Implement ViewROI and base classes (#287)

* Implement ViewROI and base classes

* Clean up Orientable header

* Move tgl to tgl subdirectory, and use target_include_directories

* Move classes to submodules

* Fix some missed references

* Fix/match UpdateWorldData

* Renaming / removing MxTypes / refactoring

* Consistent naming for Matrix

* Adjust format action

* Add Vector3/Vector4 to Data vector

* Add TGL comment

* Add a comment about Matrix4Impl

* Add ROI comment

---------

Co-authored-by: Anonymous Maarten <anonymous.maarten@gmail.com>
Co-authored-by: Christian Semmler <mail@csemmler.com>

LEGO1/viewmanager/viewroi.h

@@ -0,0 +1,47 @@
+#ifndef VIEWROI_H
+#define VIEWROI_H
+
+#include "../realtime/orientableroi.h"
+#include "../tgl/tgl.h"
+#include "viewlodlist.h"
+
+/*
+	ViewROI objects represent view objects, collections of view objects,
+	etc. Basically, anything which can be placed in a scene and manipilated
+	by the view manager is a ViewROI.
+*/
+class ViewROI : public OrientableROI {
+public:
+	inline ViewROI(Tgl::Renderer* pRenderer, ViewLODList* lodList)
+	{
+		SetLODList(lodList);
+		geometry = pRenderer->CreateGroup();
+	}
+	inline ~ViewROI();
+	inline void SetLODList(ViewLODList* lodList)
+	{
+		// ??? inherently type unsafe - kind of... because, now, ROI
+		//     does not expose SetLODs() ...
+		// solution: create pure virtual LODListBase* ROI::GetLODList()
+		// and let derived ROI classes hold the LODList
+
+		if (m_lods) {
+			reinterpret_cast<ViewLODList*>(m_lods)->Release();
+		}
+
+		m_lods = lodList;
+
+		if (m_lods) {
+			reinterpret_cast<ViewLODList*>(m_lods)->AddRef();
+		}
+	}
+	virtual float IntrinsicImportance() const;
+	virtual Tgl::Group* GetGeometry();
+	virtual const Tgl::Group* GetGeometry() const;
+
+protected:
+	Tgl::Group* geometry;
+	void UpdateWorldData(const Matrix4Data& parent2world);
+};
+
+#endif // VIEWROI_H