Add support for showing environment variables provided by osg plugins

include/osgDB/PluginQuery

@@ -40,6 +40,7 @@ class ReaderWriterInfo : public osg::Referenced
         ReaderWriter::FormatDescriptionMap  protocols;
         ReaderWriter::FormatDescriptionMap  extensions;
         ReaderWriter::FormatDescriptionMap  options;
+        ReaderWriter::FormatDescriptionMap  environment;
         ReaderWriter::Features              features;
 
     protected:

include/osgDB/ReaderWriter

@@ -63,6 +63,9 @@ class OSGDB_EXPORT ReaderWriter : public osg::Object
         /** Return which list of file extensions supported by ReaderWriter. */
         virtual const FormatDescriptionMap& supportedOptions() const { return _supportedOptions; }
 
+        /** Return which list of file environment variables supported by ReaderWriter. */
+        virtual const FormatDescriptionMap& supportedEnvironment() const { return _supportedEnvironment; }
+
         /** Return true if ReaderWriter accepts specified file extension.*/
         virtual bool acceptsExtension(const std::string& /*extension*/) const;
 
@@ -282,11 +285,15 @@ class OSGDB_EXPORT ReaderWriter : public osg::Object
           * Please note, this should usually only be used internally by subclasses of ReaderWriter. */
         void supportsOption(const std::string& opt, const std::string& description);
 
+        /** Specify env string as a supported environment string. */
+        void supportsEnvironment(const std::string& opt, const std::string& description);
+
     protected:
 
         FormatDescriptionMap _supportedProtocols;
         FormatDescriptionMap _supportedExtensions;
         FormatDescriptionMap _supportedOptions;
+        FormatDescriptionMap _supportedEnvironment;
 };
 
 }

src/osgDB/PluginQuery.cpp

@@ -82,6 +82,7 @@ bool osgDB::queryPlugin(const std::string& fileName, ReaderWriterInfoList& infoL
                 rwi->protocols = rw->supportedProtocols();
                 rwi->extensions = rw->supportedExtensions();
                 rwi->options = rw->supportedOptions();
+                rwi->environment = rw->supportedEnvironment();
                 rwi->features = rw->supportedFeatures();
 
                 infoList.push_back(rwi.get());
@@ -153,6 +154,13 @@ bool osgDB::outputPluginDetails(std::ostream& out, const std::string& fileName)
                 if (fdm_itr->first.length()>longestOptionLength) longestOptionLength = fdm_itr->first.length();
             }
 
+            for(fdm_itr = info.environment.begin();
+                fdm_itr != info.environment.end();
+                ++fdm_itr)
+            {
+                if (fdm_itr->first.length()>longestOptionLength) longestOptionLength = fdm_itr->first.length();
+            }
+
             unsigned int padLength = longestOptionLength+4;
 
             for(fdm_itr = info.protocols.begin();
@@ -175,6 +183,13 @@ bool osgDB::outputPluginDetails(std::ostream& out, const std::string& fileName)
             {
                 out<<"        options    : "<<padwithspaces(fdm_itr->first, padLength)<<fdm_itr->second<<std::endl;
             }
+
+            for(fdm_itr = info.environment.begin();
+                fdm_itr != info.environment.end();
+                ++fdm_itr)
+            {
+                out<<"        environment: "<<padwithspaces(fdm_itr->first, padLength)<<fdm_itr->second<<std::endl;
+            }
             out<<"    }"<<std::endl;
         }
         out<<"}"<<std::endl<<std::endl;

src/osgDB/ReaderWriter.cpp

@@ -128,6 +128,11 @@ void ReaderWriter::supportsOption(const std::string& fmt, const std::string& des
     _supportedOptions[fmt] = description;
 }
 
+void ReaderWriter::supportsEnvironment(const std::string& fmt, const std::string& description)
+{
+    _supportedEnvironment[fmt] = description;
+}
+
 ReaderWriter::Features ReaderWriter::supportedFeatures() const
 {
     int features = FEATURE_NONE;