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 <string> // Standard C++ string library
36 #include <osg/ref_ptr>
38 #include <osg/NodeVisitor>
39 #include <osg/Billboard>
41 #include <simgear/structure/SGReferenced.hxx>
42 #include <simgear/structure/SGSharedPtr.hxx>
43 #include <simgear/props/props.hxx>
44 #include <simgear/math/sg_random.h>
47 class SGMatModelGroup;
51 * A randomly-placeable object.
53 * SGMaterial uses this class to keep track of the model(s) and
54 * parameters for a single instance of a randomly-placeable object.
55 * The object can have more than one variant model (i.e. slightly
56 * different shapes of trees), but they are considered equivalent
57 * and interchangeable.
59 class SGMatModel : public SGReferenced {
64 * The heading type for a randomly-placed object.
73 * Get the number of variant models available for the object.
75 * @return The number of variant models.
77 int get_model_count( SGPropertyNode *prop_root );
81 * Get a randomly-selected variant model for the object.
83 * @return A randomly select model from the variants.
85 osg::Node *get_random_model( SGPropertyNode *prop_root );
89 * Get the average number of meters^2 occupied by each instance.
91 * @return The coverage in meters^2.
93 double get_coverage_m2 () const;
96 * Get the visual range of the object in meters.
98 * @return The visual range.
100 double get_range_m () const;
103 * Get a randomized visual range
105 * @return a randomized visual range
107 double get_randomized_range_m(mt* seed) const;
110 * Get the heading type for the object.
112 * @return The heading type.
114 HeadingType get_heading_type () const;
116 virtual ~SGMatModel ();
121 friend class SGMatModelGroup;
123 SGMatModel (const SGPropertyNode * node, double range_m);
128 * Actually load the models.
130 * This class uses lazy loading so that models won't be held
131 * in memory for materials that are never referenced.
133 void load_models( SGPropertyNode *prop_root );
135 std::vector<std::string> _paths;
136 mutable std::vector<osg::ref_ptr<osg::Node> > _models;
137 mutable bool _models_loaded;
140 HeadingType _heading_type;
145 * A collection of related objects with the same visual range.
147 * Grouping objects with the same range together significantly
148 * reduces the memory requirements of randomly-placed objects.
149 * Each SGMaterial instance keeps a (possibly-empty) list of
150 * object groups for placing randomly on the scenery.
152 class SGMatModelGroup : public SGReferenced {
156 virtual ~SGMatModelGroup ();
160 * Get the visual range of the object in meters.
162 * @return The visual range.
164 double get_range_m () const;
168 * Get the number of objects in the group.
170 * @return The number of objects.
172 int get_object_count () const;
176 * Get a specific object.
178 * @param index The object's index, zero-based.
179 * @return The object selected.
181 SGMatModel * get_object (int index) const;
185 friend class SGMaterial;
187 SGMatModelGroup (SGPropertyNode * node);
192 std::vector<SGSharedPtr<SGMatModel> > _objects;
195 #endif // _SG_MAT_MODEL_HXX