Merge pull request #5118 from nyalldawson/label_rotate

Fix rotate label tool

Author: nyalldawson

src/app/qgsmaptoolrotatelabel.cpp

@@ -75,7 +75,7 @@ void QgsMapToolRotateLabel::canvasPressEvent( QgsMapMouseEvent *e )
 
   if ( true )
   {
-    mCurrentMouseAzimuth = azimuthToCCW( mRotationPoint.azimuth( toMapCoordinates( e->pos() ) ) );
+    mCurrentMouseAzimuth = convertAzimuth( mRotationPoint.azimuth( toMapCoordinates( e->pos() ) ) );
 
     bool hasRotationValue;
     int rotationCol;
@@ -91,8 +91,7 @@ void QgsMapToolRotateLabel::canvasPressEvent( QgsMapMouseEvent *e )
       mRotationPreviewBox = createRotationPreviewBox();
 
       mRotationItem = new QgsPointRotationItem( mCanvas );
-      mRotationItem->setOrientation( QgsPointRotationItem::Counterclockwise );
-      mRotationItem->setSymbol( QgsApplication::getThemePixmap( QStringLiteral( "mActionRotatePointSymbols.svg" ) ).toImage() );
+      mRotationItem->setOrientation( QgsPointRotationItem::Clockwise );
       mRotationItem->setPointLocation( mRotationPoint );
       mRotationItem->setSymbolRotation( mCurrentRotation );
     }
@@ -104,15 +103,17 @@ void QgsMapToolRotateLabel::canvasMoveEvent( QgsMapMouseEvent *e )
   if ( mLabelRubberBand )
   {
     QgsPointXY currentPoint = toMapCoordinates( e->pos() );
-    double azimuth = azimuthToCCW( mRotationPoint.azimuth( currentPoint ) );
+    double azimuth = convertAzimuth( mRotationPoint.azimuth( currentPoint ) );
     double azimuthDiff = azimuth - mCurrentMouseAzimuth;
     azimuthDiff = azimuthDiff > 180 ? azimuthDiff - 360 : azimuthDiff;
 
     mCurrentRotation += azimuthDiff;
-    mCurrentRotation = mCurrentRotation - static_cast<float>( static_cast<int>( mCurrentRotation / 360 ) ) * 360; //mCurrentRotation % 360;
-    mCurrentRotation = mCurrentRotation < 0 ? 360 - mCurrentRotation : mCurrentRotation;
+    if ( mCurrentRotation >= 360 || mCurrentRotation <= -360 )
+      mCurrentRotation = std::fmod( mCurrentRotation, 360.0 );
+    if ( mCurrentRotation < 0 )
+      mCurrentRotation += 360.0;
 
-    mCurrentMouseAzimuth = azimuth - static_cast<float>( static_cast<int>( azimuth / 360 ) ) * 360;
+    mCurrentMouseAzimuth = std::fmod( azimuth, 360.0 );
 
     //if shift-modifier is pressed, round to 15 degrees
     int displayValue;
@@ -181,9 +182,10 @@ int QgsMapToolRotateLabel::roundTo15Degrees( double n )
   return ( m * 15 );
 }
 
-double QgsMapToolRotateLabel::azimuthToCCW( double a )
+double QgsMapToolRotateLabel::convertAzimuth( double a )
 {
-  return ( a > 0 ? 360 - a : -a );
+  a -= 90; // convert from 0 = north to 0 = east
+  return ( a <= -180.0 ? 360 + a : a );
 }
 
 QgsRubberBand *QgsMapToolRotateLabel::createRotationPreviewBox()
@@ -218,15 +220,15 @@ void QgsMapToolRotateLabel::setRotationPreviewBox( double rotation )
 
   for ( int i = 0; i < boxPoints.size(); ++i )
   {
-    mRotationPreviewBox->addPoint( rotatePointCounterClockwise( boxPoints.at( i ), mRotationPoint, rotation ) );
+    mRotationPreviewBox->addPoint( rotatePointClockwise( boxPoints.at( i ), mRotationPoint, rotation ) );
   }
-  mRotationPreviewBox->addPoint( rotatePointCounterClockwise( boxPoints.at( 0 ), mRotationPoint, rotation ) );
+  mRotationPreviewBox->addPoint( rotatePointClockwise( boxPoints.at( 0 ), mRotationPoint, rotation ) );
   mRotationPreviewBox->show();
 }
 
-QgsPointXY QgsMapToolRotateLabel::rotatePointCounterClockwise( const QgsPointXY &input, const QgsPointXY &centerPoint, double degrees )
+QgsPointXY QgsMapToolRotateLabel::rotatePointClockwise( const QgsPointXY &input, const QgsPointXY &centerPoint, double degrees ) const
 {
-  double rad = degrees / 180 * M_PI;
+  double rad = -degrees / 180 * M_PI;
   double v1x = input.x() - centerPoint.x();
   double v1y = input.y() - centerPoint.y();
 

src/app/qgsmaptoolrotatelabel.h

@@ -37,14 +37,14 @@ class APP_EXPORT QgsMapToolRotateLabel: public QgsMapToolLabel
   protected:
 
     static int roundTo15Degrees( double n );
-    //! Converts azimuth value to counterclockwise 0 - 360
-    static double azimuthToCCW( double a );
+    //! Converts azimuth value so that 0 is corresponds to East
+    static double convertAzimuth( double a );
 
     QgsRubberBand *createRotationPreviewBox();
     void setRotationPreviewBox( double rotation );
 
-    //! Rotates input point counterclockwise around centerPoint
-    QgsPointXY rotatePointCounterClockwise( const QgsPointXY &input, const QgsPointXY &centerPoint, double degrees );
+    //! Rotates input point clockwise around centerPoint
+    QgsPointXY rotatePointClockwise( const QgsPointXY &input, const QgsPointXY &centerPoint, double degrees ) const;
 
     double mStartRotation; //rotation value prior to start rotating
     double mCurrentRotation;

src/app/qgspointrotationitem.cpp

@@ -25,14 +25,10 @@ QgsPointRotationItem::QgsPointRotationItem( QgsMapCanvas *canvas )
   //setup font
   mFont.setPointSize( 12 );
   mFont.setBold( true );
-}
-
-QgsPointRotationItem::QgsPointRotationItem()
-  : QgsMapCanvasItem( nullptr )
-  , mOrientation( Clockwise )
-  , mRotation( 0.0 )
-{
 
+  QImage im( 24, 24, QImage::Format_ARGB32 );
+  im.fill( Qt::transparent );
+  setSymbol( im );
 }
 
 QgsPointRotationItem::~QgsPointRotationItem()

src/app/qgspointrotationitem.h

@@ -51,7 +51,7 @@ class APP_EXPORT QgsPointRotationItem: public QgsMapCanvasItem
     Orientation orientation() const { return mOrientation; }
 
   private:
-    QgsPointRotationItem();
+
     //! Converts rotation into QPainter rotation considering mOrientation
     int painterRotation( int rotation ) const;
     //! Clockwise (default) or counterclockwise