1 /**************************************************************************** 2 * 3 * ViSP, open source Visual Servoing Platform software. 4 * Copyright (C) 2005 - 2019 by Inria. All rights reserved. 5 * 6 * This software is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * See the file LICENSE.txt at the root directory of this source 11 * distribution for additional information about the GNU GPL. 12 * 13 * For using ViSP with software that can not be combined with the GNU 14 * GPL, please contact Inria about acquiring a ViSP Professional 15 * Edition License. 16 * 17 * See http://visp.inria.fr for more information. 18 * 19 * This software was developed at: 20 * Inria Rennes - Bretagne Atlantique 21 * Campus Universitaire de Beaulieu 22 * 35042 Rennes Cedex 23 * France 24 * 25 * If you have questions regarding the use of this file, please contact 26 * Inria at visp@inria.fr 27 * 28 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE 29 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 30 * 31 * Description: 32 * Pseudo-database used to handle dependencies between moments 33 * 34 * Authors: 35 * Filip Novotny 36 * 37 *****************************************************************************/ 38 /*! 39 \file vpMomentDatabase.h 40 \brief Pseudo-database used to handle dependencies between moments. 41 */ 42 #ifndef _vpMomentDatabase_h_ 43 #define _vpMomentDatabase_h_ 44 45 #include <visp3/core/vpImage.h> 46 47 #include <cstring> 48 #include <iostream> 49 #include <map> 50 51 class vpMoment; 52 class vpMomentObject; 53 54 /*! 55 \class vpMomentDatabase 56 57 \ingroup group_core_moments 58 59 \brief This class allows to register all vpMoments so they can access each 60 other according to their dependencies. 61 62 Sometimes, a moment needs to have access to other moment's values to be 63 computed. For example vpMomentCentered needs additionnal information about the 64 gravity center vpMomentGravityCenter in order to compute the moment's value 65 from a vpMomentObject. This gravity center should be stored in a 66 vpMomentDatabase where it can be accessed. 67 68 All moments in a database can access each other freely at any time. They can 69 also verify if a moment is present in the database or not. Here is a example 70 of a dependency between two moments using a vpMomentDatabase: 71 72 \code 73 #include <visp3/core/vpMomentObject.h> 74 #include <visp3/core/vpPoint.h> 75 #include <visp3/core/vpMomentGravityCenter.h> 76 #include <visp3/core/vpMomentDatabase.h> 77 #include <visp3/core/vpMomentCentered.h> 78 #include <iostream> 79 80 int main() 81 { 82 vpPoint p; 83 std::vector<vpPoint> vec_p; // vector that contains the vertices of the contour polygon 84 85 p.set_x(1); p.set_y(1); // coordinates in meters in the image plane (vertex 1) 86 vec_p.push_back(p); 87 p.set_x(2); p.set_y(2); // coordinates in meters in the image plane (vertex 2) 88 vec_p.push_back(p); 89 vpMomentObject obj(1); // Create an image moment object with 1 as 90 // maximum order (sufficient for gravity center) 91 obj.setType(vpMomentObject::DISCRETE); // The object is defined by 92 // two discrete points 93 obj.fromVector(vec_p); // Init the dense object with the polygon 94 95 vpMomentDatabase db; 96 vpMomentGravityCenter g; // declaration of gravity center 97 vpMomentCentered mc; // mc containts centered moments 98 99 g.linkTo(db); //add gravity center to database 100 mc.linkTo(db); //centered moments depend on gravity, add them to the 101 //database to grant access 102 103 db.updateAll(obj); // All of the moments must be updated, not just mc 104 105 //There is no global compute method since the order of compute calls 106 //depends on the implementation 107 g.compute(); // compute the moment 108 mc.compute(); //compute centered moments AFTER gravity center 109 110 std::cout << "Gravity center: " << g << std:: endl; // print gravity center moment 111 std::cout << "Centered moments: " << mc << std:: endl; // print centered moment 112 113 return 0; 114 } 115 \endcode 116 117 The following code outputs: 118 \code 119 Gravity center: 120 Xg=1.5, Yg=1.5 121 Centered moments: 122 2 0 123 0 x 124 \endcode 125 126 A moment is identified in the database by it's vpMoment::name method. 127 Consequently, a database can contain at most one moment of each type. Often it 128 is useful to update all moments with the same object. Shortcuts 129 (vpMomentDatabase::updateAll) are provided for that matter. 130 */ 131 class VISP_EXPORT vpMomentDatabase 132 { 133 private: 134 #ifndef DOXYGEN_SHOULD_SKIP_THIS 135 struct cmp_str { operatorcmp_str136 bool operator()(char const *a, char const *b) const { return std::strcmp(a, b) < 0; } 137 }; 138 #endif 139 std::map<const char *, vpMoment *, cmp_str> moments; 140 void add(vpMoment &moment, const char *name); 141 142 public: vpMomentDatabase()143 vpMomentDatabase() : moments() {} ~vpMomentDatabase()144 virtual ~vpMomentDatabase() {} 145 146 /** @name Inherited functionalities from vpMomentDatabase */ 147 //@{ 148 const vpMoment &get(const char *type, bool &found) const; 149 /*! 150 Get the first element in the database. 151 May be useful in case an unnamed object is present but is the only element 152 in the database. \return the first element in the database. 153 */ get_first()154 vpMoment &get_first() { return *(moments.begin()->second); } 155 156 virtual void updateAll(vpMomentObject &object); 157 //@} 158 159 friend class vpMoment; 160 friend VISP_EXPORT std::ostream &operator<<(std::ostream &os, const vpMomentDatabase &v); 161 }; 162 163 #endif 164