opensim – Blame information for rev 1

Subversion Repositories:
Rev:
Rev Author Line No. Line
1 eva 1 /*
2 * Copyright (c) Contributors, http://opensimulator.org/
3 * See CONTRIBUTORS.TXT for a full list of copyright holders.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 * * Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * * Redistributions in binary form must reproduce the above copyrightD
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * * Neither the name of the OpenSimulator Project nor the
13 * names of its contributors may be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
17 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
20 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
23 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27 using System;
28 using System.Collections.Generic;
29 using System.Text;
30  
31 using OpenSim.Framework;
32 using OpenSim.Region.Framework;
33 using OpenSim.Region.CoreModules;
34 using OpenSim.Region.Physics.Manager;
35  
36 using Nini.Config;
37 using log4net;
38  
39 using OpenMetaverse;
40  
41 namespace OpenSim.Region.Physics.BulletSPlugin
42 {
43  
44 // The physical implementation of the terrain is wrapped in this class.
45 public abstract class BSTerrainPhys : IDisposable
46 {
47 public enum TerrainImplementation
48 {
49 Heightmap = 0,
50 Mesh = 1
51 }
52  
53 protected BSScene m_physicsScene { get; private set; }
54 // Base of the region in world coordinates. Coordinates inside the region are relative to this.
55 public Vector3 TerrainBase { get; private set; }
56 public uint ID { get; private set; }
57  
58 public BSTerrainPhys(BSScene physicsScene, Vector3 regionBase, uint id)
59 {
60 m_physicsScene = physicsScene;
61 TerrainBase = regionBase;
62 ID = id;
63 }
64 public abstract void Dispose();
65 public abstract float GetTerrainHeightAtXYZ(Vector3 pos);
66 public abstract float GetWaterLevelAtXYZ(Vector3 pos);
67 }
68  
69 // ==========================================================================================
70 public sealed class BSTerrainManager : IDisposable
71 {
72 static string LogHeader = "[BULLETSIM TERRAIN MANAGER]";
73  
74 // These height values are fractional so the odd values will be
75 // noticable when debugging.
76 public const float HEIGHT_INITIALIZATION = 24.987f;
77 public const float HEIGHT_INITIAL_LASTHEIGHT = 24.876f;
78 public const float HEIGHT_GETHEIGHT_RET = 24.765f;
79 public const float WATER_HEIGHT_GETHEIGHT_RET = 19.998f;
80  
81 // If the min and max height are equal, we reduce the min by this
82 // amount to make sure that a bounding box is built for the terrain.
83 public const float HEIGHT_EQUAL_FUDGE = 0.2f;
84  
85 // Until the whole simulator is changed to pass us the region size, we rely on constants.
86 public Vector3 DefaultRegionSize = new Vector3(Constants.RegionSize, Constants.RegionSize, Constants.RegionHeight);
87  
88 // The scene that I am part of
89 private BSScene m_physicsScene { get; set; }
90  
91 // The ground plane created to keep thing from falling to infinity.
92 private BulletBody m_groundPlane;
93  
94 // If doing mega-regions, if we're region zero we will be managing multiple
95 // region terrains since region zero does the physics for the whole mega-region.
96 private Dictionary<Vector3, BSTerrainPhys> m_terrains;
97  
98 // Flags used to know when to recalculate the height.
99 private bool m_terrainModified = false;
100  
101 // If we are doing mega-regions, terrains are added from TERRAIN_ID to m_terrainCount.
102 // This is incremented before assigning to new region so it is the last ID allocated.
103 private uint m_terrainCount = BSScene.CHILDTERRAIN_ID - 1;
104 public uint HighestTerrainID { get {return m_terrainCount; } }
105  
106 // If doing mega-regions, this holds our offset from region zero of
107 // the mega-regions. "parentScene" points to the PhysicsScene of region zero.
108 private Vector3 m_worldOffset;
109 // If the parent region (region 0), this is the extent of the combined regions
110 // relative to the origin of region zero
111 private Vector3 m_worldMax;
112 private PhysicsScene MegaRegionParentPhysicsScene { get; set; }
113  
114 public BSTerrainManager(BSScene physicsScene, Vector3 regionSize)
115 {
116 m_physicsScene = physicsScene;
117 DefaultRegionSize = regionSize;
118  
119 m_terrains = new Dictionary<Vector3,BSTerrainPhys>();
120  
121 // Assume one region of default size
122 m_worldOffset = Vector3.Zero;
123 m_worldMax = new Vector3(DefaultRegionSize);
124 MegaRegionParentPhysicsScene = null;
125 }
126  
127 public void Dispose()
128 {
129 ReleaseGroundPlaneAndTerrain();
130 }
131  
132 // Create the initial instance of terrain and the underlying ground plane.
133 // This is called from the initialization routine so we presume it is
134 // safe to call Bullet in real time. We hope no one is moving prims around yet.
135 public void CreateInitialGroundPlaneAndTerrain()
136 {
137 DetailLog("{0},BSTerrainManager.CreateInitialGroundPlaneAndTerrain,region={1}", BSScene.DetailLogZero, m_physicsScene.RegionName);
138 // The ground plane is here to catch things that are trying to drop to negative infinity
139 BulletShape groundPlaneShape = m_physicsScene.PE.CreateGroundPlaneShape(BSScene.GROUNDPLANE_ID, 1f, BSParam.TerrainCollisionMargin);
140 m_groundPlane = m_physicsScene.PE.CreateBodyWithDefaultMotionState(groundPlaneShape,
141 BSScene.GROUNDPLANE_ID, Vector3.Zero, Quaternion.Identity);
142  
143 // Everything collides with the ground plane.
144 m_groundPlane.collisionType = CollisionType.Groundplane;
145  
146 m_physicsScene.PE.AddObjectToWorld(m_physicsScene.World, m_groundPlane);
147 m_physicsScene.PE.UpdateSingleAabb(m_physicsScene.World, m_groundPlane);
148  
149 // Ground plane does not move
150 m_physicsScene.PE.ForceActivationState(m_groundPlane, ActivationState.DISABLE_SIMULATION);
151  
152 BSTerrainPhys initialTerrain = new BSTerrainHeightmap(m_physicsScene, Vector3.Zero, BSScene.TERRAIN_ID, DefaultRegionSize);
153 lock (m_terrains)
154 {
155 // Build an initial terrain and put it in the world. This quickly gets replaced by the real region terrain.
156 m_terrains.Add(Vector3.Zero, initialTerrain);
157 }
158 }
159  
160 // Release all the terrain structures we might have allocated
161 public void ReleaseGroundPlaneAndTerrain()
162 {
163 DetailLog("{0},BSTerrainManager.ReleaseGroundPlaneAndTerrain,region={1}", BSScene.DetailLogZero, m_physicsScene.RegionName);
164 if (m_groundPlane.HasPhysicalBody)
165 {
166 if (m_physicsScene.PE.RemoveObjectFromWorld(m_physicsScene.World, m_groundPlane))
167 {
168 m_physicsScene.PE.DestroyObject(m_physicsScene.World, m_groundPlane);
169 }
170 m_groundPlane.Clear();
171 }
172  
173 ReleaseTerrain();
174 }
175  
176 // Release all the terrain we have allocated
177 public void ReleaseTerrain()
178 {
179 lock (m_terrains)
180 {
181 foreach (KeyValuePair<Vector3, BSTerrainPhys> kvp in m_terrains)
182 {
183 kvp.Value.Dispose();
184 }
185 m_terrains.Clear();
186 }
187 }
188  
189 // The simulator wants to set a new heightmap for the terrain.
190 public void SetTerrain(float[] heightMap) {
191 float[] localHeightMap = heightMap;
192 // If there are multiple requests for changes to the same terrain between ticks,
193 // only do that last one.
194 m_physicsScene.PostTaintObject("TerrainManager.SetTerrain-"+ m_worldOffset.ToString(), 0, delegate()
195 {
196 if (m_worldOffset != Vector3.Zero && MegaRegionParentPhysicsScene != null)
197 {
198 // If a child of a mega-region, we shouldn't have any terrain allocated for us
199 ReleaseGroundPlaneAndTerrain();
200 // If doing the mega-prim stuff and we are the child of the zero region,
201 // the terrain is added to our parent
202 if (MegaRegionParentPhysicsScene is BSScene)
203 {
204 DetailLog("{0},SetTerrain.ToParent,offset={1},worldMax={2}", BSScene.DetailLogZero, m_worldOffset, m_worldMax);
205 ((BSScene)MegaRegionParentPhysicsScene).TerrainManager.AddMegaRegionChildTerrain(
206 BSScene.CHILDTERRAIN_ID, localHeightMap, m_worldOffset, m_worldOffset + DefaultRegionSize);
207 }
208 }
209 else
210 {
211 // If not doing the mega-prim thing, just change the terrain
212 DetailLog("{0},SetTerrain.Existing", BSScene.DetailLogZero);
213  
214 UpdateTerrain(BSScene.TERRAIN_ID, localHeightMap, m_worldOffset, m_worldOffset + DefaultRegionSize);
215 }
216 });
217 }
218  
219 // Another region is calling this region and passing a terrain.
220 // A region that is not the mega-region root will pass its terrain to the root region so the root region
221 // physics engine will have all the terrains.
222 private void AddMegaRegionChildTerrain(uint id, float[] heightMap, Vector3 minCoords, Vector3 maxCoords)
223 {
224 // Since we are called by another region's thread, the action must be rescheduled onto our processing thread.
225 m_physicsScene.PostTaintObject("TerrainManager.AddMegaRegionChild" + minCoords.ToString(), id, delegate()
226 {
227 UpdateTerrain(id, heightMap, minCoords, maxCoords);
228 });
229 }
230  
231 // If called for terrain has has not been previously allocated, a new terrain will be built
232 // based on the passed information. The 'id' should be either the terrain id or
233 // BSScene.CHILDTERRAIN_ID. If the latter, a new child terrain ID will be allocated and used.
234 // The latter feature is for creating child terrains for mega-regions.
235 // If there is an existing terrain body, a new
236 // terrain shape is created and added to the body.
237 // This call is most often used to update the heightMap and parameters of the terrain.
238 // (The above does suggest that some simplification/refactoring is in order.)
239 // Called during taint-time.
240 private void UpdateTerrain(uint id, float[] heightMap, Vector3 minCoords, Vector3 maxCoords)
241 {
242 DetailLog("{0},BSTerrainManager.UpdateTerrain,call,id={1},minC={2},maxC={3}",
243 BSScene.DetailLogZero, id, minCoords, maxCoords);
244  
245 // Find high and low points of passed heightmap.
246 // The min and max passed in is usually the area objects can be in (maximum
247 // object height, for instance). The terrain wants the bounding box for the
248 // terrain so replace passed min and max Z with the actual terrain min/max Z.
249 float minZ = float.MaxValue;
250 float maxZ = float.MinValue;
251 foreach (float height in heightMap)
252 {
253 if (height < minZ) minZ = height;
254 if (height > maxZ) maxZ = height;
255 }
256 if (minZ == maxZ)
257 {
258 // If min and max are the same, reduce min a little bit so a good bounding box is created.
259 minZ -= BSTerrainManager.HEIGHT_EQUAL_FUDGE;
260 }
261 minCoords.Z = minZ;
262 maxCoords.Z = maxZ;
263  
264 Vector3 terrainRegionBase = new Vector3(minCoords.X, minCoords.Y, 0f);
265  
266 lock (m_terrains)
267 {
268 BSTerrainPhys terrainPhys;
269 if (m_terrains.TryGetValue(terrainRegionBase, out terrainPhys))
270 {
271 // There is already a terrain in this spot. Free the old and build the new.
272 DetailLog("{0},BSTErrainManager.UpdateTerrain:UpdateExisting,call,id={1},base={2},minC={3},maxC={4}",
273 BSScene.DetailLogZero, id, terrainRegionBase, minCoords, maxCoords);
274  
275 // Remove old terrain from the collection
276 m_terrains.Remove(terrainRegionBase);
277 // Release any physical memory it may be using.
278 terrainPhys.Dispose();
279  
280 if (MegaRegionParentPhysicsScene == null)
281 {
282 // This terrain is not part of the mega-region scheme. Create vanilla terrain.
283 BSTerrainPhys newTerrainPhys = BuildPhysicalTerrain(terrainRegionBase, id, heightMap, minCoords, maxCoords);
284 m_terrains.Add(terrainRegionBase, newTerrainPhys);
285  
286 m_terrainModified = true;
287 }
288 else
289 {
290 // It's possible that Combine() was called after this code was queued.
291 // If we are a child of combined regions, we don't create any terrain for us.
292 DetailLog("{0},BSTerrainManager.UpdateTerrain:AmACombineChild,taint", BSScene.DetailLogZero);
293  
294 // Get rid of any terrain that may have been allocated for us.
295 ReleaseGroundPlaneAndTerrain();
296  
297 // I hate doing this, but just bail
298 return;
299 }
300 }
301 else
302 {
303 // We don't know about this terrain so either we are creating a new terrain or
304 // our mega-prim child is giving us a new terrain to add to the phys world
305  
306 // if this is a child terrain, calculate a unique terrain id
307 uint newTerrainID = id;
308 if (newTerrainID >= BSScene.CHILDTERRAIN_ID)
309 newTerrainID = ++m_terrainCount;
310  
311 DetailLog("{0},BSTerrainManager.UpdateTerrain:NewTerrain,taint,newID={1},minCoord={2},maxCoord={3}",
312 BSScene.DetailLogZero, newTerrainID, minCoords, maxCoords);
313 BSTerrainPhys newTerrainPhys = BuildPhysicalTerrain(terrainRegionBase, id, heightMap, minCoords, maxCoords);
314 m_terrains.Add(terrainRegionBase, newTerrainPhys);
315  
316 m_terrainModified = true;
317 }
318 }
319 }
320  
321 // TODO: redo terrain implementation selection to allow other base types than heightMap.
322 private BSTerrainPhys BuildPhysicalTerrain(Vector3 terrainRegionBase, uint id, float[] heightMap, Vector3 minCoords, Vector3 maxCoords)
323 {
324 m_physicsScene.Logger.DebugFormat("{0} Terrain for {1}/{2} created with {3}",
325 LogHeader, m_physicsScene.RegionName, terrainRegionBase,
326 (BSTerrainPhys.TerrainImplementation)BSParam.TerrainImplementation);
327 BSTerrainPhys newTerrainPhys = null;
328 switch ((int)BSParam.TerrainImplementation)
329 {
330 case (int)BSTerrainPhys.TerrainImplementation.Heightmap:
331 newTerrainPhys = new BSTerrainHeightmap(m_physicsScene, terrainRegionBase, id,
332 heightMap, minCoords, maxCoords);
333 break;
334 case (int)BSTerrainPhys.TerrainImplementation.Mesh:
335 newTerrainPhys = new BSTerrainMesh(m_physicsScene, terrainRegionBase, id,
336 heightMap, minCoords, maxCoords);
337 break;
338 default:
339 m_physicsScene.Logger.ErrorFormat("{0} Bad terrain implementation specified. Type={1}/{2},Region={3}/{4}",
340 LogHeader,
341 (int)BSParam.TerrainImplementation,
342 BSParam.TerrainImplementation,
343 m_physicsScene.RegionName, terrainRegionBase);
344 break;
345 }
346 return newTerrainPhys;
347 }
348  
349 // Return 'true' of this position is somewhere in known physical terrain space
350 public bool IsWithinKnownTerrain(Vector3 pos)
351 {
352 Vector3 terrainBaseXYZ;
353 BSTerrainPhys physTerrain;
354 return GetTerrainPhysicalAtXYZ(pos, out physTerrain, out terrainBaseXYZ);
355 }
356  
357 // Return a new position that is over known terrain if the position is outside our terrain.
358 public Vector3 ClampPositionIntoKnownTerrain(Vector3 pPos)
359 {
360 float edgeEpsilon = 0.1f;
361  
362 Vector3 ret = pPos;
363  
364 // First, base addresses are never negative so correct for that possible problem.
365 if (ret.X < 0f || ret.Y < 0f)
366 {
367 ret.X = Util.Clamp<float>(ret.X, 0f, 1000000f);
368 ret.Y = Util.Clamp<float>(ret.Y, 0f, 1000000f);
369 DetailLog("{0},BSTerrainManager.ClampPositionToKnownTerrain,zeroingNegXorY,oldPos={1},newPos={2}",
370 BSScene.DetailLogZero, pPos, ret);
371 }
372  
373 // Can't do this function if we don't know about any terrain.
374 if (m_terrains.Count == 0)
375 return ret;
376  
377 int loopPrevention = 10;
378 Vector3 terrainBaseXYZ;
379 BSTerrainPhys physTerrain;
380 while (!GetTerrainPhysicalAtXYZ(ret, out physTerrain, out terrainBaseXYZ))
381 {
382 // The passed position is not within a known terrain area.
383 // NOTE that GetTerrainPhysicalAtXYZ will set 'terrainBaseXYZ' to the base of the unfound region.
384  
385 // Must be off the top of a region. Find an adjacent region to move into.
386 // The returned terrain is always 'lower'. That is, closer to <0,0>.
387 Vector3 adjacentTerrainBase = FindAdjacentTerrainBase(terrainBaseXYZ);
388  
389 if (adjacentTerrainBase.X < terrainBaseXYZ.X)
390 {
391 // moving down into a new region in the X dimension. New position will be the max in the new base.
392 ret.X = adjacentTerrainBase.X + DefaultRegionSize.X - edgeEpsilon;
393 }
394 if (adjacentTerrainBase.Y < terrainBaseXYZ.Y)
395 {
396 // moving down into a new region in the X dimension. New position will be the max in the new base.
397 ret.Y = adjacentTerrainBase.Y + DefaultRegionSize.Y - edgeEpsilon;
398 }
399 DetailLog("{0},BSTerrainManager.ClampPositionToKnownTerrain,findingAdjacentRegion,adjacentRegBase={1},oldPos={2},newPos={3}",
400 BSScene.DetailLogZero, adjacentTerrainBase, pPos, ret);
401  
402 if (loopPrevention-- < 0f)
403 {
404 // The 'while' is a little dangerous so this prevents looping forever if the
405 // mapping of the terrains ever gets messed up (like nothing at <0,0>) or
406 // the list of terrains is in transition.
407 DetailLog("{0},BSTerrainManager.ClampPositionToKnownTerrain,suppressingFindAdjacentRegionLoop", BSScene.DetailLogZero);
408 break;
409 }
410 }
411  
412 return ret;
413 }
414  
415 // Given an X and Y, find the height of the terrain.
416 // Since we could be handling multiple terrains for a mega-region,
417 // the base of the region is calcuated assuming all regions are
418 // the same size and that is the default.
419 // Once the heightMapInfo is found, we have all the information to
420 // compute the offset into the array.
421 private float lastHeightTX = 999999f;
422 private float lastHeightTY = 999999f;
423 private float lastHeight = HEIGHT_INITIAL_LASTHEIGHT;
424 public float GetTerrainHeightAtXYZ(Vector3 pos)
425 {
426 float tX = pos.X;
427 float tY = pos.Y;
428 // You'd be surprized at the number of times this routine is called
429 // with the same parameters as last time.
430 if (!m_terrainModified && (lastHeightTX == tX) && (lastHeightTY == tY))
431 return lastHeight;
432 m_terrainModified = false;
433  
434 lastHeightTX = tX;
435 lastHeightTY = tY;
436 float ret = HEIGHT_GETHEIGHT_RET;
437  
438 Vector3 terrainBaseXYZ;
439 BSTerrainPhys physTerrain;
440 if (GetTerrainPhysicalAtXYZ(pos, out physTerrain, out terrainBaseXYZ))
441 {
442 ret = physTerrain.GetTerrainHeightAtXYZ(pos - terrainBaseXYZ);
443 }
444 else
445 {
446 m_physicsScene.Logger.ErrorFormat("{0} GetTerrainHeightAtXY: terrain not found: region={1}, x={2}, y={3}",
447 LogHeader, m_physicsScene.RegionName, tX, tY);
448 DetailLog("{0},BSTerrainManager.GetTerrainHeightAtXYZ,terrainNotFound,pos={1},base={2}",
449 BSScene.DetailLogZero, pos, terrainBaseXYZ);
450 }
451  
452 lastHeight = ret;
453 return ret;
454 }
455  
456 public float GetWaterLevelAtXYZ(Vector3 pos)
457 {
458 float ret = WATER_HEIGHT_GETHEIGHT_RET;
459  
460 Vector3 terrainBaseXYZ;
461 BSTerrainPhys physTerrain;
462 if (GetTerrainPhysicalAtXYZ(pos, out physTerrain, out terrainBaseXYZ))
463 {
464 ret = physTerrain.GetWaterLevelAtXYZ(pos);
465 }
466 else
467 {
468 m_physicsScene.Logger.ErrorFormat("{0} GetWaterHeightAtXY: terrain not found: pos={1}, terrainBase={2}, height={3}",
469 LogHeader, m_physicsScene.RegionName, pos, terrainBaseXYZ, ret);
470 }
471 return ret;
472 }
473  
474 // Given an address, return 'true' of there is a description of that terrain and output
475 // the descriptor class and the 'base' fo the addresses therein.
476 private bool GetTerrainPhysicalAtXYZ(Vector3 pos, out BSTerrainPhys outPhysTerrain, out Vector3 outTerrainBase)
477 {
478 bool ret = false;
479  
480 Vector3 terrainBaseXYZ = Vector3.Zero;
481 if (pos.X < 0f || pos.Y < 0f)
482 {
483 // We don't handle negative addresses so just make up a base that will not be found.
484 terrainBaseXYZ = new Vector3(-DefaultRegionSize.X, -DefaultRegionSize.Y, 0f);
485 }
486 else
487 {
488 int offsetX = ((int)(pos.X / (int)DefaultRegionSize.X)) * (int)DefaultRegionSize.X;
489 int offsetY = ((int)(pos.Y / (int)DefaultRegionSize.Y)) * (int)DefaultRegionSize.Y;
490 terrainBaseXYZ = new Vector3(offsetX, offsetY, 0f);
491 }
492  
493 BSTerrainPhys physTerrain = null;
494 lock (m_terrains)
495 {
496 ret = m_terrains.TryGetValue(terrainBaseXYZ, out physTerrain);
497 }
498 outTerrainBase = terrainBaseXYZ;
499 outPhysTerrain = physTerrain;
500 return ret;
501 }
502  
503 // Given a terrain base, return a terrain base for a terrain that is closer to <0,0> than
504 // this one. Usually used to return an out of bounds object to a known place.
505 private Vector3 FindAdjacentTerrainBase(Vector3 pTerrainBase)
506 {
507 Vector3 ret = pTerrainBase;
508  
509 // Can't do this function if we don't know about any terrain.
510 if (m_terrains.Count == 0)
511 return ret;
512  
513 // Just some sanity
514 ret.X = Util.Clamp<float>(ret.X, 0f, 1000000f);
515 ret.Y = Util.Clamp<float>(ret.Y, 0f, 1000000f);
516 ret.Z = 0f;
517  
518 lock (m_terrains)
519 {
520 // Once down to the <0,0> region, we have to be done.
521 while (ret.X > 0f || ret.Y > 0f)
522 {
523 if (ret.X > 0f)
524 {
525 ret.X = Math.Max(0f, ret.X - DefaultRegionSize.X);
526 DetailLog("{0},BSTerrainManager.FindAdjacentTerrainBase,reducingX,terrainBase={1}", BSScene.DetailLogZero, ret);
527 if (m_terrains.ContainsKey(ret))
528 break;
529 }
530 if (ret.Y > 0f)
531 {
532 ret.Y = Math.Max(0f, ret.Y - DefaultRegionSize.Y);
533 DetailLog("{0},BSTerrainManager.FindAdjacentTerrainBase,reducingY,terrainBase={1}", BSScene.DetailLogZero, ret);
534 if (m_terrains.ContainsKey(ret))
535 break;
536 }
537 }
538 }
539  
540 return ret;
541 }
542  
543 // Although no one seems to check this, I do support combining.
544 public bool SupportsCombining()
545 {
546 return true;
547 }
548  
549 // This routine is called two ways:
550 // One with 'offset' and 'pScene' zero and null but 'extents' giving the maximum
551 // extent of the combined regions. This is to inform the parent of the size
552 // of the combined regions.
553 // and one with 'offset' as the offset of the child region to the base region,
554 // 'pScene' pointing to the parent and 'extents' of zero. This informs the
555 // child of its relative base and new parent.
556 public void Combine(PhysicsScene pScene, Vector3 offset, Vector3 extents)
557 {
558 m_worldOffset = offset;
559 m_worldMax = extents;
560 MegaRegionParentPhysicsScene = pScene;
561 if (pScene != null)
562 {
563 // We are a child.
564 // We want m_worldMax to be the highest coordinate of our piece of terrain.
565 m_worldMax = offset + DefaultRegionSize;
566 }
567 DetailLog("{0},BSTerrainManager.Combine,offset={1},extents={2},wOffset={3},wMax={4}",
568 BSScene.DetailLogZero, offset, extents, m_worldOffset, m_worldMax);
569 }
570  
571 // Unhook all the combining that I know about.
572 public void UnCombine(PhysicsScene pScene)
573 {
574 // Just like ODE, we don't do anything yet.
575 DetailLog("{0},BSTerrainManager.UnCombine", BSScene.DetailLogZero);
576 }
577  
578  
579 private void DetailLog(string msg, params Object[] args)
580 {
581 m_physicsScene.PhysicsLogging.Write(msg, args);
582 }
583 }
584 }