--- /dev/null
+/*********************************************************************
+*
+* Software License Agreement (BSD License)
+*
+* Copyright (c) 2016, Guan-Horng Liu.
+* All rights reserved.
+*
+* Redistribution and use in source and binary forms, with or without
+* modification, are permitted provided that the following conditions
+* are met:
+*
+* * Redistributions of source code must retain the above copyright
+* notice, this list of conditions and the following disclaimer.
+* * Redistributions in binary form must reproduce the above
+* copyright notice, this list of conditions and the following
+* disclaimer in the documentation and/or other materials provided
+* with the distribution.
+* * Neither the name of the the copyright holder nor the names of its
+* contributors may be used to endorse or promote products derived
+* from this software without specific prior written permission.
+*
+* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+* POSSIBILITY OF SUCH DAMAGE.
+*
+* Author: Guan-Horng Liu
+*********************************************************************/
+
+
+#include "reeds_shepp.h"
+#include <boost/math/constants/constants.hpp>
+
+
+namespace
+{
+ // The comments, variable names, etc. use the nomenclature from the Reeds & Shepp paper.
+
+ const double pi = boost::math::constants::pi<double>();
+ const double twopi = 2. * pi;
+ const double RS_EPS = 1e-6;
+ const double ZERO = 10*std::numeric_limits<double>::epsilon();
+
+ inline double mod2pi(double x)
+ {
+ double v = fmod(x, twopi);
+ if (v < -pi)
+ v += twopi;
+ else
+ if (v > pi)
+ v -= twopi;
+ return v;
+ }
+ inline void polar(double x, double y, double &r, double &theta)
+ {
+ r = sqrt(x*x + y*y);
+ theta = atan2(y, x);
+ }
+ inline void tauOmega(double u, double v, double xi, double eta, double phi, double &tau, double &omega)
+ {
+ double delta = mod2pi(u-v), A = sin(u) - sin(delta), B = cos(u) - cos(delta) - 1.;
+ double t1 = atan2(eta*A - xi*B, xi*A + eta*B), t2 = 2. * (cos(delta) - cos(v) - cos(u)) + 3;
+ tau = (t2<0) ? mod2pi(t1+pi) : mod2pi(t1);
+ omega = mod2pi(tau - u + v - phi) ;
+ }
+
+ // formula 8.1 in Reeds-Shepp paper
+ inline bool LpSpLp(double x, double y, double phi, double &t, double &u, double &v)
+ {
+ polar(x - sin(phi), y - 1. + cos(phi), u, t);
+ if (t >= -ZERO)
+ {
+ v = mod2pi(phi - t);
+ if (v >= -ZERO)
+ {
+ assert(fabs(u*cos(t) + sin(phi) - x) < RS_EPS);
+ assert(fabs(u*sin(t) - cos(phi) + 1 - y) < RS_EPS);
+ assert(fabs(mod2pi(t+v - phi)) < RS_EPS);
+ return true;
+ }
+ }
+ return false;
+ }
+ // formula 8.2
+ inline bool LpSpRp(double x, double y, double phi, double &t, double &u, double &v)
+ {
+ double t1, u1;
+ polar(x + sin(phi), y - 1. - cos(phi), u1, t1);
+ u1 = u1*u1;
+ if (u1 >= 4.)
+ {
+ double theta;
+ u = sqrt(u1 - 4.);
+ theta = atan2(2., u);
+ t = mod2pi(t1 + theta);
+ v = mod2pi(t - phi);
+ assert(fabs(2*sin(t) + u*cos(t) - sin(phi) - x) < RS_EPS);
+ assert(fabs(-2*cos(t) + u*sin(t) + cos(phi) + 1 - y) < RS_EPS);
+ assert(fabs(mod2pi(t-v - phi)) < RS_EPS);
+ return t>=-ZERO && v>=-ZERO;
+ }
+ return false;
+ }
+ void CSC(double x, double y, double phi, ReedsSheppStateSpace::ReedsSheppPath &path)
+ {
+ double t, u, v, Lmin = path.length(), L;
+ if (LpSpLp(x, y, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v)))
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[14], t, u, v);
+ Lmin = L;
+ }
+ if (LpSpLp(-x, y, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[14], -t, -u, -v);
+ Lmin = L;
+ }
+ if (LpSpLp(x, -y, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // reflect
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[15], t, u, v);
+ Lmin = L;
+ }
+ if (LpSpLp(-x, -y, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip + reflect
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[15], -t, -u, -v);
+ Lmin = L;
+ }
+ if (LpSpRp(x, y, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v)))
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[12], t, u, v);
+ Lmin = L;
+ }
+ if (LpSpRp(-x, y, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[12], -t, -u, -v);
+ Lmin = L;
+ }
+ if (LpSpRp(x, -y, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // reflect
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[13], t, u, v);
+ Lmin = L;
+ }
+ if (LpSpRp(-x, -y, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip + reflect
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[13], -t, -u, -v);
+ }
+ // formula 8.3 / 8.4 *** TYPO IN PAPER ***
+ inline bool LpRmL(double x, double y, double phi, double &t, double &u, double &v)
+ {
+ double xi = x - sin(phi), eta = y - 1. + cos(phi), u1, theta;
+ polar(xi, eta, u1, theta);
+ if (u1 <= 4.)
+ {
+ u = -2.*asin(.25 * u1);
+ t = mod2pi(theta + .5 * u + pi);
+ v = mod2pi(phi - t + u);
+ assert(fabs(2*(sin(t) - sin(t-u)) + sin(phi) - x) < RS_EPS);
+ assert(fabs(2*(-cos(t) + cos(t-u)) - cos(phi) + 1 - y) < RS_EPS);
+ assert(fabs(mod2pi(t-u+v - phi)) < RS_EPS);
+ return t>=-ZERO && u<=ZERO;
+ }
+ return false;
+ }
+ void CCC(double x, double y, double phi, ReedsSheppStateSpace::ReedsSheppPath &path)
+ {
+ double t, u, v, Lmin = path.length(), L;
+ if (LpRmL(x, y, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v)))
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[0], t, u, v);
+ Lmin = L;
+ }
+ if (LpRmL(-x, y, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[0], -t, -u, -v);
+ Lmin = L;
+ }
+ if (LpRmL(x, -y, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // reflect
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[1], t, u, v);
+ Lmin = L;
+ }
+ if (LpRmL(-x, -y, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip + reflect
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[1], -t, -u, -v);
+ Lmin = L;
+ }
+
+ // backwards
+ double xb = x*cos(phi) + y*sin(phi), yb = x*sin(phi) - y*cos(phi);
+ if (LpRmL(xb, yb, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v)))
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[0], v, u, t);
+ Lmin = L;
+ }
+ if (LpRmL(-xb, yb, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[0], -v, -u, -t);
+ Lmin = L;
+ }
+ if (LpRmL(xb, -yb, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // reflect
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[1], v, u, t);
+ Lmin = L;
+ }
+ if (LpRmL(-xb, -yb, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip + reflect
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[1], -v, -u, -t);
+ }
+ // formula 8.7
+ inline bool LpRupLumRm(double x, double y, double phi, double &t, double &u, double &v)
+ {
+ double xi = x + sin(phi), eta = y - 1. - cos(phi), rho = .25 * (2. + sqrt(xi*xi + eta*eta));
+ if (rho <= 1.)
+ {
+ u = acos(rho);
+ tauOmega(u, -u, xi, eta, phi, t, v);
+ assert(fabs(2*(sin(t)-sin(t-u)+sin(t-2*u))-sin(phi) - x) < RS_EPS);
+ assert(fabs(2*(-cos(t)+cos(t-u)-cos(t-2*u))+cos(phi)+1 - y) < RS_EPS);
+ assert(fabs(mod2pi(t-2*u-v - phi)) < RS_EPS);
+ return t>=-ZERO && v<=ZERO;
+ }
+ return false;
+ }
+ // formula 8.8
+ inline bool LpRumLumRp(double x, double y, double phi, double &t, double &u, double &v)
+ {
+ double xi = x + sin(phi), eta = y - 1. - cos(phi), rho = (20. - xi*xi - eta*eta) / 16.;
+ if (rho>=0 && rho<=1)
+ {
+ u = -acos(rho);
+ if (u >= -.5 * pi)
+ {
+ tauOmega(u, u, xi, eta, phi, t, v);
+ assert(fabs(4*sin(t)-2*sin(t-u)-sin(phi) - x) < RS_EPS);
+ assert(fabs(-4*cos(t)+2*cos(t-u)+cos(phi)+1 - y) < RS_EPS);
+ assert(fabs(mod2pi(t-v - phi)) < RS_EPS);
+ return t>=-ZERO && v>=-ZERO;
+ }
+ }
+ return false;
+ }
+ void CCCC(double x, double y, double phi, ReedsSheppStateSpace::ReedsSheppPath &path)
+ {
+ double t, u, v, Lmin = path.length(), L;
+ if (LpRupLumRm(x, y, phi, t, u, v) && Lmin > (L = fabs(t) + 2.*fabs(u) + fabs(v)))
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[2], t, u, -u, v);
+ Lmin = L;
+ }
+ if (LpRupLumRm(-x, y, -phi, t, u, v) && Lmin > (L = fabs(t) + 2.*fabs(u) + fabs(v))) // timeflip
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[2], -t, -u, u, -v);
+ Lmin = L;
+ }
+ if (LpRupLumRm(x, -y, -phi, t, u, v) && Lmin > (L = fabs(t) + 2.*fabs(u) + fabs(v))) // reflect
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[3], t, u, -u, v);
+ Lmin = L;
+ }
+ if (LpRupLumRm(-x, -y, phi, t, u, v) && Lmin > (L = fabs(t) + 2.*fabs(u) + fabs(v))) // timeflip + reflect
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[3], -t, -u, u, -v);
+ Lmin = L;
+ }
+
+ if (LpRumLumRp(x, y, phi, t, u, v) && Lmin > (L = fabs(t) + 2.*fabs(u) + fabs(v)))
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[2], t, u, u, v);
+ Lmin = L;
+ }
+ if (LpRumLumRp(-x, y, -phi, t, u, v) && Lmin > (L = fabs(t) + 2.*fabs(u) + fabs(v))) // timeflip
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[2], -t, -u, -u, -v);
+ Lmin = L;
+ }
+ if (LpRumLumRp(x, -y, -phi, t, u, v) && Lmin > (L = fabs(t) + 2.*fabs(u) + fabs(v))) // reflect
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[3], t, u, u, v);
+ Lmin = L;
+ }
+ if (LpRumLumRp(-x, -y, phi, t, u, v) && Lmin > (L = fabs(t) + 2.*fabs(u) + fabs(v))) // timeflip + reflect
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[3], -t, -u, -u, -v);
+ }
+ // formula 8.9
+ inline bool LpRmSmLm(double x, double y, double phi, double &t, double &u, double &v)
+ {
+ double xi = x - sin(phi), eta = y - 1. + cos(phi), rho, theta;
+ polar(xi, eta, rho, theta);
+ if (rho >= 2.)
+ {
+ double r = sqrt(rho*rho - 4.);
+ u = 2. - r;
+ t = mod2pi(theta + atan2(r, -2.));
+ v = mod2pi(phi - .5*pi - t);
+ assert(fabs(2*(sin(t)-cos(t))-u*sin(t)+sin(phi) - x) < RS_EPS);
+ assert(fabs(-2*(sin(t)+cos(t))+u*cos(t)-cos(phi)+1 - y) < RS_EPS);
+ assert(fabs(mod2pi(t+pi/2+v-phi)) < RS_EPS);
+ return t>=-ZERO && u<=ZERO && v<=ZERO;
+ }
+ return false;
+ }
+ // formula 8.10
+ inline bool LpRmSmRm(double x, double y, double phi, double &t, double &u, double &v)
+ {
+ double xi = x + sin(phi), eta = y - 1. - cos(phi), rho, theta;
+ polar(-eta, xi, rho, theta);
+ if (rho >= 2.)
+ {
+ t = theta;
+ u = 2. - rho;
+ v = mod2pi(t + .5*pi - phi);
+ assert(fabs(2*sin(t)-cos(t-v)-u*sin(t) - x) < RS_EPS);
+ assert(fabs(-2*cos(t)-sin(t-v)+u*cos(t)+1 - y) < RS_EPS);
+ assert(fabs(mod2pi(t+pi/2-v-phi)) < RS_EPS);
+ return t>=-ZERO && u<=ZERO && v<=ZERO;
+ }
+ return false;
+ }
+ void CCSC(double x, double y, double phi, ReedsSheppStateSpace::ReedsSheppPath &path)
+ {
+ double t, u, v, Lmin = path.length() - .5*pi, L;
+ if (LpRmSmLm(x, y, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v)))
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[4], t, -.5*pi, u, v);
+ Lmin = L;
+ }
+ if (LpRmSmLm(-x, y, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[4], -t, .5*pi, -u, -v);
+ Lmin = L;
+ }
+ if (LpRmSmLm(x, -y, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // reflect
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[5], t, -.5*pi, u, v);
+ Lmin = L;
+ }
+ if (LpRmSmLm(-x, -y, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip + reflect
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[5], -t, .5*pi, -u, -v);
+ Lmin = L;
+ }
+
+ if (LpRmSmRm(x, y, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v)))
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[8], t, -.5*pi, u, v);
+ Lmin = L;
+ }
+ if (LpRmSmRm(-x, y, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[8], -t, .5*pi, -u, -v);
+ Lmin = L;
+ }
+ if (LpRmSmRm(x, -y, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // reflect
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[9], t, -.5*pi, u, v);
+ Lmin = L;
+ }
+ if (LpRmSmRm(-x, -y, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip + reflect
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[9], -t, .5*pi, -u, -v);
+ Lmin = L;
+ }
+
+ // backwards
+ double xb = x*cos(phi) + y*sin(phi), yb = x*sin(phi) - y*cos(phi);
+ if (LpRmSmLm(xb, yb, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v)))
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[6], v, u, -.5*pi, t);
+ Lmin = L;
+ }
+ if (LpRmSmLm(-xb, yb, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[6], -v, -u, .5*pi, -t);
+ Lmin = L;
+ }
+ if (LpRmSmLm(xb, -yb, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // reflect
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[7], v, u, -.5*pi, t);
+ Lmin = L;
+ }
+ if (LpRmSmLm(-xb, -yb, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip + reflect
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[7], -v, -u, .5*pi, -t);
+ Lmin = L;
+ }
+
+ if (LpRmSmRm(xb, yb, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v)))
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[10], v, u, -.5*pi, t);
+ Lmin = L;
+ }
+ if (LpRmSmRm(-xb, yb, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[10], -v, -u, .5*pi, -t);
+ Lmin = L;
+ }
+ if (LpRmSmRm(xb, -yb, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // reflect
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[11], v, u, -.5*pi, t);
+ Lmin = L;
+ }
+ if (LpRmSmRm(-xb, -yb, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip + reflect
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[11], -v, -u, .5*pi, -t);
+ }
+ // formula 8.11 *** TYPO IN PAPER ***
+ inline bool LpRmSLmRp(double x, double y, double phi, double &t, double &u, double &v)
+ {
+ double xi = x + sin(phi), eta = y - 1. - cos(phi), rho, theta;
+ polar(xi, eta, rho, theta);
+ if (rho >= 2.)
+ {
+ u = 4. - sqrt(rho*rho - 4.);
+ if (u <= ZERO)
+ {
+ t = mod2pi(atan2((4-u)*xi -2*eta, -2*xi + (u-4)*eta));
+ v = mod2pi(t - phi);
+ assert(fabs(4*sin(t)-2*cos(t)-u*sin(t)-sin(phi) - x) < RS_EPS);
+ assert(fabs(-4*cos(t)-2*sin(t)+u*cos(t)+cos(phi)+1 - y) < RS_EPS);
+ assert(fabs(mod2pi(t-v-phi)) < RS_EPS);
+ return t>=-ZERO && v>=-ZERO;
+ }
+ }
+ return false;
+ }
+ void CCSCC(double x, double y, double phi, ReedsSheppStateSpace::ReedsSheppPath &path)
+ {
+ double t, u, v, Lmin = path.length() - pi, L;
+ if (LpRmSLmRp(x, y, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v)))
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[16], t, -.5*pi, u, -.5*pi, v);
+ Lmin = L;
+ }
+ if (LpRmSLmRp(-x, y, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[16], -t, .5*pi, -u, .5*pi, -v);
+ Lmin = L;
+ }
+ if (LpRmSLmRp(x, -y, -phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // reflect
+ {
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[17], t, -.5*pi, u, -.5*pi, v);
+ Lmin = L;
+ }
+ if (LpRmSLmRp(-x, -y, phi, t, u, v) && Lmin > (L = fabs(t) + fabs(u) + fabs(v))) // timeflip + reflect
+ path = ReedsSheppStateSpace::ReedsSheppPath(
+ ReedsSheppStateSpace::reedsSheppPathType[17], -t, .5*pi, -u, .5*pi, -v);
+ }
+
+ ReedsSheppStateSpace::ReedsSheppPath reedsShepp(double x, double y, double phi)
+ {
+ ReedsSheppStateSpace::ReedsSheppPath path;
+ CSC(x, y, phi, path);
+ CCC(x, y, phi, path);
+ CCCC(x, y, phi, path);
+ CCSC(x, y, phi, path);
+ CCSCC(x, y, phi, path);
+ return path;
+ }
+}
+
+const ReedsSheppStateSpace::ReedsSheppPathSegmentType
+ReedsSheppStateSpace::reedsSheppPathType[18][5] = {
+ { RS_LEFT, RS_RIGHT, RS_LEFT, RS_NOP, RS_NOP }, // 0
+ { RS_RIGHT, RS_LEFT, RS_RIGHT, RS_NOP, RS_NOP }, // 1
+ { RS_LEFT, RS_RIGHT, RS_LEFT, RS_RIGHT, RS_NOP }, // 2
+ { RS_RIGHT, RS_LEFT, RS_RIGHT, RS_LEFT, RS_NOP }, // 3
+ { RS_LEFT, RS_RIGHT, RS_STRAIGHT, RS_LEFT, RS_NOP }, // 4
+ { RS_RIGHT, RS_LEFT, RS_STRAIGHT, RS_RIGHT, RS_NOP }, // 5
+ { RS_LEFT, RS_STRAIGHT, RS_RIGHT, RS_LEFT, RS_NOP }, // 6
+ { RS_RIGHT, RS_STRAIGHT, RS_LEFT, RS_RIGHT, RS_NOP }, // 7
+ { RS_LEFT, RS_RIGHT, RS_STRAIGHT, RS_RIGHT, RS_NOP }, // 8
+ { RS_RIGHT, RS_LEFT, RS_STRAIGHT, RS_LEFT, RS_NOP }, // 9
+ { RS_RIGHT, RS_STRAIGHT, RS_RIGHT, RS_LEFT, RS_NOP }, // 10
+ { RS_LEFT, RS_STRAIGHT, RS_LEFT, RS_RIGHT, RS_NOP }, // 11
+ { RS_LEFT, RS_STRAIGHT, RS_RIGHT, RS_NOP, RS_NOP }, // 12
+ { RS_RIGHT, RS_STRAIGHT, RS_LEFT, RS_NOP, RS_NOP }, // 13
+ { RS_LEFT, RS_STRAIGHT, RS_LEFT, RS_NOP, RS_NOP }, // 14
+ { RS_RIGHT, RS_STRAIGHT, RS_RIGHT, RS_NOP, RS_NOP }, // 15
+ { RS_LEFT, RS_RIGHT, RS_STRAIGHT, RS_LEFT, RS_RIGHT }, // 16
+ { RS_RIGHT, RS_LEFT, RS_STRAIGHT, RS_RIGHT, RS_LEFT } // 17
+};
+
+ReedsSheppStateSpace::ReedsSheppPath::ReedsSheppPath(const ReedsSheppPathSegmentType* type,
+ double t, double u, double v, double w, double x)
+ : type_(type)
+{
+ length_[0] = t; length_[1] = u; length_[2] = v; length_[3] = w; length_[4] = x;
+ totalLength_ = fabs(t) + fabs(u) + fabs(v) + fabs(w) + fabs(x);
+}
+
+
+double ReedsSheppStateSpace::distance(double q0[3], double q1[3])
+{
+ return rho_ * reedsShepp(q0, q1).length();
+}
+
+ReedsSheppStateSpace::ReedsSheppPath ReedsSheppStateSpace::reedsShepp(double q0[3], double q1[3])
+{
+ double dx = q1[0] - q0[0], dy = q1[1] - q0[1], dth = q1[2] - q0[2];
+ double c = cos(q0[2]), s = sin(q0[2]);
+ double x = c*dx + s*dy, y = -s*dx + c*dy;
+ return ::reedsShepp(x/rho_, y/rho_, dth);
+}
+
+void ReedsSheppStateSpace::type(double q0[3], double q1[3], ReedsSheppPathTypeCallback cb, void* user_data)
+{
+ ReedsSheppPath path = reedsShepp(q0, q1);
+ for (int i=0;i<5;++i)
+ cb(path.type_[i], user_data);
+ return;
+}
+
+void ReedsSheppStateSpace::sample(double q0[3], double q1[3], double step_size, ReedsSheppPathSamplingCallback cb, void* user_data)
+{
+ ReedsSheppPath path = reedsShepp(q0, q1);
+ double dist = rho_ * path.length(); // TODO shorten path here
+
+ for (double seg=0.0; seg<=dist; seg+=step_size){
+ double qnew[3] = {};
+ interpolate(q0, path, seg/rho_, qnew);
+ cb( qnew, user_data);
+ }
+ return;
+}
+
+void ReedsSheppStateSpace::interpolate(double q0[3], ReedsSheppPath &path, double seg, double s[3])
+{
+
+ if (seg < 0.0) seg = 0.0;
+ if (seg > path.length()) seg = path.length();
+
+ double phi, v;
+
+ s[0] = s[1] = 0.0;
+ s[2] = q0[2];
+
+ for (unsigned int i=0; i<5 && seg>0; ++i)
+ {
+ if (path.length_[i]<0)
+ {
+ v = std::max(-seg, path.length_[i]);
+ seg += v;
+ }
+ else
+ {
+ v = std::min(seg, path.length_[i]);
+ seg -= v;
+ }
+ phi = s[2];
+ switch(path.type_[i])
+ {
+ case RS_LEFT:
+ s[0] += ( sin(phi+v) - sin(phi));
+ s[1] += (-cos(phi+v) + cos(phi));
+ s[2] = phi + v;
+ break;
+ case RS_RIGHT:
+ s[0] += (-sin(phi-v) + sin(phi));
+ s[1] += ( cos(phi-v) - cos(phi));
+ s[2] = phi - v;
+ break;
+ case RS_STRAIGHT:
+ s[0] += (v * cos(phi));
+ s[1] += (v * sin(phi));
+ break;
+ case RS_NOP:
+ break;
+ }
+ }
+
+ s[0] = s[0] * rho_ + q0[0];
+ s[1] = s[1] * rho_ + q0[1];
+}