Added initial cut of basic scripting support, introducing an osg::Script object to wrap up the individual scripts, osg::ScriptCallback for assigning a Script as node callback and an osg::ScriptEngine base class that plugins implement to provided support for specific scripting languages.

Provided are lua, python and V8 (for javascript) plugins that just open up enough of a link to the respective libs to run a script, there is no scene graph <-> script communication in current implementation.

src/osgPlugins/python/CMakeLists.txt

@@ -0,0 +1,13 @@
+SET(TARGET_H
+    PythonScriptEngine.h
+)
+SET(TARGET_SRC
+    PythonScriptEngine.cpp
+    ReaderWriterPython.cpp
+)
+
+SET(TARGET_EXTERNAL_LIBRARIES ${TARGET_EXTERNAL_LIBRARIES} ${PYTHON_LIBRARY})
+INCLUDE_DIRECTORIES(${PYTHON_INCLUDE_DIR} )
+
+#### end var setup  ###
+SETUP_PLUGIN(python)

src/osgPlugins/python/PythonScriptEngine.cpp

@@ -0,0 +1,58 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2013 Robert Osfield
+ *
+ * This library is open source and may be redistributed and/or modified under
+ * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
+ * (at your option) any later version.  The full license is in LICENSE file
+ * included with this distribution, and on the openscenegraph.org website.
+ *
+ * This library 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
+ * OpenSceneGraph Public License for more details.
+*/
+
+#include "PythonScriptEngine.h"
+
+using namespace python;
+
+PythonScriptEngine::PythonScriptEngine():
+    osg::ScriptEngine("python"),
+    _py_main(0)
+{
+    initialize();
+}
+
+PythonScriptEngine::PythonScriptEngine(const PythonScriptEngine& rhs, const osg::CopyOp&):
+    osg::ScriptEngine("python"),
+    _py_main(0)
+{
+    initialize();
+}
+
+PythonScriptEngine::~PythonScriptEngine()
+{
+    Py_Finalize();
+}
+
+void PythonScriptEngine::initialize()
+{
+    Py_InitializeEx(0);
+
+    _py_main = PyModule_GetDict(PyImport_AddModule("__main__"));
+}
+
+void PythonScriptEngine::run(osg::Script* script)
+{
+    if (!script || !_py_main) return;
+
+    PyObject* r = PyRun_String(script->getScript().c_str(), Py_file_input, _py_main, _py_main);
+
+    if(!r) {
+        r = PyErr_Occurred();
+
+        if(r) {
+            PyErr_Print();
+            PyErr_Clear();
+        }
+    }
+}

src/osgPlugins/python/PythonScriptEngine.h

@@ -0,0 +1,52 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2013 Robert Osfield
+ *
+ * This library is open source and may be redistributed and/or modified under
+ * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
+ * (at your option) any later version.  The full license is in LICENSE file
+ * included with this distribution, and on the openscenegraph.org website.
+ *
+ * This library 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
+ * OpenSceneGraph Public License for more details.
+*/
+
+#ifndef PYTHONSCRIPTENGINE_H
+#define PYTHONSCRIPTENGINE_H
+
+#include <osg/ScriptEngine>
+
+#include <Python.h>
+
+namespace python
+{
+
+class PythonScriptEngine : public osg::ScriptEngine
+{
+    public:
+        PythonScriptEngine();
+        PythonScriptEngine(const PythonScriptEngine& rhs, const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);
+
+        META_Object(lua, PythonScriptEngine)
+
+        virtual const std::string& getLanguage() const { return _language; }
+
+        /** run a Script.*/
+        virtual void run(osg::Script* script);
+
+        /** get the Python main object.*/
+        PyObject* getPythonMain() { return _py_main; }
+
+    protected:
+
+        void initialize();
+
+        virtual ~PythonScriptEngine();
+
+        PyObject* _py_main;
+
+};
+
+}
+
+#endif

src/osgPlugins/python/ReaderWriterPython.cpp

@@ -0,0 +1,70 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2013 Robert Osfield
+ *
+ * This library is open source and may be redistributed and/or modified under
+ * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
+ * (at your option) any later version.  The full license is in LICENSE file
+ * included with this distribution, and on the openscenegraph.org website.
+ *
+ * This library 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
+ * OpenSceneGraph Public License for more details.
+*/
+
+#include <osgDB/FileNameUtils>
+#include <osgDB/FileUtils>
+#include <osgDB/Registry>
+
+#include "PythonScriptEngine.h"
+
+class ReaderWriterPython : public osgDB::ReaderWriter
+{
+    public:
+
+        ReaderWriterPython()
+        {
+            supportsExtension("python","python script");
+        }
+
+        virtual const char* className() const { return "Python ScriptEngine plugin"; }
+
+        virtual ReadResult readObject(std::istream& fin,const osgDB::ReaderWriter::Options* options =NULL) const
+        {
+            osg::ref_ptr<osg::Script> script = new osg::Script;
+            script->setLanguage("python");
+
+            std::string str;
+            while(fin)
+            {
+                int c = fin.get();
+                if (c>=0 && c<=255)
+                {
+                    str.push_back(c);
+                }
+            }
+            script->setScript(str);
+
+            return script.release();
+        }
+
+        virtual ReadResult readObject(const std::string& file, const osgDB::ReaderWriter::Options* options =NULL) const
+        {
+            if (file=="ScriptEngine.python") return new python::PythonScriptEngine();
+
+            std::string ext = osgDB::getLowerCaseFileExtension(file);
+            if (!acceptsExtension(ext)) return ReadResult::FILE_NOT_HANDLED;
+
+            std::string fileName = osgDB::findDataFile( file, options );
+            if (fileName.empty()) return ReadResult::FILE_NOT_FOUND;
+
+            osgDB::ifstream istream(fileName.c_str(), std::ios::in);
+            if(!istream) return ReadResult::FILE_NOT_HANDLED;
+
+            return readObject(istream, options);
+        }
+
+};
+
+// now register with Registry to instantiate the above
+// reader/writer.
+REGISTER_OSGPLUGIN(python, ReaderWriterPython)