Optimize|World|SectorCluster: Avoid unnecessary Surface Decoration up…

…dates

Previously if a mapped Plane move occurred then all of the Surfaces
of LineSides in the cluster-linked Sector were marked for updating,
irrespective of whether those surfaces are actually "dependent" on
said plane.

In large maps with lots of moving planes and light decorations, this
meant a lot of unnecessary surface redecoration.

SectorCluster's internal boundary info is automatically prepared the
first time one of the dependent Planes move if needed (map hacks may
mean this info is already prepared). The boundary info is then used
to limit light decoration updates to only those Surfaces which share
a boundary edge with the cluster.

Todo for later: Free the boundary info if the dependent planes have
not moved in a while.

doomsday/client/src/world/plane.cpp

@@ -277,25 +277,23 @@ void Plane::resetSmoothedHeight()
     {
         d->heightSmoothed = newHeightSmoothed;
         d->notifySmoothedHeightChanged();
+        d->surface.markAsNeedingDecorationUpdate();
     }
-
-    d->surface.markAsNeedingDecorationUpdate();
 }
 
 void Plane::updateHeightTracking()
 {
     d->oldHeight[0] = d->oldHeight[1];
     d->oldHeight[1] = d->height;
 
-    d->surface.markAsNeedingDecorationUpdate();
-
     if(!de::fequal(d->oldHeight[0], d->oldHeight[1]))
     {
         if(de::abs(d->oldHeight[0] - d->oldHeight[1]) >= MAX_SMOOTH_MOVE)
         {
             // Too fast: make an instantaneous jump.
             d->oldHeight[0] = d->oldHeight[1];
         }
+        d->surface.markAsNeedingDecorationUpdate();
     }
 }
 

doomsday/client/src/world/sectorcluster.cpp

@@ -323,8 +323,10 @@ DENG2_OBSERVES(Plane, HeightChange)
         return flags;
     }
 
-    void initBoundaryInfo()
+    void initBoundaryInfoIfNeeded()
     {
+        if(!boundaryInfo.isNull()) return;
+
         QMap<Cluster *, HEdge *> extClusterMap;
         foreach(BspLeaf *leaf, bspLeafs)
         {
@@ -335,7 +337,8 @@ DENG2_OBSERVES(Plane, HeightChange)
                 if(!hedge->hasMapElement())
                     continue;
 
-                DENG2_ASSERT(hedge->twin().hasFace()); // Sanity check.
+                if(!hedge->twin().hasFace())
+                    continue;
 
                 BspLeaf &backLeaf = hedge->twin().face().mapElementAs<BspLeaf>();
                 if(!backLeaf.hasCluster())
@@ -427,11 +430,7 @@ DENG2_OBSERVES(Plane, HeightChange)
         {
             // Should we permanently map planes to another cluster?
 
-            // Is it time to initialize the boundary info?
-            if(boundaryInfo.isNull())
-            {
-                initBoundaryInfo();
-            }
+            initBoundaryInfoIfNeeded();
 
             foreach(HEdge *hedge, boundaryInfo->uniqueOuterEdges)
             {
@@ -480,7 +479,6 @@ DENG2_OBSERVES(Plane, HeightChange)
                 }
 
                 // Permanent mappings won't be remapped.
-                boundaryInfo.reset();
                 return;
             }
         }
@@ -502,11 +500,7 @@ DENG2_OBSERVES(Plane, HeightChange)
         if(!doFloor && !doCeiling)
             return;
 
-        // Is it time to initialize the boundary info?
-        if(boundaryInfo.isNull())
-        {
-            initBoundaryInfo();
-        }
+        initBoundaryInfoIfNeeded();
 
         // Map "this" cluster to the first outer cluster found.
         foreach(HEdge *hedge, boundaryInfo->uniqueOuterEdges)
@@ -565,6 +559,25 @@ DENG2_OBSERVES(Plane, HeightChange)
 
 #ifdef __CLIENT__
 
+    void markAllSurfacesForDecorationUpdate(Line &line)
+    {
+        LineSide &front = line.front();
+        DENG2_ASSERT(front.hasSections());
+        {
+            front.middle().markAsNeedingDecorationUpdate();
+            front.bottom().markAsNeedingDecorationUpdate();
+            front.   top().markAsNeedingDecorationUpdate();
+        }
+
+        LineSide &back = line.back();
+        if(back.hasSections())
+        {
+            back.middle().markAsNeedingDecorationUpdate();
+            back.bottom().markAsNeedingDecorationUpdate();
+            back   .top().markAsNeedingDecorationUpdate();
+        }
+    }
+
     /**
      * To be called when the height changes to update the plotted decoration
      * origins for surfaces whose material offset is dependant upon this.
@@ -573,22 +586,24 @@ DENG2_OBSERVES(Plane, HeightChange)
     {
         if(ddMapSetup) return;
 
-        foreach(LineSide *side, self.sector().sides())
+        initBoundaryInfoIfNeeded();
+
+        // Mark surfaces of the outer edge loop.
+        HEdge *base = boundaryInfo->uniqueOuterEdges.first();
+        SectorClusterCirculator it(base);
+        do
         {
-            if(side->hasSections())
-            {
-                side->middle().markAsNeedingDecorationUpdate();
-                side->bottom().markAsNeedingDecorationUpdate();
-                side   ->top().markAsNeedingDecorationUpdate();
-            }
+            markAllSurfacesForDecorationUpdate(it->mapElementAs<LineSideSegment>().line());
+        } while(&it.next() != base);
 
-            if(side->back().hasSections())
+        // Mark surfaces of the inner edge loop(s).
+        foreach(HEdge *base, boundaryInfo->uniqueInnerEdges)
+        {
+            SectorClusterCirculator it(base);
+            do
             {
-                LineSide &back = side->back();
-                back.middle().markAsNeedingDecorationUpdate();
-                back.bottom().markAsNeedingDecorationUpdate();
-                back   .top().markAsNeedingDecorationUpdate();
-            }
+                markAllSurfacesForDecorationUpdate(it->mapElementAs<LineSideSegment>().line());
+            } while(&it.next() != base);
         }
     }
 
@@ -951,10 +966,10 @@ SectorCluster *SectorClusterCirculator::getCluster(HEdge const &hedge) // static
     return hedge.face().mapElementAs<BspLeaf>().clusterPtr();
 }
 
-HEdge const &SectorClusterCirculator::getNeighbor(HEdge const &hedge, ClockDirection direction,
+HEdge &SectorClusterCirculator::getNeighbor(HEdge const &hedge, ClockDirection direction,
     SectorCluster const *cluster) // static
 {
-    HEdge const *neighbor = &hedge.neighbor(direction);
+    HEdge *neighbor = &hedge.neighbor(direction);
     // Skip over interior edges.
     if(cluster)
     {