Kstars

ksmoon.h
1 /*
2  SPDX-FileCopyrightText: 2001 Jason Harris <[email protected]>
3 
4  SPDX-License-Identifier: GPL-2.0-or-later
5 */
6 
7 #pragma once
8 
9 #include "ksplanetbase.h"
10 #include "dms.h"
11 
12 class KSSun;
13 
14 /**
15  * @class KSMoon
16  * @short Provides necessary information about the Moon.
17  * A subclass of SkyObject that provides information
18  * needed for the Moon. Specifically, KSMoon provides a moon-specific
19  * findPosition() function. Also, there is a method findPhase(), which returns
20  * the lunar phase as a floating-point number between 0.0 and 1.0.
21  *
22  * @author Jason Harris
23  * @version 1.0
24  */
25 class KSMoon : public KSPlanetBase
26 {
27  public:
29 
30  /** Default constructor. Set name="Moon". */
31  KSMoon();
32  /** Copy constructor */
33  KSMoon(const KSMoon &o);
34 
35  ~KSMoon() override;
36 
37  KSMoon *clone() const override;
38  SkyObject::UID getUID() const override;
39 
40  /**
41  * Determine the phase angle of the moon, and assign the appropriate moon image
42  * @param Sun a KSSun pointer with coordinates updated to the time of computation.
43  * If not supplied, the sun is retrieved via KStarsData
44  * @note Overrides KSPlanetBase::findPhase()
45  */
46  void findPhase(const KSSun *Sun = nullptr);
47 
48  /** @return the illuminated fraction of the Moon as seen from Earth */
49  double illum() const { return 0.5 * (1.0 - cos(Phase * dms::PI / 180.0)); }
50 
51  /** @return a short string describing the moon's phase */
52  QString phaseName() const;
53 
54  /** reimplemented from KSPlanetBase */
55  bool loadData() override;
56 
57  /** @return iPhase, which is used as a key to find the right image file */
58  inline short int getIPhase() const { return iPhase; }
59 
60  /**
61  * Reimplemented from KSPlanetBase, this function employs unique algorithms for
62  * estimating the lunar coordinates. Finding the position of the moon is
63  * much more difficult than the other planets. For one thing, the Moon is
64  * a lot closer, so we can detect smaller deviations in its orbit. Also,
65  * the Earth has a significant effect on the Moon's orbit, and their
66  * interaction is complex and nonlinear. As a result, the positions as
67  * calculated by findPosition() are only accurate to about 10 arcseconds
68  * (10 times less precise than the planets' positions!)
69  * @short moon-specific coordinate finder
70  * @param num KSNumbers pointer for the target date/time
71  * @note we don't use the Earth pointer here
72  */
73  bool findGeocentricPosition(const KSNumbers *num, const KSPlanetBase *) override;
74 
75  /**
76  * @brief updateMag calls findMagnitude() to calculate current magnitude of moon
77  * according to current phase. This function is required to perform findMagnitude()
78  * from any where in Kstars
79  */
80  void updateMag() { findMagnitude(nullptr); }
81 
82  void initPopupMenu(KSPopupMenu *pmenu) override;
83 
84  private:
85  void findMagnitude(const KSNumbers *) override;
86 
87  static bool data_loaded;
88  static int instance_count;
89 
90  /**
91  * @class MoonLRData
92  * @short Moon Longitude and radius data object
93  * Encapsulates the Longitude and radius terms of the sums
94  * used to compute the moon's position.
95  */
96  struct MoonLRData
97  {
98  int nd { 0 };
99  int nm { 0 };
100  int nm1 { 0 };
101  int nf { 0 };
102  double Li { 0 };
103  double Ri { 0 };
104  };
105 
106  static QList<MoonLRData> LRData;
107 
108  /**
109  * @class MoonBData
110  * Encapsulates the Latitude terms of the sums used to compute the moon's position.
111  * @short Moon Latitude data object
112  */
113  struct MoonBData
114  {
115  int nd { 0 };
116  int nm { 0 };
117  int nm1 { 0 };
118  int nf { 0 };
119  double Bi { 0 };
120  };
121 
122  static QList<MoonBData> BData;
123  unsigned int iPhase { 0 };
124  KSSun *defaultSun=nullptr;
125 };
SkyObject::UID getUID() const override
Return UID for object.
Definition: ksmoon.cpp:329
static constexpr double PI
PI is a const static member; it's public so that it can be used anywhere, as long as dms....
Definition: dms.h:380
virtual void findPhase()
Determine the phase of the planet.
KSMoon * clone() const override
Create copy of object.
Definition: ksmoon.cpp:76
QString phaseName() const
Definition: ksmoon.cpp:288
Provides necessary information about the Moon. A subclass of SkyObject that provides information need...
Definition: ksmoon.h:25
qint64 UID
Type for Unique object IDenticator.
Definition: skyobject.h:49
bool loadData() override
reimplemented from KSPlanetBase
Definition: ksmoon.cpp:98
Provides necessary information about the Sun.
Definition: kssun.h:23
Store several time-dependent astronomical quantities.
Definition: ksnumbers.h:42
void updateMag()
updateMag calls findMagnitude() to calculate current magnitude of moon according to current phase.
Definition: ksmoon.h:80
double illum() const
Definition: ksmoon.h:49
short int getIPhase() const
Definition: ksmoon.h:58
void initPopupMenu(KSPopupMenu *pmenu) override
Initialize the popup menut.
Definition: ksmoon.cpp:320
bool findGeocentricPosition(const KSNumbers *num, const KSPlanetBase *) override
Reimplemented from KSPlanetBase, this function employs unique algorithms for estimating the lunar coo...
Definition: ksmoon.cpp:153
KSMoon()
Default constructor.
Definition: ksmoon.cpp:64
Provides necessary information about objects in the solar system.
Definition: ksplanetbase.h:49
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