319 lines
7.6 KiB
C++
319 lines
7.6 KiB
C++
#include "MassSpringSystemSimulator.h"
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MassSpringSystemSimulator::MassSpringSystemSimulator()
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{
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m_iTestCase = 0;
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m_fMass = 10;
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m_fStiffness = 40;
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int m_iIntegrater = 0;
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auto first = addMassPoint(Vec3(0, 0, 0), Vec3(-1, 0, 0), true);
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auto second = addMassPoint(Vec3(0, 2, 0), Vec3(1, 0, 0), true);
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addSpring(first, second, 1.0);
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}
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const char* MassSpringSystemSimulator::getTestCasesStr()
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{
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//hier to change the choices
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return "Euler,LeapFrog,Midpoint";
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}
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void MassSpringSystemSimulator::initUI(DrawingUtilitiesClass* DUC)
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{
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this->DUC = DUC;
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switch (m_iTestCase)
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{
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case 0:break;
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case 1:
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break;
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case 2:
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break;
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default:break;
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}
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}
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void MassSpringSystemSimulator::reset()
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{
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m_mouse.x = m_mouse.y = 0;
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m_trackmouse.x = m_trackmouse.y = 0;
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m_oldtrackmouse.x = m_oldtrackmouse.y = 0;
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}
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void MassSpringSystemSimulator::drawFrame(ID3D11DeviceContext* pd3dImmediateContext)
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{
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for (size_t i = 0; i < springs.size(); i++) {
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auto sp = springs.at(i);
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if (!sp.isValid())
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{
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springs.erase(springs.begin() + i);
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continue;
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}
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auto mp1 = sp.mp1.lock();
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auto mp2 = sp.mp2.lock();
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DUC->setUpLighting(Vec3(), 0.4 * Vec3(1, 1, 1), 100, 0.6 * Vec3(0.97, 0.86, 1));
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DUC->drawSphere(mp1->position, Vec3(0.01));
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DUC->drawSphere(mp2->position, Vec3(0.01));
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DUC->beginLine();
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DUC->drawLine(mp1->position, Vec3(1,0,0), mp2->position, Vec3(0,1,0));
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DUC->endLine();
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}
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}
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void MassSpringSystemSimulator::notifyCaseChanged(int testCase)
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{
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m_iTestCase = testCase;
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switch (m_iTestCase)
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{
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case 0:
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cout << "Euler !\n";
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//simulateTimestep(1);
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break;
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case 1:
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break;
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case 2:
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cout << "Midpoint \n";
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//m_iNumSpheres = 100;
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//m_fSphereSize = 0.05f;
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break;
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default:
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//cout << "Demo4 !\n";
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break;
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}
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}
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void MassSpringSystemSimulator::externalForcesCalculations(float timeElapsed)
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{
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Point2D mouseDiff;
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mouseDiff.x = m_trackmouse.x - m_oldtrackmouse.x;
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mouseDiff.y = m_trackmouse.y - m_oldtrackmouse.y;
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if (mouseDiff.x != 0 || mouseDiff.y != 0)
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{
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Mat4 worldViewInv = Mat4(DUC->g_camera.GetWorldMatrix() * DUC->g_camera.GetViewMatrix());
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worldViewInv = worldViewInv.inverse();
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Vec3 inputView = Vec3((float)mouseDiff.x, (float)-mouseDiff.y, 0);
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Vec3 inputWorld = worldViewInv.transformVectorNormal(inputView);
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// find a proper scale!
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float inputScale = 0.001f;
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inputWorld = inputWorld * inputScale;
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//m_vfMovableObjectPos = m_vfMovableObjectFinalPos + inputWorld;
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}
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else {
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//m_vfMovableObjectFinalPos = m_vfMovableObjectPos;
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}
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}
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void MassSpringSystemSimulator::simulateTimestep(float timeStep)
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{
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//update current setup for each frame
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switch (m_iTestCase) {
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case 0:
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//update the masspoint
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cout << "Euler \n";
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Euler(0, 1, 0, timeStep);
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break;
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case 1:
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break;
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case 2:cout << "midpoint \n";
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Midpoint(0, 1, timeStep);
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break;
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default: break;
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}
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//Euler(0, 1, 0, timeStep);
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}
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void MassSpringSystemSimulator::onClick(int x, int y)
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{
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m_trackmouse.x = x;
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m_trackmouse.y = y;
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}
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void MassSpringSystemSimulator::onMouse(int x, int y)
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{
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m_oldtrackmouse.x = x;
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m_oldtrackmouse.y = y;
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m_trackmouse.x = x;
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m_trackmouse.y = y;
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}
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void MassSpringSystemSimulator::setMass(float mass)
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{
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m_fMass = mass;
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}
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void MassSpringSystemSimulator::setStiffness(float stiffness)
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{
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m_fStiffness = stiffness;
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}
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void MassSpringSystemSimulator::setDampingFactor(float damping)
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{
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m_fDamping = damping;
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}
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int MassSpringSystemSimulator::addMassPoint(Vec3 position, Vec3 Velocity, bool isFixed)
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{
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MassPoint masspoint;
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masspoint.position = position;
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masspoint.velocity = Velocity;
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masspoint.isFixed = isFixed;
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masspoints.push_back(std::make_shared<MassPoint>(masspoint));
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return masspoints.size() - 1;
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}
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void MassSpringSystemSimulator::addSpring(int masspoint1, int masspoint2, float initialLength)
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{
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auto mp1 = masspoints.at(masspoint1);
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auto mp2 = masspoints.at(masspoint2);
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Spring spring;
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spring.mp1 = mp1;
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spring.mp2 = mp2;
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spring.initialLength = initialLength;
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springs.push_back(spring);
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}
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int MassSpringSystemSimulator::getNumberOfMassPoints()
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{
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return masspoints.size();
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}
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int MassSpringSystemSimulator::getNumberOfSprings()
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{
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return springs.size();
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}
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Vec3 MassSpringSystemSimulator::getPositionOfMassPoint(int index)
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{
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auto mp = masspoints.at(index);
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return mp->position;
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}
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Vec3 MassSpringSystemSimulator::getVelocityOfMassPoint(int index)
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{
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auto mp = masspoints.at(index);
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return mp->velocity;
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}
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void MassSpringSystemSimulator::applyExternalForce(Vec3 force)
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{
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//eine Vorstellung: for all Masspoints, update force
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}
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int MassSpringSystemSimulator::LengthCalculator(Vec3 position1, Vec3 position2) {
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Vec3 PosVector = position1 - position2;
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//wurzel aus Vektor
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int length = sqrt(pow(PosVector.x, 2) + pow(PosVector.y, 2) + pow(PosVector.z, 2));
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return length;
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}
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Vec3 MassSpringSystemSimulator::calculatePositionTimestepEuler(Vec3 oldPosition, float timestep, Vec3 velocity)
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{
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return oldPosition + timestep * velocity;
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}
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Vec3 MassSpringSystemSimulator::calculateVelocityTimestepEuler(Vec3 oldVelocity, float timestep, Vec3 acceleration)
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{
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return oldVelocity + acceleration * timestep;
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}
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Vec3 MassSpringSystemSimulator::calculateAcceleration(Vec3 force, float mass)
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{
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return force / mass;
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}
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void MassSpringSystemSimulator::Midpoint(int index1, int index2, float timestep) {
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//here some implementation about Midpoint
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auto massPoint1 = masspoints.at(index1);
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auto massPoint2 = masspoints.at(index2);
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//old position
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auto mp = massPoint1->position;
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auto mp2 = massPoint2 ->position;
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//old Velocity
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auto mOld_v = massPoint1->velocity;
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auto m2Old_v = massPoint1->velocity;
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Vec3 PosVector = mp - mp2;
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//Abstand ausrechnen
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int d = LengthCalculator(mp, mp2);
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//normalize
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Vec3 PosNorm1 = PosVector / d;
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Vec3 PosNorm2 = -1 * PosNorm1;
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Vec3 Force = -m_fStiffness * (d - springs.at(0).initialLength) * PosNorm1;
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Vec3 Force2 = -1 * Force;
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Vec3 oldAcc = calculateAcceleration(Force,m_fMass);
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Vec3 oldAcc2 = calculateAcceleration(Force2, m_fMass);
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//Midpoint calculator
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//Pos of Midstep
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Vec3 PosOfMidstep = mp + 0.5 * timestep * mOld_v;
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Vec3 PosOfMidstep2 = mp2 + 0.5 * timestep * m2Old_v;
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//Vel at Midstep
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Vec3 VelAtMidstep = mOld_v + 0.5 * timestep * oldAcc;
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Vec3 VelAtMidstep2 = m2Old_v + 0.5 * timestep * oldAcc2;
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Vec3 NewPos = mp + timestep * VelAtMidstep;
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Vec3 NewPos2 = mp2 + timestep * VelAtMidstep2;
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Vec3 NewVel = mOld_v + timestep * oldAcc;
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Vec3 NewVel2 = m2Old_v + timestep * oldAcc2;
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cout << NewPos;
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cout << NewVel;
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massPoint1->position = NewPos;
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massPoint1->velocity = NewVel;
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massPoint2->position = NewPos2;
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massPoint2->velocity = NewVel2;
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}
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void MassSpringSystemSimulator::Euler(int index1, int index2, int indexSpring, float timestep)
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{
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//take old position and send to calculatePositionTimestepEuler
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auto mp = masspoints.at(index1);
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auto mp2 = masspoints.at(index2);
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Vec3 PosVector = mp->position - mp2->position;
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auto lengthVector = sqrt(PosVector.x * PosVector.x + PosVector.y * PosVector.y + PosVector.z * PosVector.z);
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auto normalized = PosVector / lengthVector;
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// Actual Calculation
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// Force of spring is -k * (l - L) * normalizedVector [for P2 we can take -F1)
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auto force = -m_fStiffness * (lengthVector - springs.at(0).initialLength) * normalized;
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auto foreP2 = -1 * force;
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auto veloc = calculateVelocityTimestepEuler(mp->velocity, timestep, calculateAcceleration(force, 10.));
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auto pos = calculatePositionTimestepEuler(mp->position, timestep, veloc);
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auto veloc2 = calculateVelocityTimestepEuler(mp2->velocity, timestep, calculateAcceleration(foreP2, 10.));
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auto pos2 = calculatePositionTimestepEuler(mp2->position, timestep, veloc2);
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// Update Positions and Velocity
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mp->position = pos;
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mp->velocity = veloc;
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mp2->position = pos2;
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mp2->velocity = veloc2;
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}
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