1   /* Copyright 2002-2024 CS GROUP
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  
18  package org.orekit.frames;
19  
20  import org.hipparchus.CalculusFieldElement;
21  import org.orekit.time.AbsoluteDate;
22  import org.orekit.time.FieldAbsoluteDate;
23  
24  /** Utility for Transform providers.
25   * @author Luc Maisonobe
26   * @since 9.2
27   */
28  public class TransformProviderUtils {
29  
30      /** Identity provider.
31       * <p>
32       * The transforms generated by this providers are always {@link Transform#IDENTITY}.
33       * </p>
34       */
35      public static final TransformProvider IDENTITY_PROVIDER = new TransformProvider() {
36  
37          /** Serializable UID. */
38          private static final long serialVersionUID = 20180330L;
39  
40          /** {@inheritDoc}
41           * <p>
42           * Always returns {@link Transform#IDENTITY}
43           * </p>
44           */
45          @Override
46          public Transform getTransform(final AbsoluteDate date) {
47              return Transform.IDENTITY;
48          }
49  
50          /** {@inheritDoc}
51           * <p>
52           * Always returns {@link FieldTransform#getIdentity(org.hipparchus.Field)}
53           * </p>
54           */
55          @Override
56          public <T extends CalculusFieldElement<T>> FieldTransform<T> getTransform(final FieldAbsoluteDate<T> date) {
57              return FieldTransform.getIdentity(date.getField());
58          }
59  
60      };
61  
62      /** Private constructor.
63       * <p>This class is a utility class, it should neither have a public
64       * nor a default constructor. This private constructor prevents
65       * the compiler from generating one automatically.</p>
66       */
67      private TransformProviderUtils() {
68      }
69  
70      /** Reverse a transform provider.
71       * @param provider provider to reverse
72       * @return a new provider which provide a transform similar to
73       * {@code provider.getTransform(date).getInverse()}
74       */
75      public static TransformProvider getReversedProvider(final TransformProvider provider) {
76          return new TransformProvider() {
77  
78              /** serializable UID. */
79              private static final long serialVersionUID = 20180330L;
80  
81              /** {@inheritDoc} */
82              @Override
83              public Transform getTransform(final AbsoluteDate date) {
84                  return provider.getTransform(date).getInverse();
85              }
86  
87              @Override
88              public KinematicTransform getKinematicTransform(final AbsoluteDate date) {
89                  return provider.getKinematicTransform(date).getInverse();
90              }
91  
92              @Override
93              public StaticTransform getStaticTransform(final AbsoluteDate date) {
94                  return provider.getStaticTransform(date).getInverse();
95              }
96  
97              /** {@inheritDoc} */
98              @Override
99              public <T extends CalculusFieldElement<T>> FieldTransform<T> getTransform(final FieldAbsoluteDate<T> date) {
100                 return provider.getTransform(date).getInverse();
101             }
102 
103             /** {@inheritDoc} */
104             @Override
105             public <T extends CalculusFieldElement<T>> FieldKinematicTransform<T> getKinematicTransform(final FieldAbsoluteDate<T> date) {
106                 return provider.getKinematicTransform(date).getInverse();
107             }
108 
109             /** {@inheritDoc} */
110             @Override
111             public <T extends CalculusFieldElement<T>> FieldStaticTransform<T> getStaticTransform(final FieldAbsoluteDate<T> date) {
112                 return provider.getStaticTransform(date).getInverse();
113             }
114 
115         };
116     }
117 
118     /** Combine two transform providers.
119      * @param first first provider to apply
120      * @param second second provider to apply
121      * @return a new provider which provide a transform similar to
122      * {@code new Transform(date, first.getTransform(date), second.getTransform(date))}
123      */
124     public static TransformProvider getCombinedProvider(final TransformProvider first,
125                                                         final TransformProvider second) {
126         return new TransformProvider() {
127 
128             /** serializable UID. */
129             private static final long serialVersionUID = 20180330L;
130 
131             /** {@inheritDoc} */
132             @Override
133             public Transform getTransform(final AbsoluteDate date) {
134                 return new Transform(date, first.getTransform(date), second.getTransform(date));
135             }
136 
137             /** {@inheritDoc} */
138             @Override
139             public StaticTransform getStaticTransform(final AbsoluteDate date) {
140                 return StaticTransform.compose(
141                         date,
142                         first.getStaticTransform(date),
143                         second.getStaticTransform(date)
144                 );
145             }
146 
147             /** {@inheritDoc} */
148             @Override
149             public KinematicTransform getKinematicTransform(final AbsoluteDate date) {
150                 return KinematicTransform.compose(
151                         date,
152                         first.getKinematicTransform(date),
153                         second.getKinematicTransform(date)
154                 );
155             }
156 
157             /** {@inheritDoc} */
158             @Override
159             public <T extends CalculusFieldElement<T>> FieldTransform<T> getTransform(final FieldAbsoluteDate<T> date) {
160                 return new FieldTransform<>(date, first.getTransform(date), second.getTransform(date));
161             }
162 
163             /** {@inheritDoc} */
164             @Override
165             public <T extends CalculusFieldElement<T>> FieldKinematicTransform<T> getKinematicTransform(final FieldAbsoluteDate<T> date) {
166                 return FieldKinematicTransform.compose(
167                         date,
168                         first.getKinematicTransform(date),
169                         second.getKinematicTransform(date)
170                 );
171             }
172 
173             /** {@inheritDoc} */
174             @Override
175             public <T extends CalculusFieldElement<T>> FieldStaticTransform<T> getStaticTransform(final FieldAbsoluteDate<T> date) {
176                 return FieldStaticTransform.compose(
177                         date,
178                         first.getStaticTransform(date),
179                         second.getStaticTransform(date)
180                 );
181             }
182 
183         };
184     }
185 
186 }