Added help support for display help on screen to osgProducer::Viewer.

include/osg/ApplicationUsage

@@ -34,6 +34,13 @@ class SG_EXPORT ApplicationUsage
 
         typedef std::map<std::string,std::string> UsageMap;
         
+
+        void setApplicatonName(const std::string& name) { _applicationName = name; }
+        const std::string& getApplicatonName() const { return _applicationName; }
+
+        void setDescription(const std::string& desc) { _description = desc; }
+        const std::string& getDescription() const { return _description; }
+
         enum Type
         {
             COMMAND_LINE_OPTION,
@@ -63,13 +70,16 @@ class SG_EXPORT ApplicationUsage
         const UsageMap& getKeyboardMouseBindings() const { return _keyboardMouse; }
 
 
+        void getFormatedString(std::string& str, const UsageMap& um,unsigned int widthOfOutput=80);
+
         void write(std::ostream& output,const UsageMap& um,unsigned int widthOfOutput=80);
         
         void write(std::ostream& output,unsigned int widthOfOutput=80);
 
     protected:
     
-
+        std::string _applicationName;
+        std::string _description;
         std::string _commandLineUsage;
         UsageMap    _commandLineOptions;
         UsageMap    _environmentalVariables;

include/osg/Viewport

@@ -27,6 +27,13 @@ class SG_EXPORT Viewport : public StateAttribute
     
     
         Viewport();
+        
+        Viewport(int x,int y,int width,int height):
+            _x(x),
+            _y(y),
+            _width(width),
+            _height(height) {}
+            
 
         /** Copy constructor using CopyOp to manage deep vs shallow copy.*/
         Viewport(const Viewport& vp,const CopyOp& copyop=CopyOp::SHALLOW_COPY):