From a2db511c9905561a1c899790b1a0986b8317b438 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Wed, 25 Jun 2014 15:47:59 +0000
Subject: [PATCH] Refactored the way that hole are pruned from the occluder
 hole list.

git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@14282 16af8721-9629-0410-8352-f15c8da7e697
---
 src/osg/CollectOccludersVisitor.cpp | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/src/osg/CollectOccludersVisitor.cpp b/src/osg/CollectOccludersVisitor.cpp
index 3fe2bf2f1..951fa5143 100644
--- a/src/osg/CollectOccludersVisitor.cpp
+++ b/src/osg/CollectOccludersVisitor.cpp
@@ -225,21 +225,26 @@ void CollectOccludersVisitor::removeOccludedOccluders()
                 break;
             }
 
-            // now check all the holes in the occludee against the occluder,
-            // do so in reverse order so that the iterators remain valid.
-            for(ShadowVolumeOccluder::HoleList::reverse_iterator holeItr=holeList.rbegin();
-                holeItr!=holeList.rend();
-                )
+            // now check all the holes in the occludee against the occluder, and remove the ones that won't be valid
+            unsigned int previous_valid_hole_i = 0;
+            for(unsigned int i=0; i<holeList.size(); ++i)
             {
-                if (occluder->contains((*holeItr).getReferenceVertexList()))
+                if (!occluder->contains(holeList[i].getReferenceVertexList()))
                 {
-                    holeList.erase((++holeItr).base());
-                }
-                else
-                {
-                    ++holeItr;
-                }
+                    if (previous_valid_hole_i<i)
+                    {
+                        // copy valid holes into gaps left by invalid ones
+                        holeList[previous_valid_hole_i] = holeList[i];
+                    }
 
+                    previous_valid_hole_i++;
+                }
+            }
+
+            // remove the tail of the holeList if holes have been removed.
+            if (previous_valid_hole_i<holeList.size())
+            {
+                holeList.erase(holeList.begin()+previous_valid_hole_i,holeList.end());
             }
 
         }