Polygon3D.cpp

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//
//
// Polygon3d.cpp
//
 
#include <cmath>
 
#include "Polygon3D.hpp"
#include "Polygon2D.hpp"
#include <algorithm> // for std::sort()
#include <iterator>
#include <sstream>
 
 
// ////////////////////////////////////////////////////////////
namespace datatypes
{
 
Polygon3D::Polygon3D()
{
}
 
Polygon3D::Polygon3D(const Point3D& p1)
{
        push_back(p1);          // Insert the element at the end of the list
}
 
Polygon3D::Polygon3D(const Point3D& p1, const Point3D& p2)
{
        push_back(p1);          // Insert the element at the end of the list
        push_back(p2);          // Insert the element at the end of the list
}
Polygon3D::Polygon3D(const Point3D& p1, const Point3D& p2, const Point3D& p3)
{
        push_back(p1);          // Insert the element at the end of the list
        push_back(p2);          // Insert the element at the end of the list
        push_back(p3);          // Insert the element at the end of the list
}
 
//
// Initialize this polygon with an existing one
//
Polygon3D::Polygon3D(const base_class& other_vector)
        : base_class(other_vector)
{
}
 
/*
void Polygon3D::fromString(const std::string& polyString)
{
        clear();
 
        typedef boost::tokenizer<boost::char_separator<char> > tokenizer;
        tokenizer listOfTokens(polyString, boost::char_separator<char>(Polygon2D::getSeparatorCharacters()));
        for (tokenizer::const_iterator iter = listOfTokens.begin();
                 iter != listOfTokens.end(); ++iter)
        {
                float x = boost::lexical_cast<float>(*iter);
                ++iter;
                if (iter == listOfTokens.end())
                        throw std::runtime_error("When parsing a Polygon3D string, the last point only has a x component.");
                float y = boost::lexical_cast<float>(*iter);
                ++iter;
                if (iter == listOfTokens.end())
                        throw std::runtime_error("When parsing a Polygon3D string, the last point only has a x and y component.");
                float z = boost::lexical_cast<float>(*iter);
                this->push_back(Point3D(x, y, z));
        }
}
*/
 
 
std::string Polygon3D::toString() const
{
        std::ostringstream o;
        o << *this;
        return o.str();
}
 
static bool comparePointAngleXYPlane(const Point3D& p1, const Point3D& p2)
{
        return (p1.getAngleAroundZ() < p2.getAngleAroundZ());
}
 
void Polygon3D::sortForAngleXYPlane()
{
        std::sort(begin(), end(), comparePointAngleXYPlane);
}
 
 
 
std::ostream& operator<<(std::ostream& os, const Polygon3D& poly)
{
        os << "[ ";
        if (!poly.empty())
        {
                // Polygon contains at least one element
                std::copy (poly.begin(), poly.end() - 1,
                                   std::ostream_iterator<Point3D>(os, ", "));
                os << poly.back();      // Last element of the polygon
        }
        os << " ]";
        return os;
}
 
// Important: this code exists in a very similar for in the Polygon2D class.
// Bugfixes should be applied there also.
Polygon3D Polygon3D::getMovedPath(double dist) const
{
        Polygon3D moved;
 
        // We need 2 points minimum to have a valid path
        if (size() < 2)
        {
                if (size() > 0)
                {
                        // only 1 point, move only y-direction.
                        moved.push_back(at(0) + Point3D(0.0, dist, 0.0));
                }
                return moved; // finished.
        }
 
        // Here we have at least 2 points.
 
        // We need 2 segments to calculate the shift direction.
        // Start with 90 deg angle.
        double lastAng, ang; // Angles of the path segments.
        Point3D lastPos = at(0);
 
        // The first segment is also handles in the loop. The needed but not existing preceeding segment
        // is assumed to have the same direction.
        lastAng = (at(1) - lastPos).getAngleAroundZ();
        double edgeDist; // path width in a corner, is >= dist (path width)
        Point3D shiftVec; // Vector from source edge to new edge.
        Point3D pt;
        size_t i;
        for (i = 1; i < size(); i++)
        {
                pt = at(i);
                ang = (pt - lastPos).getAngleAroundZ();
                double diffAng = normalizeRadians(lastAng - ang);
                double halfAngBetween = diffAng / 2.0;
 
                // Calculation of the length from edge to new edge
                // The direction to the new path point (new edge)  has the direction of the half angle between both segments.
                double cosHalfAngBetween = std::abs(cos(halfAngBetween));
 
                // Do not calculate moved point if path angle to small
                // This usually happens, if we have a zick-zack situation.
                if ((cosHalfAngBetween) > 0.195)  //  0.195 = cos( 1/2 * PI  +- 1/16 * PI)
                {
                        edgeDist = dist / cosHalfAngBetween;
                        shiftVec = Point3D(0.0, edgeDist, 0.0);
                        shiftVec.rotateAroundZ(lastAng - halfAngBetween);
                        Point3D np = lastPos + shiftVec;
 
                        moved.push_back(np);
                }
 
                lastAng = ang;
                lastPos = pt;
        }
        // Add last point
        moved.push_back(lastPos + shiftVec);
 
        return moved;
}
 
}       // namespace datatypes