1 // ModelRegistry.hxx -- interface to the OSG model registry
3 // Copyright (C) 2005-2007 Mathias Froehlich
4 // Copyright (C) 2007 Tim Moore <timoore@redhat.com>
6 // This program is free software; you can redistribute it and/or
7 // modify it under the terms of the GNU General Public License as
8 // published by the Free Software Foundation; either version 2 of the
9 // License, or (at your option) any later version.
11 // This program is distributed in the hope that it will be useful, but
12 // WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 // General Public License for more details.
16 // You should have received a copy of the GNU General Public License
17 // along with this program; if not, write to the Free Software
18 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
19 #ifndef _SG_MODELREGISTRY_HXX
20 #define _SG_MODELREGISTRY_HXX 1
22 #include <OpenThreads/ReentrantMutex>
24 #include <osg/ref_ptr>
26 #include <osgDB/FileUtils>
27 #include <osgDB/FileNameUtils>
28 #include <osgDB/ReaderWriter>
29 #include <osgDB/Registry>
31 #include <simgear/compiler.h>
32 #include <simgear/structure/Singleton.hxx>
37 // Class to register per file extension read callbacks with the OSG
38 // registry, mostly to control caching and post load optimization /
39 // copying that happens above the level of the ReaderWriter.
43 // Different caching and optimization strategies are needed for
44 // different file types. Most loaded files should be optimized and the
45 // optimized version should be cached. When an .osg file is
46 // substituted for another, it is assumed to be optimized already but
47 // it should be cached too (under the name of the original?). .stg
48 // files should not be cached (that's the pager's job) but the files
49 // it causes to be loaded should be. .btg files are already optimized
50 // and shouldn't be cached.
52 // Complicating this is the effect that removing CACHE_NODES has from
53 // the ReaderWriter options: it switches the object cache with an
54 // empty one, so that's not an option for the files that could be
55 // loaded from a .stg file. So, we'll let
56 // Registry::readNodeImplementation cache a loaded file and then add
57 // the optimized version to the cache ourselves, replacing the
60 // To support all these options with a minimum of duplication, the
61 // readNode function is specified as a template with a bunch of
62 // pluggable (and predefined) policies.
63 template <typename ProcessPolicy, typename CachePolicy, typename OptimizePolicy,
64 typename CopyPolicy, typename SubstitutePolicy>
65 class ModelRegistryCallback : public osgDB::Registry::ReadFileCallback {
67 ModelRegistryCallback(const std::string& extension) :
68 _processPolicy(extension), _cachePolicy(extension),
69 _optimizePolicy(extension), _copyPolicy(extension),
70 _substitutePolicy(extension)
73 virtual osgDB::ReaderWriter::ReadResult
74 readNode(const std::string& fileName,
75 const osgDB::ReaderWriter::Options* opt)
78 using namespace osgDB;
79 using osgDB::ReaderWriter;
80 Registry* registry = Registry::instance();
81 ref_ptr<osg::Node> optimizedNode = _cachePolicy.find(fileName, opt);
82 if (!optimizedNode.valid()) {
83 std::string otherFileName = _substitutePolicy.substitute(fileName,
85 ReaderWriter::ReadResult res;
86 if (!otherFileName.empty()) {
87 res = loadUsingReaderWriter(otherFileName, opt);
89 optimizedNode = res.getNode();
91 if (!optimizedNode.valid()) {
92 res = loadUsingReaderWriter(fileName, opt);
95 ref_ptr<osg::Node> processedNode
96 = _processPolicy.process(res.getNode(), fileName, opt);
97 optimizedNode = _optimizePolicy.optimize(processedNode.get(),
100 _cachePolicy.addToCache(fileName, optimizedNode.get());
102 return ReaderWriter::ReadResult(_copyPolicy.copy(optimizedNode.get(),
107 static osgDB::ReaderWriter::ReadResult
108 loadUsingReaderWriter(const std::string& fileName,
109 const osgDB::ReaderWriter::Options* opt)
111 using namespace osgDB;
112 ReaderWriter* rw = Registry::instance()
113 ->getReaderWriterForExtension(osgDB::getFileExtension(fileName));
115 return ReaderWriter::ReadResult(); // FILE_NOT_HANDLED
116 return rw->readNode(fileName, opt);
119 ProcessPolicy _processPolicy;
120 CachePolicy _cachePolicy;
121 OptimizePolicy _optimizePolicy;
122 CopyPolicy _copyPolicy;
123 SubstitutePolicy _substitutePolicy;
124 virtual ~ModelRegistryCallback() {}
127 // Predefined policies
129 struct DefaultProcessPolicy {
130 DefaultProcessPolicy(const std::string& extension) {}
131 osg::Node* process(osg::Node* node, const std::string& filename,
132 const osgDB::ReaderWriter::Options* opt);
135 struct DefaultCachePolicy {
136 DefaultCachePolicy(const std::string& extension) {}
137 osg::Node* find(const std::string& fileName,
138 const osgDB::ReaderWriter::Options* opt);
139 void addToCache(const std::string& filename, osg::Node* node);
142 struct NoCachePolicy {
143 NoCachePolicy(const std::string& extension) {}
144 osg::Node* find(const std::string& fileName,
145 const osgDB::ReaderWriter::Options* opt)
149 void addToCache(const std::string& filename, osg::Node* node) {}
152 class OptimizeModelPolicy {
154 OptimizeModelPolicy(const std::string& extension);
155 osg::Node* optimize(osg::Node* node, const std::string& fileName,
156 const osgDB::ReaderWriter::Options* opt);
158 unsigned _osgOptions;
161 struct NoOptimizePolicy {
162 NoOptimizePolicy(const std::string& extension) {}
163 osg::Node* optimize(osg::Node* node, const std::string& fileName,
164 const osgDB::ReaderWriter::Options* opt)
170 struct DefaultCopyPolicy {
171 DefaultCopyPolicy(const std::string& extension) {}
172 osg::Node* copy(osg::Node* node, const std::string& fileName,
173 const osgDB::ReaderWriter::Options* opt);
176 struct NoCopyPolicy {
177 NoCopyPolicy(const std::string& extension) {}
178 osg::Node* copy(osg::Node* node, const std::string& fileName,
179 const osgDB::ReaderWriter::Options* opt)
185 struct OSGSubstitutePolicy {
186 OSGSubstitutePolicy(const std::string& extension) {}
187 std::string substitute(const std::string& name,
188 const osgDB::ReaderWriter::Options* opt);
191 struct NoSubstitutePolicy {
192 NoSubstitutePolicy(const std::string& extension) {}
193 std::string substitute(const std::string& name,
194 const osgDB::ReaderWriter::Options* opt)
196 return std::string();
199 typedef ModelRegistryCallback<DefaultProcessPolicy, DefaultCachePolicy,
200 OptimizeModelPolicy, DefaultCopyPolicy,
201 OSGSubstitutePolicy> DefaultCallback;
203 // The manager for the callbacks
204 class ModelRegistry : public osgDB::Registry::ReadFileCallback,
205 public ReferencedSingleton<ModelRegistry> {
208 virtual osgDB::ReaderWriter::ReadResult
209 readImage(const std::string& fileName,
210 const osgDB::ReaderWriter::Options* opt);
211 virtual osgDB::ReaderWriter::ReadResult
212 readNode(const std::string& fileName,
213 const osgDB::ReaderWriter::Options* opt);
214 void addImageCallbackForExtension(const std::string& extension,
215 osgDB::Registry::ReadFileCallback*
217 void addNodeCallbackForExtension(const std::string& extension,
218 osgDB::Registry::ReadFileCallback*
220 virtual ~ModelRegistry() {}
222 typedef std::map<std::string, osg::ref_ptr<osgDB::Registry::ReadFileCallback> >
224 CallbackMap imageCallbackMap;
225 CallbackMap nodeCallbackMap;
226 osg::ref_ptr<DefaultCallback> _defaultCallback;
227 // Protect against simultaneous calls from main thread (MP models)
229 OpenThreads::ReentrantMutex readerMutex;
230 unsigned _nestingLevel;
233 // Callback that only loads the file without any caching or
235 typedef ModelRegistryCallback<DefaultProcessPolicy, NoCachePolicy,
236 NoOptimizePolicy, NoCopyPolicy,
237 NoSubstitutePolicy> LoadOnlyCallback;
239 // Proxy for registering extension-based callbacks
242 class ModelRegistryCallbackProxy
245 ModelRegistryCallbackProxy(std::string extension)
247 ModelRegistry::instance()
248 ->addNodeCallbackForExtension(extension, new T(extension));
252 #endif // _SG_MODELREGISTRY_HXX