Implement our own command-line argument parser which accepts '--name value' as well as '--name=value' and '--prop name=vale' as well as '--prop:name=value' to be compatible with the FlightGear command-line syntax.

utils/fgviewer/ArgumentParser.cxx

@@ -0,0 +1,132 @@
+// ArgumentParser.cxx -- flightgear viewer argument parser
+//
+// Copyright (C) 2021 by Erik Hofman
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+
+#include <cstring>
+#include <iostream>
+#include <string>
+#include <map>
+
+#include "ArgumentParser.hxx"
+
+ArgumentParser::ArgumentParser(int argc, char **argv) :
+   arg_num(argc),
+   arg_values(argv),
+   appName(argv[0]),
+   arguments( osg::ArgumentParser(&arg_num, arg_values) )
+{
+    for (int i=1; i<argc; i++)
+    {
+        std::string arg = argv[i];
+        std::string val;
+
+        if (arg[0] == '-')
+        {
+            std::size_t pos = arg.find('='); 
+            if (pos != std::string::npos)
+            {
+                val = arg.substr(pos+1);
+                arg = arg.substr(0, pos);
+            }
+            else if (++i<argc) {
+                val = argv[i];
+            } else {
+                val = "";
+            }
+
+            args[arg] = val;
+        }
+        else {
+            files.push_back(arg);
+        }
+    }
+}
+
+bool
+ArgumentParser::read(const char *arg)
+{
+    auto it = args.find(arg);
+    if (it != args.end())
+    {
+        args.erase(it);
+        return true;
+    }
+    return false;
+}
+
+bool
+ArgumentParser::read(const char *arg, std::string& value)
+{
+    auto it = args.find(arg);
+    if (it != args.end())
+    {
+        value = it->second;
+        args.erase(it);
+        return true;
+    }
+    return false;
+}
+ 
+bool
+ArgumentParser::read(const char *arg, std::string& name, std::string& value)
+{
+    auto it = args.find(arg);
+
+    // old fgviewer behavior: --prop name=value
+    if (it != args.end()) {
+        std::string str = it->second;
+
+        std::size_t pos = str.find("=");
+        if (pos != std::string::npos && pos != str.size())
+        {
+            value = str.substr(pos);
+            name = str.substr(0, pos);
+            args.erase(it);
+            return true;
+        }
+    }
+
+    // FlightGear behavior: --prop:name=value
+    std::string str = name;
+    str += ':'; 
+    str += name;
+
+    it = args.find(str);
+    if (it != args.end())
+    {
+        value = it->second;
+        args.erase(it);
+        return true;
+    }
+
+    return false;
+}
+
+void
+ArgumentParser::reportRemainingOptionsAsUnrecognized()
+{
+   for (auto it : args) {
+      std::cerr << "Unsupported argument: " << it.first << std::endl;
+   }
+}
+
+
+void
+ArgumentParser::writeErrorMessages(std::ostream& output)
+{
+}

utils/fgviewer/ArgumentParser.hxx

@@ -0,0 +1,57 @@
+// ArgumentParser.hxx -- flightgear viewer argument parser
+//
+// Copyright (C) 2021 by Erik Hofman
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+#pragma once
+
+#include <vector>
+#include <map>
+
+#include <osg/ArgumentParser>
+
+class ArgumentParser
+{
+public:
+    ArgumentParser(int argc, char **argv);
+    ~ArgumentParser() = default;
+
+    bool read(const char *arg);
+    bool read(const char *arg, std::string& value);
+    bool read(const char *arg, std::string& name, std::string& value);
+
+    int argc() { return files.size(); }
+    std::string& getApplicationName() { return appName; }
+
+    void reportRemainingOptionsAsUnrecognized();
+    void writeErrorMessages(std::ostream& output);
+
+    osg::ArgumentParser& osg() { return arguments; }
+
+    operator std::vector<std::string>&() { return files; }
+
+private:
+    int arg_num;
+    char **arg_values;
+    std::string appName;
+
+    std::vector<std::string> errors;
+    std::map<std::string, std::string> args;
+    std::vector<std::string> files;
+
+    osg::ArgumentParser arguments;
+};
+

utils/fgviewer/CMakeLists.txt

@@ -1,4 +1,5 @@
 set(FGVIEWER_SOURCES
+  ArgumentParser.cxx
   fgviewer.cxx
   Drawable.cxx
   Renderer.cxx

utils/fgviewer/Viewer.cxx

@@ -23,7 +23,6 @@
 #include "Viewer.hxx"
 
 #include <osg/Version>
-#include <osg/ArgumentParser>
 #include <osg/ProxyNode>
 #include <osg/PagedLOD>
 #include <osgDB/ReadFile>
@@ -34,13 +33,14 @@
 #endif
 
 #include "MEncoderCaptureOperation.hxx"
+#include "ArgumentParser.hxx"
 
 #include <cassert>
 
 namespace fgviewer  {
 
-Viewer::Viewer(osg::ArgumentParser& arguments) :
-    osgViewer::Viewer(arguments),
+Viewer::Viewer(ArgumentParser& arguments) :
+    osgViewer::Viewer(arguments.osg()),
     _sceneDataGroup(new osg::Group),
     _timeIncrement(SGTimeStamp::fromSec(0)),
     _simTime(SGTimeStamp::fromSec(0))

utils/fgviewer/Viewer.hxx

@@ -19,7 +19,6 @@
 #ifndef _FGVIEWER_VIEWER_HXX
 #define _FGVIEWER_VIEWER_HXX
 
-#include <osg/ArgumentParser>
 #include <osgViewer/Viewer>
 
 #include <simgear/math/SGMath.hxx>
@@ -31,6 +30,7 @@
 #include "Frustum.hxx"
 #include "Renderer.hxx"
 #include "SlaveCamera.hxx"
+#include "ArgumentParser.hxx"
 
 #if FG_HAVE_HLA
 #include "HLAViewerFederate.hxx"    
@@ -40,7 +40,7 @@ namespace fgviewer  {
 
 class Viewer : public osgViewer::Viewer {
 public:
-    Viewer(osg::ArgumentParser& arguments);
+    Viewer(ArgumentParser& arguments);
     virtual ~Viewer();
 
     bool readCameraConfig(const SGPropertyNode& viewerNode);

utils/fgviewer/fgviewer.cxx

@@ -21,7 +21,6 @@
 #endif
 
 #include <osg/Version>
-#include <osg/ArgumentParser>
 #include <osgDB/ReadFile>
 #include <osgViewer/ViewerEventHandlers>
 #include <osgGA/KeySwitchMatrixManipulator>
@@ -40,6 +39,7 @@
 #include <simgear/scene/model/ModelRegistry.hxx>
 #include <simgear/misc/ResourceManager.hxx>
 
+#include "ArgumentParser.hxx"
 #include "Renderer.hxx"
 #include "Viewer.hxx"
 
@@ -53,10 +53,7 @@ int
 main(int argc, char** argv)
 {
     /// Read arguments and environment variables.
-
-    // use an ArgumentParser object to manage the program arguments.
-    // FIXME implement a flightgear similar argument parser into simgear and use this one
-    osg::ArgumentParser arguments(&argc, argv);
+    ArgumentParser arguments(argc, argv);
 
     sglog().set_log_classes(SG_ALL);
     sglog().set_log_priority(SG_ALERT);