Draw SVG symbol from cached QImage unless it exceeds half of cache size, then use QPicture

- Fix #6855, SVG markers/fills larger than half cache (559^2 X 32 + SVG) are drawn with QPicture
- Fix #6861, make QPicture SVG symbols scale with Composer page zoom
- Fix #6861, make SVG symbol output to print/image more accurate by setting 'size' to double
- Update/add support for non-squared SVG via QImage and QPicture, on screen and in output to print/image
- Non-squared SVG QImage/QPicture can now be used in pattern fill, without excess space

python/core/symbology-ng/qgssvgcache.sip

@@ -46,7 +46,7 @@ class QgsSvgCache : QObject
     ~QgsSvgCache();
 
     const QImage& svgAsImage( const QString& file, int size, const QColor& fill, const QColor& outline, double outlineWidth,
-                              double widthScaleFactor, double rasterScaleFactor );
+                              double widthScaleFactor, double rasterScaleFactor, bool& fitsInCache );
     const QPicture& svgAsPicture( const QString& file, int size, const QColor& fill, const QColor& outline, double outlineWidth,
                                   double widthScaleFactor, double rasterScaleFactor );
 

src/core/symbology-ng/qgsfillsymbollayerv2.cpp

@@ -290,6 +290,7 @@ QgsSVGFillSymbolLayer::QgsSVGFillSymbolLayer( const QString& svgFilePath, double
   mOutlineWidth = 0.3;
   mAngle = angle;
   setDefaultSvgParams();
+  mSvgPattern = 0;
 }
 
 QgsSVGFillSymbolLayer::QgsSVGFillSymbolLayer( const QByteArray& svgData, double width, double angle ): QgsImageFillSymbolLayer(), mPatternWidth( width ),
@@ -300,11 +301,13 @@ QgsSVGFillSymbolLayer::QgsSVGFillSymbolLayer( const QByteArray& svgData, double
   mAngle = angle;
   setSubSymbol( new QgsLineSymbolV2() );
   setDefaultSvgParams();
+  mSvgPattern = 0;
 }
 
 QgsSVGFillSymbolLayer::~QgsSVGFillSymbolLayer()
 {
   delete mOutline;
+  delete mSvgPattern;
 }
 
 void QgsSVGFillSymbolLayer::setSvgFilePath( const QString& svgPath )
@@ -382,22 +385,55 @@ void QgsSVGFillSymbolLayer::startRender( QgsSymbolV2RenderContext& context )
     return;
   }
 
-  int size = context.outputPixelSize( mPatternWidth );
-  const QImage& patternImage = QgsSvgCache::instance()->svgAsImage( mSvgFilePath, size, mSvgFillColor, mSvgOutlineColor, mSvgOutlineWidth,
-                               context.renderContext().scaleFactor(), context.renderContext().rasterScaleFactor() );
-  QTransform brushTransform;
-  brushTransform.scale( 1.0 / context.renderContext().rasterScaleFactor(), 1.0 / context.renderContext().rasterScaleFactor() );
-  if ( !doubleNear( context.alpha(), 1.0 ) )
+  if ( mSvgPattern )
   {
-    QImage transparentImage = patternImage.copy();
-    QgsSymbolLayerV2Utils::multiplyImageOpacity( &transparentImage, context.alpha() );
-    mBrush.setTextureImage( transparentImage );
+    delete mSvgPattern;
+  }
+  mSvgPattern = 0;
+  double size = context.outputPixelSize( mPatternWidth );
+
+  //don't render pattern if symbol size is below one or above 10,000 pixels
+  if (( int )size < 1.0 || 10000.0 < size )
+  {
+    mSvgPattern = new QImage();
+    mBrush.setTextureImage( *mSvgPattern );
   }
   else
   {
-    mBrush.setTextureImage( patternImage );
+    bool fitsInCache = true;
+    const QImage& patternImage = QgsSvgCache::instance()->svgAsImage( mSvgFilePath, size, mSvgFillColor, mSvgOutlineColor, mSvgOutlineWidth,
+                                 context.renderContext().scaleFactor(), context.renderContext().rasterScaleFactor(), fitsInCache );
+
+    if ( !fitsInCache )
+    {
+      const QPicture& patternPict = QgsSvgCache::instance()->svgAsPicture( mSvgFilePath, size, mSvgFillColor, mSvgOutlineColor, mSvgOutlineWidth,
+                                    context.renderContext().scaleFactor(), 1.0 );
+      double hwRatio = 1.0;
+      if ( patternPict.width() > 0 )
+      {
+        hwRatio = ( double )patternPict.height() / ( double )patternPict.width();
+      }
+      mSvgPattern = new QImage(( int )size, ( int )( size * hwRatio ), QImage::Format_ARGB32_Premultiplied );
+      mSvgPattern->fill( 0 ); // transparent background
+
+      QPainter p( mSvgPattern );
+      p.drawPicture( QPointF( size / 2, size * hwRatio / 2 ), patternPict );
+    }
+
+    QTransform brushTransform;
+    brushTransform.scale( 1.0 / context.renderContext().rasterScaleFactor(), 1.0 / context.renderContext().rasterScaleFactor() );
+    if ( !doubleNear( context.alpha(), 1.0 ) )
+    {
+      QImage transparentImage = fitsInCache ? patternImage.copy() : mSvgPattern->copy();
+      QgsSymbolLayerV2Utils::multiplyImageOpacity( &transparentImage, context.alpha() );
+      mBrush.setTextureImage( transparentImage );
+    }
+    else
+    {
+      mBrush.setTextureImage( fitsInCache ? patternImage : *mSvgPattern );
+    }
+    mBrush.setTransform( brushTransform );
   }
-  mBrush.setTransform( brushTransform );
 
   if ( mOutline )
   {

src/core/symbology-ng/qgsfillsymbollayerv2.h

@@ -152,6 +152,9 @@ class CORE_EXPORT QgsSVGFillSymbolLayer: public QgsImageFillSymbolLayer
     QString mSvgFilePath;
     /**SVG view box (to keep the aspect ratio */
     QRectF mSvgViewBox;
+    /** SVG pattern image
+     * @note added in 1.9 */
+    QImage* mSvgPattern;
 
     //param(fill), param(outline), param(outline-width) are going
     //to be replaced in memory

src/core/symbology-ng/qgsmarkersymbollayerv2.cpp

@@ -637,55 +637,79 @@ void QgsSvgMarkerSymbolLayerV2::renderPoint( const QPointF& point, QgsSymbolV2Re
     return;
   }
 
+  double size = context.outputLineWidth( mSize );
+  //don't render symbols with size below one or above 10,000 pixels
+  if (( int )size < 1 || 10000.0 < size )
+  {
+    return;
+  }
+
   p->save();
   QPointF outputOffset = QPointF( context.outputLineWidth( mOffset.x() ), context.outputLineWidth( mOffset.y() ) );
   if ( mAngle )
     outputOffset = _rotatedOffset( outputOffset, mAngle );
   p->translate( point + outputOffset );
 
-  int size = ( int )( context.outputLineWidth( mSize ) );
-  if ( size < 1 ) //don't render symbols with size below one pixel
-  {
-    return;
-  }
-
   bool rotated = !doubleNear( mAngle, 0 );
   bool drawOnScreen = doubleNear( context.renderContext().rasterScaleFactor(), 1.0, 0.1 );
   if ( rotated )
     p->rotate( mAngle );
 
+  bool fitsInCache = true;
+  bool usePict = true;
+  double hwRatio = 1.0;
   if ( drawOnScreen && !rotated )
   {
+    usePict = false;
     const QImage& img = QgsSvgCache::instance()->svgAsImage( mPath, size, mFillColor, mOutlineColor, mOutlineWidth,
-                        context.renderContext().scaleFactor(), context.renderContext().rasterScaleFactor() );
-    //consider transparency
-    if ( !doubleNear( context.alpha(), 1.0 ) )
+                        context.renderContext().scaleFactor(), context.renderContext().rasterScaleFactor(), fitsInCache );
+    if ( fitsInCache && img.width() > 1 )
     {
-      QImage transparentImage = img.copy();
-      QgsSymbolLayerV2Utils::multiplyImageOpacity( &transparentImage, context.alpha() );
-      p->drawImage( -transparentImage.width() / 2.0, -transparentImage.height() / 2.0, transparentImage );
-    }
-    else
-    {
-      p->drawImage( -img.width() / 2.0, -img.height() / 2.0, img );
+      //consider transparency
+      if ( !doubleNear( context.alpha(), 1.0 ) )
+      {
+        QImage transparentImage = img.copy();
+        QgsSymbolLayerV2Utils::multiplyImageOpacity( &transparentImage, context.alpha() );
+        p->drawImage( -transparentImage.width() / 2.0, -transparentImage.height() / 2.0, transparentImage );
+        hwRatio = ( double )transparentImage.height() / ( double )transparentImage.width();
+      }
+      else
+      {
+        p->drawImage( -img.width() / 2.0, -img.height() / 2.0, img );
+        hwRatio = ( double )img.height() / ( double )img.width();
+      }
     }
   }
-  else
+
+  if ( usePict || !fitsInCache )
   {
     p->setOpacity( context.alpha() );
     const QPicture& pct = QgsSvgCache::instance()->svgAsPicture( mPath, size, mFillColor, mOutlineColor, mOutlineWidth,
                           context.renderContext().scaleFactor(), context.renderContext().rasterScaleFactor() );
-    p->drawPicture( 0, 0, pct );
+
+    if ( pct.width() > 1 )
+    {
+      p->drawPicture( 0, 0, pct );
+      hwRatio = ( double )pct.height() / ( double )pct.width();
+    }
   }
 
   if ( context.selected() )
   {
     QPen pen( context.selectionColor() );
-    pen.setWidth( context.outputLineWidth( 1.0 ) );
+    double penWidth = context.outputLineWidth( 1.0 );
+    if ( penWidth > size / 20 )
+    {
+      // keep the pen width from covering symbol
+      penWidth = size / 20;
+    }
+    double penOffset = penWidth / 2;
+    pen.setWidth( penWidth );
     p->setPen( pen );
     p->setBrush( Qt::NoBrush );
-    double sizePixel = context.outputLineWidth( mSize );
-    p->drawRect( QRectF( -sizePixel / 2.0, -sizePixel / 2.0, sizePixel, sizePixel ) );
+    double wSize = size + penOffset;
+    double hSize = size * hwRatio + penOffset;
+    p->drawRect( QRectF( -wSize / 2.0, -hSize / 2.0, wSize, hSize ) );
   }
 
   p->restore();

src/core/symbology-ng/qgssvgcache.cpp

@@ -16,6 +16,7 @@
  ***************************************************************************/
 
 #include "qgssvgcache.h"
+#include "qgis.h"
 #include "qgslogger.h"
 #include "qgsnetworkaccessmanager.h"
 #include "qgsmessagelog.h"
@@ -33,7 +34,7 @@
 #include <QNetworkReply>
 #include <QNetworkRequest>
 
-QgsSvgCacheEntry::QgsSvgCacheEntry(): file( QString() ), size( 0 ), outlineWidth( 0 ), widthScaleFactor( 1.0 ), rasterScaleFactor( 1.0 ), fill( Qt::black ),
+QgsSvgCacheEntry::QgsSvgCacheEntry(): file( QString() ), size( 0.0 ), outlineWidth( 0 ), widthScaleFactor( 1.0 ), rasterScaleFactor( 1.0 ), fill( Qt::black ),
     outline( Qt::black ), image( 0 ), picture( 0 )
 {
 }
@@ -107,28 +108,52 @@ QgsSvgCache::~QgsSvgCache()
 }
 
 
-const QImage& QgsSvgCache::svgAsImage( const QString& file, int size, const QColor& fill, const QColor& outline, double outlineWidth,
-                                       double widthScaleFactor, double rasterScaleFactor )
+const QImage& QgsSvgCache::svgAsImage( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
+                                       double widthScaleFactor, double rasterScaleFactor, bool& fitsInCache )
 {
+  fitsInCache = true;
   QgsSvgCacheEntry* currentEntry = cacheEntry( file, size, fill, outline, outlineWidth, widthScaleFactor, rasterScaleFactor );
 
   //if current entry image is 0: cache image for entry
+  // checks to see if image will fit into cache
   //update stats for memory usage
   if ( !currentEntry->image )
   {
-    cacheImage( currentEntry );
+    QSvgRenderer r( currentEntry->svgContent );
+    double hwRatio = 1.0;
+    if ( r.viewBoxF().width() > 0 )
+    {
+      hwRatio = r.viewBoxF().height() / r.viewBoxF().width();
+    }
+    long cachedDataSize = 0;
+    cachedDataSize += currentEntry->svgContent.size();
+    cachedDataSize += ( int )( currentEntry->size * currentEntry->size * hwRatio * 32 );
+    if ( cachedDataSize > mMaximumSize / 2 )
+    {
+      fitsInCache = false;
+      delete currentEntry->image;
+      currentEntry->image = 0;
+      //currentEntry->image = new QImage( 0, 0 );
+
+      // instead cache picture
+      cachePicture( currentEntry );
+    }
+    else
+    {
+      cacheImage( currentEntry );
+    }
     trimToMaximumSize();
   }
 
   return *( currentEntry->image );
 }
 
-const QPicture& QgsSvgCache::svgAsPicture( const QString& file, int size, const QColor& fill, const QColor& outline, double outlineWidth,
+const QPicture& QgsSvgCache::svgAsPicture( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
     double widthScaleFactor, double rasterScaleFactor )
 {
   QgsSvgCacheEntry* currentEntry = cacheEntry( file, size, fill, outline, outlineWidth, widthScaleFactor, rasterScaleFactor );
 
-  //if current entry image is 0: cache image for entry
+  //if current entry picture is 0: cache picture for entry
   //update stats for memory usage
   if ( !currentEntry->picture )
   {
@@ -139,7 +164,7 @@ const QPicture& QgsSvgCache::svgAsPicture( const QString& file, int size, const
   return *( currentEntry->picture );
 }
 
-QgsSvgCacheEntry* QgsSvgCache::insertSVG( const QString& file, int size, const QColor& fill, const QColor& outline, double outlineWidth,
+QgsSvgCacheEntry* QgsSvgCache::insertSVG( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
     double widthScaleFactor, double rasterScaleFactor )
 {
   QgsSvgCacheEntry* entry = new QgsSvgCacheEntry( file, size, outlineWidth, widthScaleFactor, rasterScaleFactor, fill, outline );
@@ -326,21 +351,38 @@ void QgsSvgCache::cacheImage( QgsSvgCacheEntry* entry )
   delete entry->image;
   entry->image = 0;
 
-  int imageSize = entry->size;
-  QImage* image = new QImage( imageSize, imageSize, QImage::Format_ARGB32_Premultiplied );
+  QSvgRenderer r( entry->svgContent );
+  double hwRatio = 1.0;
+  if ( r.viewBoxF().width() > 0 )
+  {
+    hwRatio = r.viewBoxF().height() / r.viewBoxF().width();
+  }
+  double wSize = entry->size;
+  int wImgSize = ( int )wSize;
+  if ( wImgSize < 1 )
+  {
+    wImgSize = 1;
+  }
+  double hSize = wSize * hwRatio;
+  int hImgSize = ( int )hSize;
+  if ( hImgSize < 1 )
+  {
+    hImgSize = 1;
+  }
+  // cast double image sizes to int for QImage
+  QImage* image = new QImage( wImgSize, hImgSize, QImage::Format_ARGB32_Premultiplied );
   image->fill( 0 ); // transparent background
 
   QPainter p( image );
-  QSvgRenderer r( entry->svgContent );
-  if ( r.viewBox().width() == r.viewBox().height() )
+  if ( r.viewBoxF().width() == r.viewBoxF().height() )
   {
     r.render( &p );
   }
   else
   {
-    QSize s( r.viewBox().size() );
-    s.scale( imageSize, imageSize, Qt::KeepAspectRatio );
-    QRect rect(( imageSize - s.width() ) / 2, ( imageSize - s.height() ) / 2, s.width(), s.height() );
+    QSizeF s( r.viewBoxF().size() );
+    s.scale( wSize, hSize, Qt::KeepAspectRatio );
+    QRectF rect(( wImgSize - s.width() ) / 2, ( hImgSize - s.height() ) / 2, s.width(), s.height() );
     r.render( &p, rect );
   }
 
@@ -360,18 +402,39 @@ void QgsSvgCache::cachePicture( QgsSvgCacheEntry *entry )
 
   //correct QPictures dpi correction
   QPicture* picture = new QPicture();
-  double pictureSize = entry->size  /  25.4 / ( entry->rasterScaleFactor * entry->widthScaleFactor )  * picture->logicalDpiX();
-  QRectF rect( QPointF( -pictureSize / 2.0, -pictureSize / 2.0 ), QSizeF( pictureSize, pictureSize ) );
+  QRectF rect;
+  QSvgRenderer r( entry->svgContent );
+  double hwRatio = 1.0;
+  if ( r.viewBoxF().width() > 0 )
+  {
+    hwRatio = r.viewBoxF().height() / r.viewBoxF().width();
+  }
+  bool drawOnScreen = doubleNear( entry->rasterScaleFactor, 1.0, 0.1 );
+  if ( drawOnScreen )
+  {
+    // fix to ensure rotated symbols scale with composer page (i.e. not map item) zoom
+    double wSize = entry->size;
+    double hSize = wSize * hwRatio;
+    QSizeF s( r.viewBoxF().size() );
+    s.scale( wSize, hSize, Qt::KeepAspectRatio );
+    rect = QRectF( -s.width() / 2.0, -s.height() / 2.0, s.width(), s.height() );
+  }
+  else
+  {
+    // output for print or image saving @ specific dpi
+    double scaledSize = entry->size / 25.4 / ( entry->rasterScaleFactor * entry->widthScaleFactor );
+    double wSize = scaledSize * picture->logicalDpiX();
+    double hSize = scaledSize * picture->logicalDpiY() * r.viewBoxF().height() / r.viewBoxF().width();
+    rect = QRectF( QPointF( -wSize / 2.0, -hSize / 2.0 ), QSizeF( wSize, hSize ) );
+  }
 
-
-  QSvgRenderer renderer( entry->svgContent );
-  QPainter painter( picture );
-  renderer.render( &painter, rect );
+  QPainter p( picture );
+  r.render( &p, rect );
   entry->picture = picture;
   mTotalSize += entry->picture->size();
 }
 
-QgsSvgCacheEntry* QgsSvgCache::cacheEntry( const QString& file, int size, const QColor& fill, const QColor& outline, double outlineWidth,
+QgsSvgCacheEntry* QgsSvgCache::cacheEntry( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
     double widthScaleFactor, double rasterScaleFactor )
 {
   //search entries in mEntryLookup

src/core/symbology-ng/qgssvgcache.h

@@ -36,7 +36,7 @@ class CORE_EXPORT QgsSvgCacheEntry
     ~QgsSvgCacheEntry();
 
     QString file;
-    int size; //size in pixel
+    double size; //size in pixels (cast to int for QImage)
     double outlineWidth;
     double widthScaleFactor;
     double rasterScaleFactor;
@@ -69,9 +69,9 @@ class CORE_EXPORT QgsSvgCache : public QObject
     static QgsSvgCache* instance();
     ~QgsSvgCache();
 
-    const QImage& svgAsImage( const QString& file, int size, const QColor& fill, const QColor& outline, double outlineWidth,
-                              double widthScaleFactor, double rasterScaleFactor );
-    const QPicture& svgAsPicture( const QString& file, int size, const QColor& fill, const QColor& outline, double outlineWidth,
+    const QImage& svgAsImage( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
+                              double widthScaleFactor, double rasterScaleFactor, bool& fitsInCache );
+    const QPicture& svgAsPicture( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
                                   double widthScaleFactor, double rasterScaleFactor );
 
     /**Tests if an svg file contains parameters for fill, outline color, outline width. If yes, possible default values are returned. If there are several
@@ -84,21 +84,21 @@ class CORE_EXPORT QgsSvgCache : public QObject
 
   signals:
     /** Emit a signal to be caught by qgisapp and display a msg on status bar */
-    void statusChanged( QString const &  theStatusQString );
+    void statusChanged( const QString&  theStatusQString );
 
   protected:
     //! protected constructor
     QgsSvgCache( QObject * parent = 0 );
 
     /**Creates new cache entry and returns pointer to it*/
-    QgsSvgCacheEntry* insertSVG( const QString& file, int size, const QColor& fill, const QColor& outline, double outlineWidth,
+    QgsSvgCacheEntry* insertSVG( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
                                  double widthScaleFactor, double rasterScaleFactor );
 
     void replaceParamsAndCacheSvg( QgsSvgCacheEntry* entry );
     void cacheImage( QgsSvgCacheEntry* entry );
     void cachePicture( QgsSvgCacheEntry* entry );
     /**Returns entry from cache or creates a new entry if it does not exist already*/
-    QgsSvgCacheEntry* cacheEntry( const QString& file, int size, const QColor& fill, const QColor& outline, double outlineWidth,
+    QgsSvgCacheEntry* cacheEntry( const QString& file, double size, const QColor& fill, const QColor& outline, double outlineWidth,
                                   double widthScaleFactor, double rasterScaleFactor );
 
     /**Removes the least used items until the maximum size is under the limit*/

src/gui/symbology-ng/qgssymbollayerv2widget.cpp

@@ -558,7 +558,8 @@ class QgsSvgListModel : public QAbstractListModel
           bool fillParam, outlineParam, outlineWidthParam;
           QgsSvgCache::instance()->containsParams( entry, fillParam, fill, outlineParam, outline, outlineWidthParam, outlineWidth );
 
-          const QImage& img = QgsSvgCache::instance()->svgAsImage( entry, 30, fill, outline, outlineWidth, 3.5 /*appr. 88 dpi*/, 1.0 );
+          bool fitsInCache; // should always fit in cache at these sizes (i.e. under 559 px ^ 2, or half cache size)
+          const QImage& img = QgsSvgCache::instance()->svgAsImage( entry, 30.0, fill, outline, outlineWidth, 3.5 /*appr. 88 dpi*/, 1.0, fitsInCache );
           pixmap = QPixmap::fromImage( img );
           QPixmapCache::insert( entry, pixmap );
         }