Refactor: Cleaned up map geometry construction somewhat

Added precondition assertions and effected some rename refactorings
so that we can again see the wood for the trees...

This'll do for now.

doomsday/client/include/map/line.h

@@ -414,9 +414,9 @@ class Line : public de::MapElement
 #endif // __CLIENT__
 
         /**
-         * Returns the left-most half-edge for the side.
+         * Returns a pointer the left-most half-edge for the side; otherwise @c 0.
          */
-        HEdge &leftHEdge() const;
+        HEdge *leftHEdge() const;
 
         /**
          * Change the left-most half-edge for the side.
@@ -428,9 +428,9 @@ class Line : public de::MapElement
         void setLeftHEdge(HEdge *newHEdge);
 
         /**
-         * Returns the right-most half-edge for the side.
+         * Returns a pointer to the right-most half-edge for the side; otherwise @c 0.
          */
-        HEdge &rightHEdge() const;
+        HEdge *rightHEdge() const;
 
         /**
          * Change the right-most half-edge for the side.

doomsday/client/include/map/polyobj.h

@@ -21,12 +21,16 @@
 #ifndef LIBDENG_MAP_POLYOBJ_H
 #define LIBDENG_MAP_POLYOBJ_H
 
-#include "dd_share.h"
-
 #include <QList>
 #include <QSet>
+
 #include <de/vector1.h>
 
+#include "dd_share.h"
+
+#include "map/line.h"
+#include "map/vertex.h"
+
 /**
  * @ingroup map
  */
@@ -63,7 +67,7 @@ typedef struct polyobj_s
     {
         foreach(Line *line, lines())
         {
-            delete &line->front().leftHEdge();
+            delete line->front().leftHEdge();
         }
 
         delete static_cast<Lines *>(_lines);

doomsday/client/src/map/bsp/partitioner.cpp

@@ -1771,20 +1771,22 @@ DENG2_PIMPL(Partitioner)
                 /// @todo kludge: This should not be done here!
                 if(hedge->hasLine())
                 {
-                    Line::Side &side = hedge->line().side(hedge->lineSideId());
+                    Line::Side &side = hedge->lineSide();
 
                     // Already processed?
-                    if(!side._leftHEdge)
+                    if(!side.leftHEdge())
                     {
-                        side._leftHEdge = hedge;
+                        HEdge *leftHEdge = hedge;
                         // Find the left-most hedge.
-                        while(hedgeInfo(*side._leftHEdge).prevOnSide)
-                            side._leftHEdge = hedgeInfo(*side._leftHEdge).prevOnSide;
+                        while(hedgeInfo(*leftHEdge).prevOnSide)
+                            leftHEdge = hedgeInfo(*leftHEdge).prevOnSide;
+                        side.setLeftHEdge(leftHEdge);
 
                         // Find the right-most hedge.
-                        side._rightHEdge = hedge;
-                        while(hedgeInfo(*side._rightHEdge).nextOnSide)
-                            side._rightHEdge = hedgeInfo(*side._rightHEdge).nextOnSide;
+                        HEdge *rightHEdge = hedge;
+                        while(hedgeInfo(*rightHEdge).nextOnSide)
+                            rightHEdge = hedgeInfo(*rightHEdge).nextOnSide;
+                        side.setRightHEdge(rightHEdge);
                     }
                 }
                 /// kludge end

doomsday/client/src/map/hedge.cpp

@@ -221,8 +221,8 @@ static void addWallDivNodesForPlaneIntercepts(HEdge const *hedge, walldivs_t *wa
     if(section == SS_MIDDLE && isTwoSided) return;
 
     // Only edges at line ends can/should be split.
-    if(!((hedge == &hedge->lineSide().leftHEdge()  && !doRight) ||
-         (hedge == &hedge->lineSide().rightHEdge() &&  doRight)))
+    if(!((hedge == hedge->lineSide().leftHEdge()  && !doRight) ||
+         (hedge == hedge->lineSide().rightHEdge() &&  doRight)))
         return;
 
     if(bottomZ >= topZ) return; // Obviously no division.

doomsday/client/src/map/line.cpp

@@ -135,10 +135,9 @@ Line::Side::Section const &Line::Side::section(SideSection sectionId) const
     return const_cast<Section const &>(const_cast<Side *>(this)->section(sectionId));
 }
 
-HEdge &Line::Side::leftHEdge() const
+HEdge *Line::Side::leftHEdge() const
 {
-    DENG_ASSERT(_leftHEdge != 0);
-    return *_leftHEdge;
+    return _leftHEdge;
 }
 
 void Line::Side::setLeftHEdge(HEdge *newLeftHEdge)
@@ -151,10 +150,9 @@ void Line::Side::setRightHEdge(HEdge *newRightHEdge)
     _rightHEdge = newRightHEdge;
 }
 
-HEdge &Line::Side::rightHEdge() const
+HEdge *Line::Side::rightHEdge() const
 {
-    DENG_ASSERT(_rightHEdge != 0);
-    return *_rightHEdge;
+    return _rightHEdge;
 }
 
 void Line::Side::updateMiddleSoundEmitterOrigin()

doomsday/client/src/map/polyobj.cpp

@@ -36,10 +36,12 @@ static void notifyGeometryChanged(Polyobj &po)
     // Shadow bias must be informed when surfaces move/deform.
     foreach(Line *line, po.lines())
     {
-        HEdge &hedge = line->front().leftHEdge();
+        HEdge *hedge = line->front().leftHEdge();
+        if(!hedge) continue;
+
         for(int i = 0; i < 3; ++i)
         {
-            SB_SurfaceMoved(&hedge.biasSurfaceForGeometryGroup(i));
+            SB_SurfaceMoved(&hedge->biasSurfaceForGeometryGroup(i));
         }
     }
 #else // !__CLIENT__
@@ -276,7 +278,7 @@ bool Polyobj::rotate(angle_t delta)
             line->updateSlopeType();
 
             // HEdge angle must be kept in sync.
-            line->front().leftHEdge()._angle = BANG_TO_ANGLE(line->angle());
+            line->front().leftHEdge()->_angle = BANG_TO_ANGLE(line->angle());
         }
         updateAABox();
         angle += delta;
@@ -303,7 +305,7 @@ bool Polyobj::rotate(angle_t delta)
                 line->updateSlopeType();
 
                 // HEdge angle must be kept in sync.
-                line->front().leftHEdge()._angle = BANG_TO_ANGLE(line->angle());
+                line->front().leftHEdge()->_angle = BANG_TO_ANGLE(line->angle());
             }
             updateAABox();
             angle -= delta;

doomsday/client/src/render/lumobj.cpp

@@ -1173,14 +1173,14 @@ boolean LOIT_ClipLumObjBySight(void *data, void *context)
         Polyobj *po = bspLeaf->firstPolyobj();
         foreach(Line *line, po->lines())
         {
-            HEdge &hedge = line->front().leftHEdge();
+            HEdge *hedge = line->front().leftHEdge();
 
             // Ignore half-edges facing the wrong way.
-            if(hedge._frameFlags & HEDGEINF_FACINGFRONT)
+            if(hedge->_frameFlags & HEDGEINF_FACINGFRONT)
             {
                 vec2d_t origin; V2d_Set(origin, lum->origin[VX], lum->origin[VY]);
 
-                if(V2d_Intercept2(origin, eye, hedge.v1Origin(), hedge.v2Origin(), 0, 0, 0))
+                if(V2d_Intercept2(origin, eye, hedge->v1Origin(), hedge->v2Origin(), 0, 0, 0))
                 {
                     luminousClipped[lumIdx] = 1;
                     break;

doomsday/client/src/render/rend_bias.cpp

@@ -252,7 +252,7 @@ void SB_Clear()
 
 void SB_InitForMap(char const *uniqueID)
 {
-    uint startTime = Timer_RealMilliseconds();
+    de::Time begunAt;
 
     DENG_ASSERT(theMap);
 
@@ -345,7 +345,7 @@ void SB_InitForMap(char const *uniqueID)
     foreach(Polyobj *polyobj, theMap->polyobjs())
     foreach(Line *line, polyobj->lines())
     {
-        HEdge &hedge = line->front().leftHEdge();
+        HEdge *hedge = line->front().leftHEdge();
 
         for(int i = 0; i < 3; ++i)
         {
@@ -355,11 +355,11 @@ void SB_InitForMap(char const *uniqueID)
             bsuf->illum = illums;
             illums += 4;
 
-            hedge._bsuf[i] = bsuf;
+            hedge->_bsuf[i] = bsuf;
         }
     }
 
-    VERBOSE2( Con_Message("SB_InitForMap: Done in %.2f seconds.", (Timer_RealMilliseconds() - startTime) / 1000.0f) )
+    LOG_INFO(String("SB_InitForMap: Done in %1 seconds.").arg(begunAt.since(), 0, 'g', 2));
 }
 
 void SB_SetColor(float *dest, float *src)