com.visioglobe.libVisioDevKit

Class VgPositionToolbox

java.lang.Object

com.visioglobe.libVisioDevKit.VgPositionToolbox

public class VgPositionToolbox
extends java.lang.Object

Provides various utility methods for VgEngine::VgPosition

Constructor Summary

Constructors

Constructor and Description
VgPositionToolbox(VgIEngine pEngine)

Method Summary

Methods

Modifier and Type	Method and Description
double	computeDistance(VgPositionVector pPositions) Computes the distance in meters from an ordered sequence of positions.
double	computeDistance(VgPosition pPos1, VgPosition pPos2) Computes the distance in meters between two positions.
double	computeHeadingAngle(VgPosition pPosPivot, VgPosition pPos1, VgPosition pPos2) Computes the heading angle, in degrees, between Pos1-Pivot and Pos2-Pivot.
VgPosition	computeMiddlePoint(VgPosition pPos1, VgPosition pPos2) Computes the middle point of two positions.
double	computePitchAngle(VgPosition pPosPivot, VgPosition pPos1, VgPosition pPos2) Computes the pitch angle, in degrees, between Pos1-Pivot and Pos2-Pivot.
void	convert(VgPosition pPos, VgSRSConstRefPtr pSRS) Utility method to convert a position to a given SRS.
void	delete()
VgSRSRefPtr	editGeoReferencedSRS() Returns the engine's main georeferenced SRS.
VgSRSRefPtr	editSceneSRS() Returns the scene's metric SRS.
void	geoConvert(VgPosition pPos, VgSRSConstRefPtr pSRS) Utility method to convert a position to a given SRS with geographic coherence.
VgSRSConstRefPtr	getGeoReferencedSRS() Returns the engine's main georeferenced SRS.
VgSRSConstRefPtr	getSceneSRS() Returns the scene's metric SRS.
VgPosition	offsetPosition(VgPosition pPosition, double pHeadingInDegrees, double pPitchInDegrees, double pDistanceInMeters) Offsets a position with a distance in meters given a direction.
VgPositionVector	simplifyLineForWidth(VgPositionVector pPositions, double pWidth) Utility to simplify a line (vector of positions) such that the resulting line is simpler and its turn's radius is wider than half the width.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

VgPositionToolbox

public VgPositionToolbox(VgIEngine pEngine)

Method Detail

delete

public void delete()

computeDistance

public double computeDistance(VgPositionVector pPositions)

Computes the distance in meters from an ordered sequence of positions.

Parameters:

pPositions - An ordered sequence of positions.

Returns:

The total distance in meters. 0.0 if the parameter pPositions contains 0 or 1 elements. NaN if an error occurs.

Remark:

Computes a cartesian distance, not geodesic.

computeDistance

public double computeDistance(VgPosition pPos1,
                     VgPosition pPos2)

Computes the distance in meters between two positions.

Parameters:

pPos1 - Position one

pPos2 - Position two

Returns:

The distance in meters. NaN if an error occurs.

Remark:

it computes a cartesian distance, not geodesic.

computeHeadingAngle

public double computeHeadingAngle(VgPosition pPosPivot,
                         VgPosition pPos1,
                         VgPosition pPos2)

Computes the heading angle, in degrees, between Pos1-Pivot and Pos2-Pivot.

Parameters:

pPosPivot - Pivot Position

pPos1 - Position one

pPos2 - Position two

Returns:

Heading angle in degrees [0,360] (0 for north, increasing in value starting from the east). If at least two positions are equal, the result is undefined. NaN if an error occurs.

computePitchAngle

public double computePitchAngle(VgPosition pPosPivot,
                       VgPosition pPos1,
                       VgPosition pPos2)

Computes the pitch angle, in degrees, between Pos1-Pivot and Pos2-Pivot.

Parameters:

pPosPivot - Pivot Position

pPos1 - Position 1

pPos2 - Position 2

Returns:

Pitch angle in degrees [-90,90] (0 to look "forward" towards the horizon, negative values look down). NaN if an error occurs.

computeMiddlePoint

public VgPosition computeMiddlePoint(VgPosition pPos1,
                            VgPosition pPos2)

Computes the middle point of two positions. The positions will be converted to scene SRS with geographic coherence before computing. The result position will be expressed in the georeferenced SRS.

Parameters:

pPos1 - The first position.

pPos2 - The second position.

Returns:

The middle point's position in the georeferenced SRS.

offsetPosition

public VgPosition offsetPosition(VgPosition pPosition,
                        double pHeadingInDegrees,
                        double pPitchInDegrees,
                        double pDistanceInMeters)

Offsets a position with a distance in meters given a direction.

Parameters:

pPosition - Start position

pHeadingInDegrees - Heading in degrees [0,360] (0 for north, increasing value start to east).

pPitchInDegrees - Pitch in degrees [-90,90] (0 to look "forward" towards the horizon, negative values to look down)

pDistanceInMeters - Distance in meters

Returns:

Offset position. If an error occurs, all components of the position are set to NaN.

editGeoReferencedSRS

public VgSRSRefPtr editGeoReferencedSRS()

Returns the engine's main georeferenced SRS.

getGeoReferencedSRS

public VgSRSConstRefPtr getGeoReferencedSRS()

Returns the engine's main georeferenced SRS.

editSceneSRS

public VgSRSRefPtr editSceneSRS()

Returns the scene's metric SRS.

getSceneSRS

public VgSRSConstRefPtr getSceneSRS()

Returns the scene's metric SRS.

convert

public void convert(VgPosition pPos,
           VgSRSConstRefPtr pSRS)

Utility method to convert a position to a given SRS.

Parameters:

pPos - The position to convert.

pSRS - The spatial reference system in which to convert the position. If NULL it is assumed that WGS84 is wanted.

Note:

No conversion will take place if the Geograhpical SRS hasn't been initialised. The Geograhpical SRS is initialised as a result of calling the VgIDatabase::selectDataset() method.

geoConvert

public void geoConvert(VgPosition pPos,
              VgSRSConstRefPtr pSRS)

Utility method to convert a position to a given SRS with geographic coherence.

Parameters:

pPos - The position to convert.

pSRS - The spatial reference system in which to convert the position. If NULL it is assumed that WGS84 is wanted.

simplifyLineForWidth

public VgPositionVector simplifyLineForWidth(VgPositionVector pPositions,
                                    double pWidth)

Utility to simplify a line (vector of positions) such that the resulting line is simpler and its turn's radius is wider than half the width. This function for advanced users is used for computing positions and subsequently creating lines to be seen at different distances.

Parameters:

pPositions - input vector of positions

pWidth - The width of the line that is to be simplified. The larger the width, the greater the simplifiction of the line's position vector.

Returns:

new positions vector with less or equal number of points.