points.h

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/**********************************************************************
 * File:        points.h  (Formerly coords.h)
 * Description: Coordinate class definitions.
 * Author:      Ray Smith
 *
 * (C) Copyright 1991, Hewlett-Packard Ltd.
 ** 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.
 *
 **********************************************************************/

#ifndef POINTS_H
#define POINTS_H

#include <cmath>                // for sqrt, atan2
#include <cstdio>
#include "elst.h"
#include "errcode.h"            // for ASSERT_HOST
#include "platform.h"           // for DLLSYM

class FCOORD;

class ICOORD
{
  friend class FCOORD;

  public:
    ICOORD() {
      xcoord = ycoord = 0;       //default zero
    }
    ICOORD(int16_t xin,
           int16_t yin) {
      xcoord = xin;
      ycoord = yin;
    }
    ~ICOORD () = default;

    int16_t x() const {
      return xcoord;
    }
    int16_t y() const {
      return ycoord;
    }

    void set_x(int16_t xin) {
      xcoord = xin;              //write new value
    }
    void set_y(int16_t yin) {  //value to set
      ycoord = yin;
    }

    void set_with_shrink(int x, int y);

    float sqlength() const {
      return xcoord * xcoord + ycoord * ycoord;
    }

    float length() const {
      return std::sqrt(sqlength());
    }

    float pt_to_pt_sqdist(const ICOORD &pt) const {
      ICOORD gap;

      gap.xcoord = xcoord - pt.xcoord;
      gap.ycoord = ycoord - pt.ycoord;
      return gap.sqlength ();
    }

    float pt_to_pt_dist(const ICOORD &pt) const {
      return std::sqrt(pt_to_pt_sqdist(pt));
    }

    float angle() const {
      return std::atan2(ycoord, xcoord);
    }

    bool operator== (const ICOORD & other) const {
      return xcoord == other.xcoord && ycoord == other.ycoord;
    }
    bool operator!= (const ICOORD & other) const {
      return xcoord != other.xcoord || ycoord != other.ycoord;
    }
    friend ICOORD operator! (const ICOORD &);
    friend ICOORD operator- (const ICOORD &);
    friend ICOORD operator+ (const ICOORD &, const ICOORD &);
    friend ICOORD & operator+= (ICOORD &, const ICOORD &);
    friend ICOORD operator- (const ICOORD &, const ICOORD &);
    friend ICOORD & operator-= (ICOORD &, const ICOORD &);
    friend int32_t operator% (const ICOORD &, const ICOORD &);
    friend int32_t operator *(const ICOORD &,
                            const ICOORD &);
    friend ICOORD operator *(const ICOORD &,
                             int16_t);
    friend ICOORD operator *(int16_t,
                             const ICOORD &);
    friend ICOORD & operator*= (ICOORD &, int16_t);
    friend ICOORD operator/ (const ICOORD &, int16_t);
    friend ICOORD & operator/= (ICOORD &, int16_t);
    void rotate(const FCOORD& vec);

    void setup_render(ICOORD* major_step, ICOORD* minor_step,
                      int* major, int* minor) const;

    // Writes to the given file. Returns false in case of error.
    bool Serialize(FILE* fp) const;
    // Reads from the given file. Returns false in case of error.
    // If swap is true, assumes a big/little-endian swap is needed.
    bool DeSerialize(bool swap, FILE* fp);

  protected:
    int16_t xcoord;                
    int16_t ycoord;                
};

class DLLSYM ICOORDELT:public ELIST_LINK, public ICOORD
                                 //embedded coord list
{
  public:
    ICOORDELT() = default;
    ICOORDELT (ICOORD icoord):ICOORD (icoord) {
    }
    ICOORDELT(int16_t xin,
              int16_t yin) {
      xcoord = xin;
      ycoord = yin;
    }

    static ICOORDELT* deep_copy(const ICOORDELT* src) {
      auto* elt = new ICOORDELT;
      *elt = *src;
      return elt;
    }

};

ELISTIZEH (ICOORDELT)
class DLLSYM FCOORD
{
  public:
    FCOORD() = default;
    FCOORD(float xvalue,
           float yvalue) {
      xcoord = xvalue;           //set coords
      ycoord = yvalue;
    }
    FCOORD(                  //make from ICOORD
           ICOORD icoord) {  //coords to set
      xcoord = icoord.xcoord;
      ycoord = icoord.ycoord;
    }

    float x() const {  //get coords
      return xcoord;
    }
    float y() const {
      return ycoord;
    }
    void set_x(float xin) {
      xcoord = xin;              //write new value
    }
    void set_y(float yin) {  //value to set
      ycoord = yin;
    }

    float sqlength() const {
      return xcoord * xcoord + ycoord * ycoord;
    }

    float length() const {
      return std::sqrt(sqlength());
    }

    float pt_to_pt_sqdist(const FCOORD &pt) const {
      FCOORD gap;

      gap.xcoord = xcoord - pt.xcoord;
      gap.ycoord = ycoord - pt.ycoord;
      return gap.sqlength ();
    }

    float pt_to_pt_dist(const FCOORD &pt) const {
      return std::sqrt(pt_to_pt_sqdist(pt));
    }

    float angle() const {
      return std::atan2(ycoord, xcoord);
    }
    // Returns the standard feature direction corresponding to this.
    // See binary_angle_plus_pi below for a description of the direction.
    uint8_t to_direction() const;
    // Sets this with a unit vector in the given standard feature direction.
    void from_direction(uint8_t direction);

    // Converts an angle in radians (from ICOORD::angle or FCOORD::angle) to a
    // standard feature direction as an unsigned angle in 256ths of a circle
    // measured anticlockwise from (-1, 0).
    static uint8_t binary_angle_plus_pi(double angle);
    // Inverse of binary_angle_plus_pi returns an angle in radians for the
    // given standard feature direction.
    static double angle_from_direction(uint8_t direction);
    // Returns the point on the given line nearest to this, ie the point such
    // that the vector point->this is perpendicular to the line.
    // The line is defined as a line_point and a dir_vector for its direction.
    // dir_vector need not be a unit vector.
    FCOORD nearest_pt_on_line(const FCOORD& line_point,
                              const FCOORD& dir_vector) const;

    bool normalise();

    bool operator== (const FCOORD & other) {
      return xcoord == other.xcoord && ycoord == other.ycoord;
    }
    bool operator!= (const FCOORD & other) {
      return xcoord != other.xcoord || ycoord != other.ycoord;
    }
    friend FCOORD operator! (const FCOORD &);
    friend FCOORD operator- (const FCOORD &);
    friend FCOORD operator+ (const FCOORD &, const FCOORD &);
    friend FCOORD & operator+= (FCOORD &, const FCOORD &);
    friend FCOORD operator- (const FCOORD &, const FCOORD &);
    friend FCOORD & operator-= (FCOORD &, const FCOORD &);
    friend float operator% (const FCOORD &, const FCOORD &);
    friend float operator *(const FCOORD &, const FCOORD &);
    friend FCOORD operator *(const FCOORD &, float);
    friend FCOORD operator *(float, const FCOORD &);

    friend FCOORD & operator*= (FCOORD &, float);
    friend FCOORD operator/ (const FCOORD &, float);
    void rotate(const FCOORD vec);
    // unrotate - undo a rotate(vec)
    // @param vec by vector
    void unrotate(const FCOORD &vec);
    friend FCOORD & operator/= (FCOORD &, float);

  private:
    float xcoord;                //2 floating coords
    float ycoord;
};

/**********************************************************************
 * operator!
 *
 * Rotate an ICOORD 90 degrees anticlockwise.
 **********************************************************************/

inline ICOORD
operator! (                      //rotate 90 deg anti
const ICOORD & src               //thing to rotate
) {
  ICOORD result;                 //output

  result.xcoord = -src.ycoord;
  result.ycoord = src.xcoord;
  return result;
}


/**********************************************************************
 * operator-
 *
 * Unary minus of an ICOORD.
 **********************************************************************/

inline ICOORD
operator- (                      //unary minus
const ICOORD & src               //thing to minus
) {
  ICOORD result;                 //output

  result.xcoord = -src.xcoord;
  result.ycoord = -src.ycoord;
  return result;
}


/**********************************************************************
 * operator+
 *
 * Add 2 ICOORDS.
 **********************************************************************/

inline ICOORD
operator+ (                      //sum vectors
const ICOORD & op1,              //operands
const ICOORD & op2) {
  ICOORD sum;                    //result

  sum.xcoord = op1.xcoord + op2.xcoord;
  sum.ycoord = op1.ycoord + op2.ycoord;
  return sum;
}


/**********************************************************************
 * operator+=
 *
 * Add 2 ICOORDS.
 **********************************************************************/

inline ICOORD &
operator+= (                     //sum vectors
ICOORD & op1,                    //operands
const ICOORD & op2) {
  op1.xcoord += op2.xcoord;
  op1.ycoord += op2.ycoord;
  return op1;
}


/**********************************************************************
 * operator-
 *
 * Subtract 2 ICOORDS.
 **********************************************************************/

inline ICOORD
operator- (                      //subtract vectors
const ICOORD & op1,              //operands
const ICOORD & op2) {
  ICOORD sum;                    //result

  sum.xcoord = op1.xcoord - op2.xcoord;
  sum.ycoord = op1.ycoord - op2.ycoord;
  return sum;
}


/**********************************************************************
 * operator-=
 *
 * Subtract 2 ICOORDS.
 **********************************************************************/

inline ICOORD &
operator-= (                     //subtract vectors
ICOORD & op1,                    //operands
const ICOORD & op2) {
  op1.xcoord -= op2.xcoord;
  op1.ycoord -= op2.ycoord;
  return op1;
}


/**********************************************************************
 * operator%
 *
 * Scalar product of 2 ICOORDS.
 **********************************************************************/

inline int32_t
operator% (                      //scalar product
const ICOORD & op1,              //operands
const ICOORD & op2) {
  return op1.xcoord * op2.xcoord + op1.ycoord * op2.ycoord;
}


/**********************************************************************
 * operator*
 *
 * Cross product of 2 ICOORDS.
 **********************************************************************/

inline int32_t operator *(                    //cross product
                        const ICOORD &op1,  //operands
                        const ICOORD &op2) {
  return op1.xcoord * op2.ycoord - op1.ycoord * op2.xcoord;
}


/**********************************************************************
 * operator*
 *
 * Scalar multiply of an ICOORD.
 **********************************************************************/

inline ICOORD operator *(                    //scalar multiply
                         const ICOORD &op1,  //operands
                         int16_t scale) {
  ICOORD result;                 //output

  result.xcoord = op1.xcoord * scale;
  result.ycoord = op1.ycoord * scale;
  return result;
}


inline ICOORD operator *(                   //scalar multiply
                         int16_t scale,
                         const ICOORD &op1  //operands
                        ) {
  ICOORD result;                 //output

  result.xcoord = op1.xcoord * scale;
  result.ycoord = op1.ycoord * scale;
  return result;
}


/**********************************************************************
 * operator*=
 *
 * Scalar multiply of an ICOORD.
 **********************************************************************/

inline ICOORD &
operator*= (                     //scalar multiply
ICOORD & op1,                    //operands
int16_t scale) {
  op1.xcoord *= scale;
  op1.ycoord *= scale;
  return op1;
}


/**********************************************************************
 * operator/
 *
 * Scalar divide of an ICOORD.
 **********************************************************************/

inline ICOORD
operator/ (                      //scalar divide
const ICOORD & op1,              //operands
int16_t scale) {
  ICOORD result;                 //output

  result.xcoord = op1.xcoord / scale;
  result.ycoord = op1.ycoord / scale;
  return result;
}


/**********************************************************************
 * operator/=
 *
 * Scalar divide of an ICOORD.
 **********************************************************************/

inline ICOORD &
operator/= (                     //scalar divide
ICOORD & op1,                    //operands
int16_t scale) {
  op1.xcoord /= scale;
  op1.ycoord /= scale;
  return op1;
}


/**********************************************************************
 * ICOORD::rotate
 *
 * Rotate an ICOORD by the given (normalized) (cos,sin) vector.
 **********************************************************************/

inline void ICOORD::rotate(  //rotate by vector
                           const FCOORD& vec) {
  auto tmp = static_cast<int16_t>(std::floor(xcoord * vec.x() -
                                                ycoord * vec.y() + 0.5f));
  ycoord = static_cast<int16_t>(std::floor(ycoord * vec.x() +
                                           xcoord * vec.y() + 0.5f));
  xcoord = tmp;
}


/**********************************************************************
 * operator!
 *
 * Rotate an FCOORD 90 degrees anticlockwise.
 **********************************************************************/

inline FCOORD
operator! (                      //rotate 90 deg anti
const FCOORD & src               //thing to rotate
) {
  FCOORD result;                 //output

  result.xcoord = -src.ycoord;
  result.ycoord = src.xcoord;
  return result;
}


/**********************************************************************
 * operator-
 *
 * Unary minus of an FCOORD.
 **********************************************************************/

inline FCOORD
operator- (                      //unary minus
const FCOORD & src               //thing to minus
) {
  FCOORD result;                 //output

  result.xcoord = -src.xcoord;
  result.ycoord = -src.ycoord;
  return result;
}


/**********************************************************************
 * operator+
 *
 * Add 2 FCOORDS.
 **********************************************************************/

inline FCOORD
operator+ (                      //sum vectors
const FCOORD & op1,              //operands
const FCOORD & op2) {
  FCOORD sum;                    //result

  sum.xcoord = op1.xcoord + op2.xcoord;
  sum.ycoord = op1.ycoord + op2.ycoord;
  return sum;
}


/**********************************************************************
 * operator+=
 *
 * Add 2 FCOORDS.
 **********************************************************************/

inline FCOORD &
operator+= (                     //sum vectors
FCOORD & op1,                    //operands
const FCOORD & op2) {
  op1.xcoord += op2.xcoord;
  op1.ycoord += op2.ycoord;
  return op1;
}


/**********************************************************************
 * operator-
 *
 * Subtract 2 FCOORDS.
 **********************************************************************/

inline FCOORD
operator- (                      //subtract vectors
const FCOORD & op1,              //operands
const FCOORD & op2) {
  FCOORD sum;                    //result

  sum.xcoord = op1.xcoord - op2.xcoord;
  sum.ycoord = op1.ycoord - op2.ycoord;
  return sum;
}


/**********************************************************************
 * operator-=
 *
 * Subtract 2 FCOORDS.
 **********************************************************************/

inline FCOORD &
operator-= (                     //subtract vectors
FCOORD & op1,                    //operands
const FCOORD & op2) {
  op1.xcoord -= op2.xcoord;
  op1.ycoord -= op2.ycoord;
  return op1;
}


/**********************************************************************
 * operator%
 *
 * Scalar product of 2 FCOORDS.
 **********************************************************************/

inline float
operator% (                      //scalar product
const FCOORD & op1,              //operands
const FCOORD & op2) {
  return op1.xcoord * op2.xcoord + op1.ycoord * op2.ycoord;
}


/**********************************************************************
 * operator*
 *
 * Cross product of 2 FCOORDS.
 **********************************************************************/

inline float operator *(                    //cross product
                        const FCOORD &op1,  //operands
                        const FCOORD &op2) {
  return op1.xcoord * op2.ycoord - op1.ycoord * op2.xcoord;
}


/**********************************************************************
 * operator*
 *
 * Scalar multiply of an FCOORD.
 **********************************************************************/

inline FCOORD operator *(                    //scalar multiply
                         const FCOORD &op1,  //operands
                         float scale) {
  FCOORD result;                 //output

  result.xcoord = op1.xcoord * scale;
  result.ycoord = op1.ycoord * scale;
  return result;
}


inline FCOORD operator *(                   //scalar multiply
                         float scale,
                         const FCOORD &op1  //operands
                        ) {
  FCOORD result;                 //output

  result.xcoord = op1.xcoord * scale;
  result.ycoord = op1.ycoord * scale;
  return result;
}


/**********************************************************************
 * operator*=
 *
 * Scalar multiply of an FCOORD.
 **********************************************************************/

inline FCOORD &
operator*= (                     //scalar multiply
FCOORD & op1,                    //operands
float scale) {
  op1.xcoord *= scale;
  op1.ycoord *= scale;
  return op1;
}


/**********************************************************************
 * operator/
 *
 * Scalar divide of an FCOORD.
 **********************************************************************/

inline FCOORD
operator/ (                      //scalar divide
const FCOORD & op1,              //operands
float scale) {
  FCOORD result;                 //output
  ASSERT_HOST(scale != 0.0f);
  result.xcoord = op1.xcoord / scale;
  result.ycoord = op1.ycoord / scale;
  return result;
}


/**********************************************************************
 * operator/=
 *
 * Scalar divide of an FCOORD.
 **********************************************************************/

inline FCOORD &
operator/= (                     //scalar divide
FCOORD & op1,                    //operands
float scale) {
  ASSERT_HOST(scale != 0.0f);
  op1.xcoord /= scale;
  op1.ycoord /= scale;
  return op1;
}


/**********************************************************************
 * rotate
 *
 * Rotate an FCOORD by the given (normalized) (cos,sin) vector.
 **********************************************************************/

inline void FCOORD::rotate(  //rotate by vector
                           const FCOORD vec) {
  float tmp;

  tmp = xcoord * vec.x () - ycoord * vec.y ();
  ycoord = ycoord * vec.x () + xcoord * vec.y ();
  xcoord = tmp;
}

inline void FCOORD::unrotate(const FCOORD& vec) {
  rotate(FCOORD(vec.x(), -vec.y()));
}

#endif