Modified JmeBatchRenderBackend to clear the inner buffer of the image in the atlases instead of setting a predefined byte buffer

on disposal that made all atlases in the backend use the same buffer and generated rendering issues.

jme3-niftygui/src/main/java/com/jme3/niftygui/JmeBatchRenderBackend.java

@@ -89,7 +89,6 @@ public class JmeBatchRenderBackend implements BatchRenderBackend {
   private int textureAtlasId = 1;
   private Batch currentBatch;
   private Matrix4f tempMat = new Matrix4f();
-  private ByteBuffer initialData;
 
   // this is only used for debugging purpose and will make the removed textures filled with a color
   // please note: the old way to init this via a system property has been
@@ -184,15 +183,6 @@ public class JmeBatchRenderBackend implements BatchRenderBackend {
   public int createTextureAtlas(final int width, final int height) {
     try {
       int atlasId = addTexture(createAtlasTextureInternal(width, height));
-
-      // we just initialize a second buffer here that will replace the texture atlas image
-      initialData = BufferUtils.createByteBuffer(width*height*4);
-      for (int i=0; i<width*height; i++) {
-        initialData.put((byte) 0x00);
-        initialData.put((byte) 0xff);
-        initialData.put((byte) 0x00);
-        initialData.put((byte) 0xff);
-      }
       return atlasId;
     } catch (Exception e) {
       log.log(Level.WARNING, e.getMessage(), e);
@@ -203,8 +193,17 @@ public class JmeBatchRenderBackend implements BatchRenderBackend {
 
   @Override
   public void clearTextureAtlas(final int atlasId) {
-      initialData.rewind();
-      getTextureAtlas(atlasId).getImage().setData(initialData);
+    com.jme3.texture.Image atlasImage=getTextureAtlas(atlasId).getImage();
+    ByteBuffer atlasBuffer=atlasImage.getData(0);
+    atlasBuffer.rewind();
+    for (int i=0; i<atlasImage.getWidth()*atlasImage.getHeight(); i++) {
+      atlasBuffer.put((byte) 0x00);
+      atlasBuffer.put((byte) 0xff);
+      atlasBuffer.put((byte) 0x00);
+      atlasBuffer.put((byte) 0xff);
+    }
+    atlasBuffer.rewind();
+    atlasImage.setUpdateNeeded();
   }
 
   @Override