/*
 * Copyright (C) 2017 Open Source Robotics Foundation
 *
 * 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.
 *
*/

syntax = "proto3";
package gz.msgs;
option java_package = "com.gz.msgs";
option java_outer_classname = "FrictionProtos";

/// \ingroup gz.msgs
/// \interface Friction
/// \brief Information about friction

import "gz/msgs/vector3d.proto";
import "gz/msgs/header.proto";

message Friction
{
  message Torsional
  {
    message ODE
    {
      /// \brief Force dependent slip for torsional friction, between the range
      /// of [0..1].
      double slip = 1;
    }

    /// \brief Torsional coefficient of friction in the range of [0..1].
    double coefficient = 1;

    /// \brief By default, torsional friction is calculated using the
    /// "patch_radius", which is sqrt(R*d), where "R" is the radius of the
    /// collision at the contact point (surface_radius) and "d" is the contact
    /// depth. If this flag is set to false, surface_radius and contact depth
    /// will be used instead of patch radius.
    bool use_patch_radius = 2;

    /// \brief Radius of contact patch surface, used for torsional friction.
    double patch_radius = 3;

    /// \brief Surface radius on the point of contact, used for torsional
    /// friction.
    double surface_radius = 4;

    /// \brief Torsional friction information exclusive to ODE physics engine.
    ODE ode = 5;
  }

  /// \brief Optional header data
  Header header = 1;

  /// \brief Coefficient of friction in the range of [0..1].
  double mu = 2;

  /// \brief Second coefficient of friction in the range of [0..1].
  double mu2 = 3;

  /// \brief Direction of mu1 in the collision local reference frame.
  Vector3d fdir1 = 4;

  /// \brief Force dependent slip direction 1 in collision local frame, between
  /// the range of [0..1].
  double slip1 = 5;

  /// \brief Force dependent slip direction 2 in collision local frame, between
  /// the range of [0..1].
  double slip2 = 6;

  /// \brief Torsional friction.
  Torsional torsional = 7;
}