csgeom/kdtree.h Source File (Crystal Space 2.0 Public API Reference)

| ## Public API Reference

- Main Page
- Related Pages
- Modules
- Namespaces
- Classes
- Files

- File List
- File Members

csgeom/kdtree.h
Go to the documentation of this file.

    00001 /*
    00002     Copyright (C) 2002 by Jorrit Tyberghein
    00003
    00004     This library is free software; you can redistribute it and/or
    00005     modify it under the terms of the GNU Library General Public
    00006     License as published by the Free Software Foundation; either
    00007     version 2 of the License, or (at your option) any later version.
    00008
    00009     This library is distributed in the hope that it will be useful,
    00010     but WITHOUT ANY WARRANTY; without even the implied warranty of
    00011     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    00012     Library General Public License for more details.
    00013
    00014     You should have received a copy of the GNU Library General Public
    00015     License along with this library; if not, write to the Free
    00016     Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
    00017 */
    00018
    00019 #ifndef __CS_KDTREE_H__
    00020 #define __CS_KDTREE_H__
    00021
    00022 #include "csextern.h"
    00023
    00024 #include "csgeom/box.h"
    00025
    00026 #include "csutil/blockallocator.h"
    00027 #include "csutil/ref.h"
    00028 #include "csutil/scfstr.h"
    00029 #include "csutil/scf_implementation.h"
    00030
    00031 #include "iutil/dbghelp.h"
    00032
    00039 struct iGraphics3D;
    00040 struct iString;
    00041 class csKDTree;
    00042 class csKDTreeChild;
    00043
    00050 struct iKDTreeObjectDescriptor : public virtual iBase
    00051 {
    00052   SCF_INTERFACE (iKDTreeObjectDescriptor, 0, 0, 1);
    00053
    00054   virtual csPtr<iString> DescribeObject (csKDTreeChild* child) = 0;
    00055 };
    00056
    00062 struct iKDTreeUserData : public virtual iBase
    00063 {
    00064   SCF_INTERFACE (iKDTreeUserData, 0, 0, 1);
    00065 };
    00066
    00089 typedef bool (csKDTreeVisitFunc)(csKDTree* treenode, void* userdata,
    00090         uint32 timestamp, uint32& frustum_mask);
    00091
    00095 class CS_CRYSTALSPACE_EXPORT csKDTreeChild
    00096 {
    00097 private:
    00098   friend class csKDTree;
    00099
    00100   csBox3 bbox;
    00101   void* object;                 // Pointer back to the original object.
    00102   csKDTree** leafs;             // Leafs that contain this object.
    00103   int num_leafs;
    00104   int max_leafs;
    00105
    00106 public:
    00107   uint32 timestamp;             // Timestamp of last visit to this child.
    00108
    00109 public:
    00110   csKDTreeChild ();
    00111   ~csKDTreeChild ();
    00112
    00114   void AddLeaf (csKDTree* leaf);
    00116   void RemoveLeaf (int idx);
    00118   void RemoveLeaf (csKDTree* leaf);
    00125   void ReplaceLeaf (csKDTree* old_leaf, csKDTree* new_leaf);
    00126
    00130   int FindLeaf (csKDTree* leaf);
    00131
    00135   inline const csBox3& GetBBox () const { return bbox; }
    00136
    00140   inline void* GetObject () const { return object; }
    00141 };
    00142
    00143 enum
    00144 {
    00145   CS_KDTREE_AXISINVALID = -1,
    00146   CS_KDTREE_AXISX = 0,
    00147   CS_KDTREE_AXISY = 1,
    00148   CS_KDTREE_AXISZ = 2
    00149 };
    00150
    00167 class CS_CRYSTALSPACE_EXPORT csKDTree :
    00168   public scfImplementation1<csKDTree, iDebugHelper>
    00169 {
    00170 public:
    00171   // This is used for debugging.
    00172   csRef<iKDTreeObjectDescriptor> descriptor;
    00173   void DumpObject (csKDTreeChild* object, const char* msg);
    00174   void DumpNode ();
    00175   void DumpNode (const char* msg);
    00176   static void DebugExit ();
    00177
    00178 private:
    00179   csKDTree* child1;             // If child1 is not 0 then child2 will
    00180   csKDTree* child2;             // also be not 0.
    00181   csKDTree* parent;             // 0 if this is the root.
    00182
    00183   csRef<iKDTreeUserData> userobject; // An optional user object for this node.
    00184
    00185   csBox3 node_bbox;             // Bbox of the node itself.
    00186
    00187   int split_axis;               // One of CS_KDTREE_AXIS?
    00188   float split_location;         // Where is the split?
    00189
    00190   // Objects in this node. If this node also has children (child1
    00191   // and child2) then the objects here have to be moved to these
    00192   // children. The 'Distribute()' function will do that.
    00193   csKDTreeChild** objects;
    00194   int num_objects;
    00195   int max_objects;
    00196
    00197   // Estimate of the total number of objects in this tree including children.
    00198   int estimate_total_objects;
    00199
    00200   // Minimum amount of objects in this tree before we consider splitting.
    00201   int min_split_objects;
    00202
    00203   // Disallow Distribute().
    00204   // If this flag > 0 it means that we cannot find a good split
    00205   // location for the current list of objects. So in that case we don't
    00206   // split at all and set this flag to DISALLOW_DISTRIBUTE_TIME so
    00207   // that we will no longer attempt to distribute for a while. Whenever
    00208   // objects are added or removed to this node this flag will be decreased
    00209   // so that when it becomes 0 we can make a new Distribute() attempt can
    00210   // be made. This situation should be rare though.
    00211 #define DISALLOW_DISTRIBUTE_TIME 20
    00212   int disallow_distribute;
    00213
    00214   // Current timestamp we are using for Front2Back(). Objects that
    00215   // have the same timestamp are already visited during Front2Back().
    00216   static uint32 global_timestamp;
    00217
    00219   void AddObject (csKDTreeChild* obj);
    00221   void RemoveObject (int idx);
    00223   int FindObject (csKDTreeChild* obj);
    00224
    00228   void AddObjectInt (csKDTreeChild* obj);
    00229
    00240   float FindBestSplitLocation (int axis, float& split_loc);
    00241
    00247   void DistributeLeafObjects ();
    00248
    00255   void Front2Back (const csVector3& pos, csKDTreeVisitFunc* func,
    00256         void* userdata, uint32 cur_timestamp, uint32 frustum_mask);
    00257
    00264   void TraverseRandom (csKDTreeVisitFunc* func,
    00265         void* userdata, uint32 cur_timestamp, uint32 frustum_mask);
    00266
    00270   void ResetTimestamps ();
    00271
    00275   void FlattenTo (csKDTree* node);
    00276
    00277 public:
    00279   csKDTree ();
    00281   virtual ~csKDTree ();
    00283   void SetParent (csKDTree* p) { parent = p; }
    00284
    00286   void SetObjectDescriptor (iKDTreeObjectDescriptor* descriptor)
    00287   {
    00288     csKDTree::descriptor = descriptor;
    00289   }
    00290
    00295   void SetMinimumSplitAmount (int m) { min_split_objects = m; }
    00296
    00298   void Clear ();
    00299
    00301   inline iKDTreeUserData* GetUserObject () const { return userobject; }
    00302
    00308   void SetUserObject (iKDTreeUserData* userobj);
    00309
    00317   csKDTreeChild* AddObject (const csBox3& bbox, void* object);
    00318
    00323   void UnlinkObject (csKDTreeChild* object);
    00324
    00329   void RemoveObject (csKDTreeChild* object);
    00330
    00334   void MoveObject (csKDTreeChild* object, const csBox3& new_bbox);
    00335
    00342   void Distribute ();
    00343
    00347   void FullDistribute ();
    00348
    00354   void Flatten ();
    00355
    00361   void TraverseRandom (csKDTreeVisitFunc* func,
    00362         void* userdata, uint32 frustum_mask);
    00363
    00370   void Front2Back (const csVector3& pos, csKDTreeVisitFunc* func,
    00371         void* userdata, uint32 frustum_mask);
    00372
    00380   uint32 NewTraversal ();
    00381
    00385   inline csKDTree* GetChild1 () const { return child1; }
    00386
    00390   inline csKDTree* GetChild2 () const { return child2; }
    00391
    00395   inline int GetObjectCount () const { return num_objects; }
    00396
    00403   inline int GetEstimatedObjectCount () { return estimate_total_objects; }
    00404
    00408   inline csKDTreeChild** GetObjects () const { return objects; }
    00409
    00414   inline const csBox3& GetNodeBBox () const { return node_bbox; }
    00415
    00416   // Debugging functions.
    00417   bool Debug_CheckTree (csString& str);
    00418   void Debug_Dump (csString& str, int indent);
    00419   void Debug_Statistics (int& tot_objects,
    00420         int& tot_nodes, int& tot_leaves, int depth, int& max_depth,
    00421         float& balance_quality);
    00422   csPtr<iString> Debug_Statistics ();
    00423   csTicks Debug_Benchmark (int num_iterations);
    00424
    00425   virtual int GetSupportedTests () const
    00426   {
    00427     return CS_DBGHELP_STATETEST |
    00428       CS_DBGHELP_TXTDUMP | CS_DBGHELP_BENCHMARK;
    00429   }
    00430
    00431   virtual csPtr<iString> StateTest ()
    00432   {
    00433     scfString* rc = new scfString ();
    00434     if (!Debug_CheckTree (rc->GetCsString ()))
    00435       return csPtr<iString> (rc);
    00436     delete rc;
    00437     return 0;
    00438   }
    00439
    00440   virtual csTicks Benchmark (int num_iterations)
    00441   {
    00442     return Debug_Benchmark (num_iterations);
    00443   }
    00444
    00445   virtual csPtr<iString> Dump ()
    00446   {
    00447     scfString* rc = new scfString ();
    00448     Debug_Dump (rc->GetCsString (), 0);
    00449     return csPtr<iString> (rc);
    00450   }
    00451
    00452   virtual void Dump (iGraphics3D* /*g3d*/) { }
    00453   virtual bool DebugCommand (const char*) { return false; }
    00454 };
    00455
    00458 #endif // __CS_KDTREE_H__
    00459