Drawing optimization: only redraw changed layers

The effect was: when drawing a shape on a single layer, all
layers have been redrawn. This was changed such that only
the affected layer is actually redrawn.

src/laybasic/layAnnotationShapes.h

@@ -32,6 +32,7 @@
 #include "dbLayoutStateModel.h"
 
 #include <vector>
+#include <limits>
 
 namespace lay
 {
@@ -351,7 +352,7 @@ public:
 private:
   void invalidate_state ()
   {
-    invalidate_bboxes ();
+    invalidate_bboxes (std::numeric_limits<unsigned int>::max ());
   }
 
   virtual void do_update ();

src/laybasic/layCellView.cc

@@ -79,7 +79,7 @@ LayoutHandle::LayoutHandle (db::Layout *layout, const std::string &filename)
   }
 
   mp_layout->hier_changed_event.add (this, &LayoutHandle::layout_changed);
-  mp_layout->bboxes_changed_event.add (this, &LayoutHandle::layout_changed);
+  mp_layout->bboxes_changed_any_event.add (this, &LayoutHandle::layout_changed);
   mp_layout->cell_name_changed_event.add (this, &LayoutHandle::layout_changed);
   mp_layout->prop_ids_changed_event.add (this, &LayoutHandle::layout_changed);
   mp_layout->layer_properties_changed_event.add (this, &LayoutHandle::layout_changed);

src/laybasic/layLayoutView.cc

@@ -645,7 +645,7 @@ void LayoutView::update_event_handlers ()
 
   for (unsigned int i = 0; i < cellviews (); ++i) {
     cellview (i)->layout ().hier_changed_event.add (this, &LayoutView::signal_hier_changed);
-    cellview (i)->layout ().bboxes_changed_event.add (this, &LayoutView::signal_bboxes_changed);
+    cellview (i)->layout ().bboxes_changed_event.add (this, &LayoutView::signal_bboxes_from_layer_changed, i);
     cellview (i)->layout ().dbu_changed_event.add (this, &LayoutView::signal_bboxes_changed);
     cellview (i)->layout ().prop_ids_changed_event.add (this, &LayoutView::signal_prop_ids_changed);
     cellview (i)->layout ().layer_properties_changed_event.add (this, &LayoutView::signal_layer_properties_changed);
@@ -653,7 +653,7 @@ void LayoutView::update_event_handlers ()
     cellview (i)->apply_technology_with_sender_event.add (this, &LayoutView::signal_apply_technology);
   }
 
-  annotation_shapes ().bboxes_changed_event.add (this, &LayoutView::signal_annotations_changed);
+  annotation_shapes ().bboxes_changed_any_event.add (this, &LayoutView::signal_annotations_changed);
 
   mp_canvas->viewport_changed_event.add (this, &LayoutView::viewport_changed);
 }
@@ -2066,15 +2066,35 @@ LayoutView::signal_hier_changed ()
   hier_changed_event ();
 }
 
+void
+LayoutView::signal_bboxes_from_layer_changed (unsigned int cv_index, unsigned int layer_index)
+{
+  if (layer_index == std::numeric_limits<unsigned int>::max ()) {
+
+    //  redraw all
+    signal_bboxes_changed ();
+
+  } else {
+
+    //  redraw only the layers required for redrawing
+    for (std::vector<lay::RedrawLayerInfo>::const_iterator l = mp_canvas->get_redraw_layers ().begin (); l != mp_canvas->get_redraw_layers ().end (); ++l) {
+      if (l->cellview_index == int (cv_index) && (layer_index == std::numeric_limits<unsigned int>::max () || l->layer_index == int (layer_index))) {
+        redraw_layer ((unsigned int) (l - mp_canvas->get_redraw_layers ().begin ()));
+      }
+    }
+
+    //  forward this event to our observers
+    geom_changed_event ();
+
+  }
+}
+
 void
 LayoutView::signal_bboxes_changed ()
 {
   //  schedule a redraw request for all layers
-  //  HINT: it could be optimized if we knew which layer to redraw. However, this 
-  //  is somewhat difficult to find out: first, we had to identify the layer we need to
-  //  redraw, the the layout which to redraw and then the layer views which need to be
-  //  redrawn ..
   redraw ();
+
   //  forward this event to our observers
   geom_changed_event ();
 }

src/laybasic/layLayoutView.h

@@ -2494,6 +2494,7 @@ public slots:
 
   //  event handlers used to connect to the layout object's events
   void signal_hier_changed ();
+  void signal_bboxes_from_layer_changed (unsigned int cv_index, unsigned int layer_index);
   void signal_bboxes_changed ();
   void signal_prop_ids_changed ();
   void signal_layer_properties_changed ();

src/laybasic/layRedrawThread.cc

@@ -193,6 +193,7 @@ RedrawThread::restart (const std::vector<int> &restart)
 {
   m_redraw_regions.clear ();
   m_redraw_regions.push_back (db::Box (db::Point (0, 0), db::Point (m_width, m_height)));
+  m_valid_region = m_stored_region = db::DBox ();
 
   do_start (false, 0, 0, restart, -1);
 }
@@ -241,13 +242,13 @@ RedrawThread::do_start (bool clear, const db::Vector *shift_vector, const std::v
         cv->layout ().update ();
         //  attach to the layout object to receive change notifications to stop the redraw thread
         cv->layout ().hier_changed_event.add (this, &RedrawThread::layout_changed);
-        cv->layout ().bboxes_changed_event.add (this, &RedrawThread::layout_changed);
+        cv->layout ().bboxes_changed_any_event.add (this, &RedrawThread::layout_changed);
       }
     }
     mp_view->annotation_shapes ().update ();
     //  attach to the layout object to receive change notifications to stop the redraw thread
     mp_view->annotation_shapes ().hier_changed_event.add (this, &RedrawThread::layout_changed);  //  not really required, since the shapes have no hierarchy, but for completeness ..
-    mp_view->annotation_shapes ().bboxes_changed_event.add (this, &RedrawThread::layout_changed);
+    mp_view->annotation_shapes ().bboxes_changed_any_event.add (this, &RedrawThread::layout_changed);
     mp_view->cellviews_about_to_change_event.add (this, &RedrawThread::layout_changed);
     mp_view->cellview_about_to_change_event.add (this, &RedrawThread::layout_changed_with_int);
 
@@ -275,8 +276,10 @@ RedrawThread::do_start (bool clear, const db::Vector *shift_vector, const std::v
           if (*l == draw_custom_queue_entry) {
             planes_to_init.push_back (-1); 
           } else if (*l >= 0 && *l < int (m_layers.size ())) {
-            for (int o = 0; o < planes_per_layer; ++o) {
-              planes_to_init.push_back (o + *l * planes_per_layer + special_planes_before + special_planes_after);
+            for (int i = 0; i < planes_per_layer / 3; ++i) {
+              planes_to_init.push_back (*l * (planes_per_layer / 3) + special_planes_before + i);
+              planes_to_init.push_back ((*l + m_nlayers) * (planes_per_layer / 3) + special_planes_before + i);
+              planes_to_init.push_back ((*l + m_nlayers * 2) * (planes_per_layer / 3) + special_planes_before + i);
             }
           }
         }