Adding missing file

src/Decomposition/shift_vect_converter.hpp

+/*
+ * shift_vect_converter.hpp
+ *
+ *  Created on: Feb 8, 2018
+ *      Author: i-bird
+ */
+
+#ifndef SRC_DECOMPOSITION_SHIFT_VECT_CONVERTER_HPP_
+#define SRC_DECOMPOSITION_SHIFT_VECT_CONVERTER_HPP_
+
+#include "Space/Shape/HyperCube.hpp"
+
+/*! \brief in case of high dimensions shift vector converter
+ *
+ * In case of high-dimensions the number of shift vectors explode, this class
+ * handle such case
+ *
+ */
+template<unsigned int dim, typename T>
+class shift_vect_converter
+{
+	//! Indicate which indexes are non_periodic
+	size_t red_shift_v[dim];
+
+	// indexes
+	size_t tmp[dim];
+
+	// Dimension
+	int dim_r = 0;
+
+	/*! \brief Here we generare the shift vectors for the low dimension case
+	 *
+	 * \param domain box that describe the domain
+	 *
+	 */
+	void generateShiftVectors_ld(const Box<dim,T> & domain, size_t (& bc)[dim], openfpm::vector<Point<dim,T>> & shifts)
+	{
+		shifts.resize(openfpm::math::pow(3,dim));
+
+		HyperCube<dim> hyp;
+
+		for (long int i = dim-1 ; i >= 0 ; i--)
+		{
+			std::vector<comb<dim>> cmbs = hyp.getCombinations_R(i);
+
+			for (size_t j = 0 ; j < cmbs.size() ; j++)
+			{
+				for (size_t k = 0 ; k < dim ; k++)
+				{
+					switch (cmbs[j][k])
+					{
+					case 1:
+						shifts.get(cmbs[j].lin()).template get<0>()[k] = -(domain.getHigh(k) - domain.getLow(k));
+						break;
+					case 0:
+						shifts.get(cmbs[j].lin()).template get<0>()[k] = 0;
+						break;
+					case -1:
+						shifts.get(cmbs[j].lin()).template get<0>()[k] = (domain.getHigh(k) - domain.getLow(k));
+						break;
+					}
+				}
+			}
+		}
+	}
+
+	/*! \brief Here we generare the shift vectors for the high dimension case
+	 *
+	 * \param domain box that describe the domain
+	 *
+	 */
+	void generateShiftVectors_hd(const Box<dim,T> & domain, size_t (& bc)[dim], openfpm::vector<Point<dim,T>> & shifts)
+	{
+		// get the indexes of the free degree of freedom
+		for (size_t i = 0 ; i < dim ; i++)
+		{
+			if (bc[i] == PERIODIC)
+			{
+				red_shift_v[dim_r] = i;
+				dim_r++;
+			}
+		}
+
+		HyperCube<dim> hyp;
+
+		// precalculate the nuber of shift vectors
+		size_t nsv = 0;
+		for (long int i = dim-1 ; i >= 0 ; i--)
+		{nsv += hyp.getCombinations_R_bc(i,bc).size();}
+		shifts.resize(nsv+1);
+
+		for (long int i = dim-1 ; i >= 0 ; i--)
+		{
+			std::vector<comb<dim>> cmbs = hyp.getCombinations_R_bc(i,bc);
+
+			for (size_t j = 0 ; j < cmbs.size() ; j++)
+			{
+				size_t lin_cmb = linId_hd(cmbs[j]);
+
+				for (size_t k = 0 ; k < dim ; k++)
+				{
+					switch (cmbs[j][k])
+					{
+					case 1:
+						shifts.get(lin_cmb).template get<0>()[k] = -(domain.getHigh(k) - domain.getLow(k));
+						break;
+					case 0:
+						shifts.get(lin_cmb).template get<0>()[k] = 0;
+						break;
+					case -1:
+						shifts.get(lin_cmb).template get<0>()[k] = (domain.getHigh(k) - domain.getLow(k));
+						break;
+					}
+				}
+			}
+		}
+	}
+
+public:
+
+	/*! \brief Here we generare the shift vectors for the low dimension case
+	 *
+	 * \param domain box that describe the domain
+	 *
+	 */
+	void generateShiftVectors(const Box<dim,T> & domain, size_t (& bc)[dim], openfpm::vector<Point<dim,T>> & shifts)
+	{
+		if (dim < 10)
+		{generateShiftVectors_ld(domain,bc,shifts);}
+		else
+		{generateShiftVectors_hd(domain,bc,shifts);}
+	}
+
+	/*! \brief Initialize
+	 *
+	 * \param bc boundary conditions
+	 *
+	 */
+	void Initialize(size_t (& bc)[dim])
+	{
+		// get the indexes of the free degree of freedom
+		for (size_t i = 0 ; i < dim ; i++)
+		{
+			if (bc[i] == PERIODIC)
+			{
+				red_shift_v[dim] = i;
+				dim_r++;
+			}
+		}
+	}
+
+	/*! \brief linearize the combination in case of high dimension
+	 *
+	 * \param cmb combination
+	 *
+	 */
+	size_t linId_hd(const comb<dim> & cmb)
+	{
+		size_t cul = 1;
+		size_t lin = 0;
+		for (long int i = 0 ; i < dim_r ; i++)
+		{
+			lin += cul*(cmb.c[red_shift_v[i]] + 1);
+			cul *= 3;
+		}
+
+		return lin;
+	}
+
+	/*! \brief linearize the combination in case of low dimensions
+	 *
+	 * \param cmb combination
+	 *
+	 */
+	inline size_t linId_ld(const comb<dim> & cmb)
+	{
+		return cmb.lin();
+	}
+
+	/*! \brief linearize the combination in case of high dimensions
+	 *
+	 * \param cmb combination
+	 *
+	 */
+	inline size_t linId(const comb<dim> & cmb)
+	{
+		if (dim < 10)
+		{return linId_ld(cmb);}
+
+		return linId_hd(cmb);
+	}
+
+};
+
+
+#endif /* SRC_DECOMPOSITION_SHIFT_VECT_CONVERTER_HPP_ */