Items are not recached until GAL is changed (earlier it was done on every...

Items are not recached until GAL is changed (earlier it was done on every rendering backend switch).

common/drawpanel_gal.cpp

@@ -134,6 +134,9 @@ void EDA_DRAW_PANEL_GAL::Refresh( bool eraseBackground, const wxRect* rect )
 
 void EDA_DRAW_PANEL_GAL::SwitchBackend( GalType aGalType, bool aUseShaders )
 {
+    if( aGalType == m_currentGal && m_gal != NULL )
+        return;
+
     if( m_gal )
         delete m_gal;
 
@@ -164,4 +167,6 @@ void EDA_DRAW_PANEL_GAL::SwitchBackend( GalType aGalType, bool aUseShaders )
 
     wxSize size = GetClientSize();
     m_gal->ResizeScreen( size.GetX(), size.GetY() );
+
+    m_currentGal = aGalType;
 }

include/class_drawpanel_gal.h

@@ -87,6 +87,7 @@ protected:
     KiGfx::PAINTER*          m_painter;          ///< Contains information about how to draw items
                                                  ///< using GAL
     KiGfx::WX_VIEW_CONTROLS* m_viewControls;     ///< Control for VIEW (moving, zooming, etc.)
+    GalType                  m_currentGal;       ///< Currently used GAL
 
     std::string              m_galShaderPath;    ///< Path to shader files, used in OpenGL mode
 };