skyline.h

/*
    SPDX-FileCopyrightText: 2006 Jason Harris <[email protected]>
 
    SPDX-License-Identifier: GPL-2.0-or-later
*/
 
#pragma once
 
#include "skypoint.h"
 
class dms;
class KStarsData;
 
/**
 * @class SkyLine
 *
 * A series of connected line segments in the sky, composed of SkyPoints at
 * its vertices.  SkyLines are used for constellation lines and boundaries,
 * the coordinate grid, and the equator, ecliptic and horizon.
 *
 * @note the SkyLine segments are always straight lines, they are not
 * Great Circle segments joining the two endpoints.  Therefore, line segments
 * that need to follow great circles must be approximated with many short
 * SkyLine segments.
 */
class SkyLine
{
  public:
    SkyLine() = default;
 
    ~SkyLine();
 
    /**
     * Append a segment to the list by adding a new endpoint.
     *
     * @param p the new endpoint to be added
     */
    void append(SkyPoint *p);
 
    /**
     * @return a const pointer to a point in the SkyLine
     * param i the index position of the point
     */
    inline SkyPoint *point(int i) const { return m_pList[i]; }
 
    inline QList<SkyPoint *> &points() { return m_pList; }
 
    /** Remove all points from list */
    void clear();
 
    /**
     * Set point i in the SkyLine
     *
     * @param i the index position of the point to modify
     * @param p the new SkyPoint
     */
    void setPoint(int i, SkyPoint *p);
 
    /**
     * @return the angle subtended by any line segment along the SkyLine.
     * @param i the index of the line segment to be measured.
     * If no argument is given, the first segment is assumed.
     */
    dms angularSize(int i = 0) const;
 
    void update(KStarsData *data, KSNumbers *num = nullptr);
 
  private:
    QList<SkyPoint *> m_pList;
};