VerticalSpineModel.h

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/*
 * Copyright © 2012, United States Government, as represented by the
 * Administrator of the National Aeronautics and Space Administration.
 * All rights reserved.
 * 
 * The NASA Tensegrity Robotics Toolkit (NTRT) v1 platform is licensed
 * under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0.
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
*/

#ifndef VERTICAL_SPINE_MODEL_H
#define VERTICAL_SPINE_MODEL_H

// This library
#include "core/tgModel.h" 
#include "core/tgSubject.h"
// The C++ Standard Library
#include <map>
#include <set>
#include <string>
#include <vector>

#include "sensors/tgDataObserver.h"

// Forward declarations
class tgSpringCableActuator;
class tgStructure;
class tgStructureInfo;

// Declare the configuration struct(s) here. This allows us to re-use the
// struct type later, and also pass it around in functions.

// A structure containing all the parameters of a spine vertebra (rigid body only.)
// This assumes that a vertebra is four rods.
struct ConfigVertebra {
    std::string vertebra_name; // a name for this type of vertebra. This is used for naming the rods when calling addRodPairs.
    double mass;  // mass of this rigid body, kg
    double radius;  // radius of the cylinders that make up this body (length)
    double leg_length;  // the length of one of the cylinders, a "leg" of the tetrahedron (length)
    double height;  // total height of one vertebra, from the bottommost node to topmost (length)
    double friction;  // A constant passed down to the underlying bullet physics solver (unitless)
    double rollFriction;  // A constant passed down to the underlying bullet physics solver (unitless)
    double restitution;  // A constant passed down to the underlying bullet physics solver (unitless)
};

class VerticalSpineModel: public tgSubject<VerticalSpineModel>, public tgModel
{
public: 
                
    typedef std::map<std::string, std::vector<tgSpringCableActuator*> > MuscleMap;
                
    VerticalSpineModel(size_t segments);
                
    virtual ~VerticalSpineModel()
    {}
    
    virtual void setup(tgWorld& world);
                
    virtual void step(const double dt);
                
    const std::vector<tgSpringCableActuator*>& getMuscles (const std::string& key) const;

    const std::vector<tgSpringCableActuator*>& getAllMuscles() const;
    
    size_t getSegments() const
    {
        return m_segments;
    }
    
private:
                
    static void addNodes(tgStructure& vertebra, ConfigVertebra& conf_vertebra);

    static void trace(const tgStructureInfo& structureInfo, tgModel& model);
    // A version that includes the tgStructure:
    static void trace(const tgStructure& structure,
                                      const tgStructureInfo& structureInfo, tgModel& model);

    static void addRodPairs(tgStructure& vertebra, ConfigVertebra& conf_vertebra);

    static double getDensity(ConfigVertebra& conf_vertebra);

    static double getEdgeLength(ConfigVertebra& conf_vertebra);

    static void addSegments(tgStructure& spine, const tgStructure& vertebra,
                                                    double edge, size_t segmentCount);

    static void addVertebra(tgStructure& spine, ConfigVertebra& conf_vertebra,
                                                    size_t vertebra_number);

    static void addMuscles(tgStructure& spine);

    static void mapMuscles(VerticalSpineModel::MuscleMap& muscleMap, tgModel&
                                                   model, size_t segmentCount);

    std::vector<tgSpringCableActuator*> allMuscles;
                
    MuscleMap muscleMap;
    
    const size_t m_segments;
};

#endif