Add inclination method for QgsPointV2 (#4536)

Author: lbartoletti

python/core/geometry/qgspointv2.sip

@@ -234,6 +234,14 @@ class QgsPointV2: QgsAbstractGeometry
  :rtype: float
 %End
 
+    double inclination( const QgsPointV2 &other ) const;
+%Docstring
+ Calculates inclination between this point and other one (starting from zenith = 0 to nadir = 180. Horizon = 90)
+ Returns 90.0 if the distance between this point and other one is equal to 0 (same point).
+.. versionadded:: 3.0
+ :rtype: float
+%End
+
     QgsPointV2 project( double distance, double azimuth, double inclination = 90.0 ) const;
 %Docstring
  Returns a new point which correspond to this point projected by a specified distance

src/core/geometry/qgspointv2.cpp

@@ -485,6 +485,17 @@ double QgsPointV2::azimuth( const QgsPointV2 &other ) const
   return ( atan2( dx, dy ) * 180.0 / M_PI );
 }
 
+double QgsPointV2::inclination( const QgsPointV2 &other ) const
+{
+  double distance = distance3D( other );
+  if ( qgsDoubleNear( distance, 0.0 ) )
+  {
+    return 90.0;
+  }
+  double dz = other.z() - mZ;
+
+  return ( acos( dz / distance ) * 180.0 / M_PI );
+}
 
 QgsPointV2 QgsPointV2::project( double distance, double azimuth, double inclination ) const
 {

src/core/geometry/qgspointv2.h

@@ -243,6 +243,13 @@ class CORE_EXPORT QgsPointV2: public QgsAbstractGeometry
      */
     double azimuth( const QgsPointV2 &other ) const;
 
+    /**
+     * Calculates inclination between this point and other one (starting from zenith = 0 to nadir = 180. Horizon = 90)
+     * Returns 90.0 if the distance between this point and other one is equal to 0 (same point).
+     * \since QGIS 3.0
+     */
+    double inclination( const QgsPointV2 &other ) const;
+
     /** Returns a new point which correspond to this point projected by a specified distance
      * with specified angles (azimuth and inclination).
      * M value is preserved.

src/core/qgsexpression.cpp

@@ -2921,6 +2921,25 @@ static QVariant fcnProject( const QVariantList &values, const QgsExpressionConte
   return QVariant::fromValue( QgsGeometry( new QgsPointV2( newPoint ) ) );
 }
 
+static QVariant fcnInclination( const QVariantList &values, const QgsExpressionContext *, QgsExpression *parent )
+{
+  QgsGeometry fGeom1 = getGeometry( values.at( 0 ), parent );
+  QgsGeometry fGeom2 = getGeometry( values.at( 1 ), parent );
+
+  const QgsPointV2 *pt1 = dynamic_cast<const QgsPointV2 *>( fGeom1.geometry() );
+  const QgsPointV2 *pt2 = dynamic_cast<const QgsPointV2 *>( fGeom2.geometry() );
+
+  if ( ( fGeom1.type() != QgsWkbTypes::PointGeometry ) || ( fGeom2.type() != QgsWkbTypes::PointGeometry ) ||
+       !pt1 || !pt2 )
+  {
+    parent->setEvalErrorString( QStringLiteral( "Function 'inclination' requires two points as arguments." ) );
+    return QVariant();
+  }
+
+  return pt1->inclination( *pt2 );
+
+}
+
 static QVariant fcnExtrude( const QVariantList &values, const QgsExpressionContext *, QgsExpression *parent )
 {
   if ( values.length() != 3 )
@@ -3933,6 +3952,7 @@ const QList<QgsExpression::Function *> &QgsExpression::Functions()
         << new StaticFunction( QStringLiteral( "radians" ), ParameterList() << Parameter( QStringLiteral( "degrees" ) ), fcnRadians, QStringLiteral( "Math" ) )
         << new StaticFunction( QStringLiteral( "degrees" ), ParameterList() << Parameter( QStringLiteral( "radians" ) ), fcnDegrees, QStringLiteral( "Math" ) )
         << new StaticFunction( QStringLiteral( "azimuth" ), ParameterList() << Parameter( QStringLiteral( "point_a" ) ) << Parameter( QStringLiteral( "point_b" ) ), fcnAzimuth, QStringList() << QStringLiteral( "Math" ) << QStringLiteral( "GeometryGroup" ) )
+        << new StaticFunction( QStringLiteral( "inclination" ), ParameterList() << Parameter( QStringLiteral( "point_a" ) ) << Parameter( QStringLiteral( "point_b" ) ), fcnInclination, QStringList() << QStringLiteral( "Math" ) << QStringLiteral( "GeometryGroup" ) )
         << new StaticFunction( QStringLiteral( "project" ), ParameterList() << Parameter( QStringLiteral( "point" ) ) << Parameter( QStringLiteral( "distance" ) ) << Parameter( QStringLiteral( "azimuth" ) ) << Parameter( QStringLiteral( "elevation" ), true, M_PI / 2 ), fcnProject, QStringLiteral( "GeometryGroup" ) )
         << new StaticFunction( QStringLiteral( "abs" ), ParameterList() << Parameter( QStringLiteral( "value" ) ), fcnAbs, QStringLiteral( "Math" ) )
         << new StaticFunction( QStringLiteral( "cos" ), ParameterList() << Parameter( QStringLiteral( "angle" ) ), fcnCos, QStringLiteral( "Math" ) )

tests/src/core/testqgsexpression.cpp

@@ -817,6 +817,14 @@ class TestQgsExpression: public QObject
       QTest::newRow( "project m value preserved" ) << "geom_to_wkt(project( make_point( 1, 2, 2, 5), 1, 0.0, 0.0 ) )" << false << QVariant( "PointZM (1 2 3 5)" );
       QTest::newRow( "project 2D Point" ) << "geom_to_wkt(project( point:=make_point( 1, 2), distance:=1, azimuth:=radians(0), elevation:=0 ) )" << false << QVariant( "PointZ (1 2 1)" );
       QTest::newRow( "project 3D Point" ) << "geom_to_wkt(project( make_point( 1, 2, 2), 5, radians(450), radians (450) ) )" << false << QVariant( "PointZ (6 2 2)" );
+      QTest::newRow( "inclination not geom first" ) << "inclination( 'a', make_point( 1, 2, 2 ) )" << true << QVariant();
+      QTest::newRow( "inclination not geom second" ) << " inclination( make_point( 1, 2, 2 ), 'a' )" << true << QVariant();
+      QTest::newRow( "inclination not point first" ) << "inclination( geom_from_wkt('LINESTRING(2 0,2 2, 3 2, 3 0)'), make_point( 1, 2, 2) )" << true << QVariant();
+      QTest::newRow( "inclination not point second" ) << " inclination( make_point( 1, 2, 2 ), geom_from_wkt('LINESTRING(2 0,2 2, 3 2, 3 0)') )" << true << QVariant();
+      QTest::newRow( "inclination" ) << "ceil(inclination( make_point( 159, 753, 460 ), make_point( 123, 456, 789 ) ))" << false << QVariant( 43.0 );
+      QTest::newRow( "inclination" ) << " inclination( make_point( 5, 10, 0 ), make_point( 5, 10, 5 ) )" << false << QVariant( 0.0 );
+      QTest::newRow( "inclination" ) << " inclination( make_point( 5, 10, 0 ), make_point( 5, 10, 0 ) )" << false << QVariant( 90.0 );
+      QTest::newRow( "inclination" ) << " inclination( make_point( 5, 10, 0 ), make_point( 5, 10, -5 ) )" << false << QVariant( 180.0 );
       QTest::newRow( "extrude geom" ) << "geom_to_wkt(extrude( geom_from_wkt('LineString( 1 2, 3 2, 4 3)'),1,2))" << false << QVariant( "Polygon ((1 2, 3 2, 4 3, 5 5, 4 4, 2 4, 1 2))" );
       QTest::newRow( "extrude not geom" ) << "extrude('g',5,6)" << true << QVariant();
       QTest::newRow( "extrude null" ) << "extrude(NULL,5,6)" << false << QVariant();

tests/src/core/testqgsgeometry.cpp

@@ -919,6 +919,18 @@ void TestQgsGeometry::point()
   QCOMPARE( p34.project( 5, 450 ), QgsPointV2( QgsWkbTypes::PointZM, 6, 2, 2, 5 ) );
   QCOMPARE( p34.project( 5, 450, 450 ), QgsPointV2( QgsWkbTypes::PointZM, 6, 2, 2, 5 ) );
 
+  // inclination
+  QCOMPARE( QgsPointV2( 1, 2 ).inclination( QgsPointV2( 1, 2 ) ), 90.0 );
+  QCOMPARE( QgsPointV2( QgsWkbTypes::PointZ, 1, 1, 2, 0 ).inclination( QgsPointV2( QgsWkbTypes::PointZ, 1, 1, 2, 0 ) ), 90.0 );
+  QCOMPARE( QgsPointV2( QgsWkbTypes::PointZ, 1, 2, 2 ).inclination( QgsPointV2( QgsWkbTypes::PointZ, 1, 2, 2 ).project( 5, 90, 90 ) ), 90.0 );
+  QCOMPARE( QgsPointV2( QgsWkbTypes::PointZ, 1, 2, 2 ).inclination( QgsPointV2( QgsWkbTypes::PointZ, 1, 2, 2 ).project( 5, 90, -90 ) ), 90.0 );
+  QCOMPARE( QgsPointV2( QgsWkbTypes::PointZ, 1, 2, 2 ).inclination( QgsPointV2( QgsWkbTypes::PointZ, 1, 2, 2 ).project( 5, 90, 0 ) ), 0.0 );
+  QCOMPARE( QgsPointV2( QgsWkbTypes::PointZ, 1, 2, 2 ).inclination( QgsPointV2( QgsWkbTypes::PointZ, 1, 2, 2 ).project( 5, 90, 180 ) ), 180.0 );
+  QCOMPARE( QgsPointV2( QgsWkbTypes::PointZ, 1, 2, 2 ).inclination( QgsPointV2( QgsWkbTypes::PointZ, 1, 2, 2 ).project( 5, 90, -180 ) ), 180.0 );
+  QCOMPARE( QgsPointV2( QgsWkbTypes::PointZ, 1, 2, 2 ).inclination( QgsPointV2( QgsWkbTypes::PointZ, 1, 2, 2 ).project( 5, 90, 720 ) ), 0.0 );
+  QCOMPARE( QgsPointV2( QgsWkbTypes::PointZ, 1, 2, 2 ).inclination( QgsPointV2( QgsWkbTypes::PointZ, 1, 2, 2 ).project( 5, 90, 45 ) ), 45.0 );
+  QCOMPARE( QgsPointV2( QgsWkbTypes::PointZ, 1, 2, 2 ).inclination( QgsPointV2( QgsWkbTypes::PointZ, 1, 2, 2 ).project( 5, 90, 135 ) ), 135.0 );
+
 }
 
 void TestQgsGeometry::lineString()