Refactor|Surface: Ensure Surface's owner link is never invalidated

doomsday/client/include/map/gamemap.h

@@ -301,24 +301,24 @@ SideDef* GameMap_SideDef(GameMap* map, uint idx);
 Sector* GameMap_Sector(GameMap* map, uint idx);
 
 /**
- * Lookup a Sector in the map by origin.
+ * Lookup a Sector in the map by it's sound emitter.
  *
  * @param map  GameMap instance.
- * @param ddMobjBase  ddmobj_base_t to search for.
+ * @param soundEmitter  ddmobj_base_t to search for.
  *
  * @return  Found Sector instance else @c NULL.
  */
-Sector* GameMap_SectorByBase(GameMap* map, const void* ddMobjBase);
+Sector *GameMap_SectorBySoundEmitter(GameMap *map, void const *soundEmitter);
 
 /**
- * Lookup a Surface in the map by origin.
+ * Lookup a Surface in the map by it's sound emitter.
  *
  * @param map  GameMap instance.
- * @param ddMobjBase  ddmobj_base_t to search for.
+ * @param soundEmitter  ddmobj_base_t to search for.
  *
  * @return  Found Surface instance else @c NULL.
  */
-Surface* GameMap_SurfaceByBase(GameMap* map, const void* ddMobjBase);
+Surface *GameMap_SurfaceBySoundEmitter(GameMap* map, void const *soundEmitter);
 
 /**
  * Lookup a BspLeaf by its unique index.

doomsday/client/include/map/plane.h

@@ -71,8 +71,8 @@ class Plane : public de::MapElement
     };
 
 public: /// @todo Make private:
-    Sector     *_sector;       ///< Owner of the plane.
     Surface     _surface;
+    Sector     *_sector;       ///< Owner of the plane.
     coord_t     _height;       ///< Current height.
     coord_t     _oldHeight[2];
     coord_t     _targetHeight; ///< Target height.

doomsday/client/include/map/sidedef.h

@@ -30,11 +30,11 @@
 class LineDef;
 
 /*
- * Helper macros for accessing sidedef top/middle/bottom section data elements:
+ * Helper macros for accessing sidedef surface data elements:
  */
 /// @addtogroup map
 ///@{
-#define SW_surface(n)           sections[(n)]
+#define SW_surface(n)           surface(n)
 #define SW_surfaceflags(n)      SW_surface(n).flags
 #define SW_surfaceinflags(n)    SW_surface(n).inFlags
 #define SW_surfacematerial(n)   SW_surface(n).material
@@ -126,14 +126,19 @@ struct msidedef_t
 class SideDef : public de::MapElement
 {
 public:
+    /// The given surface section reference is invalid. @ingroup errors
+    DENG2_ERROR(InvalidSectionError);
+
     /// The referenced property does not exist. @ingroup errors
     DENG2_ERROR(UnknownPropertyError);
 
     /// The referenced property is not writeable. @ingroup errors
     DENG2_ERROR(WritePropertyError);
 
 public:
-    Surface sections[3];
+    Surface _middleSurface;
+    Surface _bottomSurface;
+    Surface _topSurface;
 
     LineDef *line;
 
@@ -157,6 +162,43 @@ class SideDef : public de::MapElement
     SideDef();
     ~SideDef();
 
+    /// @todo Refactor away.
+    SideDef &operator = (SideDef const &other);
+
+    /**
+     * Returns the specified surface of the sidedef.
+     *
+     * @param surface  Identifier of the surface to return.
+     */
+    Surface &surface(int surface);
+
+    /// @copydoc section()
+    Surface const &surface(int surface) const;
+
+    /**
+     * Returns the middle surface of the sidedef.
+     */
+    inline Surface &middle() { return surface(SS_MIDDLE); }
+
+    /// @copydoc middle()
+    inline Surface const &middle() const { return surface(SS_MIDDLE); }
+
+    /**
+     * Returns the bottom surface of the sidedef.
+     */
+    inline Surface &bottom() { return surface(SS_BOTTOM); }
+
+    /// @copydoc middle()
+    inline Surface const &bottom() const { return surface(SS_BOTTOM); }
+
+    /**
+     * Returns the middle surface of the sidedef.
+     */
+    inline Surface &top() { return surface(SS_TOP); }
+
+    /// @copydoc middle()
+    inline Surface const &top() const { return surface(SS_TOP); }
+
     /**
      * Update the side's map space surface base origins according to the points
      * defined by the associated LineDef's vertices and the plane heights of the

doomsday/client/include/map/surface.h

@@ -28,15 +28,21 @@
 #ifdef __CLIENT__
 #  include "MaterialSnapshot"
 #endif
+#include <de/vector1.h>
 #include <QSet>
 
-// Internal surface flags:
+/**
+ * @defgroup surfaceInternalFlags Surface Internal Flags
+ * @ingroup map
+ */
+///@{
 #define SUIF_FIX_MISSING_MATERIAL   0x0001 ///< Current material is a fix replacement
                                            /// (not sent to clients, returned via DMU etc).
 #define SUIF_NO_RADIO               0x0002 ///< No fakeradio for this surface.
 
 #define SUIF_UPDATE_FLAG_MASK       0xff00
 #define SUIF_UPDATE_DECORATIONS     0x8000
+///@}
 
 /**
  * @ingroup map
@@ -55,33 +61,79 @@ class Surface : public de::MapElement
 #endif // __CLIENT__
 
 public:
-    ddmobj_base_t base;
-    de::MapElement *owner; ///< Either @c DMU_SIDEDEF, or @c DMU_PLANE
-    int flags; ///< SUF_ flags
-    int oldFlags;
+    /// Owning map element, either @c DMU_SIDEDEF, or @c DMU_PLANE.
+    de::MapElement &_owner;
+
+    /// Sound emitter.
+    ddmobj_base_t _soundEmitter;
+
+    /// @ref sufFlags
+    int flags;
+
+    // Bound material.
     Material *material;
+
+    // Blending mode, for rendering.
     blendmode_t blendMode;
-    float tangent[3];
-    float bitangent[3];
-    float normal[3];
-    float offset[2]; ///< [X, Y] Planar offset to surface material origin.
-    float oldOffset[2][2];
-    float visOffset[2];
-    float visOffsetDelta[2];
-    float rgba[4]; ///< Surface color tint
-    short inFlags; ///< SUIF_* flags
+
+    // Tangent space vectors:
+    vec3f_t tangent;
+    vec3f_t bitangent;
+    vec3f_t normal;
+
+    /// [X, Y] Planar offset to surface material origin.
+    vec2f_t offset;
+
+    /// Old [X, Y] Planar material origin offset. For smoothing.
+    vec2f_t _oldOffset[2];
+
+    /// Smoothed [X, Y] Planar material origin offset.
+    vec2f_t visOffset;
+
+    /// Smoother [X, Y] Planar material origin offset delta.
+    vec2f_t visOffsetDelta;
+
+    /// Surface color tint.
+    float rgba[4];
+
+    /// @ref surfaceInternalFlags
+    short inFlags;
+
+    /// Old @ref surfaceInternalFlags, for tracking changes.
+    short oldInFlags;
+
     uint numDecorations;
+
     struct surfacedecorsource_s *decorations;
 
 public:
-    Surface();
+    Surface(de::MapElement &owner);
     ~Surface();
 
+    /// @todo Refactor away.
+    Surface &operator = (Surface const &other);
+
+    /// @return @c true= is drawable (i.e., a drawable Material is bound).
+    bool isDrawable() const;
+
+    /// @return @c true= is sky-masked (i.e., a sky-masked Material is bound).
+    bool isSkyMasked() const;
+
+    /// @return @c true= is owned by some element of the Map geometry.
+    bool isAttachedToMap() const;
+
     /**
-     * Mark the surface as requiring a full update. To be called during an
-     * engine reset.
+     * Returns the owning map element. Either @c DMU_SIDEDEF, or @c DMU_PLANE.
      */
-    void update();
+    de::MapElement &owner() const;
+
+    /**
+     * Returns the sound emitter for the surface.
+     */
+    ddmobj_base_t &soundEmitter();
+
+    /// @copydoc soundEmitter()
+    ddmobj_base_t const &soundEmitter() const;
 
     /**
      * Update the Surface's map space base origin according to relevant points in
@@ -99,14 +151,11 @@ class Surface : public de::MapElement
      */
     void updateSoundEmitterOrigin();
 
-    /// @return @c true= is drawable (i.e., a drawable Material is bound).
-    bool isDrawable() const;
-
-    /// @return @c true= is sky-masked (i.e., a sky-masked Material is bound).
-    bool isSkyMasked() const;
-
-    /// @return @c true= is owned by some element of the Map geometry.
-    bool isAttachedToMap() const;
+    /**
+     * Mark the surface as requiring a full update. To be called during an
+     * engine reset.
+     */
+    void update();
 
     /**
      * Change Material bound to this surface.

doomsday/client/src/client/cl_sound.cpp

@@ -148,19 +148,19 @@ void Cl_ReadSoundDelta2(deltatype_t type, boolean skip)
     {
         // Select the origin for the sound.
         if(flags & SNDDF_PLANE_FLOOR)
-            emitter = (mobj_t*) &sector->floorSurface().base;
+            emitter = (mobj_t *) &sector->floorSurface().soundEmitter();
         else if(flags & SNDDF_PLANE_CEILING)
-            emitter = (mobj_t*) &sector->ceilingSurface().base;
+            emitter = (mobj_t *) &sector->ceilingSurface().soundEmitter();
     }
 
     if(type == DT_SIDE_SOUND)
     {
         if(flags & SNDDF_SIDE_MIDDLE)
-            emitter = (mobj_t*) &side->SW_middlesurface.base;
+            emitter = (mobj_t *) &side->SW_middlesurface.soundEmitter();
         else if(flags & SNDDF_SIDE_TOP)
-            emitter = (mobj_t*) &side->SW_topsurface.base;
+            emitter = (mobj_t *) &side->SW_topsurface.soundEmitter();
         else if(flags & SNDDF_SIDE_BOTTOM)
-            emitter = (mobj_t*) &side->SW_bottomsurface.base;
+            emitter = (mobj_t *) &side->SW_bottomsurface.soundEmitter();
     }
 
     if(flags & SNDDF_VOLUME)