Use different print font scaling factor for Mac.

Define factor in header file so it can be adjusted with one edit.


git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@4041 c8812cc2-4d05-0410-92ff-de0c093fc19c

src/qgscomposerlabel.cpp

@@ -158,7 +158,7 @@ void QgsComposerLabel::draw ( QPainter & painter )
 	//       In any case, each font scales in in different way even if painter.scale()
 	//       is used instead of font size!!! -> Postscript is never exactly the same as 
 	//       in preview.
-	double factor = 2.45;
+	double factor = QgsComposition::psFontScaleFactor();
 	
 	double pssize = factor * 72.0 * mFont.pointSizeFloat() / mComposition->resolution();
 	double psscale = pssize/size;

src/qgscomposermap.cpp

@@ -178,8 +178,7 @@ void QgsComposerMap::draw ( QPainter *painter, QgsRect *extent, QgsMapToPixel *t
 	  if ( vector->labelOn() ) {
 	      double fontScale = 25.4 * mFontScale * mComposition->scale() / 72;
 	      if ( plotStyle() == QgsComposition::Postscript ) {
-		  // I have no idea why 2.54 - it is an empirical value
-		  fontScale = 2.54 * 72.0 / mComposition->resolution();
+		  fontScale = QgsComposition::psFontScaleFactor() * 72.0 / mComposition->resolution();
 	      }
 	      vector->drawLabels (  painter, extent, transform, device, fontScale );
 	  }

src/qgscomposerscalebar.cpp

@@ -220,7 +220,7 @@ QRect QgsComposerScalebar::render ( QPainter *p )
     //       In any case, each font scales in in different way even if painter.scale()
     //       is used instead of font size!!! -> Postscript is never exactly the same as
     //       in preview.
-    double factor = 2.45;
+    double factor = QgsComposition::psFontScaleFactor();
 
     double pssize = factor * 72.0 * mFont.pointSizeFloat() / mComposition->resolution();
     double psscale = pssize/size;

src/qgscomposervectorlegend.cpp

@@ -210,13 +210,12 @@ QRect QgsComposerVectorLegend::render ( QPainter *p )
     
     // Fonts for rendering
     
-    // I have no idea why 2.54 - it is an empirical value
     // TODO: For output to Postscript the font must be scaled. But how?
     //       The factor is an empirical value.
     //       In any case, each font scales in in different way even if painter.scale()
     //       is used instead of font size!!! -> Postscript is never exactly the same as
     //       in preview.
-    double psFontFactor = 2.45;
+    double psFontFactor = QgsComposition::psFontScaleFactor();
 
     double psTitleSize = psFontFactor * 72.0 * mTitleFont.pointSizeFloat() / mComposition->resolution();
     double psSectionSize = psFontFactor * 72.0 * mSectionFont.pointSizeFloat() / mComposition->resolution();

src/qgscomposition.h

@@ -99,6 +99,21 @@ public:
 	Postscript   // Fonts need different scaling!
     };
 
+    /** \brief Font scaling factor for PostScript output
+     *
+     *  For output to Postscript the font must be scaled. But how?  
+     *  The factor is an empirical value. In any case, each font scales
+     *  in in different way even if painter.scale() is used instead of
+     *  font size!!! -> Postscript is never exactly the same as in preview.
+     */
+    static const double psFontScaleFactor() {
+#ifdef Q_OS_MACX
+    return 1.85;
+#else
+    return 2.45; // I have no idea why 2.45 - it is an empirical value
+#endif
+    }
+
     /** \brief Composition ID */
     int id ( void );
 
@@ -290,7 +305,7 @@ private:
     /** \brief Temporary item used as pointer to new objecs which must be drawn */ 
     QCanvasItem *mNewCanvasItem; 
 
-    /** \breif Resolution in DPI */
+    /** \brief Resolution in DPI */
     int mResolution; 
 
     /** \brief canvas scale */