Vamos Automotive Simulator git

//  Copyright (C) 2001-2019 Sam Varner
//
//  This file is part of Vamos Automotive Simulator.
//
//  Vamos is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  Vamos is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with Vamos.  If not, see <http://www.gnu.org/licenses/>.

#include "Material.hpp"
#include "Constants.hpp"

using namespace Vamos_Geometry;

Material::Material(Material_Type type, double friction, double restitution, double rolling,
                   double drag, const Two_Vector &bump_amplitude, double bump_wavelength,
                   std::string texture_file_name, bool smooth, bool mip_map, double width,
                   double height)
    : m_type(type),
      m_friction_factor(friction),
      m_restitution_factor(restitution),
      m_rolling_resistance_factor(rolling),
      m_drag_factor(drag),
      m_bump_amplitude(bump_amplitude),
      m_bump_wavelength(bump_wavelength),
      m_texture_file_name(texture_file_name),
      m_smooth(smooth),
      m_mip_map(mip_map),
      m_width(width),
      m_height(height)
{
}

Material::Material(Material_Type type, double friction, double restitution)
    : Material(type, friction, restitution, 0.0, 0.0, Two_Vector(),
               1.0, "", false, false, 1.0, 1.0)
{
}

inline double bump_function(double x, double y)
{
    double phase = two_pi * (x + y);
    return 0.25 * (sin(phase) + sin(root_2 * phase));
}

Three_Vector Material::bump(double x, double y) const
{
    if (m_bump_wavelength == 0.0)
        return Three_Vector();

    // To avoid interfering with the initial placement of the car, don't return a positive
    // number.
    double bump = bump_function(x / m_bump_wavelength, y / m_bump_wavelength);
    double side = m_bump_amplitude.y * bump;
    double up = m_bump_amplitude.x * (bump - 0.5);
    return Three_Vector(side, side, up);
}