RasterPmTilesAsyncLayer¶
Namespace: ThinkGeo.Core
Displays raster PMTiles content by reading tiles directly from a local PMTiles archive.
public class RasterPmTilesAsyncLayer : RasterXyzTileAsyncLayer
Inheritance object → LayerBase → AsyncLayer → XyzTilesAsyncLayer → RasterXyzTileAsyncLayer → RasterPmTilesAsyncLayer
Properties¶
FilePath¶
Gets or sets the path to the PMTiles archive that will be rendered.
public string FilePath { get; set; }
Property Value¶
Header¶
Gets the header of the opened PMTiles archive, or null before the layer is opened.
public PmTilesHeader Header { get; }
Property Value¶
MetadataJson¶
Gets the raw JSON metadata embedded in the PMTiles archive.
public string MetadataJson { get; }
Property Value¶
MaxZoomOfTheData¶
Gets or sets the highest zoom level available from the server or cache.
public int MaxZoomOfTheData { get; set; }
Property Value¶
MinZoomOfTheData¶
Gets or sets the lowest zoom level available from the server or cache.
public int MinZoomOfTheData { get; set; }
Property Value¶
RenderBeyondMinZoom¶
Gets or sets a value indicating whether tiles should be down-sampled beyond RasterXyzTileAsyncLayer.MinZoomOfTheData.
public bool RenderBeyondMinZoom { get; set; }
Property Value¶
UpperScale¶
This property gets and sets the upper threshold in the scale at which to display the image.
public double UpperScale { get; set; }
Property Value¶
double
This property gets the upper threshold in the scale at which to display the image.
Remarks:
Above the upper threshold in scale, the image will not be displayed. This, in conjunction with the LowerThreshold property, allows you to create a band in which it is suitable to display the image source. By default, the upper threshold is double.Max and lower threshold is 0. This means the image should always display.
LowerScale¶
This property gets and sets the lower threshold in the scale at which to display the image.
public double LowerScale { get; set; }
Property Value¶
double
This property gets the lower threshold in the scale at which to display the image.
Remarks:
Below the lower threshold in scale, the image will not be displayed. This, in conjunction with the UpperThreshold property, allows you to create a band in which it is suitable to display the image source. By default, the upper threshold is double.Max and lower threshold is 0. This means the image should always display.
RenderBeyondMaxZoom¶
Gets or sets a value indicating whether tiles should be up-sampled beyond RasterXyzTileAsyncLayer.MaxZoomOfTheData.
public bool RenderBeyondMaxZoom { get; set; }
Property Value¶
TileCache¶
Gets or sets the primary raster tile cache used for storing downloaded tiles.
public RasterTileCache TileCache { get; set; }
Property Value¶
ProjectedTileCache¶
Gets or sets the cache that stores reprojected tiles when a projection converter is in use.
public RasterTileCache ProjectedTileCache { get; set; }
Property Value¶
IsCacheOnly¶
Gets or sets a value indicating whether the layer should read exclusively from cache.
public bool IsCacheOnly { get; set; }
Property Value¶
ProjectionConverter¶
Gets or sets the projection converter used to transform coordinates during rendering.
public ProjectionConverter ProjectionConverter { get; set; }
Property Value¶
TileMatrixSet¶
Gets or sets the tile matrix set describing the XYZ grid.
public TileMatrixSet TileMatrixSet { get; set; }
Property Value¶
TileWidth¶
Gets or sets the TileWidth.
public int TileWidth { get; set; }
Property Value¶
TileHeight¶
Gets or sets the TileHeight.
public int TileHeight { get; set; }
Property Value¶
MaxExtent¶
This is the full extent of the matrix griding the xyz tiles. It's NOT the bounding box of the data itself.
public RectangleShape MaxExtent { get; set; }
Property Value¶
MapUnit¶
Gets or sets the MapUnit.
public GeographyUnit MapUnit { get; set; }
Property Value¶
HasBoundingBox¶
Gets or sets the HasBoundingBox.
public bool HasBoundingBox { get; }
Property Value¶
MaxConcurrentTileLoads¶
Maximum number of tiles whose load operation can be in flight at the same time during a single draw pass. Default is 4.
public int MaxConcurrentTileLoads { get; set; }
Property Value¶
Remarks:
A "load" here covers either a cache lookup, a local file read (e.g. MBTiles SQLite), or, on miss / for remote sources, an outbound HTTP request — the cap applies regardless of source.
Lower the value (down to 1, which restores the pre-14.5 sequential behavior) when the source service or your egress network rate-limits aggressive bursts — common signals are server-only "no images appear" symptoms while local development works, or HTTP 429 / empty responses surfacing in LayerBase.DrawingExceptionMode captures. Raise it for high-throughput tile servers you control or for cache-only scenarios where every load is a local read.
Name¶
Gets or sets the display name for the layer.
public string Name { get; set; }
Property Value¶
string
The name used to identify the layer within UI components such as legends.
Remarks:
The name is user defined. Assign a descriptive value so tooling such as legends and layer lists can surface a meaningful label to end users.
IsOpen¶
Gets a value indicating whether the layer is currently open.
public bool IsOpen { get; }
Property Value¶
bool
true if the layer has completed its open routine; otherwise, false.
Remarks:
This method is the concrete wrapper for the abstract method IsOpenCore. Various methods on the Layer require that it be in an open state. If one of those methods is called when the state is not open, then the method will throw an exception. To enter the open state, you must call the Layer Open method. The method will raise an exception if the current Layer is already open.
As this is a concrete public method that wraps a Core method, we reserve the right to add events and other logic to pre- or post-process data returned by the Core version of the method. In this way, we leave our framework open on our end, but also allow you the developer to extend our logic to suit your needs. If you have questions about this, please contact our support team as we would be happy to work with you on extending our framework.
IsVisible¶
Gets or sets a value indicating whether the layer is visible.
public bool IsVisible { get; set; }
Property Value¶
bool
true to draw the layer; otherwise, false.
Remarks:
If this property is set to false, the layer will not draw. We ensure this in the Draw method. This is useful for legends and other controls that control the visibility of layers.
Projection¶
Gets the projection of the layer.
public Projection Projection { get; set; }
Property Value¶
DrawingExceptionMode¶
Gets or sets how drawing exceptions are handled when the layer renders.
public DrawingExceptionMode DrawingExceptionMode { get; set; }
Property Value¶
Background¶
Gets or sets the background color used when rendering the layer.
public GeoColor Background { get; set; }
Property Value¶
GeoColor
The fill applied to areas not covered by layer content.
Transparency¶
Gets or sets the amount of transparency applied to the rendered image.
public float Transparency { get; set; }
Property Value¶
float
A value between 0 (fully transparent) and 255 (fully opaque).
Opacity¶
Gets or sets the opacity applied to the rendered image.
public float Opacity { get; set; }
Property Value¶
float
A value between 0.0 (fully transparent) and 1.0 (fully opaque).
BlueTranslation¶
Gets or sets the intensity adjustment applied to the blue channel.
public float BlueTranslation { get; set; }
Property Value¶
float
A value between -255 and 255 representing the blue channel translation.
RedTranslation¶
Gets or sets the intensity adjustment applied to the red channel.
public float RedTranslation { get; set; }
Property Value¶
float
A value between -255 and 255 representing the red channel translation.
GreenTranslation¶
Gets or sets the intensity adjustment applied to the green channel.
public float GreenTranslation { get; set; }
Property Value¶
float
A value between -255 and 255 representing the green channel translation.
KeyColors¶
Gets the collection of key colors that should be rendered as transparent.
public Collection<GeoColor> KeyColors { get; }
Property Value¶
Remarks:
Attempting to access this collection when the associated GeoCanvas does not support key colors (see GeoCanvas.SupportKeyColor) results in an exception. Add colors to this collection to ensure they render as transparent.
IsNegative¶
Gets or sets a value indicating whether the image should be rendered with inverted colors.
public bool IsNegative { get; set; }
Property Value¶
bool
true to invert the color channels; otherwise, false.
IsGrayscale¶
Gets or sets a value indicating whether the image should be converted to grayscale prior to rendering.
public bool IsGrayscale { get; set; }
Property Value¶
bool
true to apply a grayscale filter; otherwise, false.
ConcurrentAccess¶
Gets or sets how this layer behaves when more than one thread wants to draw it at once, and what a caller who wants concurrency should therefore do with it.
public ConcurrentAccess ConcurrentAccess { get; set; }
Property Value¶
ConcurrentAccess
unless the layer says otherwise: callers take turns on the one instance, which is what the screen renderer has done with a layer that did not say otherwise since this question was first asked.
Remarks:
A FeatureLayer that is not given a value of its own answers with its FeatureLayer.FeatureSource's, so a layer and the source it reads through cannot disagree about this.
ThreadSafe¶
Gets or sets the threading guarantees provided by the layer implementation.
public ThreadSafetyLevel ThreadSafe { get; set; }
Property Value¶
ThreadSafetyLevel
The level of thread safety that callers can expect when interacting with the layer.
Remarks:
Replaced by LayerBase.ConcurrentAccess and kept only so that code written against it is told, by name, what to use instead. It does not compile, so there is never a question of which of the two a caller meant: there is one value, and it is the other one. That matters because the translation was lossy in one direction - writing ThreadSafetyLevel.Unsafe could only pick ConcurrentAccess.UnsafeLock, and would silently undo a layer or source that had said ConcurrentAccess.UnsafeClone.
ColorMappings¶
Gets the color translation map that will be applied when rendering the layer.
public Dictionary<GeoColor, GeoColor> ColorMappings { get; }
Property Value¶
Dictionary<GeoColor, GeoColor>
WrappingMode¶
Gets or sets how the layer wraps when the map extent crosses world boundaries.
public WrappingMode WrappingMode { get; set; }
Property Value¶
WrappingExtent¶
Gets or sets the geographic extent to use when wrapping is enabled.
public RectangleShape WrappingExtent { get; set; }
Property Value¶
Constructors¶
RasterPmTilesAsyncLayer()¶
Initializes a new instance of the RasterPmTilesAsyncLayer class.
public RasterPmTilesAsyncLayer()
RasterPmTilesAsyncLayer(string)¶
Initializes a new instance of the RasterPmTilesAsyncLayer class using the specified file path.
public RasterPmTilesAsyncLayer(string filePath)
Parameters¶
filePath string
The path to the PMTiles archive to open.
Methods¶
OpenAsyncCore(CancellationToken)¶
Provides the overridable implementation that asynchronously opens the instance and initializes the resources it depends on.
protected Task OpenAsyncCore(CancellationToken cancellationToken)
Parameters¶
cancellationToken CancellationToken
A cancellation or authentication token, depending on context.
Returns¶
Task
A task that represents the asynchronous operation.
GetBoundingBoxCore()¶
Provides the overridable implementation that returns the bounding box that encloses the relevant geometry.
protected RectangleShape GetBoundingBoxCore()
Returns¶
RectangleShape
The result of the operation.
GetTileAsyncCore(int, long, long, float, CancellationToken)¶
Provides the overridable implementation that returns tile async for the specified parameters.
protected Task<RasterTile> GetTileAsyncCore(int zoomLevel, long x, long y, float resolutionFactor, CancellationToken cancellationToken)
Parameters¶
zoomLevel int
The zoom level.
x long
The x-coordinate, in tile columns.
y long
The y-coordinate, in tile rows.
resolutionFactor float
The resolution factor.
cancellationToken CancellationToken
A cancellation or authentication token, depending on context.
Returns¶
Task<RasterTile>
A task that represents the asynchronous operation and provides the result.
CloseAsyncCore(CancellationToken)¶
Provides the overridable implementation that asynchronously closes the instance and releases any resources it holds.
protected Task CloseAsyncCore(CancellationToken cancellationToken)
Parameters¶
cancellationToken CancellationToken
A cancellation or authentication token, depending on context.
Returns¶
Task
A task that represents the asynchronous operation.
Events¶
TileCacheGenerated¶
Occurs each time a tile is generated during the execution of RasterXyzTileAsyncLayer.GenerateTileCacheAsync(RectangleShape, int, int, float, OverwriteMode, TileCacheGenerationOptions, CancellationToken).
public event EventHandler<TileCacheGeneratedXyzTileAsyncLayerEventArgs> TileCacheGenerated;
DrawingException¶
Occurs when the DrawingException event is raised.
public event EventHandler<DrawingExceptionLayerEventArgs> DrawingException;
DrawnException¶
Occurs when the DrawnException event is raised.
public event EventHandler<DrawnExceptionLayerEventArgs> DrawnException;