From d2148ff57dbe012db50c4aa6a0065f458cae715d Mon Sep 17 00:00:00 2001
From: Mikko Mononen <memononen@gmail.com>
Date: Thu, 17 Nov 2011 19:11:12 +0000
Subject: [PATCH] Added better state control for tile cache obstacles.

---
 DetourTileCache/Include/DetourTileCache.h  |  9 ++-
 DetourTileCache/Source/DetourTileCache.cpp | 81 +++++++++++++++++-----
 2 files changed, 69 insertions(+), 21 deletions(-)

diff --git a/DetourTileCache/Include/DetourTileCache.h b/DetourTileCache/Include/DetourTileCache.h
index 2d46e15..9f30d26 100644
--- a/DetourTileCache/Include/DetourTileCache.h
+++ b/DetourTileCache/Include/DetourTileCache.h
@@ -29,9 +29,10 @@ struct dtCompressedTile
 
 enum ObstacleState
 {
-	OBS_EMPTY,
-	OBS_NEW,
-	OBS_PROCESSED,
+	DT_OBSTACLE_EMPTY,
+	DT_OBSTACLE_PROCESSING,
+	DT_OBSTACLE_PROCESSED,
+	DT_OBSTACLE_REMOVING,
 };
 
 static const int DT_MAX_TOUCHED_TILES = 8;
@@ -39,9 +40,11 @@ struct dtTileCacheObstacle
 {
 	float pos[3], radius, height;
 	dtCompressedTileRef touched[DT_MAX_TOUCHED_TILES];
+	dtCompressedTileRef pending[DT_MAX_TOUCHED_TILES];
 	unsigned short salt;
 	unsigned char state;
 	unsigned char ntouched;
+	unsigned char npending;
 	dtTileCacheObstacle* next;
 };
 
diff --git a/DetourTileCache/Source/DetourTileCache.cpp b/DetourTileCache/Source/DetourTileCache.cpp
index 2af3cfe..889848e 100644
--- a/DetourTileCache/Source/DetourTileCache.cpp
+++ b/DetourTileCache/Source/DetourTileCache.cpp
@@ -363,7 +363,7 @@ dtObstacleRef dtTileCache::addObstacle(const float* pos, const float radius, con
 	unsigned short salt = ob->salt;
 	memset(ob, 0, sizeof(dtTileCacheObstacle));
 	ob->salt = salt;
-	ob->state = OBS_NEW;
+	ob->state = DT_OBSTACLE_PROCESSING;
 	dtVcopy(ob->pos, pos);
 	ob->radius = radius;
 	ob->height = height;
@@ -454,8 +454,6 @@ dtStatus dtTileCache::update(const float /*dt*/, dtNavMesh* navmesh)
 			
 			if (req->action == REQUEST_ADD)
 			{
-				// Add and init obstacle.
-				ob->state = OBS_PROCESSED;
 				// Find touched tiles.
 				float bmin[3], bmax[3];
 				getObstacleBounds(ob, bmin, bmax);
@@ -464,29 +462,32 @@ dtStatus dtTileCache::update(const float /*dt*/, dtNavMesh* navmesh)
 				queryTiles(bmin, bmax, ob->touched, &ntouched, DT_MAX_TOUCHED_TILES);
 				ob->ntouched = (unsigned char)ntouched;
 				// Add tiles to update list.
+				ob->npending = 0;
 				for (int j = 0; j < ob->ntouched; ++j)
 				{
-					if (m_nupdate < MAX_UPDATE && !contains(m_update, m_nupdate, ob->touched[j]))
-						m_update[m_nupdate++] = ob->touched[j];
+					if (m_nupdate < MAX_UPDATE)
+					{
+						if (!contains(m_update, m_nupdate, ob->touched[j]))
+							m_update[m_nupdate++] = ob->touched[j];
+						ob->pending[ob->npending++] = ob->touched[j];
+					}
 				}
 			}
 			else if (req->action == REQUEST_REMOVE)
 			{
-				// Remove obstacle.
-				ob->state = OBS_EMPTY;
+				// Prepare to remove obstacle.
+				ob->state = DT_OBSTACLE_REMOVING;
 				// Add tiles to update list.
+				ob->npending = 0;
 				for (int j = 0; j < ob->ntouched; ++j)
 				{
-					if (m_nupdate < MAX_UPDATE && !contains(m_update, m_nupdate, ob->touched[j]))
-						m_update[m_nupdate++] = ob->touched[j];
+					if (m_nupdate < MAX_UPDATE)
+					{
+						if (!contains(m_update, m_nupdate, ob->touched[j]))
+							m_update[m_nupdate++] = ob->touched[j];
+						ob->pending[ob->npending++] = ob->touched[j];
+					}
 				}
-				// Update salt, salt should never be zero.
-				ob->salt = (ob->salt+1) & ((1<<16)-1);
-				if (ob->salt == 0)
-					ob->salt++;
-				// Return obstacle to free list.
-				ob->next = m_nextFreeObstacle;
-				m_nextFreeObstacle = ob;
 			}
 		}
 		
@@ -496,8 +497,52 @@ dtStatus dtTileCache::update(const float /*dt*/, dtNavMesh* navmesh)
 	// Process updates
 	if (m_nupdate)
 	{
-		dtStatus status = buildNavMeshTile(m_update[m_nupdate-1], navmesh);
+		// Build mesh
+		const dtCompressedTileRef ref = m_update[0];
+		dtStatus status = buildNavMeshTile(ref, navmesh);
 		m_nupdate--;
+		if (m_nupdate > 0)
+			memmove(m_update, m_update+1, m_nupdate*sizeof(dtCompressedTileRef));
+
+		// Update obstacle states.
+		for (int i = 0; i < m_params.maxObstacles; ++i)
+		{
+			dtTileCacheObstacle* ob = &m_obstacles[i];
+			if (ob->state == DT_OBSTACLE_PROCESSING || ob->state == DT_OBSTACLE_REMOVING)
+			{
+				// Remove handled tile from pending list.
+				for (int j = 0; j < (int)ob->npending; j++)
+				{
+					if (ob->pending[j] == ref)
+					{
+						ob->pending[j] = ob->pending[(int)ob->npending-1];
+						ob->npending--;
+						break;
+					}
+				}
+				
+				// If all pending tiles processed, change state.
+				if (ob->npending == 0)
+				{
+					if (ob->state == DT_OBSTACLE_PROCESSING)
+					{
+						ob->state = DT_OBSTACLE_PROCESSED;
+					}
+					else if (ob->state == DT_OBSTACLE_REMOVING)
+					{
+						ob->state = DT_OBSTACLE_EMPTY;
+						// Update salt, salt should never be zero.
+						ob->salt = (ob->salt+1) & ((1<<16)-1);
+						if (ob->salt == 0)
+							ob->salt++;
+						// Return obstacle to free list.
+						ob->next = m_nextFreeObstacle;
+						m_nextFreeObstacle = ob;
+					}
+				}
+			}
+		}
+			
 		if (dtStatusFailed(status))
 			return status;
 	}
@@ -550,7 +595,7 @@ dtStatus dtTileCache::buildNavMeshTile(const dtCompressedTileRef ref, dtNavMesh*
 	for (int i = 0; i < m_params.maxObstacles; ++i)
 	{
 		const dtTileCacheObstacle* ob = &m_obstacles[i];
-		if (ob->state != OBS_PROCESSED)
+		if (ob->state == DT_OBSTACLE_EMPTY || ob->state == DT_OBSTACLE_REMOVING)
 			continue;
 		if (contains(ob->touched, ob->ntouched, ref))
 		{