Rope.cpp

/***************************************************************************
 *   This file is part of OpenCAL: Open Computer Animation Library         *
 *   I created OpenCAL as my master's thesis Computer Science (multimedia) *
 *   at the tUL university in Diepenbeek, Belgium                          *
 *                                                                         *
 *   Copyright (C) 2003-2004 by Jeroen Dierckx                             *
 *   jeroen.dierckx@student.luc.ac.be                                      *
 *                                                                         *
 ***************************************************************************/

// Includes
#include "Rope.h"
#include <OpenCAL/PointMass.h>
#include <OpenCAL/Spring.h>
#include <OpenCAL/System.h>
#include <OpenCAL/Renderer.h>
using namespace OpenCAL;

#include <OpenCAL/Vector3.h>
#include <OpenCAL/Material.h>
using namespace Utils;

using namespace std;


/******************************
* Constructors and destructor *
******************************/

Rope::Rope(System *parent, const Vector3 &from, const Vector3 &to)
: MassSpringSystem(parent)
{
    constructRope(from, to);
}

Rope::~Rope()
{
}


/************************
* Get and set functions *
************************/


/******************
* Other functions *
******************/

void Rope::render()
{
    if(m_parent->numObjects() == 0) return;

    Renderer *renderer = m_parent->getRenderer();
    if(!renderer) return;

    for(unsigned int i = 1; i < m_parent->numObjects(); ++i)
        renderer->renderLine(getPoint(i - 1)->getPosition(), getPoint(i)->getPosition());
}

/*
#ifdef USE_OPENGL
void Rope::drawGL()
{
    MassSpringSystem::drawGL();

    return; // TEMP

    //if(!m_draw) return;

    Utils::Material mat;
    mat.setAmbient(Color::red);
    mat.setAmbient(Color::red);
    mat.applyGL();

    // Draw the rope
    glBegin(GL_LINE_STRIP);
        for(unsigned int i = 0; i < m_parent->numObjects(); ++i)
            glVertex3fv(getPoint(i)->getPosition());
    glEnd();
}
#endif // USE_OPENGL
*/


/**********************
* Protected functions *
**********************/

void Rope::constructRope(const Vector3 &from, const Vector3 &to)
{
    // For now, we use the same parameters as in the nehe.gamedev.net rope tutorial
    const int precision = 20; // Particles per unit length
    const float stiffness = 100.0f;
    const float damping = 0.2f;
    const float mass = 1.0f; // Mass per unit length

    float distance = from.distance(to);
    int particles = (int) (distance * precision);
    float massEach = distance * mass / (float) particles;

    PointMass *prevMass = new PointMass(this, massEach);
    //prevMass->disableDraw();
    prevMass->setPosition(from);
    //prevMass->setInfiniteMass();

    for(int i = 1; i < particles; ++i)
    {
        PointMass *mass = new PointMass(this, massEach);
        //mass->disableDraw();
        mass->setPosition(from.blended((float) (i + 1) / (float) particles, to));
        //if(i == (particles - 1))
        //  mass->setInfiniteMass();

        Spring *spring = new Spring(this, prevMass, mass);
        spring->setStiffness(stiffness);
        spring->setDamping(damping);
        spring->setDraw(true);

        prevMass = mass;
    }
}

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