Fix Pcbnew markers in nanometer build with proper scaling factor. Use double in Zoom()

common/drawpanel.cpp

@@ -207,13 +207,13 @@ void EDA_DRAW_PANEL::CrossHairOn( wxDC* DC )
 }
 
 
-int EDA_DRAW_PANEL::GetZoom()
+double EDA_DRAW_PANEL::GetZoom()
 {
     return GetScreen()->GetZoom();
 }
 
 
-void EDA_DRAW_PANEL::SetZoom( int zoom )
+void EDA_DRAW_PANEL::SetZoom( double zoom )
 {
     GetScreen()->SetZoom( zoom );
 }

common/zoom.cpp

@@ -60,8 +60,11 @@ void EDA_DRAW_FRAME::Zoom_Automatique( bool aWarpPointer )
     BASE_SCREEN* screen = GetScreen();
 
     // Set the best zoom and get center point.
-    double bestzoom = BestZoom();
 
+    // BestZoom() can compute an illegal zoom if the client window size
+    // is small, say because frame is not maximized.  So use the clamping form
+    // of SetZoom():
+    double bestzoom = BestZoom();
     screen->SetScalingFactor( bestzoom );
 
     if( screen->m_FirstRedraw )

include/class_drawpanel.h

@@ -243,8 +243,9 @@ public:
     void OnScrollWin( wxCommandEvent& event );
     void OnScroll( wxScrollWinEvent& event );
 
-    void SetZoom( int mode );
-    int GetZoom();
+    void SetZoom( double mode );
+    double GetZoom();
+
     void SetGrid( const wxRealPoint& size );
     wxRealPoint GetGrid();
 

pcbnew/class_marker_pcb.cpp

@@ -15,7 +15,8 @@
 #include <layers_id_colors_and_visibility.h>
 
 
-#define SCALING_FACTOR 30       // Adjust the actual size of markers, when using default shape
+/// Adjust the actual size of markers, when using default shape
+#define SCALING_FACTOR      DMils2iu( 30 )
 
 
 MARKER_PCB::MARKER_PCB( BOARD_ITEM* aParent ) :