TreeLoader3D bug (PATCH) - Ogre Addon Forums

Fish

01-01-2009 19:24:47

When attempting to get a TreeLoader3D iterator using TreeIterator3D TreeLoader3D::getTrees() and the process enters the TreeIterator3D::TreeIterator3D(TreeLoader3D *trees) constructor, it could be possible that the trees->pageGridList is empty and an STL assertion thrown when currentGrid->second is attempted in currentTreeList = &trees->_getGridPage(currentGrid->second, currentX, currentZ);

The following patch prevents this error from occurring by testing if trees->pageGridList is empty. If the GridList is empty then the hasMore flag is set to false and the function returns. This won't prevent all fatal errors with this iterator but I think it needs to be stated in the documentation, "Be sure to test hasMoreElements() before using any other members of TreeIterator3D" to minimize the risk of a fatal exception. I think that statement is pretty obvious to most of us but I included the documentation patch below so that it is explicit.

-Fish



Index: TreeLoader3D.cpp

===================================================================

--- TreeLoader3D.cpp	(revision 2589)

+++ TreeLoader3D.cpp	(working copy)

@@ -488,7 +488,15 @@

 {

 	TreeIterator3D::trees = trees;

 

-	//Setup iterators

+    // Test if the GridList has anything in it

+    if(trees->pageGridList.empty())

+    {

+        // If not, set hasMore to false and return.

+        hasMore = false;

+        return;

+    }

+

+    //Setup iterators

 	currentGrid = trees->pageGridList.begin();

 	currentX = 0; currentZ = 0;

 	currentTreeList = &trees->_getGridPage(currentGrid->second, currentX, currentZ);



Index: TreeLoader3D.h

===================================================================

--- TreeLoader3D.h	(revision 2589)

+++ TreeLoader3D.h	(working copy)

@@ -105,6 +105,8 @@

 	to this TreeLoader3D fairly efficiently.

 

 	\see The TreeIterator class documentation for more info.

+    \warning Be sure to test TreeIterator3D::hasMoreElements() before calling other members of the 

+    TreeIterator3D class.

 	*/

 	TreeIterator3D getTrees();