From 77ebf643531c90ea712b496e23c48f0b0671f43d Mon Sep 17 00:00:00 2001
From: jackpoz <giacomopoz@gmail.com>
Date: Wed, 19 Feb 2014 21:00:14 +0100
Subject: [PATCH] Fix rcMergePolyMeshes() ignoring portals of input meshes.

Copy the portals from input meshes on border to the output mesh.
---
 Recast/Source/RecastMesh.cpp | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/Recast/Source/RecastMesh.cpp b/Recast/Source/RecastMesh.cpp
index 534a72e..8af609b 100644
--- a/Recast/Source/RecastMesh.cpp
+++ b/Recast/Source/RecastMesh.cpp
@@ -1324,6 +1324,12 @@ bool rcMergePolyMeshes(rcContext* ctx, rcPolyMesh** meshes, const int nmeshes, r
 		const unsigned short ox = (unsigned short)floorf((pmesh->bmin[0]-mesh.bmin[0])/mesh.cs+0.5f);
 		const unsigned short oz = (unsigned short)floorf((pmesh->bmin[2]-mesh.bmin[2])/mesh.cs+0.5f);
 		
+		bool isMinX = (ox == 0);
+		bool isMinZ = (oz == 0);
+		bool isMaxX = ((unsigned short)floorf((mesh.bmax[0] - pmesh->bmax[0]) / mesh.cs + 0.5f)) == 0;
+		bool isMaxZ = ((unsigned short)floorf((mesh.bmax[2] - pmesh->bmax[2]) / mesh.cs + 0.5f)) == 0;
+		bool isOnBorder = (isMinX || isMinZ || isMaxX || isMaxZ);
+
 		for (int j = 0; j < pmesh->nverts; ++j)
 		{
 			unsigned short* v = &pmesh->verts[j*3];
@@ -1344,6 +1350,36 @@ bool rcMergePolyMeshes(rcContext* ctx, rcPolyMesh** meshes, const int nmeshes, r
 				if (src[k] == RC_MESH_NULL_IDX) break;
 				tgt[k] = vremap[src[k]];
 			}
+
+			if (isOnBorder)
+			{
+				for (int k = mesh.nvp; k < mesh.nvp * 2; ++k)
+				{
+					if (src[k] & 0x8000 && src[k] != 0xffff)
+					{
+						unsigned short dir = src[k] & 0xf;
+						switch (dir)
+						{
+							case 0: // Portal x-
+								if (isMinX)
+									tgt[k] = src[k];
+								break;
+							case 1: // Portal z+
+								if (isMaxZ)
+									tgt[k] = src[k];
+								break;
+							case 2: // Portal x+
+								if (isMaxX)
+									tgt[k] = src[k];
+								break;
+							case 3: // Portal z-
+								if (isMinZ)
+									tgt[k] = src[k];
+								break;
+						}
+					}
+				}
+			}
 		}
 	}