1 // moon.hxx -- model earth's moon
2 //
3 // Written by Durk Talsma. Originally started October 1997, for distribution
4 // with the FlightGear project. Version 2 was written in August and
5 // September 1998. This code is based upon algorithms and data kindly
6 // provided by Mr. Paul Schlyter. (pausch@saaf.se).
7 //
8 // Separated out rendering pieces and converted to ssg by Curt Olson,
9 // March 2000
10 //
11 // This library is free software; you can redistribute it and/or
12 // modify it under the terms of the GNU Library General Public
13 // License as published by the Free Software Foundation; either
14 // version 2 of the License, or (at your option) any later version.
15 //
16 // This library is distributed in the hope that it will be useful,
17 // but WITHOUT ANY WARRANTY; without even the implied warranty of
18 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19 // Library General Public License for more details.
20 //
21 // You should have received a copy of the GNU General Public License
22 // along with this program; if not, write to the Free Software
23 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
24 //
25 // $Id$
26 
27 
28 #ifndef _SG_MOON_HXX_
29 #define _SG_MOON_HXX_
30 
31 
32 #include <osg/ref_ptr>
33 #include <osg/MatrixTransform>
34 #include <osg/Material>
35 
36 #include <simgear/math/SGMath.hxx>
37 #include <simgear/structure/SGReferenced.hxx>
38 
39 #include <simgear/misc/sg_path.hxx>
40 
41 
42 class SGMoon : public SGReferenced {
43 
44     osg::ref_ptr<osg::MatrixTransform> moon_transform;
45     osg::ref_ptr<osg::Material> orb_material;
46 
47     double prev_moon_angle;
48 
49 public:
50 
51     // Constructor
52     SGMoon( void );
53 
54     // Destructor
55     ~SGMoon( void );
56 
57     // build the moon object
58     osg::Node *build( SGPath path, double moon_size );
59 
60     // repaint the moon colors based on current value of moon_anglein
61     // degrees relative to verticle
62     // 0 degrees = high noon
63     // 90 degrees = moon rise/set
64     // 180 degrees = darkest midnight
65     bool repaint( double moon_angle );
66 
67     // reposition the moon at the specified right ascension and
68     // declination, offset by our current position (p) so that it
69     // appears fixed at a great distance from the viewer.  Also add in
70     // an optional rotation (i.e. for the current time of day.)
71     bool reposition( double rightAscension, double declination,
72 		     double moon_dist  );
73 };
74 
75 
76 #endif // _SG_MOON_HXX_
77