Force wmts resolution to 90 dpi if paint device dpi is < 225

Ref: a169ad1a1e34406d72fe9dd860d8d3ede4adb855
kadas-albireo · Dec 22, 2016 · 09bb1c8 · 09bb1c8
1 parent 7c0259c
commit 09bb1c8
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Showing 2 changed files with 51 additions and 5 deletions.
diff --git a/src/core/raster/qgsrasterdrawer.cpp b/src/core/raster/qgsrasterdrawer.cpp
@@ -16,6 +16,7 @@
  ***************************************************************************/
 
 #include "qgslogger.h"
+#include "qgsrasterdataprovider.h"
 #include "qgsrasterdrawer.h"
 #include "qgsrasteriterator.h"
 #include "qgsrasterviewport.h"
@@ -41,9 +42,29 @@ void QgsRasterDrawer::draw( QPainter* p, QgsRasterViewPort* viewPort, const QgsM
     return;
   }
 
+  int width = viewPort->mWidth;
+  int height = viewPort->mHeight;
+  QgsMapToPixel mapToPixel( *theQgsMapToPixel );
+  double scaleFactor = 1.0;
+
+  if ( ctx && isWMTSLayer( mIterator->input() ) ) //wmts case, comply with standard pixel size of 0.28mm from specification
+  {
+    scaleFactor = ( 1.0 / 0.28 * 25.4 ) / p->device()->logicalDpiX();
+    if ( scaleFactor < 0.4 )
+    {
+      width = width * scaleFactor;
+      height = height * scaleFactor;
+      mapToPixel.setParameters( ctx->extent().width() / width, ctx->extent().xMinimum(), ctx->extent().yMinimum(), height );
+    }
+    else
+    {
+      scaleFactor = 1.0;
+    }
+  }
+
   // last pipe filter has only 1 band
   int bandNumber = 1;
-  mIterator->startRasterRead( bandNumber, viewPort->mWidth, viewPort->mHeight, viewPort->mDrawnExtent );
+  mIterator->startRasterRead( bandNumber, width, height, viewPort->mDrawnExtent );
 
   //number of cols/rows in output pixels
   int nCols = 0;
@@ -90,15 +111,15 @@ void QgsRasterDrawer::draw( QPainter* p, QgsRasterViewPort* viewPort, const QgsM
       }
     }
 
-    drawImage( p, viewPort, img, topLeftCol, topLeftRow, theQgsMapToPixel );
+    drawImage( p, viewPort, img, topLeftCol, topLeftRow, scaleFactor, &mapToPixel );
     QgsDebugMsg( "Block drawn" );
 
     delete block;
     if ( ctx && ctx->renderingStopped() ) { break; }
   }
 }
 
-void QgsRasterDrawer::drawImage( QPainter* p, QgsRasterViewPort* viewPort, const QImage& img, int topLeftCol, int topLeftRow, const QgsMapToPixel* theQgsMapToPixel ) const
+void QgsRasterDrawer::drawImage( QPainter* p, QgsRasterViewPort* viewPort, const QImage& img, int topLeftCol, int topLeftRow, double scaleFactor, const QgsMapToPixel* theQgsMapToPixel ) const
 {
   if ( !p || !viewPort )
   {
@@ -132,7 +153,16 @@ void QgsRasterDrawer::drawImage( QPainter* p, QgsRasterViewPort* viewPort, const
     }
   }
 
-  p->drawImage( tlPoint, img );
+  if ( qgsDoubleNear( scaleFactor, 1.0 ) )
+  {
+    p->drawImage( tlPoint, img );
+  }
+  else
+  {
+    QRect source( 0, 0, img.width(), img.height() );
+    QRect target( tlPoint.x(), tlPoint.y(), img.width() / scaleFactor, img.height() / scaleFactor );
+    p->drawImage( target, img, source );
+  }
 
 #if 0
   // For debugging:
@@ -155,3 +185,17 @@ void QgsRasterDrawer::drawImage( QPainter* p, QgsRasterViewPort* viewPort, const
   p->restore();
 }
 
+bool QgsRasterDrawer::isWMTSLayer( const QgsRasterInterface* iface )
+{
+  if ( iface && iface->srcInput() )
+  {
+    const QgsRasterDataProvider* provider  = dynamic_cast<const QgsRasterDataProvider*>( iface->srcInput() );
+    QVariant resolutions = provider->property( "resolutions" );
+    if ( provider->name() == "wms" && !resolutions.isNull() )
+    {
+      return true;
+    }
+  }
+  return false;
+}
+
diff --git a/src/core/raster/qgsrasterdrawer.h b/src/core/raster/qgsrasterdrawer.h
@@ -48,10 +48,12 @@ class CORE_EXPORT QgsRasterDrawer
       @param topLeftRow Top position relative to top border of viewport
       @param mapToPixel map to device coordinate transformation info
              (not available in python bindings) */
-    void drawImage( QPainter* p, QgsRasterViewPort* viewPort, const QImage& img, int topLeftCol, int topLeftRow, const QgsMapToPixel* mapToPixel = 0 ) const;
+    void drawImage( QPainter* p, QgsRasterViewPort* viewPort, const QImage& img, int topLeftCol, int topLeftRow, double scaleFactor, const QgsMapToPixel* mapToPixel = 0 ) const;
 
   private:
     QgsRasterIterator* mIterator;
+
+    static bool isWMTSLayer( const QgsRasterInterface* iface );
 };
 
 #endif // QGSRASTERDRAWER_H