sort blocks from biggest to smallest (in terms of their segment count…

…s) before doing greedy extend)

lod/impl/halLodGraph.cpp

@@ -254,6 +254,11 @@ void LodGraph::computeAdjacencies()
 
 void LodGraph::optimizeByExtension()
 {
+  // Put bigger blocks first because (we hope) they tend to represent
+  // more information and we'd rather extend them than, say, a block
+  // that represents a little insertion. 
+  std::sort(_blocks.begin(), _blocks.end(), LodBlockPBigger());
+
   for (BlockIterator bi = _blocks.begin(); bi != _blocks.end(); ++bi)
   {
     (*bi)->extend();

lod/inc/halLodBlock.h

@@ -22,6 +22,11 @@ class LodBlock;
 
 std::ostream& operator<<(std::ostream& os, const LodBlock& block);
 
+struct LodBlockPBigger
+{
+   bool operator()(const LodBlock* b1, const LodBlock* b2) const;
+};
+
 /* A block is a list of homolgous segments.  All these segments must
  * be the same length.  The block's destructor will free all segments
  * it contains. 
@@ -98,6 +103,13 @@ class LodBlock
    const LodBlock& operator=(const LodBlock&) const;
 };
 
+inline bool LodBlockPBigger::operator()(const LodBlock* b1, 
+                                        const LodBlock* b2) const
+{
+  bool bigger = b1->getNumSegments() > b2->getNumSegments();
+  return bigger;
+}
+
 inline hal_size_t LodBlock::getNumSegments() const
 {
   return _segments.size();