Interface ICoverageSource

Namespace

EncDotNet.S100.Pipelines.Coverage

Assembly

EncDotNet.S100.Core.dll

Read access to a gridded (regular-grid) coverage dataset for consumption by CoveragePipeline. Product adapters (S-102 bathymetry, S-104 water level, S-111 surface currents) implement this interface over their decoded HDF5 content.

public interface ICoverageSource

Remarks

A source is stateful: SelectTime(DateTime) and SelectOverviewLevel(int) change what subsequent Metadata reads and Sample(GridRegion, CancellationToken) calls return. Implementations are not required to be thread-safe; callers that share a source must serialise the select-then-sample sequence.

Grid geometry is expressed in the grid's native CRS (HorizontalCRS), which may be a projected system such as UTM rather than WGS-84.

Properties

AvailableOverviewLevels

The overview levels this source can serve, in increasing order. Level 0 is always the native (base) grid; higher levels are downsampled (level N = 2^N × coarser per axis). Sources without an overview pyramid return a single-element list describing the base grid.

IReadOnlyList<CoverageOverviewLevel> AvailableOverviewLevels { get; }

Property Value

IReadOnlyList<CoverageOverviewLevel>

AvailableTimes

The time steps this coverage can be sampled at, in the order the dataset stores them. Empty for static products (S-102); populated for time-varying products (S-104, S-111).

IReadOnlyList<DateTime> AvailableTimes { get; }

Property Value

IReadOnlyList<DateTime>

Metadata

File-level metadata: extent, grid geometry, CRS, no-data sentinel and the value fields the source carries. Available immediately after the source is constructed.

CoverageMetadata Metadata { get; }

Property Value

CoverageMetadata

Remarks

Implementations may build a new instance on every read. The GridMetadata reflects the currently selected overview level (see SelectOverviewLevel(int)).

SelectedOverviewLevel

The level index currently selected by SelectOverviewLevel(int). Defaults to 0 (base grid).

int SelectedOverviewLevel { get; }

Property Value

int

Methods

Sample(GridRegion, CancellationToken)

Copies the requested grid region into a SampledCoverage. The underlying grid is already resident in memory (the HDF5 read happens at construction time), so this is a CPU-bound copy rather than an I/O operation; cancellationToken lets a large copy be abandoned cooperatively. The method remains synchronous.

SampledCoverage Sample(GridRegion region, CancellationToken cancellationToken = default)

Parameters

region GridRegion

The grid subset and stride to sample.

cancellationToken CancellationToken

Signals that the render has been cancelled.

Returns

SampledCoverage

The sampled values for every field in ValueFields, at the currently selected time step and overview level. The result's Metadata describes the geometry of the sampled sub-grid itself (output row/column count, origin and spacing in the native CRS), so GetPosition(int, int) locates each output cell. How cells skipped by a stride greater than one are combined (plain decimation or a reduction such as S-102's shoalest-depth minimum) is source-specific. An empty region yields a zero-cell sample.

Exceptions

OperationCanceledException

cancellationToken was cancelled during the copy.

SelectOverviewLevel(int)

Selects the overview level to serve on subsequent Metadata reads and Sample(GridRegion, CancellationToken) calls. After the call, Metadata's GridMetadata reflects the level's rows/cols/spacing so viewport-derived GridRegions pick up the correct geometry automatically. Sources without a pyramid must accept level == 0 as a no-op; other values may throw or be silently clamped (see the source's documentation).

void SelectOverviewLevel(int level)

Parameters

level int

Zero-based level index, expected to be in [0, AvailableOverviewLevels.Count - 1].

SelectTime(DateTime)

Selects the time step served by subsequent Sample(GridRegion, CancellationToken) calls.

void SelectTime(DateTime time)

Parameters

time DateTime

The requested time. Time-varying sources select the exact match in AvailableTimes when present, otherwise the nearest available time step. Static sources treat the call as a no-op.