Added 'required layers' option for drawn items.

common/view/view.cpp

@@ -454,13 +454,21 @@ struct VIEW::drawItem
     {
         GAL* gal = view->GetGAL();
 
+        aItem->ViewGetRequiredLayers( layers, layersCount );
+
+        // Conditions that have te be fulfilled for an item to be drawn
+        bool drawCondition = aItem->ViewIsVisible() &&
+                             aItem->ViewGetLOD( currentLayer->id ) < view->m_scale &&
+                             view->isEveryLayerEnabled( layers, layersCount );
+        if( !drawCondition )
+            return;
+
         if( currentLayer->cached )
         {
             // Draw using cached information or create one
             int group = aItem->getGroup( currentLayer->id );
 
-            if( group >= 0 && aItem->ViewIsVisible() &&
-                aItem->ViewGetLOD( currentLayer->id ) < view->m_scale )
+            if( group >= 0 )
             {
                 gal->DrawGroup( group );
             }
@@ -472,8 +480,7 @@ struct VIEW::drawItem
                 gal->EndGroup();
             }
         }
-        else if( aItem->ViewIsVisible() &&
-                 aItem->ViewGetLOD( currentLayer->id ) < view->m_scale )
+        else
         {
             // Immediate mode
             view->m_painter->Draw( aItem, currentLayer->id );
@@ -482,6 +489,7 @@ struct VIEW::drawItem
 
     const VIEW_LAYER* currentLayer;
     VIEW* view;
+    int layersCount, layers[VIEW_MAX_LAYERS];
 };
 
 
@@ -652,6 +660,18 @@ void VIEW::clearGroupCache()
 }
 
 
+bool VIEW::isEveryLayerEnabled( const int aLayers[], int aCount ) const
+{
+    for( int i = 0; i < aCount; ++i )
+    {
+        if( !m_layers.at( aLayers[i] ).enabled )
+            return false;
+    }
+
+    return true;
+}
+
+
 void VIEW::RecacheAllItems( bool aImmediately )
 {
     BOX2I r;

common/view/view_item.cpp

@@ -48,6 +48,13 @@ void VIEW_ITEM::ViewSetVisible( bool aIsVisible )
 }
 
 
+void VIEW_ITEM::ViewGetRequiredLayers( int aLayers[], int& aCount ) const
+{
+    // By default there is no layer required
+    aCount = 0;
+}
+
+
 void VIEW_ITEM::ViewUpdate( int aUpdateFlags, bool aForceImmediateRedraw )
 {
     m_view->invalidateItem( this, aUpdateFlags );

include/view/view.h

@@ -403,6 +403,9 @@ private:
         return i->renderingOrder > j->renderingOrder;
     }
 
+    /// Checks if every layer stored in aLayers array is enabled.
+    bool isEveryLayerEnabled( const int aLayers[], int aCount ) const;
+
     /// Contains set of possible displayed layers and its properties
     LayerMap    m_layers;
 

include/view/view_item.h

@@ -207,6 +207,16 @@ public:
      */
     virtual void ViewGetLayers( int aLayers[], int& aCount ) const = 0;
 
+    /**
+     * Function ViewGetRequiredLayers()
+     * Returns the all the layers that are required for an item to be drawn. Eg. there is no point
+     * to draw netnames, when the track is not visible - so track layer should be marked as
+     * required.
+     * @param aLayers[]: output layer index array
+     * @param aCount: number of layer indices in aLayers[]
+     */
+    virtual void ViewGetRequiredLayers( int aLayers[], int& aCount ) const;
+
     /**
      * Function ViewSetVisible()
      * Sets the item visibility.