From 2aa70cb4976fb8e62f3723fe0466be3108f61151 Mon Sep 17 00:00:00 2001
From: Mikko Mononen <memononen@gmail.com>
Date: Sun, 21 Nov 2010 14:52:55 +0000
Subject: [PATCH] Fix for issue 144. Treat region borders as empty in
 floodRegions() to allow 1 width regions to grow next to tile border. Made
 area marking code not to override RC_NULL_AREA.

---
 Recast/Source/RecastArea.cpp   |  5 ++++-
 Recast/Source/RecastRegion.cpp | 19 ++++++++-----------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/Recast/Source/RecastArea.cpp b/Recast/Source/RecastArea.cpp
index e89caee..c18277b 100644
--- a/Recast/Source/RecastArea.cpp
+++ b/Recast/Source/RecastArea.cpp
@@ -322,7 +322,8 @@ void rcMarkBoxArea(rcContext* ctx, const float* bmin, const float* bmax, unsigne
 				rcCompactSpan& s = chf.spans[i];
 				if ((int)s.y >= miny && (int)s.y <= maxy)
 				{
-					chf.areas[i] = areaId;
+					if (chf.areas[i] != RC_NULL_AREA)
+						chf.areas[i] = areaId;
 				}
 			}
 		}
@@ -393,6 +394,8 @@ void rcMarkConvexPolyArea(rcContext* ctx, const float* verts, const int nverts,
 			for (int i = (int)c.index, ni = (int)(c.index+c.count); i < ni; ++i)
 			{
 				rcCompactSpan& s = chf.spans[i];
+				if (chf.areas[i] == RC_NULL_AREA)
+					continue;
 				if ((int)s.y >= miny && (int)s.y <= maxy)
 				{
 					float p[3];
diff --git a/Recast/Source/RecastRegion.cpp b/Recast/Source/RecastRegion.cpp
index 6ad9fa5..131a5b8 100644
--- a/Recast/Source/RecastRegion.cpp
+++ b/Recast/Source/RecastRegion.cpp
@@ -283,6 +283,8 @@ static bool floodRegion(int x, int y, int i,
 				if (chf.areas[ai] != area)
 					continue;
 				unsigned short nr = srcReg[ai];
+				if (nr & RC_BORDER_REG) // Do not take borders into account.
+					continue;
 				if (nr != 0 && nr != r)
 					ar = nr;
 				
@@ -319,16 +321,13 @@ static bool floodRegion(int x, int y, int i,
 				const int ai = (int)chf.cells[ax+ay*w].index + rcGetCon(cs, dir);
 				if (chf.areas[ai] != area)
 					continue;
-				if (chf.dist[ai] >= lev)
+				if (chf.dist[ai] >= lev && srcReg[ai] == 0)
 				{
-					if (srcReg[ai] == 0)
-					{
-						srcReg[ai] = r;
-						srcDist[ai] = 0;
-						stack.push(ax);
-						stack.push(ay);
-						stack.push(ai);
-					}
+					srcReg[ai] = r;
+					srcDist[ai] = 0;
+					stack.push(ax);
+					stack.push(ay);
+					stack.push(ai);
 				}
 			}
 		}
@@ -1242,7 +1241,6 @@ bool rcBuildRegions(rcContext* ctx, rcCompactHeightfield& chf,
 				{
 					if (chf.dist[i] < level || srcReg[i] != 0 || chf.areas[i] == RC_NULL_AREA)
 						continue;
-					
 					if (floodRegion(x, y, i, level, regionId, chf, srcReg, srcDist, stack))
 						regionId++;
 				}
@@ -1250,7 +1248,6 @@ bool rcBuildRegions(rcContext* ctx, rcCompactHeightfield& chf,
 		}
 		
 		ctx->stopTimer(RC_TIMER_BUILD_REGIONS_FLOOD);
-		
 	}
 	
 	// Expand current regions until no empty connected cells found.