TSLTerrainVSInputTerrainDatabase Class Reference

Inheritance diagram for TSLTerrainVSInputTerrainDatabase:

Public Member Functions
	TSLTerrainVSInputTerrainDatabase (TSLTerrainDatabase *database, TSLMUExtent displayExtent, unsigned int displayWidth, unsigned int displayHeight)
virtual bool	getData (unsigned int x, unsigned int y, double &value, const TSLTerrainVSAlgorithm::Parameters &params)
void	displayParameters (TSLMUExtent displayExtent, unsigned int displayWidth, unsigned int displayHeight)
virtual bool	valid (const TSLTerrainVSAlgorithm::Parameters &params) const
void	cacheLimit (unsigned int limit)
virtual void	processFinished ()
virtual const TSLCoordinateSystem *	coordinateSystem ()
Public Member Functions inherited from TSLTerrainVSInput
virtual TSLMUExtent	queryExtent () const
virtual unsigned int	width () const
virtual unsigned int	height () const
void	inc ()
void	dec ()
virtual bool	offsetToLatLong (unsigned int x, unsigned int y, double &lat, double &lon)
virtual bool	offsetToMU (unsigned int x, unsigned int y, double &muX, double &muY)
virtual bool	MUToOffset (double muX, double muY, unsigned int &x, unsigned int &y)
virtual bool	LatLongToOffset (double lat, double lon, unsigned int &x, unsigned int &y)
virtual double	postDistanceX ()
virtual double	postDistanceY ()

Additional Inherited Members
Protected Member Functions inherited from TSLTerrainVSInput
	TSLTerrainVSInput (unsigned int width, unsigned int height, TSLMUExtent extent, TSLCoordinateSystem *coordinateSystem)
	TSLTerrainVSInput ()
	TSLTerrainVSInput (const TSLTerrainVSInput &other)
virtual	~TSLTerrainVSInput ()
Protected Attributes inherited from TSLTerrainVSInput
unsigned int	m_width
unsigned int	m_height
TSLCoordinateSystem *	m_coordinateSystem
double	m_postDistanceX
double	m_postDistanceY
TSLMUExtent	m_extent

Constructor & Destructor Documentation

TSLTerrainVSInputTerrainDatabase()

TSLTerrainVSInputTerrainDatabase::TSLTerrainVSInputTerrainDatabase	(	TSLTerrainDatabase *	database,
		TSLMUExtent	displayExtent,
		unsigned int	displayWidth,
		unsigned int	displayHeight )

Constructor.

Initialises the base parameters of the input object.

The displayExtent, width and height are used to select an appropriate layer, and data resolution from the terrain database.

Parameters

database	The TSLTerrainDatabase to read input data from. The application is responsible for deleting this object.
displayExtent	The extent currently displayed by an application
displayWidth	The width of an application's current display
displayHeight	The height of an application's current display

Member Function Documentation

cacheLimit()

void TSLTerrainVSInputTerrainDatabase::cacheLimit

(

unsigned int

limit

)

Set the maximum size of the cache, in MB.

The initial cache size limit is 64MB.

coordinateSystem()

virtual const TSLCoordinateSystem * TSLTerrainVSInputTerrainDatabase::coordinateSystem ( )

virtual

Query the coordinate system of the input data.

This object must provide a coordinate system in order for viewshed operations, and any height adjustment calculations to be valid.

Reimplemented from TSLTerrainVSInput.

displayParameters()

void TSLTerrainVSInputTerrainDatabase::displayParameters	(	TSLMUExtent	displayExtent,
		unsigned int	displayWidth,
		unsigned int	displayHeight )

Constructor.

Initialises the base parameters of the input object.

The displayExtent, width and height are used to select an appropriate layer, and data resolution from the terrain database.

Parameters

displayExtent	The extent currently displayed by an application
displayWidth	The width of an application's current display
displayHeight	The height of an application's current display

getData()

virtual bool TSLTerrainVSInputTerrainDatabase::getData ( unsigned int x, unsigned int y, double & value, const TSLTerrainVSAlgorithm::Parameters & params )

virtual

Query a height value from the input data.

If the valid() method has returned false, this method will never be called by the viewshed algorithm.

The location given to this method is specified as an offset, from the bottom-left of the data.

This method should set the value parameter to the requested height value, and return true. If there is no height data available for the requested location this method should return false.

Parameters

x	The x offset to query
y	The y offset to query
value	Storage for the height value
params	The parameters of the viewshed operation

Implements TSLTerrainVSInput.

processFinished()

virtual void TSLTerrainVSInputTerrainDatabase::processFinished ( )

virtual

This method will be called by the viewshed algorithm when the viewshed calculation has finished.

This object uses this method to cleanup the per-thread storage used in the caching mechanism.

Implements TSLTerrainVSInput.

valid()

virtual bool TSLTerrainVSInputTerrainDatabase::valid ( const TSLTerrainVSAlgorithm::Parameters & params ) const

virtual

This method will be called by the viewshed algorithm, to provide the input object with a mechanism for initialisation, and an opportunity to terminate the viewshed calculation if required.

The extent provided by params.m_viewShedMUExtent should not be considered valid during this call, as it will not have been fully calculated.

The TSLTerrainVSInputTerrainDatabase object is considered valid if: The provided TSLTerrainDatabase is not empty. The provided TSLTerrainDatabase contains data, for the provided extent.

Parameters

params

The parameters of the viewshed operation.

Returns

true if the input object is valid, or false otherwise.

Implements TSLTerrainVSInput.