Merge pull request #80 from nebsar/develop

Avoid NullPointerException and Fix the Anchor Point of Military Symbology

Author: EMaksymenko

src/gov/nasa/worldwind/symbology/milstd2525/MilStd2525TacticalSymbol.java

@@ -2,25 +2,25 @@
  * Copyright 2006-2009, 2017, 2020 United States Government, as represented by the
  * Administrator of the National Aeronautics and Space Administration.
  * All rights reserved.
- * 
+ *
  * The NASA World Wind Java (WWJ) platform is licensed under the Apache License,
  * Version 2.0 (the "License"); you may not use this file except in compliance
  * with the License. You may obtain a copy of the License at
  * http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software distributed
  * under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
  * CONDITIONS OF ANY KIND, either express or implied. See the License for the
  * specific language governing permissions and limitations under the License.
- * 
+ *
  * NASA World Wind Java (WWJ) also contains the following 3rd party Open Source
  * software:
- * 
+ *
  *     Jackson Parser – Licensed under Apache 2.0
  *     GDAL – Licensed under MIT
  *     JOGL – Licensed under  Berkeley Software Distribution (BSD)
  *     Gluegen – Licensed under Berkeley Software Distribution (BSD)
- * 
+ *
  * A complete listing of 3rd Party software notices and licenses included in
  * NASA World Wind Java (WWJ)  can be found in the WorldWindJava-v2.2 3rd-party
  * notices and licenses PDF found in code directory.
@@ -540,15 +540,18 @@ protected void layoutDynamicModifiers(DrawContext dc, AVList modifiers, OrderedS
             double length = this.iconRect.getHeight();
             Boolean directionOnly = true;
             Object d = this.getModifier(SymbologyConstants.SPEED_LEADER_SCALE);
-            if (d != null && d instanceof Number)
+            if (d != null && d instanceof Number) {
                 directionOnly = false;
                 length *= ((Number) d).doubleValue();
-
+            }
             if (this.useGroundHeadingIndicator)
             {
                 List<? extends Point2D> points = MilStd2525Util.computeGroundHeadingIndicatorPoints(dc, osym.placePoint,
-                    (Angle) o, length, this.iconRect.getHeight(), directionOnly);
-                this.addLine(dc, Offset.BOTTOM_CENTER, points, LAYOUT_RELATIVE, points.size() - 1, osym);
+                        (Angle) o, length, this.iconRect.getHeight(), directionOnly);
+                if (directionOnly)
+                    this.addLine(dc, Offset.BOTTOM_CENTER, points, LAYOUT_RELATIVE, points.size() - 4, osym);
+                else
+                    this.addLine(dc, Offset.BOTTOM_CENTER, points, LAYOUT_RELATIVE, points.size() - 1, osym);
             }
             else
             {
@@ -770,4 +773,4 @@ else if (this.getOffset() == null && this.iconRect != null)
             osym.dy = -this.iconRect.getCenterY();
         }
     }
-}
+}