- fixed: The node builder did not check if all segs could be split properly.

Also removed some fudging that tried to work around this case but produced
  a broken BSP tree on other maps.



SVN r2071 (trunk)

docs/rh-log.txt

@@ -1,3 +1,10 @@
+January 1, 2010  (Changes by Graf Zahl)
+- fixed: The node builder did not check if all segs could be split properly.
+  Also removed some fudging that tried to work around this case but produced
+  a broken BSP tree on other maps.
+- Added Blzut3's Solaris patch.
+- Fixed: Heretic's Weredragon (Beast) should not have a melee state.
+
 January 1, 2010  (SBARINFO update)
 - Reorganized the SBarInfo code.
 - Added interpolate(<speed>) flag to drawnumber, drawbar, and drawgem.  The old
@@ -6,10 +13,6 @@ January 1, 2010  (SBARINFO update)
 - As an extension to the previous you can now use comparison operators on
   inventory items and armortype in drawswitchableimage.
   
-January 1, 2010  (Changes by Graf Zahl)
-- Added Blzut3's Solaris patch.
-- Fixed: Heretic's Weredragon (Beast) should not have a melee state.
-
 December 31, 2009  (Changes by Graf Zahl)
 - fixed: FastProjectile was missing all sky checks when the projectile's move
   was blocked.

src/nodebuild.cpp

@@ -114,6 +114,17 @@ int FNodeBuilder::CreateNode (DWORD set, fixed_t bbox[4])
 		DWORD set1, set2;
 
 		SplitSegs (set, node, splitseg, set1, set2);
+
+		// Check if the set could be split. It may happen that all segs end up on the same side
+		// in which case we need to create a subsector from such a set.
+		if (set1 == DWORD_MAX)
+		{
+			return 0x80000000 | CreateSubsector (set2, bbox);
+		}
+		else if (set2 == DWORD_MAX)
+		{
+			return 0x80000000 | CreateSubsector (set1, bbox);
+		}
 		D(PrintSet (1, set1));
 		D(Printf (PRINT_LOG, "(%d,%d) delta (%d,%d) from seg %d\n", node.x>>16, node.y>>16, node.dx>>16, node.dy>>16, splitseg));
 		D(PrintSet (2, set2));
@@ -490,7 +501,9 @@ int FNodeBuilder::SelectSplitter (DWORD set, node_t &node, DWORD &splitseg, int
 
 int FNodeBuilder::Heuristic (node_t &node, DWORD set, bool honorNoSplit)
 {
-	int score = 0;
+	int score = 1000000;	// a high base so that segs that come too close to a splitter
+							// still can be weighed extremely negatively but preventing 
+							// them from creating a negative score.
 	int segsInSet = 0;
 	int counts[2] = { 0, 0 };
 	int realSegs[2] = { 0, 0 };
@@ -767,6 +780,27 @@ void FNodeBuilder::SplitSegs (DWORD set, node_t &node, DWORD splitseg, DWORD &ou
 			newvert.y += fixed_t(frac * double(Vertices[seg->v2].y - newvert.y));
 			vertnum = VertexMap->SelectVertexClose (newvert);
 
+			if (vertnum == seg->v1 || vertnum == seg->v2)
+			{
+				// Check if the resulting split vertex matches one of the line's ends.
+				// In this case this seg must not be split
+				if ((vertnum == seg->v1 && sidev2 == -1) || (vertnum == seg->v2 && sidev1 == -1))
+				{
+					side = 0;
+					sidev1 = 0;
+					seg->next = outset0;
+					outset0 = set;
+				}
+				else
+				{
+					side = 1;
+					sidev2 = 0;
+					seg->next = outset1;
+					outset1 = set;
+				}
+				break;
+			}
+
 			seg2 = SplitSeg (set, vertnum, sidev1);
 
 			Segs[seg2].next = outset0;
@@ -841,7 +875,7 @@ void FNodeBuilder::SplitSegs (DWORD set, node_t &node, DWORD splitseg, DWORD &ou
 		set = next;
 	}
 	FixSplitSharers (node);
-	if (GLNodes)
+	if (GLNodes && outset0 != DWORD_MAX && outset1 != DWORD_MAX)
 	{
 		AddMinisegs (node, splitseg, outset0, outset1);
 	}

src/p_setup.cpp

@@ -2712,6 +2712,7 @@ static void P_GroupLines (bool buildmap)
 	FBoundingBox		bbox;
 	bool				flaggedNoFronts = false;
 	unsigned int		ii, jj;
+	TArray<int>			nosector;
 
 	for (i = 0; i < (int)countof(times); ++i)
 	{
@@ -2722,7 +2723,13 @@ static void P_GroupLines (bool buildmap)
 	times[0].Clock();
 	for (i = 0; i < numsubsectors; i++)
 	{
-		subsectors[i].sector = segs[subsectors[i].firstline].sidedef->sector;
+		side_t *side = segs[subsectors[i].firstline].sidedef;
+		if (side != NULL) subsectors[i].sector = side->sector;
+		else
+		{
+			subsectors[i].sector = NULL;
+			nosector.Push(i);
+		}
 		subsectors[i].validcount = validcount;
 
 		double accumx = 0.0, accumy = 0.0;
@@ -2737,6 +2744,48 @@ static void P_GroupLines (bool buildmap)
 		subsectors[i].CenterX = fixed_t(accumx * 0.5 / subsectors[i].numlines);
 		subsectors[i].CenterY = fixed_t(accumy * 0.5 / subsectors[i].numlines);
 	}
+	for(unsigned i=0;i<nosector.Size(); i++)
+	{
+		subsector_t *sub = &subsectors[nosector[i]];
+		for(unsigned j=0;j<sub->numlines; j++)
+		{
+			seg_t *seg = &segs[sub->firstline + j];
+			if (seg->frontsector != NULL)
+			{
+				sub->sector = seg->frontsector;
+				break;
+			}
+			if (seg->PartnerSeg != NULL && seg->PartnerSeg->backsector != NULL)
+			{
+				sub->sector = seg->PartnerSeg->backsector;
+				break;
+			}
+		}
+		// we still haven't found a matching sector. Check the back sides of this subsector's segs next
+		if (sub->sector == NULL)	
+		{
+			for(unsigned j=0;j<sub->numlines; j++)
+			{
+				seg_t *seg = &segs[sub->firstline + j];
+				if (seg->backsector != NULL)
+				{
+					sub->sector = seg->backsector;
+					break;
+				}
+				if (seg->PartnerSeg != NULL && seg->PartnerSeg->frontsector != NULL)
+				{
+					sub->sector = seg->PartnerSeg->frontsector;
+					break;
+				}
+			}
+		}
+		if (sub->sector == NULL)
+		{
+			sub->sector = &sectors[0];	// prevent crashes. This hopefully does not matter because
+										// any subsector going through here is malformed.
+			Printf("Unable to assign a sector to subsector %d\n", subsectors[i].firstline);
+		}
+	}
 	times[0].Unclock();
 
 	// count number of lines in each sector

src/r_bsp.cpp

@@ -1026,6 +1026,7 @@ void R_Subsector (subsector_t *sub)
 #endif
 
 	frontsector = sub->sector;
+	if (sub->sector == NULL) return;
 	frontsector->MoreFlags |= SECF_DRAWN;
 	count = sub->numlines;
 	line = &segs[sub->firstline];