LineSegment.cc

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/******************************************************************************
 * Project:  libspatialindex - A C++ library for spatial indexing
 * Author:   Marios Hadjieleftheriou, mhadji@gmail.com
 ******************************************************************************
 * Copyright (c) 2004, Marios Hadjieleftheriou
 *
 * All rights reserved.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
******************************************************************************/
 
#include <cstring>
#include <cmath>
#include <limits>
 
#include <spatialindex/SpatialIndex.h>
 
using namespace SpatialIndex;
 
LineSegment::LineSegment()
= default;
 
LineSegment::LineSegment(const double* pStartPoint, const double* pEndPoint, uint32_t dimension)
    : m_dimension(dimension)
{
    // no need to initialize arrays to 0 since if a bad_alloc is raised the destructor will not be called.
 
    m_pStartPoint = new double[m_dimension];
    m_pEndPoint = new double[m_dimension];
    memcpy(m_pStartPoint, pStartPoint, m_dimension * sizeof(double));
    memcpy(m_pEndPoint, pEndPoint, m_dimension * sizeof(double));
}
 
LineSegment::LineSegment(const Point& startPoint, const Point& endPoint)
    : m_dimension(startPoint.m_dimension)
{
    if (startPoint.m_dimension != endPoint.m_dimension)
        throw Tools::IllegalArgumentException(
            "LineSegment::LineSegment: Points have different dimensionalities."
        );
 
    // no need to initialize arrays to 0 since if a bad_alloc is raised the destructor will not be called.
 
    m_pStartPoint = new double[m_dimension];
    m_pEndPoint = new double[m_dimension];
    memcpy(m_pStartPoint, startPoint.m_pCoords, m_dimension * sizeof(double));
    memcpy(m_pEndPoint, endPoint.m_pCoords, m_dimension * sizeof(double));
}
 
LineSegment::LineSegment(const LineSegment& l)
    : m_dimension(l.m_dimension)
{
    // no need to initialize arrays to 0 since if a bad_alloc is raised the destructor will not be called.
 
    m_pStartPoint = new double[m_dimension];
    m_pEndPoint = new double[m_dimension];
    memcpy(m_pStartPoint, l.m_pStartPoint, m_dimension * sizeof(double));
    memcpy(m_pEndPoint, l.m_pEndPoint, m_dimension * sizeof(double));
}
 
LineSegment::~LineSegment()
{
    delete[] m_pStartPoint;
    delete[] m_pEndPoint;
}
 
LineSegment& LineSegment::operator=(const LineSegment& l)
{
    if (this != &l)
    {
        makeDimension(l.m_dimension);
        memcpy(m_pStartPoint, l.m_pStartPoint, m_dimension * sizeof(double));
        memcpy(m_pEndPoint, l.m_pEndPoint, m_dimension * sizeof(double));
    }
 
    return *this;
}
 
bool LineSegment::operator==(const LineSegment& l) const
{
    if (m_dimension != l.m_dimension)
        throw Tools::IllegalArgumentException(
            "LineSegment::operator==: LineSegments have different number of dimensions."
        );
 
    for (uint32_t i = 0; i < m_dimension; ++i)
    {
        if (
            m_pStartPoint[i] < l.m_pStartPoint[i] - std::numeric_limits<double>::epsilon() ||
            m_pStartPoint[i] > l.m_pStartPoint[i] + std::numeric_limits<double>::epsilon())  return false;
 
        if (
            m_pEndPoint[i] < l.m_pEndPoint[i] - std::numeric_limits<double>::epsilon() ||
            m_pEndPoint[i] > l.m_pEndPoint[i] + std::numeric_limits<double>::epsilon())  return false;
    }
 
    return true;
}
 
//
// IObject interface
//
LineSegment* LineSegment::clone()
{
    return new LineSegment(*this);
}
 
//
// ISerializable interface
//
uint32_t LineSegment::getByteArraySize()
{
    return (sizeof(uint32_t) + m_dimension * sizeof(double) * 2);
}
 
void LineSegment::loadFromByteArray(const uint8_t* ptr)
{
    uint32_t dimension;
    memcpy(&dimension, ptr, sizeof(uint32_t));
    ptr += sizeof(uint32_t);
 
    makeDimension(dimension);
    memcpy(m_pStartPoint, ptr, m_dimension * sizeof(double));
    ptr += m_dimension * sizeof(double);
    memcpy(m_pEndPoint, ptr, m_dimension * sizeof(double));
    //ptr += m_dimension * sizeof(double);
}
 
void LineSegment::storeToByteArray(uint8_t** data, uint32_t& len)
{
    len = getByteArraySize();
    *data = new uint8_t[len];
    uint8_t* ptr = *data;
 
    memcpy(ptr, &m_dimension, sizeof(uint32_t));
    ptr += sizeof(uint32_t);
    memcpy(ptr, m_pStartPoint, m_dimension * sizeof(double));
    ptr += m_dimension * sizeof(double);
    memcpy(ptr, m_pEndPoint, m_dimension * sizeof(double));
    //ptr += m_dimension * sizeof(double);
}
 
//
// IShape interface
//
bool LineSegment::intersectsShape(const IShape& s) const
{
    const LineSegment* ps = dynamic_cast<const LineSegment*>(&s);
    if (ps != nullptr) return intersectsLineSegment(*ps);
 
    const Region* pr = dynamic_cast<const Region*>(&s);
    if (pr != nullptr) return intersectsRegion(*pr);
 
    throw Tools::IllegalStateException(
        "LineSegment::intersectsShape: Not implemented yet!"
    );
}
 
bool LineSegment::containsShape(const IShape&) const
{
    return false;
}
 
bool LineSegment::touchesShape(const IShape&) const
{
    throw Tools::IllegalStateException(
        "LineSegment::touchesShape: Not implemented yet!"
    );
}
 
void LineSegment::getCenter(Point& out) const
{
    double* coords = new double[m_dimension];
    for (uint32_t cDim = 0; cDim < m_dimension; ++cDim)
    {
        coords[cDim] =
            (std::abs(m_pStartPoint[cDim] - m_pEndPoint[cDim]) / 2.0) +
            std::min(m_pStartPoint[cDim], m_pEndPoint[cDim]);
    }
 
    out = Point(coords, m_dimension);
    delete[] coords;
}
 
uint32_t LineSegment::getDimension() const
{
    return m_dimension;
}
 
void LineSegment::getMBR(Region& out) const
{
    double* low = new double[m_dimension];
    double* high = new double[m_dimension];
    for (uint32_t cDim = 0; cDim < m_dimension; ++cDim)
    {
        low[cDim] = std::min(m_pStartPoint[cDim], m_pEndPoint[cDim]);
        high[cDim] = std::max(m_pStartPoint[cDim], m_pEndPoint[cDim]);
    }
 
    out = Region(low, high, m_dimension);
    delete[] low;
    delete[] high;
}
 
double LineSegment::getArea() const
{
    return 0.0;
}
 
double LineSegment::getMinimumDistance(const IShape& s) const
{
    const Point* ppt = dynamic_cast<const Point*>(&s);
    if (ppt != nullptr)
    {
        return getMinimumDistance(*ppt);
    }
 
/*
    const Region* pr = dynamic_cast<const Region*>(&s);
    if (pr != 0)
    {
        return pr->getMinimumDistance(*this);
    }
*/
 
    throw Tools::IllegalStateException(
        "LineSegment::getMinimumDistance: Not implemented yet!"
    );
}
 
double LineSegment::getMinimumDistance(const Point& p) const
{
    if (m_dimension == 1)
        throw Tools::NotSupportedException(
            "LineSegment::getMinimumDistance: Use an Interval instead."
        );
 
    if (m_dimension != 2)
        throw Tools::NotSupportedException(
            "LineSegment::getMinimumDistance: Distance for high dimensional spaces not supported!"
        );
 
    if (m_pEndPoint[0] >= m_pStartPoint[0] - std::numeric_limits<double>::epsilon() &&
        m_pEndPoint[0] <= m_pStartPoint[0] + std::numeric_limits<double>::epsilon()) return std::abs(p.m_pCoords[0] - m_pStartPoint[0]);
 
    if (m_pEndPoint[1] >= m_pStartPoint[1] - std::numeric_limits<double>::epsilon() &&
        m_pEndPoint[1] <= m_pStartPoint[1] + std::numeric_limits<double>::epsilon()) return std::abs(p.m_pCoords[1] - m_pStartPoint[1]);
 
    double x1 = m_pStartPoint[0];
    double x2 = m_pEndPoint[0];
    double x0 = p.m_pCoords[0];
    double y1 = m_pStartPoint[1];
    double y2 = m_pEndPoint[1];
    double y0 = p.m_pCoords[1];
 
    return std::abs((x2 - x1) * (y1 - y0) - (x1 - x0) * (y2 - y1)) / (std::sqrt((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1)));
}
 
bool LineSegment::intersectsRegion(const Region& r) const
{
    if (m_dimension != 2)
        throw Tools::NotSupportedException(
            "LineSegment::intersectsRegion: only supported for 2 dimensions"
        );
 
    if (m_dimension != r.m_dimension)
        throw Tools::IllegalArgumentException(
            "LineSegment::intersectsRegion: LineSegment and Region have different number of dimensions."
        );
 
    return r.intersectsLineSegment((*this));
}
 
bool LineSegment::intersectsLineSegment(const LineSegment& l) const
{
    if (m_dimension != 2)
        throw Tools::NotSupportedException(
            "LineSegment::intersectsLineSegment: only supported for 2 dimensions"
        );
 
    if (m_dimension != l.m_dimension)
        throw Tools::IllegalArgumentException(
            "LineSegment::intersectsLineSegment: LineSegments have different number of dimensions."
        );
 
    // use Geometry::intersects
    Point p1, p2, p3, p4;
    p1 = Point(m_pStartPoint, 2);
    p2 = Point(m_pEndPoint, 2);
    p3 = Point(l.m_pStartPoint, 2);
    p4 = Point(l.m_pEndPoint, 2);
    return intersects(p1, p2, p3, p4);
}
 
// assuming moving from start to end, positive distance is from right hand side.
double LineSegment::getRelativeMinimumDistance(const Point& p) const
{
    if (m_dimension == 1)
        throw Tools::NotSupportedException(
            "LineSegment::getRelativeMinimumDistance: Use an Interval instead."
        );
 
    if (m_dimension != 2)
        throw Tools::NotSupportedException(
            "LineSegment::getRelativeMinimumDistance: Distance for high dimensional spaces not supported!"
        );
 
    if (m_pEndPoint[0] >= m_pStartPoint[0] - std::numeric_limits<double>::epsilon() &&
        m_pEndPoint[0] <= m_pStartPoint[0] + std::numeric_limits<double>::epsilon())
    {
        if (m_pStartPoint[1] < m_pEndPoint[1]) return m_pStartPoint[0] - p.m_pCoords[0];
        if (m_pStartPoint[1] >= m_pEndPoint[1]) return p.m_pCoords[0] - m_pStartPoint[0];
    }
 
    if (m_pEndPoint[1] >= m_pStartPoint[1] - std::numeric_limits<double>::epsilon() &&
        m_pEndPoint[1] <= m_pStartPoint[1] + std::numeric_limits<double>::epsilon())
    {
        if (m_pStartPoint[0] < m_pEndPoint[0]) return p.m_pCoords[1] - m_pStartPoint[1];
        if (m_pStartPoint[0] >= m_pEndPoint[0]) return m_pStartPoint[1] - p.m_pCoords[1];
    }
 
    double x1 = m_pStartPoint[0];
    double x2 = m_pEndPoint[0];
    double x0 = p.m_pCoords[0];
    double y1 = m_pStartPoint[1];
    double y2 = m_pEndPoint[1];
    double y0 = p.m_pCoords[1];
 
    return ((x1 - x0) * (y2 - y1) - (x2 - x1) * (y1 - y0)) / (std::sqrt((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1)));
}
 
double LineSegment::getRelativeMaximumDistance(const Region& r) const
{
    if (m_dimension == 1)
        throw Tools::NotSupportedException(
            "LineSegment::getRelativeMaximumDistance: Use an Interval instead."
        );
 
    if (m_dimension != 2)
        throw Tools::NotSupportedException(
            "LineSegment::getRelativeMaximumDistance: Distance for high dimensional spaces not supported!"
        );
 
    // clockwise.
    double d1 = getRelativeMinimumDistance(Point(r.m_pLow, 2));
 
    double coords[2];
    coords[0] = r.m_pLow[0];
    coords[1] = r.m_pHigh[1];
    double d2 = getRelativeMinimumDistance(Point(coords, 2));
 
    double d3 = getRelativeMinimumDistance(Point(r.m_pHigh, 2));
 
    coords[0] = r.m_pHigh[0];
    coords[1] = r.m_pLow[1];
    double d4 = getRelativeMinimumDistance(Point(coords, 2));
 
    return std::max(d1, std::max(d2, std::max(d3, d4)));
}
 
double LineSegment::getAngleOfPerpendicularRay()
{
    if (m_dimension == 1)
        throw Tools::NotSupportedException(
            "LineSegment::getAngleOfPerpendicularRay: Use an Interval instead."
        );
 
    if (m_dimension != 2)
        throw Tools::NotSupportedException(
            "LineSegment::getAngleOfPerpendicularRay: Distance for high dimensional spaces not supported!"
        );
 
    if (m_pStartPoint[0] >= m_pEndPoint[0] - std::numeric_limits<double>::epsilon() &&
        m_pStartPoint[0] <= m_pEndPoint[0] + std::numeric_limits<double>::epsilon()) return 0.0;
 
    if (m_pStartPoint[1] >= m_pEndPoint[1] - std::numeric_limits<double>::epsilon() &&
        m_pStartPoint[1] <= m_pEndPoint[1] + std::numeric_limits<double>::epsilon()) return M_PI_2;
 
    return std::atan(-(m_pStartPoint[0] - m_pEndPoint[0]) / (m_pStartPoint[1] - m_pEndPoint[1]));
}
 
void LineSegment::makeInfinite(uint32_t dimension)
{
    makeDimension(dimension);
    for (uint32_t cIndex = 0; cIndex < m_dimension; ++cIndex)
    {
        m_pStartPoint[cIndex] = std::numeric_limits<double>::max();
        m_pEndPoint[cIndex] = std::numeric_limits<double>::max();
    }
}
 
void LineSegment::makeDimension(uint32_t dimension)
{
    if (m_dimension != dimension)
    {
        delete[] m_pStartPoint;
        delete[] m_pEndPoint;
 
        // remember that this is not a constructor. The object will be destructed normally if
        // something goes wrong (bad_alloc), so we must take care not to leave the object at an intermediate state.
        m_pStartPoint = nullptr;
        m_pEndPoint = nullptr;
 
        m_dimension = dimension;
        m_pStartPoint = new double[m_dimension];
        m_pEndPoint = new double[m_dimension];
    }
}
 
// compute double the area of the triangle created by points a, b and c (only for 2 dimensional points)
double LineSegment::doubleAreaTriangle(const SpatialIndex::Point &a, const SpatialIndex::Point &b, const SpatialIndex::Point &c) {
    double *pA, *pB, *pC;
    pA = a.m_pCoords; pB = b.m_pCoords; pC = c.m_pCoords;
    return (((pB[0] - pA[0]) * (pC[1] - pA[1])) - ((pC[0] - pA[0]) * (pB[1] - pA[1])));
}
 
// determine whether point c is to the left of the segment comprised of points a & b (2-d only)
bool LineSegment::leftOf(const SpatialIndex::Point &a, const SpatialIndex::Point &b, const SpatialIndex::Point &c) {
    return (doubleAreaTriangle(a, b, c) > 0);
}
 
// determine whether all 3 points are on the same line
bool LineSegment::collinear(const SpatialIndex::Point &a, const SpatialIndex::Point &b, const SpatialIndex::Point &c) {
    return (doubleAreaTriangle(a, b, c) == 0);
}
 
// determine whether the segment comprised of a, b and segment of c, d intersect (exclusive of their endpoints..hence the "Proper")
bool LineSegment::intersectsProper(const SpatialIndex::Point &a, const SpatialIndex::Point &b, const SpatialIndex::Point &c, const SpatialIndex::Point &d) {
    if ( collinear(a, b, c) || collinear(a, b, d) ||
         collinear(c, d, a) || collinear(c, d, b)) {
        return false;
    }
    return ((leftOf(a, b, c) ^ leftOf(a, b, d)) &&
            (leftOf(c, d, a) ^ leftOf(c, d, b)));
}
 
// if the points are collinear, is c between a & b
bool LineSegment::between(const SpatialIndex::Point &a, const SpatialIndex::Point &b, const SpatialIndex::Point &c) {
    if ( !collinear(a, b, c) ) {
        return false;
    }
    double *pA, *pB, *pC;
    pA = a.m_pCoords; pB = b.m_pCoords; pC = c.m_pCoords;
    if ( pA[0] != pB[0] ) { // a & b are not on the same vertical, compare on x axis
        return  between(pA[0], pB[0], pC[0]);
    } else { // a & b are a vertical segment, we need to compare on y axis
        return between(pA[1], pB[1], pC[1]);
    }
}
 
bool LineSegment::between(double a, double b, double c) {
    return ( ((a <= c) && (c <= b)) || ((a >= c) && (c >= b)) );
}
 
// intersection test, including endpoints
bool LineSegment::intersects(const SpatialIndex::Point &a, const SpatialIndex::Point &b, const SpatialIndex::Point &c, const SpatialIndex::Point &d) {
    if (intersectsProper(a, b, c, d)) {
        return true;
    } 
    else if ( between(a, b, c) || between(a, b, d) ||
              between(c, d, a) || between(c, d, b) ) { 
        return true;
    }
    else { 
        return false;
    }
}
 
std::ostream& SpatialIndex::operator<<(std::ostream& os, const LineSegment& l)
{
    for (uint32_t cDim = 0; cDim < l.m_dimension; ++cDim)
    {
        os << l.m_pStartPoint[cDim] << ", " << l.m_pEndPoint[cDim] << " ";
    }
 
    return os;
}