From 116a6866d61f5ee210a27f20bb97a2672d95366d Mon Sep 17 00:00:00 2001
From: David Rose <david@ddrose.com>
Date: Sat, 17 Nov 2001 16:11:50 +0000
Subject: [PATCH] fix couch bug, take 2

---
 panda/src/builder/mesherFanMaker.I | 25 ++++++++++++++-----------
 panda/src/builder/mesherFanMaker.h |  6 ++++--
 panda/src/builder/mesherTempl.I    | 14 +++++++++++++-
 3 files changed, 31 insertions(+), 14 deletions(-)

diff --git a/panda/src/builder/mesherFanMaker.I b/panda/src/builder/mesherFanMaker.I
index 67d1b9e191..344371dd28 100644
--- a/panda/src/builder/mesherFanMaker.I
+++ b/panda/src/builder/mesherFanMaker.I
@@ -149,7 +149,7 @@ compute_angle() const {
 
 template <class PrimType>
 int MesherFanMaker<PrimType>::
-build() {
+build(pvector<Prim> &unrolled_tris) {
   nassertr(_edges.size() == _strips.size(), 0);
 
   int num_tris = _edges.size();
@@ -215,12 +215,12 @@ build() {
       if ( !((*si)->_prims.front() == (*last_si)->_prims.front()) ||
            !(*si)->is_coplanar_with(*(*last_si), _bucket->_coplanar_threshold)) {
         // Here's the end of a run of matching pieces.
-        count += unroll(last_si, si, last_ei, ei);
+        count += unroll(last_si, si, last_ei, ei, unrolled_tris);
         last_si = si;
         last_ei = ei;
       }
     }
-    count += unroll(last_si, si, last_ei, ei);
+    count += unroll(last_si, si, last_ei, ei, unrolled_tris);
 
     return count;
 
@@ -261,7 +261,8 @@ build() {
 template <class PrimType>
 int MesherFanMaker<PrimType>::
 unroll(Strips::iterator strip_begin, Strips::iterator strip_end,
-       Edges::iterator edge_begin, Edges::iterator edge_end) {
+       Edges::iterator edge_begin, Edges::iterator edge_end,
+       pvector<Prim> &unrolled_tris) {
   Edges::iterator ei;
   Strips::iterator si;
 
@@ -300,7 +301,13 @@ unroll(Strips::iterator strip_begin, Strips::iterator strip_end,
 
   if (_bucket->_show_quads) {
     // If we're showing quads, also show retesselated triangles.
-    _mesher->add_prim(poly, MO_fanpoly);
+
+    // We can't add it directly to the mesher, that's unsafe; instead,
+    // we'll just add it to the end of the unrolled_tris list.  This
+    // does mean we won't be able to color it a fancy color, but too
+    // bad.
+    //_mesher->add_prim(poly, MO_fanpoly);
+    unrolled_tris.push_back(poly);
 
   } else {
     // Now decompose the new polygon into triangles.
@@ -308,12 +315,8 @@ unroll(Strips::iterator strip_begin, Strips::iterator strip_end,
     result = expand(poly, *_bucket, back_inserter(tris));
 
     if (result) {
-      // Now add each triangle back into the mesher.
-      pvector<Prim>::iterator ti;
-
-      for (ti = tris.begin(); ti != tris.end(); ++ti) {
-        _mesher->add_prim(*ti);
-      }
+      unrolled_tris.insert(unrolled_tris.end(),
+                           tris.begin(), tris.end());
     }
   }
 
diff --git a/panda/src/builder/mesherFanMaker.h b/panda/src/builder/mesherFanMaker.h
index 676fa29ec3..76a6f307e2 100644
--- a/panda/src/builder/mesherFanMaker.h
+++ b/panda/src/builder/mesherFanMaker.h
@@ -31,6 +31,7 @@
 #include "mesherStrip.h"
 
 #include "plist.h"
+#include "pvector.h"
 
 
 template <class PrimType>
@@ -63,9 +64,10 @@ public:
   bool join(MesherFanMaker &other);
   float compute_angle() const;
 
-  int build();
+  int build(pvector<Prim> &unrolled_tris);
   int unroll(Strips::iterator strip_begin, Strips::iterator strip_end,
-             Edges::iterator edge_begin, Edges::iterator edge_end);
+             Edges::iterator edge_begin, Edges::iterator edge_end,
+             pvector<Prim> &unrolled_tris);
 
   ostream &output(ostream &out) const;
 
diff --git a/panda/src/builder/mesherTempl.I b/panda/src/builder/mesherTempl.I
index 744de6e88e..d4072e36ea 100644
--- a/panda/src/builder/mesherTempl.I
+++ b/panda/src/builder/mesherTempl.I
@@ -495,6 +495,8 @@ template <class PrimType>
 void MesherTempl<PrimType>::
 find_fans() {
 #ifdef SUPPORT_FANS
+  pvector<Prim> unrolled_tris;
+
   // Consider all vertices.  Any vertex with over a certain number of
   // edges connected to it is eligible to become a fan.
 
@@ -555,11 +557,21 @@ find_fans() {
 
       for (fi = fans.begin(); fi != fans.end(); ++fi) {
         if ((*fi).is_valid()) {
-          (*fi).build();
+          (*fi).build(unrolled_tris);
         }
       }
     }
   }
+
+  // Finally, add back in the triangles we might have produced by
+  // unrolling some of the fans.  We can't add these back in safely
+  // until we're done traversing all the vertices and primitives we
+  // had in the first place (since adding them will affect the edge
+  // lists).
+  pvector<Prim>::iterator ti;
+  for (ti = unrolled_tris.begin(); ti != unrolled_tris.end(); ++ti) {
+    add_prim(*ti);
+  }
 #endif
 }