QGIS API Documentation
2.4.0-Chugiak
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General purpose distance and area calculator. More...
#include <qgsdistancearea.h>
Public Member Functions | |
QgsDistanceArea () | |
Constructor. More... | |
~QgsDistanceArea () | |
Destructor. More... | |
QgsDistanceArea (const QgsDistanceArea &origDA) | |
Copy constructor. More... | |
QgsDistanceArea & | operator= (const QgsDistanceArea &origDA) |
Assignment operator. More... | |
void | setEllipsoidalMode (bool flag) |
sets whether coordinates must be projected to ellipsoid before measuring More... | |
bool | ellipsoidalEnabled () const |
returns projections enabled flag More... | |
void | setSourceCrs (long srsid) |
sets source spatial reference system (by QGIS CRS) More... | |
void | setSourceCrs (const QgsCoordinateReferenceSystem &srcCRS) |
Sets source spatial reference system (by QGIS CRS) More... | |
void | setSourceAuthId (QString authid) |
sets source spatial reference system by authid More... | |
long | sourceCrs () const |
returns source spatial reference system More... | |
bool | geographic () const |
What sort of coordinate system is being used? More... | |
bool | setEllipsoid (const QString &ellipsoid) |
sets ellipsoid by its acronym More... | |
bool | setEllipsoid (double semiMajor, double semiMinor) |
Sets ellipsoid by supplied radii. More... | |
const QString & | ellipsoid () const |
returns ellipsoid's acronym More... | |
double | ellipsoidSemiMajor () const |
returns ellipsoid's semi major axis More... | |
double | ellipsoidSemiMinor () const |
returns ellipsoid's semi minor axis More... | |
double | ellipsoidInverseFlattening () const |
returns ellipsoid's inverse flattening More... | |
double | measure (QgsGeometry *geometry) |
general measurement (line distance or polygon area) More... | |
double | measurePerimeter (QgsGeometry *geometry) |
measures perimeter of polygon More... | |
double | measureLine (const QList< QgsPoint > &points) |
measures line More... | |
double | measureLine (const QgsPoint &p1, const QgsPoint &p2) |
measures line with one segment More... | |
double | measurePolygon (const QList< QgsPoint > &points) |
measures polygon area More... | |
double | bearing (const QgsPoint &p1, const QgsPoint &p2) |
compute bearing - in radians More... | |
void | convertMeasurement (double &measure, QGis::UnitType &measureUnits, QGis::UnitType displayUnits, bool isArea) |
Helper for conversion between physical units. More... | |
Static Public Member Functions | |
static QString | textUnit (double value, int decimals, QGis::UnitType u, bool isArea, bool keepBaseUnit=false) |
Protected Member Functions | |
const unsigned char * | measureLine (const unsigned char *feature, double *area, bool hasZptr=false) |
measures line distance, line points are extracted from WKB More... | |
const unsigned char * | measurePolygon (const unsigned char *feature, double *area, double *perimeter, bool hasZptr=false) |
measures polygon area and perimeter, vertices are extracted from WKB More... | |
double | computeDistanceBearing (const QgsPoint &p1, const QgsPoint &p2, double *course1=NULL, double *course2=NULL) |
calculates distance from two points on ellipsoid based on inverse Vincenty's formulae More... | |
double | computeDistanceFlat (const QgsPoint &p1, const QgsPoint &p2) |
uses flat / planimetric / Euclidean distance More... | |
double | computeDistance (const QList< QgsPoint > &points) |
calculate distance with given coordinates (does not do a transform anymore) More... | |
double | computePolygonArea (const QList< QgsPoint > &points) |
calculates area of polygon on ellipsoid algorithm has been taken from GRASS: gis/area_poly1.c More... | |
double | computePolygonFlatArea (const QList< QgsPoint > &points) |
void | computeAreaInit () |
precalculates some values (must be called always when changing ellipsoid) More... | |
Private Member Functions | |
void | _copy (const QgsDistanceArea &origDA) |
Copy helper. More... | |
double | getQ (double x) |
double | getQbar (double x) |
Private Attributes | |
QgsCoordinateTransform * | mCoordTransform |
used for transforming coordinates from source CRS to ellipsoid's coordinates More... | |
bool | mEllipsoidalMode |
indicates whether we will transform coordinates More... | |
QString | mEllipsoid |
ellipsoid acronym (from table tbl_ellipsoids) More... | |
double | mSemiMajor |
ellipsoid parameters More... | |
double | mSemiMinor |
double | mInvFlattening |
double | m_QA |
double | m_QB |
double | m_QC |
double | m_QbarA |
double | m_QbarB |
double | m_QbarC |
double | m_QbarD |
double | m_AE |
double | m_Qp |
double | m_E |
double | m_TwoPI |
General purpose distance and area calculator.
Definition at line 34 of file qgsdistancearea.h.
QgsDistanceArea::QgsDistanceArea | ( | ) |
Constructor.
Definition at line 41 of file qgsdistancearea.cpp.
References GEO_NONE, GEOCRS_ID, mCoordTransform, mEllipsoidalMode, setEllipsoid(), and setSourceCrs().
QgsDistanceArea::~QgsDistanceArea | ( | ) |
QgsDistanceArea::QgsDistanceArea | ( | const QgsDistanceArea & | origDA | ) |
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Copy helper.
Copy helper. Avoid Sqlite3 accesses.
Definition at line 75 of file qgsdistancearea.cpp.
References computeAreaInit(), QgsCoordinateTransform::destCRS(), mCoordTransform, mEllipsoid, mEllipsoidalMode, mInvFlattening, mSemiMajor, mSemiMinor, and QgsCoordinateTransform::sourceCrs().
Referenced by operator=(), and QgsDistanceArea().
compute bearing - in radians
Definition at line 613 of file qgsdistancearea.cpp.
References computeDistanceBearing(), GEO_NONE, mCoordTransform, mEllipsoid, mEllipsoidalMode, QgsCoordinateTransform::transform(), QgsPoint::x(), and QgsPoint::y().
Referenced by QgsTransectSample::createSample().
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precalculates some values (must be called always when changing ellipsoid)
Definition at line 786 of file qgsdistancearea.cpp.
References getQ(), m_AE, m_E, M_PI, m_QA, m_QB, m_QbarA, m_QbarB, m_QbarC, m_QbarD, m_QC, m_Qp, m_TwoPI, mSemiMajor, and mSemiMinor.
Referenced by _copy(), and setEllipsoid().
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calculate distance with given coordinates (does not do a transform anymore)
Definition at line 720 of file qgsdistancearea.cpp.
References computeDistanceBearing(), computeDistanceFlat(), GEO_NONE, QgsMessageLog::logMessage(), mEllipsoid, mEllipsoidalMode, and tr.
Referenced by measurePolygon().
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calculates distance from two points on ellipsoid based on inverse Vincenty's formulae
Points p1 and p2 are expected to be in degrees and in currently used ellipsoid
Definition at line 638 of file qgsdistancearea.cpp.
References DEG2RAD, M_PI, mInvFlattening, mSemiMajor, mSemiMinor, QgsPoint::x(), and QgsPoint::y().
Referenced by bearing(), computeDistance(), and measureLine().
uses flat / planimetric / Euclidean distance
Definition at line 715 of file qgsdistancearea.cpp.
References QgsPoint::x(), and QgsPoint::y().
Referenced by computeDistance(), and measureLine().
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calculates area of polygon on ellipsoid algorithm has been taken from GRASS: gis/area_poly1.c
Definition at line 815 of file qgsdistancearea.cpp.
References computePolygonFlatArea(), DEG2RAD, GEO_NONE, getQ(), getQbar(), m_AE, m_E, M_PI, m_Qp, m_TwoPI, mEllipsoid, mEllipsoidalMode, and QgsDebugMsgLevel.
Referenced by measurePolygon().
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Definition at line 872 of file qgsdistancearea.cpp.
References size.
Referenced by computePolygonArea().
void QgsDistanceArea::convertMeasurement | ( | double & | measure, |
QGis::UnitType & | measureUnits, | ||
QGis::UnitType | displayUnits, | ||
bool | isArea | ||
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Helper for conversion between physical units.
Definition at line 1022 of file qgsdistancearea.cpp.
References QGis::Degrees, QGis::Feet, QGis::fromUnitToUnitFactor(), GEO_NONE, QgsCoordinateReferenceSystem::mapUnits(), mCoordTransform, mEllipsoid, mEllipsoidalMode, QGis::Meters, QGis::NauticalMiles, QgsDebugMsg, QgsCoordinateTransform::sourceCrs(), and QGis::toLiteral().
Referenced by QgsMapToolIdentify::convertMeasurement().
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returns ellipsoid's acronym
Definition at line 80 of file qgsdistancearea.h.
Referenced by setEllipsoid().
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returns projections enabled flag
Definition at line 53 of file qgsdistancearea.h.
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returns ellipsoid's inverse flattening
Definition at line 87 of file qgsdistancearea.h.
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returns ellipsoid's semi major axis
Definition at line 83 of file qgsdistancearea.h.
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returns ellipsoid's semi minor axis
Definition at line 85 of file qgsdistancearea.h.
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What sort of coordinate system is being used?
Definition at line 70 of file qgsdistancearea.h.
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Definition at line 764 of file qgsdistancearea.cpp.
References m_QA, m_QB, and m_QC.
Referenced by computeAreaInit(), and computePolygonArea().
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Definition at line 775 of file qgsdistancearea.cpp.
References m_QbarA, m_QbarB, m_QbarC, and m_QbarD.
Referenced by computePolygonArea().
double QgsDistanceArea::measure | ( | QgsGeometry * | geometry | ) |
general measurement (line distance or polygon area)
Definition at line 257 of file qgsdistancearea.cpp.
References QgsGeometry::asWkb(), measureLine(), measurePolygon(), QgsDebugMsg, QGis::WKBLineString, QGis::WKBLineString25D, QGis::WKBMultiLineString, QGis::WKBMultiLineString25D, QGis::WKBMultiPolygon, QGis::WKBMultiPolygon25D, QGis::WKBPolygon, and QGis::WKBPolygon25D.
Referenced by QgsTransectSample::createSample(), fcnGeomArea(), fcnGeomLength(), QgsMapToolIdentify::featureDerivedAttributes(), QgsGeometryAnalyzer::perimeterMeasure(), and QgsGeometryAnalyzer::simpleMeasure().
double QgsDistanceArea::measureLine | ( | const QList< QgsPoint > & | points | ) |
measures line
Definition at line 413 of file qgsdistancearea.cpp.
References computeDistanceBearing(), GEO_NONE, QgsMessageLog::logMessage(), mCoordTransform, mEllipsoid, mEllipsoidalMode, tr, and QgsCoordinateTransform::transform().
Referenced by QgsComposerScaleBar::mapWidth(), measure(), measureLine(), and QgsTransectSample::otherTransectWithinDistance().
measures line with one segment
Definition at line 455 of file qgsdistancearea.cpp.
References computeDistanceBearing(), computeDistanceFlat(), QgsCoordinateTransform::destCRS(), GEO_NONE, QgsMessageLog::logMessage(), mCoordTransform, mEllipsoid, mEllipsoidalMode, QgsDebugMsgLevel, QgsCoordinateTransform::sourceCrs(), QgsCoordinateReferenceSystem::toProj4(), QgsPoint::toString(), tr, and QgsCoordinateTransform::transform().
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measures line distance, line points are extracted from WKB
Definition at line 386 of file qgsdistancearea.cpp.
References measureLine(), and QgsDebugMsg.
double QgsDistanceArea::measurePerimeter | ( | QgsGeometry * | geometry | ) |
measures perimeter of polygon
Definition at line 328 of file qgsdistancearea.cpp.
References QgsGeometry::asWkb(), measurePolygon(), QgsDebugMsg, QGis::WKBLineString, QGis::WKBLineString25D, QGis::WKBMultiLineString, QGis::WKBMultiLineString25D, QGis::WKBMultiPolygon, QGis::WKBMultiPolygon25D, QGis::WKBPolygon, and QGis::WKBPolygon25D.
Referenced by fcnGeomPerimeter(), and QgsMapToolIdentify::featureDerivedAttributes().
double QgsDistanceArea::measurePolygon | ( | const QList< QgsPoint > & | points | ) |
measures polygon area
Definition at line 586 of file qgsdistancearea.cpp.
References computePolygonArea(), GEO_NONE, QgsMessageLog::logMessage(), mCoordTransform, mEllipsoid, mEllipsoidalMode, tr, and QgsCoordinateTransform::transform().
Referenced by measure(), and measurePerimeter().
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measures polygon area and perimeter, vertices are extracted from WKB
Definition at line 491 of file qgsdistancearea.cpp.
References computeDistance(), computePolygonArea(), GEO_NONE, QgsMessageLog::logMessage(), mCoordTransform, mEllipsoid, mEllipsoidalMode, QgsDebugMsg, tr, and QgsCoordinateTransform::transform().
QgsDistanceArea & QgsDistanceArea::operator= | ( | const QgsDistanceArea & | origDA | ) |
bool QgsDistanceArea::setEllipsoid | ( | const QString & | ellipsoid | ) |
sets ellipsoid by its acronym
Definition at line 112 of file qgsdistancearea.cpp.
References computeAreaInit(), QgsCoordinateReferenceSystem::createFromProj4(), ellipsoid(), GEO_NONE, QgsMessageLog::logMessage(), mCoordTransform, mEllipsoid, mInvFlattening, mSemiMajor, mSemiMinor, QgsDebugMsg, QgsCoordinateReferenceSystem::saveAsUserCRS(), QgsCoordinateTransform::setDestCRS(), QgsApplication::srsDbFilePath(), QgsCoordinateReferenceSystem::srsid(), QgsCoordinateReferenceSystem::toProj4(), and tr.
Referenced by QgsMapToolIdentify::featureDerivedAttributes(), QgsComposerScaleBar::mapWidth(), and QgsDistanceArea().
bool QgsDistanceArea::setEllipsoid | ( | double | semiMajor, |
double | semiMinor | ||
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Sets ellipsoid by supplied radii.
Definition at line 245 of file qgsdistancearea.cpp.
References computeAreaInit(), mEllipsoid, mInvFlattening, mSemiMajor, and mSemiMinor.
void QgsDistanceArea::setEllipsoidalMode | ( | bool | flag | ) |
sets whether coordinates must be projected to ellipsoid before measuring
Definition at line 88 of file qgsdistancearea.cpp.
References mEllipsoidalMode.
Referenced by QgsTransectSample::createSample(), QgsMapToolIdentify::featureDerivedAttributes(), QgsExpression::initGeomCalculator(), QgsComposerScaleBar::mapWidth(), and QgsMapRenderer::setProjectionsEnabled().
void QgsDistanceArea::setSourceAuthId | ( | QString | authid | ) |
sets source spatial reference system by authid
Definition at line 105 of file qgsdistancearea.cpp.
References QgsCoordinateReferenceSystem::createFromOgcWmsCrs(), mCoordTransform, and QgsCoordinateTransform::setSourceCrs().
void QgsDistanceArea::setSourceCrs | ( | long | srsid | ) |
sets source spatial reference system (by QGIS CRS)
Definition at line 93 of file qgsdistancearea.cpp.
References QgsCoordinateReferenceSystem::createFromSrsId(), mCoordTransform, and QgsCoordinateTransform::setSourceCrs().
Referenced by QgsAttributeEditorContext::adjustForLayer(), QgsTransectSample::createSample(), QgsMapToolIdentify::featureDerivedAttributes(), QgsComposerScaleBar::mapWidth(), QgsDistanceArea(), and QgsMapRenderer::setDestinationCrs().
void QgsDistanceArea::setSourceCrs | ( | const QgsCoordinateReferenceSystem & | srcCRS | ) |
Sets source spatial reference system (by QGIS CRS)
Definition at line 100 of file qgsdistancearea.cpp.
References mCoordTransform, and QgsCoordinateTransform::setSourceCrs().
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returns source spatial reference system
Definition at line 68 of file qgsdistancearea.h.
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Definition at line 893 of file qgsdistancearea.cpp.
References QGis::Degrees, QGis::Feet, QGis::Meters, QGis::NauticalMiles, QgsDebugMsg, tr, and QGis::UnknownUnit.
Referenced by QgsMapToolIdentify::featureDerivedAttributes().
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Definition at line 179 of file qgsdistancearea.h.
Referenced by computeAreaInit(), and computePolygonArea().
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Definition at line 181 of file qgsdistancearea.h.
Referenced by computeAreaInit(), and computePolygonArea().
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Definition at line 177 of file qgsdistancearea.h.
Referenced by computeAreaInit(), and getQ().
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Definition at line 177 of file qgsdistancearea.h.
Referenced by computeAreaInit(), and getQ().
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Definition at line 178 of file qgsdistancearea.h.
Referenced by computeAreaInit(), and getQbar().
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Definition at line 178 of file qgsdistancearea.h.
Referenced by computeAreaInit(), and getQbar().
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Definition at line 178 of file qgsdistancearea.h.
Referenced by computeAreaInit(), and getQbar().
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Definition at line 178 of file qgsdistancearea.h.
Referenced by computeAreaInit(), and getQbar().
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Definition at line 177 of file qgsdistancearea.h.
Referenced by computeAreaInit(), and getQ().
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Definition at line 180 of file qgsdistancearea.h.
Referenced by computeAreaInit(), and computePolygonArea().
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Definition at line 182 of file qgsdistancearea.h.
Referenced by computeAreaInit(), and computePolygonArea().
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used for transforming coordinates from source CRS to ellipsoid's coordinates
Definition at line 159 of file qgsdistancearea.h.
Referenced by _copy(), bearing(), convertMeasurement(), measureLine(), measurePolygon(), QgsDistanceArea(), setEllipsoid(), setSourceAuthId(), setSourceCrs(), and ~QgsDistanceArea().
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ellipsoid acronym (from table tbl_ellipsoids)
Definition at line 165 of file qgsdistancearea.h.
Referenced by _copy(), bearing(), computeDistance(), computePolygonArea(), convertMeasurement(), measureLine(), measurePolygon(), and setEllipsoid().
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indicates whether we will transform coordinates
Definition at line 162 of file qgsdistancearea.h.
Referenced by _copy(), bearing(), computeDistance(), computePolygonArea(), convertMeasurement(), measureLine(), measurePolygon(), QgsDistanceArea(), and setEllipsoidalMode().
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Definition at line 168 of file qgsdistancearea.h.
Referenced by _copy(), computeDistanceBearing(), and setEllipsoid().
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ellipsoid parameters
Definition at line 168 of file qgsdistancearea.h.
Referenced by _copy(), computeAreaInit(), computeDistanceBearing(), and setEllipsoid().
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Definition at line 168 of file qgsdistancearea.h.
Referenced by _copy(), computeAreaInit(), computeDistanceBearing(), and setEllipsoid().