add QgsDistanceArea tests and enhance QgsGeometry tests a bit

(in preparation for a QgsGeometry wkb update)

Author: jef-n

python/core/qgsgeometry.sip

@@ -199,7 +199,7 @@ class QgsGeometry
      * Searches for the closest vertex in this geometry to the given point.
      * @param point Specifiest the point for search
      * @param atVertex Receives index of the closest vertex
-     * @return The squared cartesian distance is also returned in sqrDist, negative number on error
+     * @return The squared cartesian distance, negative number on error
      */
     double closestVertexWithContext( const QgsPoint& point, int& atVertex /Out/ );
 
@@ -213,7 +213,7 @@ class QgsGeometry
      * @param epsilon epsilon for segment snapping (added in 1.8)
      * @return The squared cartesian distance is also returned in sqrDist, negative number on error
      */
-    double closestSegmentWithContext( const QgsPoint& point, QgsPoint& minDistPoint /Out/, int& beforeVertex /Out/ );
+    double closestSegmentWithContext( const QgsPoint& point, QgsPoint& minDistPoint /Out/, int& afterVertex /Out/ );
 
     /**Adds a new ring to this geometry. This makes only sense for polygon and multipolygons.
      @return 0 in case of success (ring added), 1 problem with geometry type, 2 ring not closed,

tests/src/python/CMakeLists.txt

@@ -33,3 +33,4 @@ ADD_PYTHON_TEST(PyQgsVectorFileWriter test_qgsvectorfilewriter.py)
 ADD_PYTHON_TEST(PyQgsSpatialiteProvider test_qgsspatialiteprovider.py)
 ADD_PYTHON_TEST(PyQgsZonalStatistics test_qgszonalstatistics.py)
 ADD_PYTHON_TEST(PyQgsAppStartup test_qgsappstartup.py)
+ADD_PYTHON_TEST(PyQgsDistanceArea test_qgsdistancearea.py)

tests/src/python/test_qgsdistancearea.py

@@ -0,0 +1,128 @@
+# -*- coding: utf-8 -*-
+"""QGIS Unit tests for QgsDistanceArea.
+
+.. note:: This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+"""
+__author__ = 'Jürgen E. Fischer'
+__date__ = '19/01/2014'
+__copyright__ = 'Copyright 2014, The QGIS Project'
+# This will get replaced with a git SHA1 when you do a git archive
+__revision__ = '$Format:%H$'
+
+import os
+
+import qgis
+
+from qgis.core import (QgsGeometry,
+                       QgsPoint,
+                       QgsDistanceArea,
+                       QGis)
+
+from utilities import (getQgisTestApp,
+                       TestCase,
+                       unittest)
+
+from PyQt4.QtCore import qDebug
+
+# Convenience instances in case you may need them
+# not used in this test
+
+QGISAPP, CANVAS, IFACE, PARENT = getQgisTestApp()
+
+class TestQgsDistanceArea(TestCase):
+
+    def testMeasureLine(self):
+        #   +-+
+        #   | |
+        # +-+ +
+	linestring = QgsGeometry.fromPolyline(
+          [ QgsPoint(0,0), QgsPoint(1,0), QgsPoint(1,1), QgsPoint(2,1), QgsPoint(2,0), ]
+	)
+	da = QgsDistanceArea()
+        length = da.measure(linestring)
+	myMessage = ('Expected:\n%f\nGot:\n%f\n' %
+		      (4, length))
+        assert length == 4, myMessage
+
+    def testMeasureMultiLine(self):
+        #   +-+ +-+-+
+        #   | | |   |
+        # +-+ + +   +-+
+	linestring = QgsGeometry.fromMultiPolyline(
+	  [
+            [ QgsPoint(0,0), QgsPoint(1,0), QgsPoint(1,1), QgsPoint(2,1), QgsPoint(2,0), ],
+            [ QgsPoint(3,0), QgsPoint(3,1), QgsPoint(5,1), QgsPoint(5,0), QgsPoint(6,0), ]
+          ]
+	)
+	da = QgsDistanceArea()
+        length = da.measure(linestring)
+	myMessage = ('Expected:\n%f\nGot:\n%f\n' %
+		      (9, length))
+        assert length == 9, myMessage
+
+    def testMeasurePolygon(self):
+	# +-+-+
+        # |   |
+        # + +-+
+	# | |
+        # +-+
+        polygon = QgsGeometry.fromPolygon(
+          [[
+            QgsPoint(0,0), QgsPoint(1,0), QgsPoint(1,1), QgsPoint(2,1), QgsPoint(2,2), QgsPoint(0,2), QgsPoint(0,0),
+          ]]
+        )
+
+	da = QgsDistanceArea()
+        area = da.measure(polygon)
+        assert area == 3, 'Expected:\n%f\nGot:\n%f\n' % (3, area)
+
+	perimeter = da.measurePerimeter(polygon)
+        assert perimeter == 8, 'Expected:\n%f\nGot:\n%f\n' % (8, perimeter)
+
+    def testMeasurePolygonWithHole(self):
+	# +-+-+-+
+        # |     |
+        # + +-+ +
+        # | | | |
+        # + +-+ +
+        # |     |
+	# +-+-+-+
+        polygon = QgsGeometry.fromPolygon(
+          [
+	    [ QgsPoint(0,0), QgsPoint(3,0), QgsPoint(3,3), QgsPoint(0,3), QgsPoint(0,0) ],
+	    [ QgsPoint(1,1), QgsPoint(2,1), QgsPoint(2,2), QgsPoint(1,2), QgsPoint(1,1) ],
+          ]
+        )
+	da = QgsDistanceArea()
+        area = da.measure(polygon)
+        assert area == 8, "Expected:\n%f\nGot:\n%f\n" % (8, area)
+
+	perimeter = da.measurePerimeter(polygon)
+        assert perimeter == 12, "Expected:\n%f\nGot:\n%f\n" % (12, perimeter)
+
+    def testMeasureMultiPolygon(self):
+	# +-+-+ +-+-+
+        # |   | |   |
+        # + +-+ +-+ +
+	# | |     | |
+        # +-+     +-+
+        polygon = QgsGeometry.fromMultiPolygon(
+	  [
+	    [ [ QgsPoint(0,0), QgsPoint(1,0), QgsPoint(1,1), QgsPoint(2,1), QgsPoint(2,2), QgsPoint(0,2), QgsPoint(0,0), ] ],
+            [ [ QgsPoint(4,0), QgsPoint(5,0), QgsPoint(5,2), QgsPoint(3,2), QgsPoint(3,1), QgsPoint(4,1), QgsPoint(4,0), ] ]
+	  ]
+        )
+
+	da = QgsDistanceArea()
+        area = da.measure(polygon)
+        assert area == 6, 'Expected:\n%f\nGot:\n%f\n' % (6, area)
+
+	perimeter = da.measurePerimeter(polygon)
+        assert perimeter == 16, "Expected:\n%f\nGot:\n%f\n" % (16, perimeter)
+
+if __name__ == '__main__':
+    unittest.main()
+