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Merge pull request #4771 from m-kuhn/closest_point

Closest point
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m-kuhn committed Jun 26, 2017
2 parents 81653d6 + fd8158b commit 1dca3327c1d1bdd8520d8308c46715c0d7422270
@@ -37,10 +37,12 @@ class QgsGeometryUtils
:rtype: QgsPoint
%End

static double closestPointMeasure( const QgsAbstractGeometry &geom, const QgsPoint &pt );
static QgsPoint closestPoint( const QgsAbstractGeometry &geometry, const QgsPoint &point );
%Docstring
Returns measure of nearest point on a geometry for a specified point or NaN if geometry does not have measures
:rtype: float
Returns the nearest point on a segment of a ``geometry``
for the specified ``point``. The z and m values will be linearly interpolated between
the two neighbouring vertices.
:rtype: QgsPoint
%End

static double distanceToVertex( const QgsAbstractGeometry &geom, QgsVertexId id );
@@ -29,6 +29,8 @@ class QgsLineString: QgsCurve
QgsLineString( const QVector<QgsPoint> &points );
%Docstring
Construct a linestring from a vector of points.
Z and M type will be set based on the type of the first point
in the vector.
.. versionadded:: 3.0
%End

@@ -73,7 +75,7 @@ class QgsLineString: QgsCurve
%Docstring
Returns the z-coordinate of the specified node in the line string.
\param index index of node, where the first node in the line is 0
:return: z-coordinate of node, or 0.0 if index is out of bounds or the line
:return: z-coordinate of node, or ``nan`` if index is out of bounds or the line
does not have a z dimension
.. seealso:: setZAt()
:rtype: float
@@ -83,7 +85,7 @@ class QgsLineString: QgsCurve
%Docstring
Returns the m value of the specified node in the line string.
\param index index of node, where the first node in the line is 0
:return: m value of node, or 0.0 if index is out of bounds or the line
:return: m value of node, or ``nan`` if index is out of bounds or the line
does not have m values
.. seealso:: setMAt()
:rtype: float
@@ -31,9 +31,12 @@ bool QgsCurve::isClosed() const
//don't consider M-coordinates when testing closedness
QgsPoint start = startPoint();
QgsPoint end = endPoint();
return ( qgsDoubleNear( start.x(), end.x(), 1E-8 ) &&
qgsDoubleNear( start.y(), end.y(), 1E-8 ) &&
qgsDoubleNear( start.z(), end.z(), 1E-8 ) );

bool closed = qgsDoubleNear( start.x(), end.x(), 1E-8 ) &&
qgsDoubleNear( start.y(), end.y(), 1E-8 );
if ( is3D() && closed )
closed &= qgsDoubleNear( start.z(), end.z(), 1E-8 ) || ( qIsNaN( start.z() ) && qIsNaN( end.z() ) );
return closed;
}

bool QgsCurve::isRing() const
@@ -93,33 +93,38 @@ QgsPoint QgsGeometryUtils::closestVertex( const QgsAbstractGeometry &geom, const
return minDistPoint;
}

double QgsGeometryUtils::closestPointMeasure( const QgsAbstractGeometry &geom, const QgsPoint &pt )
QgsPoint QgsGeometryUtils::closestPoint( const QgsAbstractGeometry &geometry, const QgsPoint &point )
{
if ( QgsWkbTypes::hasM( geom.wkbType() ) )
{
QgsPoint closestPoint;
QgsVertexId vertexAfter;
bool leftOf;
geom.closestSegment( pt, closestPoint, vertexAfter, &leftOf, DEFAULT_SEGMENT_EPSILON );
if ( vertexAfter.isValid() )
QgsPoint closestPoint;
QgsVertexId vertexAfter;
bool leftOf;
geometry.closestSegment( point, closestPoint, vertexAfter, &leftOf, DEFAULT_SEGMENT_EPSILON );
if ( vertexAfter.isValid() )
{
QgsPoint pointAfter = geometry.vertexAt( vertexAfter );
if ( vertexAfter.vertex > 0 )
{
QgsPoint pointAfter = geom.vertexAt( vertexAfter );
if ( vertexAfter.vertex > 0 )
{
QgsVertexId vertexBefore = vertexAfter;
vertexBefore.vertex--;
QgsPoint pointBefore = geom.vertexAt( vertexBefore );
double length = pointBefore.distance( pointAfter );
double distance = pointBefore.distance( closestPoint );
return pointBefore.m() + ( pointAfter.m() - pointBefore.m() ) * distance / length;
}
QgsVertexId vertexBefore = vertexAfter;
vertexBefore.vertex--;
QgsPoint pointBefore = geometry.vertexAt( vertexBefore );
double length = pointBefore.distance( pointAfter );
double distance = pointBefore.distance( closestPoint );

if ( qgsDoubleNear( distance, 0.0 ) )
closestPoint = pointBefore;
else if ( qgsDoubleNear( distance, length ) )
closestPoint = pointAfter;
else
{
return pointAfter.m();
if ( QgsWkbTypes::hasZ( geometry.wkbType() ) && length )
closestPoint.addZValue( pointBefore.z() + ( pointAfter.z() - pointBefore.z() ) * distance / length );
if ( QgsWkbTypes::hasM( geometry.wkbType() ) )
closestPoint.addMValue( pointBefore.m() + ( pointAfter.m() - pointBefore.m() ) * distance / length );
}
}
}
return std::numeric_limits<double>::quiet_NaN();

return closestPoint;
}

double QgsGeometryUtils::distanceToVertex( const QgsAbstractGeometry &geom, QgsVertexId id )
@@ -44,9 +44,12 @@ class CORE_EXPORT QgsGeometryUtils
*/
static QgsPoint closestVertex( const QgsAbstractGeometry &geom, const QgsPoint &pt, QgsVertexId &id SIP_OUT );

/** Returns measure of nearest point on a geometry for a specified point or NaN if geometry does not have measures
/**
* Returns the nearest point on a segment of a \a geometry
* for the specified \a point. The z and m values will be linearly interpolated between
* the two neighbouring vertices.
*/
static double closestPointMeasure( const QgsAbstractGeometry &geom, const QgsPoint &pt );
static QgsPoint closestPoint( const QgsAbstractGeometry &geometry, const QgsPoint &point );

/** Returns the distance along a geometry from its first vertex to the specified vertex.
* \param geom geometry
@@ -380,8 +380,8 @@ QgsPoint QgsLineString::pointN( int i ) const

double x = mX.at( i );
double y = mY.at( i );
double z = 0;
double m = 0;
double z = std::numeric_limits<double>::quiet_NaN();
double m = std::numeric_limits<double>::quiet_NaN();

bool hasZ = is3D();
if ( hasZ )
@@ -441,15 +441,15 @@ double QgsLineString::zAt( int index ) const
if ( index >= 0 && index < mZ.size() )
return mZ.at( index );
else
return 0.0;
return std::numeric_limits<double>::quiet_NaN();
}

double QgsLineString::mAt( int index ) const
{
if ( index >= 0 && index < mM.size() )
return mM.at( index );
else
return 0.0;
return std::numeric_limits<double>::quiet_NaN();
}

void QgsLineString::setXAt( int index, double x )
@@ -44,6 +44,8 @@ class CORE_EXPORT QgsLineString: public QgsCurve

/**
* Construct a linestring from a vector of points.
* Z and M type will be set based on the type of the first point
* in the vector.
* \since QGIS 3.0
*/
QgsLineString( const QVector<QgsPoint> &points );
@@ -81,15 +83,15 @@ class CORE_EXPORT QgsLineString: public QgsCurve

/** Returns the z-coordinate of the specified node in the line string.
* \param index index of node, where the first node in the line is 0
* \returns z-coordinate of node, or 0.0 if index is out of bounds or the line
* \returns z-coordinate of node, or ``nan`` if index is out of bounds or the line
* does not have a z dimension
* \see setZAt()
*/
double zAt( int index ) const;

/** Returns the m value of the specified node in the line string.
* \param index index of node, where the first node in the line is 0
* \returns m value of node, or 0.0 if index is out of bounds or the line
* \returns m value of node, or ``nan`` if index is out of bounds or the line
* does not have m values
* \see setMAt()
*/
@@ -332,8 +332,8 @@ void QgsMapToolIdentify::closestPointAttributes( const QgsAbstractGeometry &geom
// measure
if ( QgsWkbTypes::hasM( geometry.wkbType() ) )
{
double measure = QgsGeometryUtils::closestPointMeasure( geometry, QgsPoint( layerPoint.x(), layerPoint.y() ) );
QString str = QLocale::system().toString( measure, 'g', 10 );
QgsPoint closestPoint = QgsGeometryUtils::closestPoint( geometry, QgsPoint( layerPoint.x(), layerPoint.y() ) );
QString str = QLocale::system().toString( closestPoint.m(), 'g', 10 );
derivedAttributes.insert( QStringLiteral( "Closest point M" ), str );
}
}
@@ -1317,8 +1317,8 @@ void TestQgsGeometry::lineString()
QCOMPARE( l9.zAt( 0 ), 3.0 );
QCOMPARE( l9.zAt( 1 ), 13.0 );
QCOMPARE( l9.zAt( 2 ), 23.0 );
QCOMPARE( l9.zAt( -1 ), 0.0 ); //out of range
QCOMPARE( l9.zAt( 11 ), 0.0 ); //out of range
QVERIFY( qIsNaN( l9.zAt( -1 ) ) ); //out of range
QVERIFY( qIsNaN( l9.zAt( 11 ) ) ); //out of range

l9.setZAt( 0, 53.0 );
QCOMPARE( l9.zAt( 0 ), 53.0 );
@@ -1330,8 +1330,8 @@ void TestQgsGeometry::lineString()
QCOMPARE( l9.mAt( 0 ), 4.0 );
QCOMPARE( l9.mAt( 1 ), 14.0 );
QCOMPARE( l9.mAt( 2 ), 24.0 );
QCOMPARE( l9.mAt( -1 ), 0.0 ); //out of range
QCOMPARE( l9.mAt( 11 ), 0.0 ); //out of range
QVERIFY( qIsNaN( l9.mAt( -1 ) ) ); //out of range
QVERIFY( qIsNaN( l9.mAt( 11 ) ) ); //out of range

l9.setMAt( 0, 54.0 );
QCOMPARE( l9.mAt( 0 ), 54.0 );
@@ -1346,8 +1346,8 @@ void TestQgsGeometry::lineString()
<< QgsPoint( QgsWkbTypes::PointM, 21, 22, 0, 24 ) );

//basically we just don't want these to crash
QCOMPARE( l9.zAt( 0 ), 0.0 );
QCOMPARE( l9.zAt( 1 ), 0.0 );
QVERIFY( qIsNaN( l9.zAt( 0 ) ) );
QVERIFY( qIsNaN( l9.zAt( 1 ) ) );
l9.setZAt( 0, 53.0 );
l9.setZAt( 1, 63.0 );

@@ -1357,8 +1357,8 @@ void TestQgsGeometry::lineString()
<< QgsPoint( 21, 22 ) );

//basically we just don't want these to crash
QCOMPARE( l9.mAt( 0 ), 0.0 );
QCOMPARE( l9.mAt( 1 ), 0.0 );
QVERIFY( qIsNaN( l9.mAt( 0 ) ) );
QVERIFY( qIsNaN( l9.mAt( 1 ) ) );
l9.setMAt( 0, 53.0 );
l9.setMAt( 1, 63.0 );

@@ -55,6 +55,7 @@ class TestQgsGeometryUtils: public QObject
void testGradient();
void testCoefficients();
void testPerpendicularSegment();
void testClosestPoint();
};


@@ -633,5 +634,41 @@ void TestQgsGeometryUtils::testPerpendicularSegment()
QCOMPARE( line.pointN( 1 ), line_r.pointN( 1 ) );
}

void TestQgsGeometryUtils::testClosestPoint()
{
QgsLineString linestringZ( QVector<QgsPoint>()
<< QgsPoint( 1, 1, 1 )
<< QgsPoint( 1, 3, 2 ) );

QgsPoint pt1 = QgsGeometryUtils::closestPoint( linestringZ, QgsPoint( 1, 0 ) );
QGSCOMPARENEAR( pt1.z(), 1, 0.0001 );
QVERIFY( qIsNaN( pt1.m() ) );

QgsLineString linestringM( QVector<QgsPoint>()
<< QgsPoint( 1, 1, std::numeric_limits<double>::quiet_NaN(), 1 )
<< QgsPoint( 1, 3, std::numeric_limits<double>::quiet_NaN(), 2 ) );

QgsPoint pt2 = QgsGeometryUtils::closestPoint( linestringM, QgsPoint( 1, 4 ) );
QVERIFY( qIsNaN( pt2.z() ) );
QGSCOMPARENEAR( pt2.m(), 2, 0.0001 );

QgsLineString linestringZM( QVector<QgsPoint>()
<< QgsPoint( 1, 1, 1, 1 )
<< QgsPoint( 1, 3, 2, 2 ) );

QgsPoint pt3 = QgsGeometryUtils::closestPoint( linestringZM, QgsPoint( 2, 2 ) );
QGSCOMPARENEAR( pt3.z(), 1.5, 0.0001 );
QGSCOMPARENEAR( pt3.m(), 1.5, 0.0001 );

QgsLineString linestringDuplicatedPoint( QVector<QgsPoint>()
<< QgsPoint( 1, 1, 1, 1 )
<< QgsPoint( 1, 1, 1, 1 )
<< QgsPoint( 1, 3, 2, 2 ) );

QgsPoint pt4 = QgsGeometryUtils::closestPoint( linestringDuplicatedPoint, QgsPoint( 1, 0 ) );
QGSCOMPARENEAR( pt4.z(), 1, 0.0001 );
QGSCOMPARENEAR( pt4.m(), 1, 0.0001 );
}

QGSTEST_MAIN( TestQgsGeometryUtils )
#include "testqgsgeometryutils.moc"

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