Extended PlanarSegmentation class

First attempt for a labelling algorithm -- currently, no tunable
parameters etc., but the principle is sound.

SegmentationAlgorithms/PlanarSegmentation.cpp

@@ -3,6 +3,7 @@
 *	@brief	Functions for the planar segmentation algorithm
 */
 
+#include <list>
 #include "PlanarSegmentation.h"
 
 namespace psalm
@@ -25,6 +26,41 @@ mesh PlanarSegmentation::apply_to(mesh& input_mesh)
 {
 	mesh res;
 
+	this->label_planar_vertices(input_mesh);
+	this->label_nonplanar_faces(input_mesh);
+	this->label_regions(input_mesh);
+
+	size_t cur_region = 0;
+	size_t written = 0;
+	do
+	{
+		for(size_t i = 0; i < input_mesh.num_vertices(); i++)
+		{
+			if(input_mesh.get_vertex(i)->region != std::numeric_limits<size_t>::max())
+			{
+				if(input_mesh.get_vertex(i)->region == cur_region)
+				{
+					written++;
+					std::cout << input_mesh.get_vertex(i)->get_position();
+				}
+			}
+		}
+
+		std::cout << "\n\n";
+
+		if(written == 0)
+			break;
+		else
+		{
+			cur_region++;
+			written = 0;
+			continue;
+		}
+	}
+	while(true);
+
+	return(res);
+
 	/*
 	*	FIXME: This assumes that the vertex IDs are numbered
 	*	sequentially. If this is not the case, the function will
@@ -72,4 +108,169 @@ mesh PlanarSegmentation::apply_to(mesh& input_mesh)
 	return(res);
 }
 
+/*!
+*	Labels all planar vertices of a given input mesh. The result of this
+*	function is stored locally within the class.
+*
+*	@param input_mesh Mesh that is going to be labelled
+*/
+
+void PlanarSegmentation::label_planar_vertices(mesh& input_mesh)
+{
+	planar_vertices.clear();
+	for(size_t i = 0; i < input_mesh.num_vertices(); i++)
+	{
+		vertex* v = input_mesh.get_vertex(i);
+		double curvature = v->calc_rms_curvature();
+
+		// TODO: This should use a user-definable threshold value for
+		// determining the necessary curvature...
+		if(curvature < 0.05)
+			planar_vertices.push_back(v);
+		else
+			nonplanar_vertices.push_back(v);
+	}
+}
+
+/*!
+*	Labels nonplanar faces of the given input mesh. A face is nonplanar if
+*	at least one of its vertices is nonplanar.
+*
+*	@param input_mesh Mesh that is going to be labelled
+*/
+
+void PlanarSegmentation::label_nonplanar_faces(mesh& input_mesh)
+{
+	nonplanar_faces.clear();
+	for(size_t i = 0; i < input_mesh.num_faces(); i++)
+	{
+		face* f = input_mesh.get_face(i);
+		for(size_t j = 0; j < f->num_vertices(); j++)
+		{
+			vertex* v = f->get_vertex(j);
+
+			// TODO: Lookup could be optimized by using maps or
+			// fixed-size arrays...
+			if(std::find(planar_vertices.begin(), planar_vertices.end(), v) == planar_vertices.end())
+			{
+				nonplanar_faces.push_back(f);
+				break;
+			}
+		}
+	}
+}
+
+/*!
+*	Labels different regions in the given input mesh. Essentially, this is
+*	a breadth-first-search that tries to reach vertices of nonplanar faces,
+*	starting with a given vertex of a nonplanar face. Only edges to other
+*	nonplanar faces are taken into account. Each face reached from the
+*	starting vertex gets assigned the same region.
+*
+*	@param input_mesh Mesh whose regions are to be labelled
+*/
+
+void PlanarSegmentation::label_regions(mesh& input_mesh)
+{
+	size_t cur_region = 0;
+	while(nonplanar_vertices.size() > 0)
+	{
+		std::list<vertex*> unprocessed_vertices;
+
+		vertex* v = nonplanar_vertices.front();
+		if(v->region != std::numeric_limits<size_t>::max())
+		{
+			nonplanar_vertices.erase(nonplanar_vertices.begin());
+			continue;
+		}
+
+		unprocessed_vertices.push_back(v);
+		while(unprocessed_vertices.size() > 0)
+		{
+			vertex* v = unprocessed_vertices.front();
+			v->region = cur_region;
+			std::vector<const vertex*> neighbours = v->get_neighbours();
+			for(size_t i = 0; i < neighbours.size(); i++)
+			{
+				vertex* w = const_cast<vertex*>(neighbours[i]);
+
+				// TODO: Optimize
+				if(std::find(planar_vertices.begin(), planar_vertices.end(), w) != planar_vertices.end())
+				{
+					// skip planar vertices -- only the
+					// nonplanar regions should be labelled
+					continue;
+				}
+
+				if(w->region == std::numeric_limits<size_t>::max())
+				{
+					w->region = cur_region;
+					unprocessed_vertices.push_back(w);
+				}
+			}
+
+			unprocessed_vertices.pop_front();
+		}
+
+		cur_region++;
+		nonplanar_vertices.erase(nonplanar_vertices.begin());
+	}
+	/*
+	std::list<vertex*> unprocessed_vertices;
+	while(nonplanar_faces.size() > 0)
+	{
+		face* f = nonplanar_faces.front();
+		for(size_t i = 0; i < f->num_vertices(); i++)
+		{
+			vertex* v = f->get_vertex(i);
+
+			// TODO: Optimize
+			if(std::find(planar_vertices.begin(), planar_vertices.end(), v) != planar_vertices.end())
+			{
+				// skip planar vertices -- only nonplanar
+				// regions should be labelled
+				continue;
+			}
+
+			// Check if vertex has been visited already
+			if(v->region == std::numeric_limits<size_t>::max())
+			{
+				v->region = cur_region;
+				unprocessed_vertices.push_back(v);
+			}
+		}
+
+		nonplanar_faces.erase(nonplanar_faces.begin());
+
+		while(unprocessed_vertices.size() > 0)
+		{
+			vertex* v = unprocessed_vertices.front();
+			std::vector<const vertex*> neighbours = v->get_neighbours();
+			for(size_t i = 0; i < neighbours.size(); i++)
+			{
+				vertex* w = const_cast<vertex*>(neighbours[i]);
+
+				// TODO: Optimize
+				if(std::find(planar_vertices.begin(), planar_vertices.end(), w) != planar_vertices.end())
+				{
+					// skip planar vertices -- only the
+					// nonplanar regions should be labelled
+					continue;
+				}
+
+				if(w->region == std::numeric_limits<size_t>::max())
+				{
+					w->region = cur_region;
+					unprocessed_vertices.push_back(w);
+				}
+			}
+
+			unprocessed_vertices.pop_front();
+		}
+
+		cur_region++;
+	}
+	*/
+}
+
 } // end of namespace "psalm"

SegmentationAlgorithms/PlanarSegmentation.h

@@ -21,6 +21,15 @@ class PlanarSegmentation : public SegmentationAlgorithm
 {
 	public:
 		mesh apply_to(mesh& input_mesh);
+
+	private:
+		void label_planar_vertices(mesh& input_mesh);
+		void label_nonplanar_faces(mesh& input_mesh);
+		void label_regions(mesh& input_mesh);
+
+		std::vector<vertex*>	planar_vertices;
+		std::vector<vertex*>	nonplanar_vertices;
+		std::vector<face*>	nonplanar_faces;
 };
 
 } // end of namespace "psalm"