ContactCableDemo.cpp

/*
* 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.
*/

#include "ContactCableDemo.h"
#include "core/tgModelVisitor.h"
#include "core/tgBulletUtil.h"
#include "core/tgWorld.h"
#include "core/tgSpringCableActuator.h"
#include "core/tgSpringCableActuator.h"
#include "core/tgRod.h"
#include "core/tgBox.h"
#include "core/tgBaseRigid.h"
#include "tgcreator/tgBuildSpec.h"
#include "tgcreator/tgRodInfo.h"
#include "tgcreator/tgBoxInfo.h"
#include "tgcreator/tgStructure.h"
#include "tgcreator/tgStructureInfo.h"
#include "tgcreator/tgBasicContactCableInfo.h"

#include "core/tgBulletSpringCable.h"
#include "core/tgSpringCableAnchor.h"

// The Bullet Physics Library
#include "BulletDynamics/Dynamics/btRigidBody.h"

ContactCableDemo::ContactCableDemo()
{
}

ContactCableDemo::~ContactCableDemo()
{
}

void ContactCableDemo::setup(tgWorld& world)
{


                const double rodDensity = 1; // Note: This needs to be high enough or things fly apart...
                const double rodRadius = 0.25;
                const tgRod::Config rodConfig(rodRadius, rodDensity);
                const tgRod::Config rodConfig2(rodRadius, 0.0);
                const tgBox::Config boxConfig(rodRadius, rodRadius, rodDensity);
                
                tgStructure s;
                
                s.addNode(0, 2, 0); // 0
                s.addNode(0, 4, 0); // 1
                s.addNode(0, 12, 0); // 2
                s.addNode(0, 14, 0); // 3
                
                
                // Static rod that the others will run into
                s.addNode(-1, 8, 5); // 4
                s.addNode(1, 8, 5); // 5

                s.addPair(0, 1, "rod");
                s.addPair(2, 3, "box");
                
                s.addPair(4, 5, "rod");

                s.addPair(1, 2, "muscle");
                s.move(btVector3(0, 0, 0));


                // Move the structure so it doesn't start in the ground
                s.move(btVector3(0, 0, 0));
                s.addRotation(btVector3(0.0, 0.0, 0.0), btVector3(0.0, 1.0, 0.0), M_PI/4);
                tgSpringCableActuator::Config muscleConfig(1000, 0, 0.0, false, 600000000);
                
                // Create the build spec that uses tags to turn the structure into a real model
                tgBuildSpec spec;
                
                spec.addBuilder("rod2", new tgRodInfo(rodConfig2));
                spec.addBuilder("box", new tgBoxInfo(boxConfig));
                spec.addBuilder("rod", new tgRodInfo(rodConfig));
                spec.addBuilder("muscle", new tgBasicContactCableInfo(muscleConfig));

                // Create your structureInfo
                tgStructureInfo structureInfo(s, spec);
                // Use the structureInfo to build ourselves
                structureInfo.buildInto(*this, world);
                // We could now use tgCast::filter or similar to pull out the
                // models (e.g. muscles) that we want to control.
                allRods.clear();
                allMuscles.clear();
                allMuscles = tgCast::filter<tgModel, tgSpringCableActuator> (getDescendants());
                allRods = tgCast::filter<tgModel, tgBaseRigid> (getDescendants());
                
                btRigidBody* body = allRods[0]->getPRigidBody();
                btRigidBody* body2 = allRods[1]->getPRigidBody();
                
                // Apply initial impulse
                btVector3 impulse(0.4, 0.0, 0.4);
                body->applyCentralImpulse(impulse);
                body2->applyCentralImpulse(impulse);
                
                btRigidBody* body3 = allRods[2]->getPRigidBody();
                
                std::cout << body3->getCenterOfMassTransform () << std::endl;
                
                notifySetup();
                totalTime = 0.0;
                tgModel::setup(world);
}

void ContactCableDemo::teardown()
{
                tgModel::teardown();
}

void ContactCableDemo::step(double dt)
{
                totalTime += dt;
                
                tgModel::step(dt);
                
                btVector3 vCom(0, 0, 0);
                btScalar mass = 0;
                btScalar energy = 0;
                for (std::size_t i = 0; i < allRods.size(); i++)
                {
                                tgBaseRigid& ri = *(allRods[i]);
                                btRigidBody* body = ri.getPRigidBody();
                                btVector3 localVel = body->getLinearVelocity();
                                vCom += localVel * ri.mass();
                                energy += localVel.length2() * ri.mass();// + body->getAngularVelocity().length2() ;
                                mass += ri.mass();
                }
                
                btVector3 forceSum(0.0, 0.0, 0.0);
                
                const std::vector<const tgSpringCableAnchor*>& anchorList = allMuscles[0]->getSpringCable()->getAnchors();
                int n = anchorList.size();
                for (std::size_t i = 0; i < n; i++)
                {
                                forceSum += anchorList[i]->getForce();
                }
                
#if (0)         
    std::cout << "Time " << totalTime << std::endl;
                std::cout << "Momentum " << vCom << std::endl;
                std::cout << "Energy " << energy << std::endl;
                std::cout << "Other Momentum " << getMomentum() << std::endl;
                std::cout << "Force sum " << forceSum << std::endl;
                std::cout << "Length " << allMuscles[0]->getCurrentLength();
                std::cout << " Dist " << (anchorList[0]->getWorldPosition() - anchorList[n-1]->getWorldPosition()).length() << std::endl;
                std::cout << "Anchors: " << n << std::endl;
                
                if (energy > 20){
                                std::cout << "Here!" << std::endl;
                }
#endif
}

void ContactCableDemo::onVisit(const tgModelVisitor& r) const
{
                r.render(*this);
                tgModel::onVisit(r);
}

double ContactCableDemo::getEnergy() const
{
                double energy = 0;
                btScalar mass = 0;
                for (std::size_t i = 0; i < allRods.size(); i++)
                {
                                tgBaseRigid* ri = allRods[i];
                                btRigidBody* body = ri->getPRigidBody();
                                btVector3 localVel = body->getLinearVelocity();
                                energy += localVel.length2() * ri->mass();// + body->getAngularVelocity().length2() ;
                                mass += ri->mass();
                }
                
                return energy;
}

btVector3 ContactCableDemo::getMomentum() const
{
                btVector3 vCom(0, 0, 0);
                btScalar mass = 0;

                for (std::size_t i = 0; i < allRods.size(); i++)
                {
                                tgBaseRigid* ri = allRods[i];
                                btRigidBody* body = ri->getPRigidBody();
                                btVector3 localVel = body->getLinearVelocity();
                                vCom += localVel * ri->mass();
                                mass += ri->mass();
                }
                
                return vCom;
}

btVector3 ContactCableDemo::getVelocityOfBody(int body_num) const
{
                assert(body_num < allRods.size() && body_num >= 0);
                tgBaseRigid* ri = allRods[body_num];
                btRigidBody* body = ri->getPRigidBody();
                
                return body->getLinearVelocity();
}