19139 metadata document is available for a specific language. Inherited from DataSet |
| HighestRasterValue | Finds the highest raster value inside the given polygon. Inherited from DataSet |
| Initialize | Initializes the dataset. Inherited from DataSet |
| ISearchable.Search | Overloaded. Searches for features with an attribute whose value match the specified search text. Inherited from ISearchable |
| SetLocalizedDescription | Sets a dataset description in a specific language. Inherited from DataSet |
| SetLocalizedDisplayName | Sets a dataset display name in a specific language. Inherited from DataSet |
| SetLocalizedIsoMetadataDocument | Sets the path to an ISO 19139 metadata document for the dataset, for a specific language. Inherited from DataSet |
| TryGetFloatValueAt | Overloaded. Gets the float value from a raster cell at the specified position. Inherited from DataSet |
| TryGetNormalizedFloatValueAt | Overloaded. Gets the float value from a raster cell at the specified position, normalized by Scale and Offset. Inherited from DataSet |
| TryGetValueAt | Overloaded. Gets the integer value from a raster cell at the specified position. Inherited from DataSet |