TSLGPkgTilesTable Class Reference

Inheritance diagram for TSLGPkgTilesTable:

Detailed Description

This class encapsulates the information contained within a geopackage tiles table.

It provides the ability to query the tile pyramid levels contained with the tiles table, and to query raster tiles based on extent and resolution.

Public Member Functions
const TSLGPkgPyramidLevel *	getLevel (double zoomLevel) const
const TSLGPkgPyramidLevel *	getLevel (int index) const
const TSLGPkgPyramidLevel *	getLevelWithZoomLevel (int zoomLevel) const
bool	getTileIndices (const double zoomScale, const TSLMUExtent &extent, int &pyramidLevel, TSLCoordSet &tileIndices) const
unsigned int	numberOfDefinedPyramidLevels () const
unsigned int	numberOfPyramidLevelsWithTileData () const
Public Member Functions inherited from TSLGPkgContentTable
const char *	name () const
const char *	description () const
const TSLMUExtent &	getMUExtent () const
const char *	lastChange () const
const char *	identifier () const
const TSLGPkgMetadataContainer *	queryMetadata () const
const TSLCoordinateSystem *	querySpatialReferenceSystem () const
TSLGPkgContentTableTypeEnum	type () const

Member Function Documentation

getLevel() [1/2]

const TSLGPkgPyramidLevel * TSLGPkgTilesTable::getLevel

(

double

zoomLevel

)

const

Query the tile pyramid level that best matches the provided zoom level.

The level is selected based on the pixel height of the pyramid levels.

Parameters

zoomLevel

The ideal pixel height of the layer to return.

Returns

the pyramid level which best matches the provided zoom level, or NULL if an appropriate level could not be selected.

getLevel() [2/2]

const TSLGPkgPyramidLevel * TSLGPkgTilesTable::getLevel

(

int

index

)

const

Query a specific pyramid level.

The number of levels can be queried using the numberOfDefinedLevels method.

Parameters

index

The index of the pyramid level to return.

Returns

the pyramid level for the provided index, or NULL if not found.

getLevelWithZoomLevel()

const TSLGPkgPyramidLevel * TSLGPkgTilesTable::getLevelWithZoomLevel

(

int

zoomLevel

)

const

Query a specific pyramid level.

Returns the Pyramid Level for the Zoom Level passed. The Zoom Level is the value defined in the Tile Matrix Table.

Parameters

zoomLevel

The value of the pyramid Zoom Level to return.

Returns

the pyramid level for the provided zoom level, or NULL if not found.

getTileIndices()

bool TSLGPkgTilesTable::getTileIndices	(	const double	zoomScale,
		const TSLMUExtent &	extent,
		int &	pyramidLevel,
		TSLCoordSet &	tileIndices ) const

Query the indices of raster tiles, base on extent and resolution.

The pyramid level will be selected based on the zoomScale parameter, and the pixel height of each pyramid level. The tile indices will be populated with the offsets(column, row) of each tile, relative to the bottom-left. Empty raster tiles will not be added to the tileIndices parameter.

Parameters

zoomScale	The requested pixel height for the tiles.
extent	The extent to return tiles in. This extent is specified in the units of the tile table's coordinate system.
pyramidLevel	This will be populated with the selected pyramid level index.
tileIndices	This set will be populated with the queried tile indices.

Returns

true if the query was successful, or false otherwise.

numberOfDefinedPyramidLevels()

unsigned int TSLGPkgTilesTable::numberOfDefinedPyramidLevels

(

)

const

Query the number of defined pyramid levels.

This is the number of pyramid levels defined by an entry in the gpkg_tile_ matrix table.

Returns the number of defined pyramid levels.

numberOfPyramidLevelsWithTileData()

unsigned int TSLGPkgTilesTable::numberOfPyramidLevelsWithTileData

(

)

const

Query the number of pyramid levels, which contain data.

This may be different than the number of defined pyramid levels.

Returns the number of pyramid levels, which contain tile data.