EDA_DRAW_PANEL_GAL: redraw stuff in a single place, with "coalescing"

Redraws can be requested way too often than it is required. This commit adds redraw timeout:
- if the view became dirty and there has been no redraw for longer than certain time, it is redrawed immediately
- otherwise, we wait for the next frame

This in general improves smoothness of rendering.

common/drawpanel_gal.cpp

@@ -91,6 +91,11 @@ EDA_DRAW_PANEL_GAL::EDA_DRAW_PANEL_GAL( wxWindow* aParentWindow, wxWindowID aWin
 	Connect( wxEVT_KEY_UP,      wxEventHandler( EDA_DRAW_PANEL_GAL::onEvent ), NULL, this );
 	Connect( wxEVT_KEY_DOWN,    wxEventHandler( EDA_DRAW_PANEL_GAL::onEvent ), NULL, this );
     Connect( wxEVT_ENTER_WINDOW, wxEventHandler (EDA_DRAW_PANEL_GAL::onEnter ), NULL, this );
+    
+
+    m_refreshTimer.SetOwner( this );
+    Connect( wxEVT_TIMER, wxTimerEventHandler( EDA_DRAW_PANEL_GAL::onRefreshTimer ), NULL, this );
+
     this->SetFocus();
 }
 
@@ -113,6 +118,9 @@ EDA_DRAW_PANEL_GAL::~EDA_DRAW_PANEL_GAL()
 
 void EDA_DRAW_PANEL_GAL::onPaint( wxPaintEvent& WXUNUSED( aEvent ) )
 {
+    m_pendingRefresh = false;
+    m_lastRefresh = wxGetLocalTimeMillis();
+
 #ifdef __WXDEBUG__
     prof_counter time;
     prof_start( &time, false );
@@ -147,13 +155,33 @@ void EDA_DRAW_PANEL_GAL::onSize( wxSizeEvent& aEvent )
 }
 
 
-void EDA_DRAW_PANEL_GAL::Refresh( bool eraseBackground, const wxRect* rect )
+void EDA_DRAW_PANEL_GAL::onRefreshTimer( wxTimerEvent& aEvent )
 {
     wxPaintEvent redrawEvent;
     wxPostEvent( this, redrawEvent );
 }
 
 
+void EDA_DRAW_PANEL_GAL::Refresh( bool eraseBackground, const wxRect* rect )
+{
+    if(m_pendingRefresh)
+        return;
+
+    wxLongLong t = wxGetLocalTimeMillis();
+    wxLongLong delta = t - m_lastRefresh;
+
+    if(t >= MinRefreshPeriod)
+    {
+        wxPaintEvent redrawEvent;
+        wxPostEvent( this, redrawEvent );
+        m_pendingRefresh = true;
+    } else {
+        m_refreshTimer.Start ( (MinRefreshPeriod - t).ToLong(), true );
+        m_pendingRefresh = true;
+    }
+} 
+
+
 void EDA_DRAW_PANEL_GAL::SwitchBackend( GalType aGalType )
 {
     // Do not do anything if the currently used GAL is correct
@@ -208,6 +236,7 @@ void EDA_DRAW_PANEL_GAL::onEvent( wxEvent& aEvent )
         m_eventDispatcher->DispatchWxEvent( aEvent );
     }
 
+	if(m_view->IsDirty())
         Refresh();
 }
 

common/view/wx_view_controls.cpp

@@ -196,8 +196,7 @@ void WX_VIEW_CONTROLS::onTimer( wxTimerEvent& aEvent )
 
         dir = m_view->ToWorld( dir, false );
         m_view->SetCenter( m_view->GetCenter() + dir * m_autoPanSpeed );
-
-        m_parentPanel->Refresh();
+        m_view->MakeDirty();
     }
     break;
 

include/class_drawpanel_gal.h

@@ -116,8 +116,15 @@ protected:
     void onSize( wxSizeEvent& aEvent );
     void onEvent( wxEvent& aEvent );
     void onEnter( wxEvent& aEvent );
+    void onRefreshTimer ( wxTimerEvent& aEvent );
     void skipEvent( wxEvent& aEvent );
 
+    static const int MinRefreshPeriod = 17;             ///< 60 FPS.
+
+    wxLongLong               m_lastRefresh;      ///< Last time the panel was refreshed
+    bool                     m_pendingRefresh;
+    wxTimer                  m_refreshTimer;
+
     KiGfx::GAL*              m_gal;              ///< Interface for drawing objects on a 2D-surface
     KiGfx::VIEW*             m_view;             ///< Stores view settings (scale, center, etc.)
                                                  ///< and items to be drawn

include/view/view.h

@@ -443,6 +443,11 @@ public:
         return ( m_layers.at( aLayer ).target == TARGET_CACHED );
     }
 
+    void MakeDirty()
+    {
+        for(int i = 0; i < TARGETS_NUMBER; i++)
+            m_dirtyTargets[i] = true;
+    }
 
     static const int VIEW_MAX_LAYERS = 128;      ///* maximum number of layers that may be shown