Add an easy to use Z/M default value constructor to QgsPoint

Author: m-kuhn

python/core/geometry/qgspoint.sip

@@ -22,9 +22,36 @@ class QgsPoint: QgsAbstractGeometry
 %End
   public:
 
-    QgsPoint( double x = 0.0, double y = 0.0, double z = 0.0, double m = 0.0 );
-%Docstring
- Construct a point with the provided initial coordinate values.
+    QgsPoint( double x = 0.0, double y = 0.0, SIP_PYOBJECT z = Py_None, SIP_PYOBJECT m = Py_None ) [( double x = 0.0, double y = 0.0, double z = 0.0, double m = 0.0 )];
+    % Docstring
+    Construct a point with the provided initial coordinate values.
+
+    If only z and m are not specified, the type will be a 2D point.
+    If any or both of the others are specified, the Z and M values will be added accordingly.
+%End
+%MethodCode
+    double z;
+    double m;
+
+    if ( a2 == Py_None )
+    {
+      z = std::numeric_limits<double>::quiet_NaN();
+    }
+    else
+    {
+      z = PyFloat_AsDouble( a2 );
+    }
+
+    if ( a3 == Py_None )
+    {
+      m = std::numeric_limits<double>::quiet_NaN();
+    }
+    else
+    {
+      m = PyFloat_AsDouble( a3 );
+    }
+
+    sipCpp = new sipQgsPoint( a0, a1, z, m );
 %End
 
     explicit QgsPoint( const QgsPointXY &p );

src/core/geometry/qgspoint.cpp

@@ -38,7 +38,17 @@ QgsPoint::QgsPoint( double x, double y, double z, double m )
   , mZ( z )
   , mM( m )
 {
-  mWkbType = QgsWkbTypes::Point;
+  if ( qIsNaN( z ) )
+  {
+    if ( qIsNaN( m ) )
+      mWkbType = QgsWkbTypes::Point;
+    else
+      mWkbType = QgsWkbTypes::PointM;
+  }
+  else if ( qIsNaN( m ) )
+    mWkbType = QgsWkbTypes::PointZ;
+  else
+    mWkbType = QgsWkbTypes::PointZM;
 }
 
 QgsPoint::QgsPoint( const QgsPointXY &p )

src/core/geometry/qgspoint.h

@@ -46,8 +46,44 @@ class CORE_EXPORT QgsPoint: public QgsAbstractGeometry
 
     /**
      * Construct a point with the provided initial coordinate values.
+     *
+     * If only z and m are not specified, the type will be a 2D point.
+     * If any or both of the others are specified, the Z and M values will be added accordingly.
      */
-    QgsPoint( double x = 0.0, double y = 0.0, double z = 0.0, double m = 0.0 );
+    QgsPoint( double x = 0.0, double y = 0.0, double z = std::numeric_limits<double>::quiet_NaN(), double m = std::numeric_limits<double>::quiet_NaN() ) SIP_SKIP;
+#ifdef SIP_RUN
+    QgsPoint( double x = 0.0, double y = 0.0, SIP_PYOBJECT z = Py_None, SIP_PYOBJECT m = Py_None ) [( double x = 0.0, double y = 0.0, double z = 0.0, double m = 0.0 )];
+    % Docstring
+    Construct a point with the provided initial coordinate values.
+
+    If only z and m are not specified, the type will be a 2D point.
+    If any or both of the others are specified, the Z and M values will be added accordingly.
+    % End
+    % MethodCode
+    double z;
+    double m;
+
+    if ( a2 == Py_None )
+    {
+      z = std::numeric_limits<double>::quiet_NaN();
+    }
+    else
+    {
+      z = PyFloat_AsDouble( a2 );
+    }
+
+    if ( a3 == Py_None )
+    {
+      m = std::numeric_limits<double>::quiet_NaN();
+    }
+    else
+    {
+      m = PyFloat_AsDouble( a3 );
+    }
+
+    sipCpp = new sipQgsPoint( a0, a1, z, m );
+    % End
+#endif
 
     /** Construct a QgsPoint from a QgsPointXY object
      */

tests/src/python/test_qgsgeometry.py

@@ -4129,6 +4129,12 @@ def testCompare(self):
         self.assertFalse(QgsGeometry.compare(lp, lp2))
         self.assertTrue(QgsGeometry.compare(lp, lp2, 1e-6))
 
+    def testPoint(self):
+        self.assertEqual(QgsPoint(1, 2).wkbType(), QgsWkbTypes.Point)
+        self.assertEqual(QgsPoint(1, 2, 3).wkbType(), QgsWkbTypes.PointZ)
+        self.assertEqual(QgsPoint(1, 2, m=3).wkbType(), QgsWkbTypes.PointM)
+        self.assertEqual(QgsPoint(1, 2, 3, 4).wkbType(), QgsWkbTypes.PointZM)
+
 
 if __name__ == '__main__':
     unittest.main()