[composer] Fix order of vertices returned by mapPolygon when map rota…

…tion is set, fix drawing overview frame when either map is rotated (fix #10644)

python/core/composer/qgscomposermap.sip

@@ -141,8 +141,11 @@ class QgsComposerMap : QgsComposerItem
     void toggleAtlasPreview();
 
     /**Returns a pointer to the current map extent, which is either the original user specified
-      extent or the temporary atlas-driven feature extent depending on the current atlas state of the composition.
-      Both a const and non-const version are included.*/
+     * extent or the temporary atlas-driven feature extent depending on the current atlas state
+     * of the composition. Both a const and non-const version are included.
+     * @returns pointer to current map extent
+     * @see visibleExtentPolygon
+    */
     const QgsRectangle* currentMapExtent() const;
 
     PreviewMode previewMode() const;
@@ -478,6 +481,14 @@ class QgsComposerMap : QgsComposerItem
     */
     int numberExportLayers() const;
 
+    /**Returns a polygon representing the current visible map extent, considering map extents and rotation.
+     * If the map rotation is 0, the result is the same as currentMapExtent
+     * @returns polygon with the four corner points representing the visible map extent. The points are
+     * clockwise, starting at the top-left point
+     * @see currentMapExtent
+    */
+    QPolygonF visibleExtentPolygon() const;
+
   signals:
     void extentChanged();
 

src/core/composer/qgscomposermap.cpp

@@ -2075,8 +2075,7 @@ QPolygonF QgsComposerMap::transformedMapPolygon() const
   //qWarning("transformed:");
   //qWarning(QString::number(dx).toLocal8Bit().data());
   //qWarning(QString::number(dy).toLocal8Bit().data());
-  QPolygonF poly;
-  mapPolygon( poly );
+  QPolygonF poly = visibleExtentPolygon();
   poly.translate( -dx, -dy );
   return poly;
 }
@@ -2146,30 +2145,32 @@ void QgsComposerMap::mapPolygon( const QgsRectangle& extent, QPolygonF& poly ) c
   dx = rotationPoint.x() - extent.xMinimum();
   dy = rotationPoint.y() - extent.yMaximum();
   rotate( mMapRotation, dx, dy );
-  poly << QPointF( rotationPoint.x() + dx, rotationPoint.y() + dy );
+  poly << QPointF( rotationPoint.x() - dx, rotationPoint.y() - dy );
 
   //top right point
   dx = rotationPoint.x() - extent.xMaximum();
   dy = rotationPoint.y() - extent.yMaximum();
   rotate( mMapRotation, dx, dy );
-  poly << QPointF( rotationPoint.x() + dx, rotationPoint.y() + dy );
+  poly << QPointF( rotationPoint.x() - dx, rotationPoint.y() - dy );
 
   //bottom right point
   dx = rotationPoint.x() - extent.xMaximum();
   dy = rotationPoint.y() - extent.yMinimum();
   rotate( mMapRotation, dx, dy );
-  poly << QPointF( rotationPoint.x() + dx, rotationPoint.y() + dy );
+  poly << QPointF( rotationPoint.x() - dx, rotationPoint.y() - dy );
 
   //bottom left point
   dx = rotationPoint.x() - extent.xMinimum();
   dy = rotationPoint.y() - extent.yMinimum();
   rotate( mMapRotation, dx, dy );
-  poly << QPointF( rotationPoint.x() + dx, rotationPoint.y() + dy );
+  poly << QPointF( rotationPoint.x() - dx, rotationPoint.y() - dy );
 }
 
-void QgsComposerMap::mapPolygon( QPolygonF& poly ) const
+QPolygonF QgsComposerMap::visibleExtentPolygon() const
 {
-  return mapPolygon( *currentMapExtent(), poly );
+  QPolygonF poly;
+  mapPolygon( *currentMapExtent(), poly );
+  return poly;
 }
 
 void QgsComposerMap::requestedExtent( QgsRectangle& extent ) const
@@ -2569,9 +2570,13 @@ void QgsComposerMap::drawOverviewMapExtent( QPainter* p )
     return;
   }
 
-  QgsRectangle otherExtent = *overviewFrameMap->currentMapExtent();
-  QgsRectangle thisExtent = *currentMapExtent();
-  QgsRectangle intersectRect = thisExtent.intersect( &otherExtent );
+  //get polygon for other overview frame map's extent (use visibleExtentPolygon as it accounts for map rotation)
+  QPolygonF otherExtent = overviewFrameMap->visibleExtentPolygon();
+
+  //get current map's extent as a QPolygonF
+  QPolygonF thisExtent = visibleExtentPolygon();
+  //intersect the two
+  QPolygonF intersectExtent = thisExtent.intersected( otherExtent );
 
   //setup painter scaling to dots so that raster symbology is drawn to scale
   double dotsPerMM = p->device()->logicalDpiX() / 25.4;
@@ -2596,12 +2601,15 @@ void QgsComposerMap::drawOverviewMapExtent( QPainter* p )
 
   //construct a polygon corresponding to the intersecting map extent
   //need to scale line to dots, rather then mm, since the painter has been scaled to dots
+  QTransform mapTransform;
+  QPolygonF thisRectPoly = QPolygonF( QRectF( 0, 0, dotsPerMM *  rect().width(), dotsPerMM *  rect().height() ) );
+
+  //workaround QT Bug #21329
+  thisRectPoly.pop_back();
+  //create transform from map coordinates to painter coordinates
+  QTransform::quadToQuad( thisExtent, thisRectPoly, mapTransform );
   QPolygonF intersectPolygon;
-  double x = dotsPerMM * ( intersectRect.xMinimum() - thisExtent.xMinimum() ) / thisExtent.width() * rect().width();
-  double y = dotsPerMM * ( thisExtent.yMaximum() - intersectRect.yMaximum() ) / thisExtent.height() * rect().height();
-  double width = dotsPerMM * intersectRect.width() / thisExtent.width() * rect().width();
-  double height = dotsPerMM * intersectRect.height() / thisExtent.height() * rect().height();
-  intersectPolygon << QPointF( x, y ) << QPointF( x + width, y ) << QPointF( x + width, y + height ) << QPointF( x, y + height ) << QPointF( x, y );
+  intersectPolygon = mapTransform.map( intersectExtent );
 
   QList<QPolygonF> rings; //empty list
   if ( !mOverviewInverted )

src/core/composer/qgscomposermap.h

@@ -175,8 +175,11 @@ class CORE_EXPORT QgsComposerMap : public QgsComposerItem
     void toggleAtlasPreview();
 
     /**Returns a pointer to the current map extent, which is either the original user specified
-      extent or the temporary atlas-driven feature extent depending on the current atlas state of the composition.
-      Both a const and non-const version are included.*/
+     * extent or the temporary atlas-driven feature extent depending on the current atlas state
+     * of the composition. Both a const and non-const version are included.
+     * @returns pointer to current map extent
+     * @see visibleExtentPolygon
+    */
     QgsRectangle* currentMapExtent();
     const QgsRectangle* currentMapExtent() const;
 
@@ -513,6 +516,14 @@ class CORE_EXPORT QgsComposerMap : public QgsComposerItem
     */
     int numberExportLayers() const;
 
+    /**Returns a polygon representing the current visible map extent, considering map extents and rotation.
+     * If the map rotation is 0, the result is the same as currentMapExtent
+     * @returns polygon with the four corner points representing the visible map extent. The points are
+     * clockwise, starting at the top-left point
+     * @see currentMapExtent
+    */
+    QPolygonF visibleExtentPolygon() const;
+
   signals:
     void extentChanged();
 
@@ -703,10 +714,7 @@ class CORE_EXPORT QgsComposerMap : public QgsComposerItem
     /**Returns extent that considers rotation and shift with mOffsetX / mOffsetY*/
     QPolygonF transformedMapPolygon() const;
     double maxExtension() const;
-    /**Returns the polygon of the map extent. If rotation == 0, the result is the same as mExtent
-    @param poly out: the result polygon with the four corner points. The points are clockwise, starting at the top-left point
-    @return true in case of success*/
-    void mapPolygon( QPolygonF& poly ) const;
+
     /** mapPolygon variant using a given extent */
     void mapPolygon( const QgsRectangle& extent, QPolygonF& poly ) const;
 

tests/src/core/testqgscomposermap.cpp

@@ -39,12 +39,15 @@ class TestQgsComposerMap: public QObject
     void grid(); //test if grid and grid annotation works
     void crossGrid(); //test if grid "cross" mode works
     void overviewMap(); //test if overview map frame works
+    void overviewMapRotated(); //test if overview map frame works with rotated overview
+    void overviewMapRotated2(); //test if overview map frame works with rotated map
     void overviewMapBlending(); //test if blend modes with overview map frame works
     void overviewMapInvert(); //test if invert of overview map frame works
     void uniqueId(); //test if map id is adapted when doing copy paste
     void zebraStyle(); //test zebra map border style
     void overviewMapCenter(); //test if centering of overview map frame works
     void worldFileGeneration(); // test world file generation
+    void mapPolygonVertices(); // test mapPolygon function with no map rotation
 
   private:
     QgsComposition* mComposition;
@@ -176,6 +179,39 @@ void TestQgsComposerMap::overviewMap()
   QVERIFY( testResult );
 }
 
+void TestQgsComposerMap::overviewMapRotated()
+{
+  QgsComposerMap* overviewMap = new QgsComposerMap( mComposition, 20, 130, 70, 70 );
+  overviewMap->setFrameEnabled( true );
+  mComposition->addComposerMap( overviewMap );
+  mComposerMap->setNewExtent( QgsRectangle( 785462.375, 3341423.125, 789262.375, 3343323.125 ) ); //zoom in
+  mComposerMap->setMapRotation( 30 );
+  overviewMap->setNewExtent( QgsRectangle( 781662.375, 3339523.125, 793062.375, 3350923.125 ) );
+  overviewMap->setOverviewFrameMap( mComposerMap->id() );
+  QgsCompositionChecker checker( "composermap_overview_rotated", mComposition );
+
+  bool testResult = checker.testComposition( mReport, 0, 100 );
+  mComposition->removeComposerItem( overviewMap );
+  mComposerMap->setMapRotation( 0 );
+  QVERIFY( testResult );
+}
+
+void TestQgsComposerMap::overviewMapRotated2()
+{
+  QgsComposerMap* overviewMap = new QgsComposerMap( mComposition, 20, 130, 70, 70 );
+  overviewMap->setFrameEnabled( true );
+  mComposition->addComposerMap( overviewMap );
+  mComposerMap->setNewExtent( QgsRectangle( 785462.375, 3341423.125, 789262.375, 3343323.125 ) ); //zoom in
+  overviewMap->setMapRotation( 30 );
+  overviewMap->setNewExtent( QgsRectangle( 781662.375, 3339523.125, 793062.375, 3350923.125 ) );
+  overviewMap->setOverviewFrameMap( mComposerMap->id() );
+  QgsCompositionChecker checker( "composermap_overview_rotated2", mComposition );
+
+  bool testResult = checker.testComposition( mReport, 0, 100 );
+  mComposition->removeComposerItem( overviewMap );
+  QVERIFY( testResult );
+}
+
 void TestQgsComposerMap::overviewMapBlending()
 {
   QgsComposerMap* overviewMapBlend = new QgsComposerMap( mComposition, 20, 130, 70, 70 );
@@ -292,6 +328,43 @@ void TestQgsComposerMap::worldFileGeneration()
   QVERIFY( fabs( d - 2.4136 ) < 0.001 );
   QVERIFY( fabs( e + 4.17997 ) < 0.001 );
   QVERIFY( fabs( f - 3.34241e+06 ) < 1e+03 );
+
+  mComposition->setGenerateWorldFile( false );
+  mComposerMap->setMapRotation( 0.0 );
+
+}
+
+void TestQgsComposerMap::mapPolygonVertices()
+{
+  mComposerMap->setNewExtent( QgsRectangle( 781662.375, 3339523.125, 793062.375, 3345223.125 ) );
+  QPolygonF visibleExtent = mComposerMap->visibleExtentPolygon();
+
+  //vertices should be returned in clockwise order starting at the top-left point
+  QVERIFY( fabs( visibleExtent[0].x() - 781662.375 ) < 0.001 );
+  QVERIFY( fabs( visibleExtent[0].y() - 3345223.125 ) < 0.001 );
+  QVERIFY( fabs( visibleExtent[1].x() - 793062.375 ) < 0.001 );
+  QVERIFY( fabs( visibleExtent[1].y() - 3345223.125 ) < 0.001 );
+  QVERIFY( fabs( visibleExtent[2].x() - 793062.375 ) < 0.001 );
+  QVERIFY( fabs( visibleExtent[2].y() - 3339523.125 ) < 0.001 );
+  QVERIFY( fabs( visibleExtent[3].x() - 781662.375 ) < 0.001 );
+  QVERIFY( fabs( visibleExtent[3].y() - 3339523.125 ) < 0.001 );
+
+  //now test with rotated map
+  mComposerMap->setMapRotation( 10 );
+  visibleExtent = mComposerMap->visibleExtentPolygon();
+
+  //vertices should be returned in clockwise order starting at the top-left point
+  QVERIFY( fabs( visibleExtent[0].x() - 781254.0735015 ) < 0.001 );
+  QVERIFY( fabs( visibleExtent[0].y() - 3344190.0324834 ) < 0.001 );
+  QVERIFY( fabs( visibleExtent[1].x() - 792480.881886 ) < 0.001 );
+  QVERIFY( fabs( visibleExtent[1].y() - 3346169.62171 ) < 0.001 );
+  QVERIFY( fabs( visibleExtent[2].x() - 793470.676499 ) < 0.001 );
+  QVERIFY( fabs( visibleExtent[2].y() - 3340556.21752 ) < 0.001 );
+  QVERIFY( fabs( visibleExtent[3].x() - 782243.868114 ) < 0.001 );
+  QVERIFY( fabs( visibleExtent[3].y() - 3338576.62829 ) < 0.001 );
+
+  mComposerMap->setMapRotation( 0 );
+
 }
 
 QTEST_MAIN( TestQgsComposerMap )