gamemap.h

/** @file gamemap.h Gamemap.
 *
 * @authors Copyright © 2003-2013 Jaakko Keränen <jaakko.keranen@iki.fi>
 * @authors Copyright © 2006-2013 Daniel Swanson <danij@dengine.net>
 *
 * @par License
 * GPL: http://www.gnu.org/licenses/gpl.html
 *
 * <small>This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version. This program is distributed in the hope that it
 * will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
 * Public License for more details. You should have received a copy of the GNU
 * General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA</small>
 */

#ifndef LIBDENG_GAMEMAP_H
#define LIBDENG_GAMEMAP_H

#include "p_maptypes.h"
#include "p_particle.h"
#include "plane.h"
#include <EntityDatabase>
#include <de/mathutil.h>

struct thinkerlist_s;
struct clmoinfo_s;
struct generators_s;

/// @todo Remove me.
struct blockmap_s;

/**
 * The client mobjs are stored into a hash for quickly locating a ClMobj by its identifier.
 */
#define CLIENT_MOBJ_HASH_SIZE       (256)

/**
 * @ingroup map
 */
typedef struct cmhash_s {
    struct clmoinfo_s *first, *last;
} cmhash_t;

#define CLIENT_MAX_MOVERS          1024 // Definitely enough!

/**
 * @ingroup map
 */
typedef enum {
    CPT_FLOOR,
    CPT_CEILING
} clplanetype_t;

struct clplane_s;
struct clpolyobj_s;

/**
 * @ingroup map
 */
typedef struct skyfix_s {
    coord_t height;
} skyfix_t;

/**
 * @ingroup map
 */
class GameMap
{
public:
    typedef QList<Vertex *> Vertexes;
    typedef QList<Sector *> Sectors;
    typedef QList<LineDef *> Lines;
    typedef QList<SideDef *> SideDefs;

    typedef QList<HEdge *> HEdges;
    typedef QList<BspNode *> BspNodes;
    typedef QList<BspLeaf *> BspLeafs;

public:
    Uri *uri;
    char uniqueId[256];

    AABoxd aaBox;

    struct thinkers_s {
        int idtable[2048]; // 65536 bits telling which IDs are in use.
        ushort iddealer;

        size_t numLists;
        struct thinkerlist_s **lists;
        boolean inited;
    } thinkers;

    // Client only data:
    cmhash_t clMobjHash[CLIENT_MOBJ_HASH_SIZE];

    struct clplane_s *clActivePlanes[CLIENT_MAX_MOVERS];
    struct clpolyobj_s *clActivePolyobjs[CLIENT_MAX_MOVERS];
    // End client only data.

    Vertexes _vertexes;
    Sectors _sectors;
    Lines _lines;
    SideDefs _sideDefs;

    uint numPolyObjs;
    Polyobj **polyObjs;

    de::MapElement *_bspRoot;

    /// BSP object LUTs:
    HEdges hedges;
    BspNodes bspNodes;
    BspLeafs bspLeafs;

    EntityDatabase *entityDatabase;

private:
    struct generators_s *_generators;

    PlaneSet _trackedPlanes;
    SurfaceSet _scrollingSurfaces;
#ifdef __CLIENT__
    SurfaceSet _decoratedSurfaces;
    SurfaceSet _glowingSurfaces;
#endif

public:
    struct blockmap_s *mobjBlockmap;
    struct blockmap_s *polyobjBlockmap;
    struct blockmap_s *lineBlockmap;
    struct blockmap_s *bspLeafBlockmap;

    nodepile_t mobjNodes, lineNodes; // All kinds of wacky links.
    nodeindex_t *lineLinks; // Indices to roots.

    coord_t globalGravity; // The defined gravity for this map.
    coord_t effectiveGravity; // The effective gravity for this map.

    int ambientLightLevel; // Ambient lightlevel for the current map.

    skyfix_t skyFix[2]; // [floor, ceiling]

    /// Current LOS trace state.
    /// @todo Refactor to support concurrent traces.
    TraceOpening traceOpening;
    divline_t traceLOS;

public:
    GameMap();

    virtual ~GameMap();

    Vertexes const &vertexes() const { return _vertexes; }

    inline uint vertexCount() const { return vertexes().size(); }

    SideDefs const &sideDefs() const { return _sideDefs; }

    inline uint sideDefCount() const { return sideDefs().size(); }

    Lines const &lines() const { return _lines; }

    inline uint lineCount() const { return lines().size(); }

    Sectors const &sectors() const { return _sectors; }

    inline uint sectorCount() const { return sectors().size(); }

    /**
     * Returns the root element for the map's BSP tree.
     */
    de::MapElement *bspRoot() const;

    uint hedgeCount() const { return hedges.count(); }

    uint bspNodeCount() const { return bspNodes.count(); }

    uint bspLeafCount() const { return bspLeafs.count(); }

    /**
     * Determine the BSP leaf on the back side of the BS partition that lies in front
     * of the specified point within the map's coordinate space.
     *
     * @note Always returns a valid BspLeaf although the point may not actually lay
     *       within it (however it is on the same side of the space partition)!
     *
     * @param point  XY coordinates of the point to test.
     *
     * @return     BspLeaf instance for that BSP node's leaf.
     */
    BspLeaf *bspLeafAtPoint(const_pvec2d_t point);

    /**
     * @copybrief bspLeafAtPoint()
     * @param x  X coordinate of the point to test.
     * @param y  Y coordinate of the point to test.
     * @return   BspLeaf instance for that BSP node's leaf.
     */
    inline BspLeaf *bspLeafAtPoint(coord_t x, coord_t y) {
        coord_t point[2] = { x, y };
        return bspLeafAtPoint(point);
    }

    /**
     * Traces a line of sight.
     *
     * @param from          World position, trace origin coordinates.
     * @param to            World position, trace target coordinates.
     * @param flags         Line Sight Flags (LS_*) @ref lineSightFlags
     *
     * @return              @c true if the traverser function returns @c true
     *                      for all visited lines.
     */
    bool lineOfSight(const_pvec3d_t from, const_pvec3d_t to, coord_t bottomSlope,
                     coord_t topSlope, int flags);

    /**
     * Link the specified @a bspLeaf in internal data structures for
     * bookkeeping purposes.
     *
     * @todo Does this really need to be public? -ds
     *
     * @param bspLeaf  BspLeaf to be linked.
     */
    void linkBspLeaf(BspLeaf &bspLeaf);

    /**
     * Link the specified @a line in any internal data structures for
     * bookkeeping purposes.
     *
     * @todo Does this really need to be public? -ds
     *
     * @param line  Line to be linked.
     */
    void linkLine(LineDef &line);

    /**
     * Link the specified @a mobj in any internal data structures for
     * bookkeeping purposes. Should be called AFTER mobj translation to
     * (re-)insert the mobj.
     *
     * @param mobj  Mobj to be linked.
     */
    void linkMobj(struct mobj_s &mobj);

    /**
     * Unlink the specified @a mobj from any internal data structures for
     * bookkeeping purposes. Should be called BEFORE mobj translation to
     * extract the mobj.
     *
     * @param mobj  Mobj to be unlinked.
     */
    bool unlinkMobj(struct mobj_s &mobj);

    /**
     * Link the specified @a polyobj in any internal data structures for
     * bookkeeping purposes. Should be called AFTER Polyobj rotation and/or
     * translation to (re-)insert the polyobj.
     *
     * @param polyobj  Polyobj to be linked.
     */
    void linkPolyobj(Polyobj &polyobj);

    /**
     * Unlink the specified @a polyobj from any internal data structures for
     * bookkeeping purposes. Should be called BEFORE Polyobj rotation and/or
     * translation to extract the polyobj.
     *
     * @param polyobj  Polyobj to be unlinked.
     */
    void unlinkPolyobj(Polyobj &polyobj);

    /**
     * Retrieve a pointer to the Generators collection for the map. If no collection
     * has yet been constructed a new empty collection will be initialized.
     *
     * @return  Generators collection for the map.
     */
    struct generators_s *generators();

#ifdef __CLIENT__

    /**
     * Returns the set of decorated surfaces for the map.
     */
    SurfaceSet /*const*/ &decoratedSurfaces();

    /**
     * Returns the set of glowing surfaces for the map.
     */
    SurfaceSet /*const*/ &glowingSurfaces();

#endif // __CLIENT__

    /**
     * $smoothmatoffset: interpolate the visual offset.
     */
    void lerpScrollingSurfaces(bool resetNextViewer = false);

    /**
     * $smoothmatoffset: Roll the surface material offset tracker buffers.
     */
    void updateScrollingSurfaces();

    /**
     * Returns the set of scrolling surfaces for the map.
     */
    SurfaceSet /*const*/ &scrollingSurfaces();

    /**
     * $smoothplane: interpolate the visual offset.
     */
    void lerpTrackedPlanes(bool resetNextViewer = false);

    /**
     * $smoothplane: Roll the height tracker buffers.
     */
    void updateTrackedPlanes();

    /**
     * Returns the set of tracked planes for the map.
     */
    PlaneSet /*const*/ &trackedPlanes();

public: ///@ todo make private:

    /**
     * @pre Axis-aligned bounding boxes of all Sectors must be initialized.
     */
    void updateBounds();

    void addSurfaceToLists(Surface &suf);

#ifdef __CLIENT__
    void buildSurfaceLists();
#endif

    /**
     * To be called in response to a Material property changing which may
     * require updating any map surfaces which are presently using it.
     *
     * @todo Replace with a de::Observers-based mechanism.
     */
    void updateSurfacesOnMaterialChange(Material &material);
};

/**
 * Change the global "current" map.
 */
void P_SetCurrentMap(GameMap *map);

/**
 * This ID is the name of the lump tag that marks the beginning of map
 * data, e.g. "MAP03" or "E2M8".
 */
Uri const *GameMap_Uri(GameMap *map);

/// @return  The old 'unique' identifier of the map.
char const *GameMap_OldUniqueId(GameMap *map);

void GameMap_Bounds(GameMap *map, coord_t *min, coord_t *max);

/**
 * Retrieve the current effective gravity multiplier for this map.
 *
 * @param map  GameMap instance.
 * @return  Effective gravity multiplier for this map.
 */
coord_t GameMap_Gravity(GameMap *map);

/**
 * Change the effective gravity multiplier for this map.
 *
 * @param map  GameMap instance.
 * @param gravity  New gravity multiplier.
 * @return  Same as @a map for caller convenience.
 */
GameMap *GameMap_SetGravity(GameMap *map, coord_t gravity);

/**
 * Return the effective gravity multiplier to that originally defined for this map.
 *
 * @param map  GameMap instance.
 * @return  Same as @a map for caller convenience.
 */
GameMap *GameMap_RestoreGravity(GameMap *map);

/**
 * Retrieve an immutable copy of the LOS trace line.
 *
 * @param map  GameMap instance.
 */
divline_t const *GameMap_TraceLOS(GameMap *map);

/**
 * Retrieve an immutable copy of the LOS TraceOpening state.
 *
 * @param map  GameMap instance.
 */
TraceOpening const *GameMap_TraceOpening(GameMap *map);

/**
 * Update the TraceOpening state for according to the opening defined by the
 * inner-minimal planes heights which intercept @a line
 *
 * If @a line is not owned by the map this is a no-op.
 *
 * @param map  GameMap instance.
 * @param line  Map line to configure the opening for.
 */
void GameMap_SetTraceOpening(GameMap *map, LineDef *line);

/**
 * Retrieve the map-global ambient light level.
 *
 * @param map  GameMap instance.
 * @return  Ambient light level.
 */
int GameMap_AmbientLightLevel(GameMap *map);

coord_t GameMap_SkyFix(GameMap *map, boolean ceiling);

#define GameMap_SkyFixCeiling(m)       GameMap_SkyFix((m), true)
#define GameMap_SkyFixFloor(m)         GameMap_SkyFix((m), false)

GameMap *GameMap_SetSkyFix(GameMap *map, boolean ceiling, coord_t height);

#define GameMap_SetSkyFixCeiling(m, h) GameMap_SetSkyFix((m), true, (h))
#define GameMap_SetSkyFixFloor(m, h)   GameMap_SetSkyFix((m), false, (h))

/**
 * Fixing the sky means that for adjacent sky sectors the lower sky
 * ceiling is lifted to match the upper sky. The raising only affects
 * rendering, it has no bearing on gameplay.
 */
void GameMap_InitSkyFix(GameMap *map);

void GameMap_UpdateSkyFixForSector(GameMap *map, Sector *sec);

/**
 * Lookup a SideDef by its unique index.
 *
 * @param map  GameMap instance.
 * @param idx  Unique index of the sidedef.
 * @return  Pointer to SideDef with this index else @c NULL if @a idx is not valid.
 */
SideDef *GameMap_SideDef(GameMap *map, uint idx);

/**
 * Lookup a Sector by its unique index.
 *
 * @param map  GameMap instance.
 * @param idx  Unique index of the sector.
 * @return  Pointer to Sector with this index else @c NULL if @a idx is not valid.
 */
Sector *GameMap_Sector(GameMap *map, uint idx);

/**
 * Lookup a Sector in the map by it's sound emitter.
 *
 * @param map  GameMap instance.
 * @param soundEmitter  ddmobj_base_t to search for.
 *
 * @return  Found Sector instance else @c NULL.
 */
Sector *GameMap_SectorBySoundEmitter(GameMap *map, void const *soundEmitter);

/**
 * Lookup a Surface in the map by it's sound emitter.
 *
 * @param map  GameMap instance.
 * @param soundEmitter  ddmobj_base_t to search for.
 *
 * @return  Found Surface instance else @c NULL.
 */
Surface *GameMap_SurfaceBySoundEmitter(GameMap* map, void const *soundEmitter);

/**
 * Lookup a BspLeaf by its unique index.
 *
 * @param map  GameMap instance.
 * @param idx  Unique index of the bsp leaf.
 * @return  Pointer to BspLeaf with this index else @c NULL if @a idx is not valid.
 */
BspLeaf *GameMap_BspLeaf(GameMap *map, uint idx);

/**
 * Lookup a HEdge by its unique index.
 *
 * @param map  GameMap instance.
 * @param idx  Unique index of the hedge.
 * @return  Pointer to HEdge with this index else @c NULL if @a idx is not valid.
 */
HEdge *GameMap_HEdge(GameMap *map, uint idx);

/**
 * Lookup a BspNode by its unique index.
 *
 * @param map  GameMap instance.
 * @param idx  Unique index of the bsp node.
 * @return  Pointer to BspNode with this index else @c NULL if @a idx is not valid.
 */
BspNode *GameMap_BspNode(GameMap *map, uint idx);

/**
 * Lookup the unique index for @a vertex.
 *
 * @param map  GameMap instance.
 * @param vtx  Vertex to lookup.
 * @return  Unique index for the Vertex else @c -1 if not present.
 */
int GameMap_VertexIndex(GameMap *map, Vertex const *vtx);

/**
 * Lookup the unique index for @a line.
 *
 * @param map  GameMap instance.
 * @param line  Line to lookup.
 * @return  Unique index for the Line else @c -1 if not present.
 */
int GameMap_LineDefIndex(GameMap *map, LineDef const *line);

/**
 * Lookup the unique index for @a sideDef.
 *
 * @param map  GameMap instance.
 * @param side  SideDef to lookup.
 * @return  Unique index for the SideDef else @c -1 if not present.
 */
int GameMap_SideDefIndex(GameMap *map, SideDef const *side);

/**
 * Lookup the unique index for @a sector.
 *
 * @param map  GameMap instance.
 * @param sector  Sector to lookup.
 * @return  Unique index for the Sector else @c -1 if not present.
 */
int GameMap_SectorIndex(GameMap *map, Sector const *sector);

/**
 * Lookup the unique index for @a bspLeaf.
 *
 * @param map  GameMap instance.
 * @param bspLeaf  BspLeaf to lookup.
 * @return  Unique index for the BspLeaf else @c -1 if not present.
 */
int GameMap_BspLeafIndex(GameMap *map, BspLeaf const *bspLeaf);

/**
 * Lookup the unique index for @a hedge.
 *
 * @param map  GameMap instance.
 * @param hedge  HEdge to lookup.
 * @return  Unique index for the HEdge else @c -1 if not present.
 */
int GameMap_HEdgeIndex(GameMap *map, HEdge const *hedge);

/**
 * Lookup the unique index for @a node.
 *
 * @param map  GameMap instance.
 * @param bspNode  BspNode to lookup.
 * @return  Unique index for the BspNode else @c -1 if not present.
 */
int GameMap_BspNodeIndex(GameMap *map, BspNode const *bspNode);

/**
 * Retrieve the number of Vertex instances owned by this.
 *
 * @param map  GameMap instance.
 * @return  Number Vertexes.
 */
uint GameMap_VertexCount(GameMap *map);

/**
 * Retrieve the number of LineDef instances owned by this.
 *
 * @param map  GameMap instance.
 * @return  Number LineDef.
 */
uint GameMap_LineDefCount(GameMap *map);

/**
 * Retrieve the number of SideDef instances owned by this.
 *
 * @param map  GameMap instance.
 * @return  Number SideDef.
 */
uint GameMap_SideDefCount(GameMap *map);

/**
 * Retrieve the number of Sector instances owned by this.
 *
 * @param map  GameMap instance.
 * @return  Number Sector.
 */
uint GameMap_SectorCount(GameMap *map);

/**
 * Retrieve the number of BspLeaf instances owned by this.
 *
 * @param map  GameMap instance.
 * @return  Number BspLeaf.
 */
uint GameMap_BspLeafCount(GameMap *map);

/**
 * Retrieve the number of HEdge instances owned by this.
 *
 * @param map  GameMap instance.
 * @return  Number HEdge.
 */
uint GameMap_HEdgeCount(GameMap *map);

/**
 * Retrieve the number of BspNode instances owned by this.
 *
 * @param map  GameMap instance.
 * @return  Number BspNode.
 */
uint GameMap_BspNodeCount(GameMap *map);

/**
 * Retrieve the number of Polyobj instances owned by this.
 *
 * @param map  GameMap instance.
 * @return  Number Polyobj.
 */
uint GameMap_PolyobjCount(GameMap *map);

/**
 * Lookup a Polyobj in the map by unique ID.
 *
 * @param map  GameMap instance.
 * @param id  Unique identifier of the Polyobj to be found.
 * @return  Found Polyobj instance else @c NULL.
 */
Polyobj *GameMap_PolyobjByID(GameMap *map, uint id);

/**
 * Lookup a Polyobj in the map by tag.
 *
 * @param map  GameMap instance.
 * @param tag  Tag associated with the Polyobj to be found.
 * @return  Found Polyobj instance else @c NULL.
 */
Polyobj *GameMap_PolyobjByTag(GameMap *map, int tag);

/**
 * Lookup a Polyobj in the map by origin.
 *
 * @param map  GameMap instance.
 * @param ddMobjBase  ddmobj_base_t to search for.
 *
 * @return  Found Polyobj instance else @c NULL.
 */
Polyobj *GameMap_PolyobjByBase(GameMap *map, void *ddMobjBase);

/**
 * Have the thinker lists been initialized yet?
 * @param map       GameMap instance.
 */
boolean GameMap_ThinkerListInited(GameMap *map);

/**
 * Init the thinker lists.
 *
 * @param map       GameMap instance.
 * @param flags     @c 0x1 = Init public thinkers.
 *                  @c 0x2 = Init private (engine-internal) thinkers.
 */
void GameMap_InitThinkerLists(GameMap *map, byte flags);

/**
 * Iterate the list of thinkers making a callback for each.
 *
 * @param map  GameMap instance.
 * @param thinkFunc  If not @c NULL, only make a callback for thinkers
 *                   whose function matches this.
 * @param flags  Thinker filter flags.
 * @param callback  The callback to make. Iteration will continue
 *                  until a callback returns a non-zero value.
 * @param context  Passed to the callback function.
 */
int GameMap_IterateThinkers(GameMap *map, thinkfunc_t thinkFunc, byte flags,
    int (*callback) (thinker_t *th, void *), void *context);

/**
 * @param map  GameMap instance.
 * @param thinker  Thinker to be added.
 * @param makePublic  @c true = @a thinker will be visible publically
 *                    via the Doomsday public API thinker interface(s).
 */
void GameMap_ThinkerAdd(GameMap *map, thinker_t *thinker, boolean makePublic);

/**
 * Deallocation is lazy -- it will not actually be freed until its
 * thinking turn comes up.
 *
 * @param map   GameMap instance.
 */
void GameMap_ThinkerRemove(GameMap *map, thinker_t *thinker);

/**
 * Locates a mobj by it's unique identifier in the map.
 *
 * @param map   GameMap instance.
 * @param id    Unique id of the mobj to lookup.
 */
struct mobj_s *GameMap_MobjByID(GameMap *map, int id);

/**
 * @param map   GameMap instance.
 * @param id    Thinker id to test.
 */
boolean GameMap_IsUsedMobjID(GameMap* map, thid_t id);

/**
 * @param map   GameMap instance.
 * @param id    New thinker id.
 * @param inUse In-use state of @a id. @c true = the id is in use.
 */
void GameMap_SetMobjID(GameMap *map, thid_t id, boolean inUse);

/**
 * @param map  GameMap instance.
 */
void GameMap_InitClMobjs(GameMap *map);

/**
 * To be called when the client is shut down.
 */
void GameMap_DestroyClMobjs(GameMap *map);

/**
 * Deletes hidden, unpredictable or nulled mobjs for which we have not received
 * updates in a while.
 *
 * @param map  GameMap instance.
 */
void GameMap_ExpireClMobjs(GameMap *map);

/**
 * Reset the client status. To be called when the map changes.
 *
 * @param map  GameMap instance.
 */
void GameMap_ClMobjReset(GameMap *map);

/**
 * Iterate the client mobj hash, exec the callback on each. Abort if callback
 * returns @c false.
 *
 * @param map       GameMap instance.
 * @param callback  Function to callback for each client mobj.
 * @param context   Data pointer passed to the callback.
 *
 * @return  If the callback returns @c false.
 */
boolean GameMap_ClMobjIterator(GameMap *map, boolean (*callback) (struct mobj_s *, void *), void *context);

/**
 * Allocate a new client-side plane mover.
 *
 * @param map  GameMap instance.
 * @return  The new mover or @c NULL if arguments are invalid.
 */
struct clplane_s *GameMap_NewClPlane(GameMap *map, uint sectornum, clplanetype_t type,
    coord_t dest, float speed);

/**
 * Initialize all Polyobjs in the map. To be called after map load.
 *
 * @param map  GameMap instance.
 */
void GameMap_InitPolyobjs(GameMap *map);

/**
 * Initialize the node piles and link rings. To be called after map load.
 *
 * @param map  GameMap instance.
 */
void GameMap_InitNodePiles(GameMap *map);

int GameMap_MobjsBoxIterator(GameMap *map, AABoxd const *box,
    int (*callback) (struct mobj_s *, void *), void *parameters);

int GameMap_LineDefsBoxIterator(GameMap *map, AABoxd const *box,
    int (*callback) (LineDef *, void *), void *parameters);

int GameMap_PolyobjLinesBoxIterator(GameMap *map, AABoxd const *box,
    int (*callback) (LineDef *, void *), void *parameters);

/**
 * Lines and Polyobj Lines (note Polyobj Lines are iterated first).
 *
 * @note validCount should be incremented before calling this to begin a new logical traversal.
 *       Otherwise Lines marked with a validCount equal to this will be skipped over (can
 *       be used to avoid processing a Line multiple times during complex / non-linear traversals.
 */
int GameMap_AllLineDefsBoxIterator(GameMap *map, AABoxd const *box,
    int (*callback) (LineDef *, void *), void *parameters);

int GameMap_BspLeafsBoxIterator(GameMap *map, AABoxd const *box, Sector *sector,
    int (*callback) (BspLeaf *, void *), void *parameters);

/**
 * @note validCount should be incremented before calling this to begin a new logical traversal.
 *       Otherwise LineDefs marked with a validCount equal to this will be skipped over (can
 *       be used to avoid processing a LineDef multiple times during complex / non-linear traversals.
 */
int GameMap_PolyobjsBoxIterator(GameMap *map, AABoxd const *box,
    int (*callback) (struct polyobj_s *, void *), void *parameters);

int GameMap_PolyobjIterator(GameMap *map, int (*callback) (Polyobj *, void *), void *parameters);

/**
 * Traces a line between @a from and @a to, making a callback for each
 * interceptable object linked within Blockmap cells which cover the path this
 * defines.
 */
int GameMap_PathTraverse(GameMap *map, const_pvec2d_t from, const_pvec2d_t to,
    int flags, traverser_t callback, void *parameters = 0);

inline int GameMap_PathTraverse(GameMap *map, coord_t fromX, coord_t fromY,
    coord_t toX, coord_t toY, int flags, traverser_t callback, void *parameters = 0)
{
    coord_t from[2] = { fromX, fromY };
    coord_t to[2] = { toX, toY };
    return GameMap_PathTraverse(map, from, to, flags, callback, parameters);
}

/**
 * Private member functions:
 */

/**
 * Construct an initial (empty) Mobj Blockmap for this map.
 *
 * @param map  GameMap instance.
 * @param min  Minimal coordinates for the map.
 * @param max  Maximal coordinates for the map.
 */
void GameMap_InitMobjBlockmap(GameMap *map, const_pvec2d_t min, const_pvec2d_t max);

/**
 * Construct an initial (empty) LineDef Blockmap for this map.
 *
 * @param map  GameMap instance.
 * @param min  Minimal coordinates for the map.
 * @param max  Maximal coordinates for the map.
 */
void GameMap_InitLineDefBlockmap(GameMap *map, const_pvec2d_t min, const_pvec2d_t max);

/**
 * Construct an initial (empty) BspLeaf Blockmap for this map.
 *
 * @param map  GameMap instance.
 * @param min  Minimal coordinates for the map.
 * @param max  Maximal coordinates for the map.
 */
void GameMap_InitBspLeafBlockmap(GameMap *map, const_pvec2d_t min, const_pvec2d_t max);

/**
 * Construct an initial (empty) Polyobj Blockmap for this map.
 *
 * @param map  GameMap instance.
 * @param min  Minimal coordinates for the map.
 * @param max  Maximal coordinates for the map.
 */
void GameMap_InitPolyobjBlockmap(GameMap *map, const_pvec2d_t min, const_pvec2d_t max);

// The current map.
DENG_EXTERN_C GameMap *theMap;

#endif // LIBDENG_GAMEMAP_H