1   /* Contributed in the public domain.
2    * Licensed to CS GROUP (CS) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * CS licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *   http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.orekit.files.ccsds.definitions;
18  
19  import org.hipparchus.CalculusFieldElement;
20  import org.orekit.bodies.CelestialBody;
21  import org.orekit.frames.FieldTransform;
22  import org.orekit.frames.Frame;
23  import org.orekit.frames.Transform;
24  import org.orekit.frames.TransformProvider;
25  import org.orekit.time.AbsoluteDate;
26  import org.orekit.time.FieldAbsoluteDate;
27  
28  /**
29   * A reference frame created from the {@code REF_FRAME} and {@code CENTER_NAME} is a CCSDS
30   * OPM, OMM, or OEM file.
31   *
32   * @author Evan Ward
33   */
34  public class ModifiedFrame extends Frame {
35  
36      /** Serializable UID. */
37      private static final long serialVersionUID = 20170619L;
38  
39      /** Reference frame used to create this frame. */
40      private final CelestialBodyFrame refFrame;
41  
42      /** Value of the CENTER_NAME keyword in the ODM file used to create this frame. */
43      private final String centerName;
44  
45      /**
46       * Create a CCSDS reference frame by changing the origin of an existing frame.
47       *
48       * @param frame      the existing frame that specifies the orientation.
49       * @param refFrame   the reference frame used to create this frame.
50       * @param body       the new origin.
51       * @param centerName the value of the {@code CENTER_NAME} key word used to create
52       *                   {@code body}.
53       */
54      public ModifiedFrame(final Frame frame,
55                           final CelestialBodyFrame refFrame,
56                           final CelestialBody body,
57                           final String centerName) {
58          super(frame, new OriginTransformProvider(body, frame),
59                body.getName() + "/" + frame.getName(), frame.isPseudoInertial());
60          this.refFrame   = refFrame;
61          this.centerName = centerName;
62      }
63  
64      /**
65       * Get the CCSDS reference frame.
66       *
67       * @return the reference frame used to create this frame.
68       */
69      public CelestialBodyFrame getRefFrame() {
70          return refFrame;
71      }
72  
73      /**
74       * Get the CCSDS center name.
75       *
76       * @return the value of the {@code CENTER_NAME} key word used to specify the origin of
77       * this frame.
78       */
79      public String getCenterName() {
80          return centerName;
81      }
82  
83      /** Transform provider for {@link ModifiedFrame}. */
84      private static class OriginTransformProvider implements TransformProvider {
85  
86          /** Serializable UID. */
87          private static final long serialVersionUID = 20170619L;
88  
89          /** The new origin. */
90          private final CelestialBody body;
91  
92          /** The original frame, specifying the orientation. */
93          private final Frame frame;
94  
95          /**
96           * Create a transform provider to change the origin of an existing frame.
97           *
98           * @param frame the existing frame that specifies the orientation.
99           * @param body  the new origin.
100          */
101         OriginTransformProvider(final CelestialBody body, final Frame frame) {
102             this.body = body;
103             this.frame = frame;
104         }
105 
106         @Override
107         public Transform getTransform(final AbsoluteDate date) {
108             return new Transform(date, body.getPVCoordinates(date, frame).negate());
109         }
110 
111         @Override
112         public <T extends CalculusFieldElement<T>> FieldTransform<T> getTransform(
113                 final FieldAbsoluteDate<T> date) {
114             return new FieldTransform<>(
115                     date,
116                     body.getPVCoordinates(date, frame).negate());
117         }
118 
119     }
120 
121 }