Fixed third-person camera movement bug in the viewer.

Fixed a bug that caused the viewer to render "random" polygons in some special cases. 
ASE: Added parsing support for *GROUP nodes. Improved light & camera handling (still WIP). Fixed a bug that was caused by a recent change. Improved logging.
Updated PretransformVertices. The step works now (and supports line and point meshes). Important: The position of the step in the pipeline has changed. No unit test yet.
Minor fixes to SortByPType. Added a config option that allows users to specify which primitive types they don't need. 
Added WIP version of an Irrlicht Scene Loader (.irr).
Added a small helper class ("BatchLoader") to make it easy for loaders to load subsequent meshes from external files (needed for irr and lws).
Added test models for IRR. Added dwarf.x from the Irrlicht repository (readme included) to the test X files.
[Current TODO: Fix bugs in: AC, 3DS, LWO. Finish MDR and OG. Implement: IRR, LWS. Write some more ut's ... ]

git-svn-id: https://assimp.svn.sourceforge.net/svnroot/assimp/trunk@197 67173fc5-114c-0410-ac8e-9d2fd5bffc1f

code/BaseImporter.cpp

@@ -139,4 +139,124 @@ bool BaseImporter::SearchFileHeaderForToken(IOSystem* pIOHandler,
 }
 
 
+// ------------------------------------------------------------------------------------------------
+struct LoadRequest
+{
+	LoadRequest(const std::string& _file, unsigned int _flags)
+		:	file	(_file)
+		,	flags	(_flags)
+		,	scene	(NULL)
+		,	refCnt	(1)
+		,	loaded	(false)
+	{}
+
+	const std::string file;
+	unsigned int flags;
+	unsigned int refCnt;
+
+	aiScene* scene;
+	bool loaded;
+
+	bool operator== (const std::string& f)
+		{return file == f;}
+};
+
+struct BatchData
+{
+	// IO system to be used for all imports
+	IOSystem* pIOSystem;
+
+	// Importer used to load all meshes
+	Importer* pImporter;
+
+	// List of all imports
+	std::list<LoadRequest> requests;
+};
+
+// ------------------------------------------------------------------------------------------------
+BatchLoader::BatchLoader(IOSystem* pIO)
+{
+	ai_assert(NULL != pIO);
+
+	pimpl = new BatchData();
+	BatchData* data = ( BatchData* )pimpl;
+	data->pIOSystem = pIO;
+	data->pImporter = new Importer();
+}
+
+// ------------------------------------------------------------------------------------------------
+BatchLoader::~BatchLoader()
+{
+	// delete all scenes wthat have not been polled by the user
+	BatchData* data = ( BatchData* )pimpl;
+	for (std::list<LoadRequest>::iterator it = data->requests.begin();
+		it != data->requests.end(); ++it)
+	{
+		delete (*it).scene;
+	}
+	delete data->pImporter;
+	delete data;
+}
+
+// ------------------------------------------------------------------------------------------------
+void BatchLoader::AddLoadRequest	(const std::string& file)
+{
+	// no threaded implementation for the moment
+	BatchData* data = ( BatchData* )pimpl;
+	std::list<LoadRequest>::iterator it = std::find(data->requests.begin(),
+		data->requests.end(), file);
+
+	if (it != data->requests.end())
+	{
+		(*it).refCnt++;
+		return;
+	}
+	data->requests.push_back(LoadRequest(file,0));
+}
+
+
+// ------------------------------------------------------------------------------------------------
+aiScene* BatchLoader::GetImport		(const std::string& file)
+{
+	// no threaded implementation for the moment
+	BatchData* data = ( BatchData* )pimpl;
+	std::list<LoadRequest>::iterator it = std::find(data->requests.begin(),
+		data->requests.end(), file);
+	if (it != data->requests.end() && (*it).loaded)
+	{
+		aiScene* sc = (*it).scene;
+		if (!(--(*it).refCnt))
+		{
+			data->requests.erase(it);
+		}
+		return sc;
+	}
+	return NULL;
+}
+
+
+// ------------------------------------------------------------------------------------------------
+void BatchLoader::LoadAll()
+{
+	BatchData* data = ( BatchData* )pimpl;
+
+	// no threaded implementation for the moment
+	for (std::list<LoadRequest>::iterator it = data->requests.begin();
+		it != data->requests.end(); ++it)
+	{
+		// no postprocessing for the moment except validation
+		// in debug builds
+		unsigned int pp = 0;
+#ifdef _DEBUG
+		pp |= aiProcess_ValidateDataStructure;
+#endif
+
+		data->pImporter->ReadFile((*it).file,pp);
+		(*it).scene = const_cast<aiScene*>(data->pImporter->GetOrphanedScene());
+		(*it).loaded = true;
+	}
+}
+
+
+