Fixed issue where the BAtchNode was throwing an ArrayIndexOutOfBound exception when batch was called twice in a row

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@10496 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

engine/src/core/com/jme3/scene/BatchNode.java

@@ -186,7 +186,6 @@ public class BatchNode extends Node implements Savable {
 
     protected void doBatch() {
         Map<Material, List<Geometry>> matMap = new HashMap<Material, List<Geometry>>();    
-        maxVertCount = 0;
         int nbGeoms = 0;
 
         gatherGeomerties(matMap, this, needsFullRebatch);
@@ -197,6 +196,11 @@ public class BatchNode extends Node implements Savable {
             batches.clear();
             batchesByGeom.clear();
         }        
+        //only reset maxVertCount if there is something new to batch
+        if (matMap.size() > 0) {
+            maxVertCount = 0;
+        }
+        
         for (Map.Entry<Material, List<Geometry>> entry : matMap.entrySet()) {
             Mesh m = new Mesh();
             Material material = entry.getKey();
@@ -238,7 +242,9 @@ public class BatchNode extends Node implements Savable {
 
         logger.log(Level.FINE, "Batched {0} geometries in {1} batches.", new Object[]{nbGeoms, batches.size()});
 
-
+        //init the temp arrays if something has been batched only.
+        if(matMap.size()>0){
+            //TODO these arrays should be allocated by chunk instead to avoid recreating them each time the batch is changed.
             //init temp float arrays
             tmpFloat = new float[maxVertCount * 3];
             tmpFloatN = new float[maxVertCount * 3];
@@ -246,6 +252,7 @@ public class BatchNode extends Node implements Savable {
                 tmpFloatT = new float[maxVertCount * 4];
             }
         }
+    }
 
     //in case the detached spatial is a node, we unbatch all geometries in its subegraph
     @Override