From: havoc <havoc@d7cf8633-e32d-0410-b094-e92efae38249>
Date: Tue, 26 Nov 2002 20:38:41 +0000 (+0000)
Subject: BuildTriangleNeighbors now detects edges shared by three triangles, fixes weird shado... 
X-Git-Tag: RELEASE_0_2_0_RC1~55
X-Git-Url: http://de.git.xonotic.org/?p=xonotic%2Fdarkplaces.git;a=commitdiff_plain;h=3474fdc002ec14ac862470cd9496e656e64e09c9

BuildTriangleNeighbors now detects edges shared by three triangles, fixes weird shadow bugs in a few places


git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@2651 d7cf8633-e32d-0410-b094-e92efae38249
---

diff --git a/model_shared.c b/model_shared.c
index 591d8ac1..323931dc 100644
--- a/model_shared.c
+++ b/model_shared.c
@@ -384,19 +384,30 @@ static void Mod_Print (void)
 			Con_Printf ("%4iK %s\n", mod->mempool ? (mod->mempool->totalsize + 1023) / 1024 : 0, mod->name);
 }
 
-int Mod_FindTriangleWithEdge(const int *elements, int numtriangles, int start, int end)
+int Mod_FindTriangleWithEdge(const int *elements, int numtriangles, int start, int end, int ignore)
 {
-	int i;
+	int i, match, count;
+	count = 0;
+	match = -1;
 	for (i = 0;i < numtriangles;i++, elements += 3)
 	{
-		if (elements[0] == start && elements[1] == end)
-			return i;
-		if (elements[1] == start && elements[2] == end)
-			return i;
-		if (elements[2] == start && elements[0] == end)
-			return i;
+		     if ((elements[0] == start && elements[1] == end)
+		      || (elements[1] == start && elements[2] == end)
+		      || (elements[2] == start && elements[0] == end))
+		{
+			if (i != ignore)
+				match = i;
+			count++;
+		}
+		else if ((elements[1] == start && elements[0] == end)
+		      || (elements[2] == start && elements[1] == end)
+		      || (elements[0] == start && elements[2] == end))
+			count++;
 	}
-	return -1;
+	// detect edges shared by three triangles and make them seams
+	if (count > 2)
+		match = -1;
+	return match;
 }
 
 void Mod_BuildTriangleNeighbors(int *neighbors, const int *elements, int numtriangles)
@@ -405,9 +416,9 @@ void Mod_BuildTriangleNeighbors(int *neighbors, const int *elements, int numtria
 	const int *e;
 	for (i = 0, e = elements, n = neighbors;i < numtriangles;i++, e += 3, n += 3)
 	{
-		n[0] = Mod_FindTriangleWithEdge(elements, numtriangles, e[1], e[0]);
-		n[1] = Mod_FindTriangleWithEdge(elements, numtriangles, e[2], e[1]);
-		n[2] = Mod_FindTriangleWithEdge(elements, numtriangles, e[0], e[2]);
+		n[0] = Mod_FindTriangleWithEdge(elements, numtriangles, e[1], e[0], i);
+		n[1] = Mod_FindTriangleWithEdge(elements, numtriangles, e[2], e[1], i);
+		n[2] = Mod_FindTriangleWithEdge(elements, numtriangles, e[0], e[2], i);
 	}
 }
 
diff --git a/model_shared.h b/model_shared.h
index 8f504282..cfebccbe 100644
--- a/model_shared.h
+++ b/model_shared.h
@@ -308,7 +308,7 @@ void Mod_LoadModels(void);
 extern model_t *loadmodel;
 extern char loadname[32];	// for hunk tags
 
-int Mod_FindTriangleWithEdge(const int *elements, int numtriangles, int start, int end);
+int Mod_FindTriangleWithEdge(const int *elements, int numtriangles, int start, int end, int ignore);
 void Mod_BuildTriangleNeighbors(int *neighbors, const int *elements, int numtriangles);
 void Mod_ValidateElements(const int *elements, int numtriangles, int numverts, const char *filename, int fileline);
 void Mod_BuildTextureVectorsAndNormals(int numverts, int numtriangles, const float *vertex, const float *texcoord, const int *elements, float *svectors, float *tvectors, float *normals);