Port dxf export improvements to QGIS 3

Author: mhugent

python/core/auto_generated/dxf/qgsdxfexport.sip.in

@@ -397,10 +397,21 @@ Write mtext (MTEXT)
 .. versionadded:: 2.15
 %End
 
-    static double mapUnitScaleFactor( double scale, QgsUnitTypes::RenderUnit symbolUnits, QgsUnitTypes::DistanceUnit mapUnits );
+    static double mapUnitScaleFactor( double scaleDenominator, QgsUnitTypes::RenderUnit symbolUnits, QgsUnitTypes::DistanceUnit mapUnits, double mapUnitsPerPixel = 1.0 );
 %Docstring
-Calculates a scaling factor to convert from map units to a specified symbol unit.
-The ``scale`` parameter indicates the scale denominator, e.g. 1000.0 for a 1:1000 map.
+Returns scale factor for conversion to map units
+@param scaleDenominator the map scale denominator
+@param symbolUnits the symbol output units
+@param mapUnits the map units
+@param mapUnitsPerPixel Map units per pixel*
+%End
+
+    void clipValueToMapUnitScale( double &value, const QgsMapUnitScale &scale, double pixelToMMFactor ) const;
+%Docstring
+Clips value to scale minimum/maximum
+@param value the value to clip
+@param scale the scale dependent minimum/maximum values
+@param pixelToMMFactor pixels per mm*
 %End
 
     static QString dxfLayerName( const QString &name );

src/core/dxf/qgsdxfexport.cpp

@@ -930,7 +930,7 @@ void QgsDxfExport::writeBlocks()
     writeGroup( 1, QLatin1String( "" ) );
 
     // maplayer 0 -> block receives layer from INSERT statement
-    ml->writeDxf( *this, mapUnitScaleFactor( mSymbologyScale, ml->sizeUnit(), mMapUnits ), QStringLiteral( "0" ), ctx );
+    ml->writeDxf( *this, mapUnitScaleFactor( mSymbologyScale, ml->sizeUnit(), mMapUnits, ctx.renderContext().mapToPixel().mapUnitsPerPixel() ), QStringLiteral( "0" ), ctx );
 
     writeGroup( 0, QStringLiteral( "ENDBLK" ) );
     writeHandle();
@@ -966,6 +966,9 @@ void QgsDxfExport::writeEntities()
   ctx.setMapToPixel( QgsMapToPixel( 1.0 / mFactor, mExtent.center().x(), mExtent.center().y(), mExtent.width() * mFactor,
                                     mExtent.height() * mFactor, 0 ) );
 
+  ctx.expressionContext().appendScope( QgsExpressionContextUtils::projectScope( QgsProject::instance() ) );
+  ctx.expressionContext().appendScope( QgsExpressionContextUtils::globalScope() );
+
   // label engine
   QgsLabelingEngine engine;
   engine.setMapSettings( mMapSettings );
@@ -3435,7 +3438,7 @@ void QgsDxfExport::writePoint( const QgsPoint &pt, const QString &layer, const Q
     const QgsMarkerSymbolLayer *msl = dynamic_cast< const QgsMarkerSymbolLayer * >( symbolLayer );
     if ( msl && symbol )
     {
-      if ( symbolLayer->writeDxf( *this, mapUnitScaleFactor( mSymbologyScale, msl->sizeUnit(), mMapUnits ), layer, ctx, QPointF( pt.x(), pt.y() ) ) )
+      if ( symbolLayer->writeDxf( *this, mapUnitScaleFactor( mSymbologyScale, msl->sizeUnit(), mMapUnits, ctx.renderContext().mapToPixel().mapUnitsPerPixel() ), layer, ctx, QPointF( pt.x(), pt.y() ) ) )
       {
         return;
       }
@@ -3982,14 +3985,53 @@ QgsRenderContext QgsDxfExport::renderContext() const
   return context;
 }
 
-double QgsDxfExport::mapUnitScaleFactor( double scale, QgsUnitTypes::RenderUnit symbolUnits, QgsUnitTypes::DistanceUnit mapUnits )
+double QgsDxfExport::mapUnitScaleFactor( double scaleDenominator, QgsUnitTypes::RenderUnit symbolUnits, QgsUnitTypes::DistanceUnit mapUnits, double mapUnitsPerPixel )
 {
   if ( symbolUnits == QgsUnitTypes::RenderMapUnits )
   {
     return 1.0;
   }
-  // MM symbol unit
-  return scale * QgsUnitTypes::fromUnitToUnitFactor( QgsUnitTypes::DistanceMeters, mapUnits ) / 1000.0;
+  else if ( symbolUnits == QgsUnitTypes::RenderMillimeters )
+  {
+    return ( scaleDenominator * QgsUnitTypes::fromUnitToUnitFactor( QgsUnitTypes::DistanceMeters, mapUnits ) / 1000.0 );
+  }
+  else if ( symbolUnits == QgsUnitTypes::RenderPixels )
+  {
+    return mapUnitsPerPixel;
+  }
+  return 1.0;
+}
+
+void QgsDxfExport::clipValueToMapUnitScale( double &value, const QgsMapUnitScale &scale, double pixelToMMFactor ) const
+{
+  if ( !scale.minSizeMMEnabled && !scale.maxSizeMMEnabled )
+  {
+    return;
+  }
+
+  double mapUnitsPerPixel = mMapSettings.mapToPixel().mapUnitsPerPixel();
+
+  double minSizeMU = -DBL_MAX;
+  if ( scale.minSizeMMEnabled )
+  {
+    minSizeMU = scale.minSizeMM * pixelToMMFactor * mapUnitsPerPixel;
+  }
+  if ( !qgsDoubleNear( scale.minScale, 0.0 ) )
+  {
+    minSizeMU = qMax( minSizeMU, value );
+  }
+  value = qMax( value, minSizeMU );
+
+  double maxSizeMU = DBL_MAX;
+  if ( scale.maxSizeMMEnabled )
+  {
+    maxSizeMU = scale.maxSizeMM * pixelToMMFactor * mapUnitsPerPixel;
+  }
+  if ( !qgsDoubleNear( scale.maxScale, 0.0 ) )
+  {
+    maxSizeMU = qMin( maxSizeMU, value );
+  }
+  value = qMin( value, maxSizeMU );
 }
 
 QList< QPair< QgsSymbolLayer *, QgsSymbol * > > QgsDxfExport::symbolLayers( QgsRenderContext &context )
@@ -4122,7 +4164,7 @@ void QgsDxfExport::writeLinetype( const QString &styleName, const QVector<qreal>
   QVector<qreal>::const_iterator dashIt = pattern.constBegin();
   for ( ; dashIt != pattern.constEnd(); ++dashIt )
   {
-    length += ( *dashIt * mapUnitScaleFactor( mSymbologyScale, u, mMapUnits ) );
+    length += ( *dashIt * mapUnitScaleFactor( mSymbologyScale, u, mMapUnits, mMapSettings.mapToPixel().mapUnitsPerPixel() ) );
   }
 
   writeGroup( 0, QStringLiteral( "LTYPE" ) );
@@ -4143,7 +4185,7 @@ void QgsDxfExport::writeLinetype( const QString &styleName, const QVector<qreal>
   {
     // map units or mm?
     double segmentLength = ( isGap ? -*dashIt : *dashIt );
-    segmentLength *= mapUnitScaleFactor( mSymbologyScale, u, mMapUnits );
+    segmentLength *= mapUnitScaleFactor( mSymbologyScale, u, mMapUnits, mMapSettings.mapToPixel().mapUnitsPerPixel() );
     writeGroup( 49, segmentLength );
     writeGroup( 74, 0 );
     isGap = !isGap;

src/core/dxf/qgsdxfexport.h

@@ -385,10 +385,19 @@ class CORE_EXPORT QgsDxfExport
     void writeMText( const QString &layer, const QString &text, const QgsPoint &pt, double width, double angle, const QColor &color );
 
     /**
-     * Calculates a scaling factor to convert from map units to a specified symbol unit.
-     * The \a scale parameter indicates the scale denominator, e.g. 1000.0 for a 1:1000 map.
-     */
-    static double mapUnitScaleFactor( double scale, QgsUnitTypes::RenderUnit symbolUnits, QgsUnitTypes::DistanceUnit mapUnits );
+     * Returns scale factor for conversion to map units
+    * @param scaleDenominator the map scale denominator
+    * @param symbolUnits the symbol output units
+    * @param mapUnits the map units
+    * @param mapUnitsPerPixel Map units per pixel*/
+    static double mapUnitScaleFactor( double scaleDenominator, QgsUnitTypes::RenderUnit symbolUnits, QgsUnitTypes::DistanceUnit mapUnits, double mapUnitsPerPixel = 1.0 );
+
+    /**
+     * Clips value to scale minimum/maximum
+    * @param value the value to clip
+    * @param scale the scale dependent minimum/maximum values
+    * @param pixelToMMFactor pixels per mm*/
+    void clipValueToMapUnitScale( double &value, const QgsMapUnitScale &scale, double pixelToMMFactor ) const;
 
     //! Returns cleaned layer name for use in DXF
     static QString dxfLayerName( const QString &name );

src/core/dxf/qgsdxfpaintengine.cpp

@@ -24,6 +24,7 @@ QgsDxfPaintEngine::QgsDxfPaintEngine( const QgsDxfPaintDevice *dxfDevice, QgsDxf
   : QPaintEngine( QPaintEngine::AllFeatures /*QPaintEngine::PainterPaths | QPaintEngine::PaintOutsidePaintEvent*/ )
   , mPaintDevice( dxfDevice )
   , mDxf( dxf )
+  , mOpacity( 1.0 )
 {
 }
 
@@ -60,6 +61,11 @@ void QgsDxfPaintEngine::updateState( const QPaintEngineState &state )
 
   if ( state.state() & QPaintEngine::DirtyBrush )
     mBrush = state.brush();
+
+  if ( state.state() & QPaintEngine::DirtyOpacity )
+  {
+    mOpacity = state.opacity();
+  }
 }
 
 void QgsDxfPaintEngine::setRing( QgsPointSequence &polyline, const QPointF *points, int pointCount )
@@ -82,12 +88,12 @@ void QgsDxfPaintEngine::drawPolygon( const QPointF *points, int pointCount, Poly
   if ( mode == QPaintEngine::PolylineMode )
   {
     if ( mPen.style() != Qt::NoPen && mPen.brush().style() != Qt::NoBrush )
-      mDxf->writePolyline( polygon.at( 0 ), mLayer, QStringLiteral( "CONTINUOUS" ), mPen.color(), currentWidth() );
+      mDxf->writePolyline( polygon.at( 0 ), mLayer, QStringLiteral( "CONTINUOUS" ), penColor(), currentWidth() );
   }
   else
   {
     if ( mBrush.style() != Qt::NoBrush )
-      mDxf->writePolygon( polygon, mLayer, QStringLiteral( "SOLID" ), mBrush.color() );
+      mDxf->writePolygon( polygon, mLayer, QStringLiteral( "SOLID" ), brushColor() );
   }
 }
 
@@ -118,7 +124,7 @@ void QgsDxfPaintEngine::drawPath( const QPainterPath &path )
   endPolygon();
 
   if ( !mPolygon.isEmpty() && mBrush.style() != Qt::NoBrush )
-    mDxf->writePolygon( mPolygon, mLayer, QStringLiteral( "SOLID" ), mBrush.color() );
+    mDxf->writePolygon( mPolygon, mLayer, QStringLiteral( "SOLID" ), brushColor() );
 
   mPolygon.clear();
 }
@@ -194,7 +200,7 @@ void QgsDxfPaintEngine::drawLines( const QLineF *lines, int lineCount )
   {
     mDxf->writeLine( toDxfCoordinates( lines[i].p1() ),
                      toDxfCoordinates( lines[i].p2() ),
-                     mLayer, QStringLiteral( "CONTINUOUS" ), mPen.color(), currentWidth() );
+                     mLayer, QStringLiteral( "CONTINUOUS" ), penColor(), currentWidth() );
   }
 }
 
@@ -287,3 +293,25 @@ int QgsDxfPaintEngine::faculty( int n )
 
   return result;
 }
+
+QColor QgsDxfPaintEngine::penColor() const
+{
+  if ( qgsDoubleNear( mOpacity, 1.0 ) )
+  {
+    return mPen.color();
+  }
+  QColor c = mPen.color();
+  c.setAlphaF( c.alphaF() * mOpacity );
+  return c;
+}
+
+QColor QgsDxfPaintEngine::brushColor() const
+{
+  if ( qgsDoubleNear( mOpacity, 1.0 ) )
+  {
+    return mBrush.color();
+  }
+  QColor c = mBrush.color();
+  c.setAlphaF( c.alphaF() * mOpacity );
+  return c;
+}

src/core/dxf/qgsdxfpaintengine.h

@@ -64,6 +64,8 @@ class CORE_EXPORT QgsDxfPaintEngine: public QPaintEngine
     QTransform mTransform;
     QPen mPen;
     QBrush mBrush;
+    //! Opacity
+    double mOpacity;
     QString mLayer;
     QPointF mShift;
     QgsRingSequence mPolygon;
@@ -87,6 +89,11 @@ class CORE_EXPORT QgsDxfPaintEngine: public QPaintEngine
     static int lower( int n, int i );
     static double power( double a, int b );
     static int faculty( int n );
+
+    //! Returns current pen color
+    QColor penColor() const;
+    //! Returns current brush color
+    QColor brushColor() const;
 };
 
 #endif // QGSDXFPAINTENGINE_H

src/core/symbology/qgsfillsymbollayer.cpp

@@ -406,7 +406,7 @@ double QgsSimpleFillSymbolLayer::dxfWidth( const QgsDxfExport &e, QgsSymbolRende
     context.setOriginalValueVariable( mStrokeWidth );
     width = mDataDefinedProperties.valueAsDouble( QgsSymbolLayer::PropertyStrokeWidth, context.renderContext().expressionContext(), mStrokeWidth );
   }
-  return width * e.mapUnitScaleFactor( e.symbologyScale(), mStrokeWidthUnit, e.mapUnits() );
+  return width * e.mapUnitScaleFactor( e.symbologyScale(), mStrokeWidthUnit, e.mapUnits(), context.renderContext().mapToPixel().mapUnitsPerPixel() );
 }
 
 QColor QgsSimpleFillSymbolLayer::dxfColor( QgsSymbolRenderContext &context ) const
@@ -1672,7 +1672,7 @@ double QgsImageFillSymbolLayer::dxfWidth( const QgsDxfExport &e, QgsSymbolRender
     context.setOriginalValueVariable( mStrokeWidth );
     width = mDataDefinedProperties.valueAsDouble( QgsSymbolLayer::PropertyWidth, context.renderContext().expressionContext(), mStrokeWidth );
   }
-  return width * e.mapUnitScaleFactor( e.symbologyScale(), mStrokeWidthUnit, e.mapUnits() );
+  return width * e.mapUnitScaleFactor( e.symbologyScale(), mStrokeWidthUnit, e.mapUnits(), context.renderContext().mapToPixel().mapUnitsPerPixel() );
 }
 
 QColor QgsImageFillSymbolLayer::dxfColor( QgsSymbolRenderContext &context ) const

src/core/symbology/qgslinesymbollayer.cpp

@@ -594,15 +594,18 @@ Qt::PenStyle QgsSimpleLineSymbolLayer::dxfPenStyle() const
 double QgsSimpleLineSymbolLayer::dxfWidth( const QgsDxfExport &e, QgsSymbolRenderContext &context ) const
 {
   double width = mWidth;
-
   if ( mDataDefinedProperties.isActive( QgsSymbolLayer::PropertyStrokeWidth ) )
   {
     context.setOriginalValueVariable( mWidth );
-    width = mDataDefinedProperties.valueAsDouble( QgsSymbolLayer::PropertyStrokeWidth, context.renderContext().expressionContext(), mWidth )
-            * e.mapUnitScaleFactor( e.symbologyScale(), widthUnit(), e.mapUnits() );
+    width = mDataDefinedProperties.valueAsDouble( QgsSymbolLayer::PropertyStrokeWidth, context.renderContext().expressionContext(), mWidth );
   }
 
-  return width * e.mapUnitScaleFactor( e.symbologyScale(), widthUnit(), e.mapUnits() );
+  width *= e.mapUnitScaleFactor( e.symbologyScale(), widthUnit(), e.mapUnits(), context.renderContext().mapToPixel().mapUnitsPerPixel() );
+  if ( mWidthUnit == QgsUnitTypes::RenderMapUnits )
+  {
+    e.clipValueToMapUnitScale( width, mWidthMapUnitScale, context.renderContext().scaleFactor() );
+  }
+  return width;
 }
 
 QColor QgsSimpleLineSymbolLayer::dxfColor( QgsSymbolRenderContext &context ) const
@@ -625,7 +628,13 @@ double QgsSimpleLineSymbolLayer::dxfOffset( const QgsDxfExport &e, QgsSymbolRend
     context.setOriginalValueVariable( mOffset );
     offset = mDataDefinedProperties.valueAsDouble( QgsSymbolLayer::PropertyOffset, context.renderContext().expressionContext(), mOffset );
   }
-  return offset;
+
+  offset *= e.mapUnitScaleFactor( e.symbologyScale(), offsetUnit(), e.mapUnits(), context.renderContext().mapToPixel().mapUnitsPerPixel() );
+  if ( mOffsetUnit == QgsUnitTypes::RenderMapUnits )
+  {
+    e.clipValueToMapUnitScale( offset, mOffsetMapUnitScale, context.renderContext().scaleFactor() );
+  }
+  return -offset; //direction seems to be inverse to symbology offset
 }
 
 /////////