Sector: Enumerate referencing map line sides instead of lines

Maintaining a list of map lines which reference the sector is useful.
However, more useful is a list of the referencing map line sides, as
this then simplifies the logic for any users of this list (there is
no need to then deduce which side(s) of the line has the reference).

doomsday/client/include/map/sector.h

@@ -30,11 +30,11 @@
 #include <de/Vector>
 
 #include "MapElement"
+#include "Line"
 #include "Plane"
 
 class BspLeaf;
 class GameMap;
-class Line;
 class Surface;
 
 /**
@@ -71,7 +71,7 @@ class Sector : public de::MapElement,
     static float const DEFAULT_LIGHT_LEVEL; ///< 1.f
     static de::Vector3f const DEFAULT_LIGHT_COLOR; ///< red=1.f green=1.f, blue=1.f
 
-    typedef QList<Line *> Lines;
+    typedef QList<Line::Side *> Sides;
     typedef QList<Plane *> Planes;
     typedef QList<BspLeaf *> BspLeafs;
 
@@ -196,28 +196,31 @@ class Sector : public de::MapElement,
     inline Surface const &ceilingSurface() const { return ceiling().surface(); }
 
     /**
-     * Provides access to the list of lines which reference the sector,
+     * Provides access to the list of line sides which reference the sector,
      * for efficient traversal.
      */
-    Lines const &lines() const;
+    Sides const &sides() const;
 
     /**
-     * Returns the total number of lines which reference the sector.
+     * Returns the total number of line sides which reference the sector.
      */
-    inline uint lineCount() const { return uint(lines().count()); }
+    inline uint sideCount() const { return uint(sides().count()); }
 
     /**
-     * (Re)Build the line list for the sector.
+     * (Re)Build the side list for the sector.
+     *
+     * @note In the special case of self-referencing line, only the front side
+     * reference is added to this list.
      *
      * @attention The behavior of some algorithms used in the DOOM game logic
      * is dependant upon the order of this list. For example, EV_DoFloor and
      * EV_BuildStairs. That same order is used here, for compatibility.
      *
-     * Order: Original line index, ascending.
+     * Order: Original @em line index, ascending.
      *
-     * @param map  Map to collate lines from. @todo Refactor away.
+     * @param map  Map to collate sides from. @todo Refactor away.
      */
-    void buildLines(GameMap const &map);
+    void buildSides(GameMap const &map);
 
     /**
      * Provides access to the list of BSP leafs which reference the sector, for

doomsday/client/src/audio/s_environ.cpp

@@ -147,7 +147,7 @@ static void setBspLeafSectorOwner(ownerlist_t *ownerList, BspLeaf *bspLeaf)
 
 static void findBspLeafsAffectingSector(GameMap *map, Sector *sec)
 {
-    if(!sec || !sec->lineCount()) return;
+    if(!sec || !sec->sideCount()) return;
 
     ownerlist_t bspLeafOwnerList;
     std::memset(&bspLeafOwnerList, 0, sizeof(bspLeafOwnerList));
@@ -314,7 +314,7 @@ static boolean calcBspLeafReverb(BspLeaf *bspLeaf)
 
 static void calculateSectorReverb(Sector *sec)
 {
-    if(!sec || !sec->lineCount()) return;
+    if(!sec || !sec->sideCount()) return;
 
     uint spaceVolume = int((sec->ceiling().height() - sec->floor().height()) * sec->roughArea());
 

doomsday/client/src/map/gamemap.cpp

@@ -171,7 +171,7 @@ DENG2_PIMPL(GameMap)
         foreach(Sector *sector, self._sectors)
         {
             sector->buildBspLeafs(self);
-            sector->buildLines(self);
+            sector->buildSides(self);
             sector->updateAABox();
             sector->updateRoughArea();
 
@@ -193,21 +193,20 @@ DENG2_PIMPL(GameMap)
             }
 
             // Link wall surface emitters:
-            foreach(Line *line, sector->lines())
+            foreach(Line::Side *side, sector->sides())
             {
-                if(line->frontSectorPtr() == sector)
+                if(side->hasSections())
                 {
-                    Line::Side &side = line->front();
-                    sector->linkSoundEmitter(side.middleSoundEmitter());
-                    sector->linkSoundEmitter(side.bottomSoundEmitter());
-                    sector->linkSoundEmitter(side.topSoundEmitter());
+                    sector->linkSoundEmitter(side->middleSoundEmitter());
+                    sector->linkSoundEmitter(side->bottomSoundEmitter());
+                    sector->linkSoundEmitter(side->topSoundEmitter());
                 }
-                if(line->hasBackSections() && line->backSectorPtr() == sector)
+                if(side->line().isSelfReferencing() && side->back().hasSections())
                 {
-                    Line::Side &side = line->back();
-                    sector->linkSoundEmitter(side.middleSoundEmitter());
-                    sector->linkSoundEmitter(side.bottomSoundEmitter());
-                    sector->linkSoundEmitter(side.topSoundEmitter());
+                    Line::Side &back = side->back();
+                    sector->linkSoundEmitter(back.middleSoundEmitter());
+                    sector->linkSoundEmitter(back.bottomSoundEmitter());
+                    sector->linkSoundEmitter(back.topSoundEmitter());
                 }
             }
 
@@ -288,7 +287,7 @@ DENG2_PIMPL(GameMap)
 
     void updateMapSkyFixForSector(Sector const &sector)
     {
-        if(!sector.lineCount()) return;
+        if(!sector.sideCount()) return;
 
         bool const skyFloor = sector.floorSurface().hasSkyMaskedMaterial();
         bool const skyCeil  = sector.ceilingSurface().hasSkyMaskedMaterial();
@@ -329,14 +328,12 @@ DENG2_PIMPL(GameMap)
 
         // Update for middle textures on two sided lines which intersect the
         // floor and/or ceiling of their front and/or back sectors.
-        foreach(Line *line, sector.lines())
+        foreach(Line::Side *side, sector.sides())
         {
-            Line::Side &side = line->frontSectorPtr() == &sector? line->front() : line->back();
+            if(!side->hasSections()) continue;
+            if(!side->middle().hasMaterial()) continue;
 
-            if(!side.hasSections()) continue;
-            if(!side.middle().hasMaterial()) continue;
-
-            HEdge const *hedge     = side.leftHEdge();
+            HEdge const *hedge     = side->leftHEdge();
             Sector const *frontSec = hedge->wallSectionSector(HEdge::Front);
             Sector const *backSec  = hedge->wallSectionSector(HEdge::Back);
 
@@ -345,7 +342,7 @@ DENG2_PIMPL(GameMap)
 
             coord_t bottomZ, topZ;
             Vector2f materialOrigin;
-            R_SideSectionCoords(side, Line::Side::Middle, frontSec, backSec,
+            R_SideSectionCoords(*side, Line::Side::Middle, frontSec, backSec,
                                 &bottomZ, &topZ, &materialOrigin);
             if(skyCeil && topZ + materialOrigin.y > self.skyFixCeiling())
             {
@@ -673,7 +670,7 @@ void GameMap::buildSurfaceLists()
     foreach(Sector *sector, _sectors)
     {
         // Skip sectors with no lines as their planes will never be drawn.
-        if(!sector->lineCount()) continue;
+        if(!sector->sideCount()) continue;
 
         foreach(Plane *plane, sector->planes())
         {
@@ -1973,29 +1970,29 @@ static void addMissingMaterial(Line::Side &side, int section)
 
 void GameMap::updateMissingMaterialsForLinesOfSector(Sector const &sec)
 {
-    foreach(Line *line, sec.lines())
+    foreach(Line::Side *side, sec.sides())
     {
         /**
          * Do as in the original Doom if the texture has not been defined -
          * extend the floor/ceiling to fill the space (unless it is skymasked),
          * or if there is a midtexture use that instead.
          */
-        if(line->hasBackSector())
+        if(side->hasSector() && side->back().hasSector())
         {
-            Sector const &frontSec = line->frontSector();
-            Sector const &backSec  = line->backSector();
+            Sector const &frontSec = side->sector();
+            Sector const &backSec  = side->back().sector();
 
             // A potential bottom section fix?
             if(!(frontSec.floorSurface().hasSkyMaskedMaterial() &&
                   backSec.floorSurface().hasSkyMaskedMaterial()))
             {
                 if(frontSec.floor().height() < backSec.floor().height())
                 {
-                    addMissingMaterial(line->front(), Line::Side::Bottom);
+                    addMissingMaterial(*side, Line::Side::Bottom);
                 }
                 else if(frontSec.floor().height() > backSec.floor().height())
                 {
-                    addMissingMaterial(line->back(), Line::Side::Bottom);
+                    addMissingMaterial(side->back(), Line::Side::Bottom);
                 }
             }
 
@@ -2005,18 +2002,18 @@ void GameMap::updateMissingMaterialsForLinesOfSector(Sector const &sec)
             {
                 if(backSec.ceiling().height() < frontSec.ceiling().height())
                 {
-                    addMissingMaterial(line->front(), Line::Side::Top);
+                    addMissingMaterial(*side, Line::Side::Top);
                 }
                 else if(backSec.ceiling().height() > frontSec.ceiling().height())
                 {
-                    addMissingMaterial(line->back(), Line::Side::Top);
+                    addMissingMaterial(side->back(), Line::Side::Top);
                 }
             }
         }
         else
         {
             // A potential middle section fix.
-            addMissingMaterial(line->front(), Line::Side::Middle);
+            addMissingMaterial(*side, Line::Side::Middle);
         }
     }
 }

doomsday/client/src/map/p_dmu.cpp

@@ -402,9 +402,9 @@ int P_Iteratep(void *elPtr, uint prop, void *context, int (*callback) (void *p,
         switch(prop)
         {
         case DMU_LINE:
-            foreach(Line *line, elem->castTo<Sector>()->lines())
+            foreach(Line::Side *side, elem->castTo<Sector>()->sides())
             {
-                int result = callback(line, context);
+                int result = callback(&side->line(), context);
                 if(result) return result;
             }
             return false; // Continue iteration

doomsday/client/src/map/p_maputil.cpp

@@ -482,9 +482,9 @@ int GameMap_SectorTouchingMobjsIterator(GameMap *map, Sector *sector,
 
     // Collate mobjs linked to the sector's lines.
     linknode_t const *ln = map->lineNodes.nodes;
-    foreach(Line *line, sector->lines())
+    foreach(Line::Side *side, sector->sides())
     {
-        nodeindex_t root = map->lineLinks[line->indexInMap()];
+        nodeindex_t root = map->lineLinks[side->line().indexInMap()];
 
         for(nodeindex_t nix = ln[root].next; nix != root; nix = ln[nix].next)
         {

doomsday/client/src/map/p_particle.cpp

@@ -179,7 +179,7 @@ void P_MapSpawnPlaneParticleGens()
     foreach(Sector *sector, theMap->sectors())
     {
         // Only planes of sectors with volume on the world X/Y axis support generators.
-        if(!sector->lineCount()) continue;
+        if(!sector->sideCount()) continue;
 
         for(uint i = 0; i < 2; ++i)
         {
@@ -361,7 +361,7 @@ void P_SpawnPlaneParticleGen(ded_ptcgen_t const *def, Plane *plane)
     if(isDedicated || !useParticles) return;
     if(!def || !plane) return;
     // Only planes in sectors with volume on the world X/Y axis can support generators.
-    if(!plane->sector().lineCount()) return;
+    if(!plane->sector().sideCount()) return;
 
     // Plane we spawn relative to may not be this one.
     Plane::Type relPlane = plane->type();

doomsday/client/src/map/plane.cpp

@@ -172,19 +172,18 @@ DENG2_PIMPL(Plane)
 
         // Mark the decor lights on the sides of this plane as requiring
         // an update.
-        foreach(Line *line, sector->lines())
+        foreach(Line::Side *side, sector->sides())
         {
-            if(line->hasFrontSections())
+            if(side->hasSections())
             {
-                Line::Side &front = line->front();
-                front.middle().markAsNeedingDecorationUpdate();
-                front.bottom().markAsNeedingDecorationUpdate();
-                front.top().markAsNeedingDecorationUpdate();
+                side->middle().markAsNeedingDecorationUpdate();
+                side->bottom().markAsNeedingDecorationUpdate();
+                side->top().markAsNeedingDecorationUpdate();
             }
 
-            if(line->hasBackSections())
+            if(side->back().hasSections())
             {
-                Line::Side &back = line->back();
+                Line::Side &back = side->back();
                 back.middle().markAsNeedingDecorationUpdate();
                 back.bottom().markAsNeedingDecorationUpdate();
                 back.top().markAsNeedingDecorationUpdate();

doomsday/client/src/map/sector.cpp

@@ -54,8 +54,8 @@ DENG2_PIMPL(Sector)
     /// List of planes (owned).
     Planes planes;
 
-    /// List of lines which reference the sector (not owned).
-    Lines lines;
+    /// List of line sides which reference the sector (not owned).
+    Sides sides;
 
     /// List of BSP leafs which reference the sector (not owned).
     BspLeafs bspLeafs;
@@ -229,36 +229,40 @@ Plane const &Sector::plane(int planeIndex) const
     return const_cast<Plane const &>(const_cast<Sector &>(*this).plane(planeIndex));
 }
 
-Sector::Lines const &Sector::lines() const
+Sector::Sides const &Sector::sides() const
 {
-    return d->lines;
+    return d->sides;
 }
 
-void Sector::buildLines(GameMap const &map)
+void Sector::buildSides(GameMap const &map)
 {
-    d->lines.clear();
+    d->sides.clear();
 
 #ifdef DENG2_QT_4_7_OR_NEWER
     uint count = 0;
     foreach(Line *line, map.lines())
     {
-        if(line->frontSectorPtr() == this ||
-           line->backSectorPtr()  == this)
+        if(line->front().sectorPtr() == this ||
+           line->back().sectorPtr()  == this)
             ++count;
     }
 
     if(0 == count) return;
 
-    d->lines.reserve(count);
+    d->sides.reserve(count);
 #endif
 
     foreach(Line *line, map.lines())
     {
-        if(line->frontSectorPtr() == this ||
-           line->backSectorPtr()  == this)
+        if(line->front().sectorPtr() == this)
         {
-            // Ownership of the line is not given to the sector.
-            d->lines.append(line);
+            // Ownership of the side is not given to the sector.
+            d->sides.append(&line->front());
+        }
+        else if(line->back().sectorPtr()  == this)
+        {
+            // Ownership of the side is not given to the sector.
+            d->sides.append(&line->back());
         }
     }
 }
@@ -424,10 +428,10 @@ void Sector::planeHeightChanged(Plane &plane, coord_t oldHeight)
     }
 
     // Update the sound emitter origins for all dependent wall surfaces.
-    foreach(Line *line, d->lines)
+    foreach(Line::Side *side, d->sides)
     {
-        line->front().updateAllSoundEmitterOrigins();
-        line->back().updateAllSoundEmitterOrigins();
+        side->updateAllSoundEmitterOrigins();
+        side->back().updateAllSoundEmitterOrigins();
     }
 
 #ifdef __CLIENT__

doomsday/client/src/render/r_lgrid.cpp

@@ -457,7 +457,7 @@ void LG_InitForMap(void)
     {
         count = changedCount = 0;
 
-        if(sector->lineCount())
+        if(sector->sideCount())
         {
             // Clear the bitfields.
             std::memset(indexBitfield, 0, bitfieldSize);

doomsday/client/src/render/r_main.cpp

@@ -1399,8 +1399,8 @@ void Rend_CacheForMap()
 
         foreach(Sector *sector, theMap->sectors())
         {
-            // Skip sectors with no lines as their planes will never be drawn.
-            if(!sector->lineCount()) continue;
+            // Skip sectors with no line sides as their planes will never be drawn.
+            if(!sector->sideCount()) continue;
 
             foreach(Plane *plane, sector->planes())
             {