ENH: resolve zoom bug for j2k images

Code/Common/mvdGLImageWidget.cxx

@@ -220,7 +220,7 @@ GLImageWidget
   ImageModelRenderer::RenderingContext context(
     datasetModel->GetSelectedImageModel(),
     region, isotropicZoom, 
-    width(), height()
+    width(), height(), m_ImageViewManipulator->HasZoomChanged()
   );
 
     // use the model renderer to paint the requested region of the image.

Code/Common/mvdImageModelRenderer.cxx

@@ -101,7 +101,9 @@ void ImageModelRenderer::paintGL( const RenderingContext& context )
   if (!m_IsMoving)
     {
     // request the data for the current region
-    m_Buffer = viModel->RasterizeRegion(scaledRegion, context.m_IsotropicZoom);
+    m_Buffer = viModel->RasterizeRegion(scaledRegion, 
+                                        context.m_IsotropicZoom, 
+                                        context.m_ForceRefresh);
     }
 
   // current resolution

Code/Common/mvdImageModelRenderer.h

@@ -75,12 +75,14 @@ public:
                        unsigned int width = 0,
                        unsigned int height = 0,
                        int dx = 0,
-                       int dy = 0) :
+                       int dy = 0,
+                       bool refresh = true) :
        m_AbstractImageModel( model ),
        m_ImageRegion( region ),
        m_IsotropicZoom( zoom ),
        m_WidgetWidth(width),
-       m_WidgetHeight(height)
+       m_WidgetHeight(height),
+       m_ForceRefresh(refresh)
     {
     }
 
@@ -89,6 +91,7 @@ public:
     double       m_IsotropicZoom;
     unsigned int m_WidgetWidth;
     unsigned int m_WidgetHeight;
+    bool         m_ForceRefresh;
   };
 
 //

Code/Common/mvdImageViewManipulator.cxx

@@ -51,7 +51,8 @@ ImageViewManipulator
   QObject( parent ),
   m_NavigationContext(),
   m_MouseContext(),
-  m_IsotropicZoom(1)
+  m_IsotropicZoom(1),
+  m_PreviousIsotropicZoom(1.)
 {
   // TODO: Remove later because initialized in struct's default constructor and resizeEvent().
   this->InitializeContext(1,1);
@@ -95,6 +96,8 @@ void
 ImageViewManipulator
 ::mouseMoveEvent( QMouseEvent * event)
 {
+  m_PreviousIsotropicZoom = m_IsotropicZoom;
+
   // Update the mouse context
   m_MouseContext.dx = -event->x() + m_MouseContext.xMove;
   m_MouseContext.dy = -event->y() + m_MouseContext.yMove;
@@ -196,6 +199,8 @@ void
 ImageViewManipulator
 ::Zoom(const double scale)
 {
+  m_PreviousIsotropicZoom = m_IsotropicZoom;
+
   // compute the new size
   double sizeX = m_NavigationContext.m_SizeXBeforeConstrain / scale;
   double sizeY = m_NavigationContext.m_SizeYBeforeConstrain / scale;

Code/Common/mvdImageViewManipulator.h

@@ -108,6 +108,19 @@ public:
     return m_IsotropicZoom;
   }
 
+  inline
+    bool HasZoomChanged() const
+  {
+    bool res = false;
+
+    if (vcl_abs(m_IsotropicZoom - m_PreviousIsotropicZoom) > 0.00000001 )
+      {
+      res = true;
+      }
+
+    return res;
+  }
+
   /*
   const MouseContextType&  GetMouseContextType() const
   {
@@ -121,6 +134,8 @@ public:
     // set back the zoom to 1
     m_IsotropicZoom = 1.;
 
+    m_PreviousIsotropicZoom = 1.;
+
     // store the image largest region
     m_NavigationContext.m_ModelImageRegion = largestRegion;
 
@@ -217,6 +232,7 @@ private:
   MouseContextType       m_MouseContext;
 
   double                 m_IsotropicZoom;
+  double                 m_PreviousIsotropicZoom;
 
 //
 // SLOTS.

Code/Common/mvdVectorImageModel.cxx

@@ -256,7 +256,7 @@ VectorImageModel
 /*******************************************************************************/
 unsigned char *
 VectorImageModel
-::RasterizeRegion( const ImageRegionType& region, const double zoomFactor)
+::RasterizeRegion( const ImageRegionType& region, const double zoomFactor, bool refresh)
 {
   m_Region = region;
 
@@ -271,7 +271,8 @@ VectorImageModel
 
   // Don't do anything if the region did not changed
   if ( m_PreviousRegion!=region ||
-       m_Settings.IsDirty() )
+       m_Settings.IsDirty() ||
+       refresh )
     {
     // check that the current and the previous region have some pixels in
     // common 
@@ -281,7 +282,8 @@ VectorImageModel
     // if the first time or no pixels in common , reload all
     if ( res &&
 	 m_PreviousRegion!=ImageRegionType() &&
-	 !m_Settings.IsDirty() )
+	 !m_Settings.IsDirty() &&
+         !refresh )
       {
       // Compute loaded region, and the four regions not loaded yet
       // within the new requested region
@@ -348,10 +350,11 @@ VectorImageModel
       // rasterize the region
       this->DumpImagePixelsWithinRegionIntoBuffer(region);
       }
-
-    m_Settings.ClearDirty();
     }
 
+  // settings changes have been taken into account, clean the dirty flag
+  m_Settings.ClearDirty();
+
   // Store the region
   m_PreviousRegion = region;
   

Code/Common/mvdVectorImageModel.h

@@ -282,7 +282,9 @@ public:
   void LoadFile( const QString& filename, int w, int h );
 
   /** Rasterize the buffered region in a buffer */
-  unsigned char * RasterizeRegion(const ImageRegionType& region, const double zoomFactor);
+  unsigned char * RasterizeRegion(const ImageRegionType& region,
+                                  const double zoomFactor,
+                                  bool refresh);
 
   /**
    * Following the zoom factor, get the best level of detail knowing