1 // matmodel.hxx -- class to handle models tied to a material property
3 // Written by David Megginson, December 2001
5 // Copyright (C) 1998 - 2003 Curtis L. Olson - http://www.flightgear.org/~curt
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
24 #ifndef _SG_MAT_MODEL_HXX
25 #define _SG_MAT_MODEL_HXX
28 # error This library requires C++
31 #include <simgear/compiler.h>
33 #include STL_STRING // Standard C++ string library
35 #include <osg/ref_ptr>
38 #include <simgear/structure/SGReferenced.hxx>
39 #include <simgear/structure/SGSharedPtr.hxx>
40 #include <simgear/props/props.hxx>
45 class SGMatModelGroup;
50 * A randomly-placeable object.
52 * SGMaterial uses this class to keep track of the model(s) and
53 * parameters for a single instance of a randomly-placeable object.
54 * The object can have more than one variant model (i.e. slightly
55 * different shapes of trees), but they are considered equivalent
56 * and interchangeable.
58 class SGMatModel : public SGReferenced {
63 * The heading type for a randomly-placed object.
72 * Get the number of variant models available for the object.
74 * @return The number of variant models.
76 int get_model_count( SGModelLib *modellib,
77 const string &fg_root,
78 SGPropertyNode *prop_root,
79 double sim_time_sec );
83 * Get a specific variant model for the object.
85 * @param index The index of the model.
88 osg::Node *get_model( int index,
90 const string &fg_root,
91 SGPropertyNode *prop_root,
92 double sim_time_sec );
96 * Get a randomly-selected variant model for the object.
98 * @return A randomly select model from the variants.
100 osg::Node *get_random_model( SGModelLib *modellib,
101 const string &fg_root,
102 SGPropertyNode *prop_root,
103 double sim_time_sec );
107 * Get the average number of meters^2 occupied by each instance.
109 * @return The coverage in meters^2.
111 double get_coverage_m2 () const;
115 * Get the heading type for the object.
117 * @return The heading type.
119 HeadingType get_heading_type () const;
121 virtual ~SGMatModel ();
125 friend class SGMatModelGroup;
127 SGMatModel (const SGPropertyNode * node, double range_m);
132 * Actually load the models.
134 * This class uses lazy loading so that models won't be held
135 * in memory for materials that are never referenced.
137 void load_models( SGModelLib *modellib,
138 const string &fg_root,
139 SGPropertyNode *prop_root,
140 double sim_time_sec );
142 vector<string> _paths;
143 mutable vector<osg::ref_ptr<osg::Node> > _models;
144 mutable bool _models_loaded;
147 HeadingType _heading_type;
152 * A collection of related objects with the same visual range.
154 * Grouping objects with the same range together significantly
155 * reduces the memory requirements of randomly-placed objects.
156 * Each SGMaterial instance keeps a (possibly-empty) list of
157 * object groups for placing randomly on the scenery.
159 class SGMatModelGroup : public SGReferenced {
163 virtual ~SGMatModelGroup ();
167 * Get the visual range of the object in meters.
169 * @return The visual range.
171 double get_range_m () const;
175 * Get the number of objects in the group.
177 * @return The number of objects.
179 int get_object_count () const;
183 * Get a specific object.
185 * @param index The object's index, zero-based.
186 * @return The object selected.
188 SGMatModel * get_object (int index) const;
192 friend class SGMaterial;
194 SGMatModelGroup (SGPropertyNode * node);
199 vector<SGSharedPtr<SGMatModel> > _objects;
203 #endif // _SG_MAT_MODEL_HXX