1 // matmodel.cxx -- class to handle models tied to a material property
3 // Written by David Megginson, started May 1998.
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.
25 # include <simgear_config.h>
28 #include <simgear/compiler.h>
33 #include <osg/AlphaFunc>
36 #include <osg/StateSet>
37 #include <osg/Transform>
39 #ifdef SG_MATH_EXCEPTION_CLASH
43 #include <simgear/debug/logstream.hxx>
44 #include <simgear/math/sg_random.h>
45 #include <simgear/misc/sg_path.hxx>
46 #include <simgear/misc/sgstream.hxx>
47 #include <simgear/scene/model/modellib.hxx>
49 #include "matmodel.hxx"
52 ////////////////////////////////////////////////////////////////////////
53 // Local static functions.
54 ////////////////////////////////////////////////////////////////////////
57 * Internal method to test whether a file exists.
59 * TODO: this should be moved to a SimGear library of local file
63 local_file_exists( const string& path ) {
64 sg_gzifstream in( path );
65 if ( ! in.is_open() ) {
74 ////////////////////////////////////////////////////////////////////////
75 // Implementation of SGMatModel.
76 ////////////////////////////////////////////////////////////////////////
78 SGMatModel::SGMatModel (const SGPropertyNode * node, double range_m)
79 : _models_loaded(false),
80 _coverage_m2(node->getDoubleValue("coverage-m2", 1000000)),
84 if (_coverage_m2 < 1000) {
85 SG_LOG(SG_INPUT, SG_ALERT, "Random object coverage " << _coverage_m2
86 << " is too small, forcing, to 1000");
90 // Note all the model paths
91 vector <SGPropertyNode_ptr> path_nodes = node->getChildren("path");
92 for (unsigned int i = 0; i < path_nodes.size(); i++)
93 _paths.push_back(path_nodes[i]->getStringValue());
95 // Note the heading type
96 string hdg = node->getStringValue("heading-type", "fixed");
98 _heading_type = HEADING_FIXED;
99 } else if (hdg == "billboard") {
100 _heading_type = HEADING_BILLBOARD;
101 } else if (hdg == "random") {
102 _heading_type = HEADING_RANDOM;
104 _heading_type = HEADING_FIXED;
105 SG_LOG(SG_INPUT, SG_ALERT, "Unknown heading type: " << hdg
106 << "; using 'fixed' instead.");
109 // uncomment to preload models
113 SGMatModel::~SGMatModel ()
118 SGMatModel::get_model_count( SGModelLib *modellib,
119 const string &fg_root,
120 SGPropertyNode *prop_root,
121 double sim_time_sec )
123 load_models( modellib, fg_root, prop_root, sim_time_sec );
124 return _models.size();
128 SGMatModel::load_models ( SGModelLib *modellib,
129 const string &fg_root,
130 SGPropertyNode *prop_root,
131 double sim_time_sec )
133 // Load model only on demand
134 if (!_models_loaded) {
135 for (unsigned int i = 0; i < _paths.size(); i++) {
136 osg::Node *entity = modellib->load_model( fg_root, _paths[i],
137 prop_root, sim_time_sec,
138 /*cache_object*/ true );
140 // FIXME: this stuff can be handled
141 // in the XML wrapper as well (at least,
142 // the billboarding should be handled
145 // Create multiple LoD nodes so instead of all objects
146 // of the same type appearing at once, some appear further
149 // Very basic hardcoded distribution:
151 // 2 at 1.5 times normal range
152 // 1 at 2 time normal range.
154 // We achieve this by creating the three different LoD
155 // nodes and adding them to the _models list multiple times.
157 osg::LOD * lod1 = new osg::LOD;
158 lod1->setName("Model LOD");
159 lod1->setRangeMode(osg::LOD::DISTANCE_FROM_EYE_POINT);
160 lod1->setRange(0, 0, _range_m);
162 osg::LOD * lod15 = new osg::LOD;
163 lod15->setName("Model LOD - 1.5");
164 lod15->setRangeMode(osg::LOD::DISTANCE_FROM_EYE_POINT);
165 lod15->setRange(0, 0, 1.5 * _range_m);
167 osg::LOD * lod2 = new osg::LOD;
168 lod2->setName("Model LOD - 2.0");
169 lod2->setRangeMode(osg::LOD::DISTANCE_FROM_EYE_POINT);
170 lod2->setRange(0, 0, 2.0 * _range_m);
172 if (_heading_type == HEADING_BILLBOARD) {
173 // if the model is a billboard, it is likely :
174 // 1. a branch with only leaves,
175 // 2. a tree or a non rectangular shape faked by transparency
176 // We add alpha clamp then
177 osg::StateSet* stateSet = entity->getOrCreateStateSet();
178 osg::AlphaFunc* alphaFunc =
179 new osg::AlphaFunc(osg::AlphaFunc::GREATER, 0.01f);
180 stateSet->setAttributeAndModes(alphaFunc,
181 osg::StateAttribute::OVERRIDE);
182 stateSet->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
184 lod1->addChild(entity);
185 lod15->addChild(entity);
186 lod2->addChild(entity);
188 lod1->addChild(entity);
189 lod15->addChild(entity);
190 lod2->addChild(entity);
193 // Vary the distribution of LoDs by adding multiple times.
194 _models.push_back(lod1);
195 _models.push_back(lod1);
196 _models.push_back(lod1);
197 _models.push_back(lod1);
199 _models.push_back(lod15);
200 _models.push_back(lod15);
202 _models.push_back(lod2);
205 SG_LOG(SG_INPUT, SG_ALERT, "Failed to load object " << _paths[i]);
209 _models_loaded = true;
213 SGMatModel::get_model( int index,
214 SGModelLib *modellib,
215 const string &fg_root,
216 SGPropertyNode *prop_root,
217 double sim_time_sec )
219 load_models( modellib, fg_root, prop_root, sim_time_sec ); // comment this out if preloading models
220 return _models[index].get();
224 SGMatModel::get_random_model( SGModelLib *modellib,
225 const string &fg_root,
226 SGPropertyNode *prop_root,
227 double sim_time_sec )
229 load_models( modellib, fg_root, prop_root, sim_time_sec ); // comment this out if preloading models
230 int nModels = _models.size();
231 int index = int(sg_random() * nModels);
232 if (index >= nModels)
234 return _models[index].get();
238 SGMatModel::get_coverage_m2 () const
243 SGMatModel::HeadingType
244 SGMatModel::get_heading_type () const
246 return _heading_type;
251 ////////////////////////////////////////////////////////////////////////
252 // Implementation of SGMatModelGroup.
253 ////////////////////////////////////////////////////////////////////////
255 SGMatModelGroup::SGMatModelGroup (SGPropertyNode * node)
256 : _range_m(node->getDoubleValue("range-m", 2000))
258 // Load the object subnodes
259 vector<SGPropertyNode_ptr> object_nodes =
260 ((SGPropertyNode *)node)->getChildren("object");
261 for (unsigned int i = 0; i < object_nodes.size(); i++) {
262 const SGPropertyNode * object_node = object_nodes[i];
263 if (object_node->hasChild("path"))
264 _objects.push_back(new SGMatModel(object_node, _range_m));
266 SG_LOG(SG_INPUT, SG_ALERT, "No path supplied for object");
270 SGMatModelGroup::~SGMatModelGroup ()
275 SGMatModelGroup::get_range_m () const
281 SGMatModelGroup::get_object_count () const
283 return _objects.size();
287 SGMatModelGroup::get_object (int index) const
289 return _objects[index];
295 // end of matmodel.cxx