Added new header for Eigen utility classes.

These make passing data between Eigen vector and matrix types and plain
C arrays more convenient.

source/blender/physics/CMakeLists.txt

@@ -45,6 +45,7 @@ set(SRC
 	intern/implicit.h
 	intern/implicit_blender.c
 	intern/implicit_eigen.cpp
+	intern/eigen_utils.h
 
 	BPH_mass_spring.h
 )

source/blender/physics/intern/eigen_utils.h

@@ -0,0 +1,228 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) Blender Foundation
+ * All rights reserved.
+ *
+ * The Original Code is: all of this file.
+ *
+ * Contributor(s): Lukas Toenne
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+#ifndef __EIGEN_UTILS_H__
+#define __EIGEN_UTILS_H__
+
+/** \file eigen_utils.h
+ *  \ingroup bph
+ */
+
+#ifdef __GNUC__
+#  pragma GCC diagnostic push
+/* XXX suppress verbose warnings in eigen */
+#  pragma GCC diagnostic ignored "-Wlogical-op"
+#endif
+
+#include <Eigen/Sparse>
+#include <Eigen/src/Core/util/DisableStupidWarnings.h>
+
+#ifdef __GNUC__
+#  pragma GCC diagnostic pop
+#endif
+
+#include "BLI_utildefines.h"
+
+
+typedef float Scalar;
+
+/* slightly extended Eigen vector class
+ * with conversion to/from plain C float array
+ */
+class fVector : public Eigen::Vector3f {
+public:
+	typedef float *ctype;
+	
+	fVector()
+	{
+	}
+	
+	fVector(const ctype &v)
+	{
+		for (int k = 0; k < 3; ++k)
+			coeffRef(k) = v[k];
+	}
+	
+	fVector& operator = (const ctype &v)
+	{
+		for (int k = 0; k < 3; ++k)
+			coeffRef(k) = v[k];
+		return *this;
+	}
+	
+	operator ctype()
+	{
+		return data();
+	}
+};
+
+/* slightly extended Eigen matrix class
+ * with conversion to/from plain C float array
+ */
+class fMatrix : public Eigen::Matrix3f {
+public:
+	typedef float (*ctype)[3];
+	
+	fMatrix()
+	{
+	}
+	
+	fMatrix(const ctype &v)
+	{
+		for (int k = 0; k < 3; ++k)
+			for (int l = 0; l < 3; ++l)
+				coeffRef(l, k) = v[k][l];
+	}
+	
+	fMatrix& operator = (const ctype &v)
+	{
+		for (int k = 0; k < 3; ++k)
+			for (int l = 0; l < 3; ++l)
+				coeffRef(l, k) = v[k][l];
+		return *this;
+	}
+	
+	operator ctype()
+	{
+		return (ctype)data();
+	}
+};
+
+/* Extension of dense Eigen vectors,
+ * providing 3-float block access for blenlib math functions
+ */
+class lVector : public Eigen::VectorXf {
+public:
+	typedef Eigen::VectorXf base_t;
+	
+	lVector()
+	{
+	}
+	
+	template <typename T>
+	lVector& operator = (T rhs)
+	{
+		base_t::operator=(rhs);
+		return *this;
+	}
+	
+	float* v3(int vertex)
+	{
+		return &coeffRef(3 * vertex);
+	}
+	
+	const float* v3(int vertex) const
+	{
+		return &coeffRef(3 * vertex);
+	}
+};
+
+typedef Eigen::Triplet<Scalar> Triplet;
+typedef std::vector<Triplet> TripletList;
+
+typedef Eigen::SparseMatrix<Scalar> lMatrix;
+
+/* Constructor type that provides more convenient handling of Eigen triplets
+ * for efficient construction of sparse 3x3 block matrices.
+ * This should be used for building lMatrix instead of writing to such lMatrix directly (which is very inefficient).
+ * After all elements have been defined using the set() method, the actual matrix can be filled using construct().
+ */
+struct lMatrixCtor {
+	lMatrixCtor()
+	{
+	}
+	
+	void reset()
+	{
+		m_trips.clear();
+	}
+	
+	void reserve(int numverts)
+	{
+		/* reserve for diagonal entries */
+		m_trips.reserve(numverts * 9);
+	}
+	
+	void add(int i, int j, const fMatrix &m)
+	{
+		i *= 3;
+		j *= 3;
+		for (int k = 0; k < 3; ++k)
+			for (int l = 0; l < 3; ++l)
+				m_trips.push_back(Triplet(i + k, j + l, m.coeff(l, k)));
+	}
+	
+	void sub(int i, int j, const fMatrix &m)
+	{
+		i *= 3;
+		j *= 3;
+		for (int k = 0; k < 3; ++k)
+			for (int l = 0; l < 3; ++l)
+				m_trips.push_back(Triplet(i + k, j + l, -m.coeff(l, k)));
+	}
+	
+	inline void construct(lMatrix &m)
+	{
+		m.setFromTriplets(m_trips.begin(), m_trips.end());
+		m_trips.clear();
+	}
+	
+private:
+	TripletList m_trips;
+};
+
+typedef Eigen::ConjugateGradient<lMatrix, Eigen::Lower, Eigen::DiagonalPreconditioner<Scalar> > ConjugateGradient;
+
+using Eigen::ComputationInfo;
+
+BLI_INLINE void print_lvector(const lVector &v)
+{
+	for (int i = 0; i < v.rows(); ++i) {
+		if (i > 0 && i % 3 == 0)
+			printf("\n");
+		
+		printf("%f,\n", v[i]);
+	}
+}
+
+BLI_INLINE void print_lmatrix(const lMatrix &m)
+{
+	for (int j = 0; j < m.rows(); ++j) {
+		if (j > 0 && j % 3 == 0)
+			printf("\n");
+		
+		for (int i = 0; i < m.cols(); ++i) {
+			if (i > 0 && i % 3 == 0)
+				printf("  ");
+			
+			implicit_print_matrix_elem(m.coeff(j, i));
+		}
+		printf("\n");
+	}
+}
+
+#endif