Fix 8 year-old segfault.

[geda-gaf/berndj.git] / libgeda / src / o_arc_basic.c

/* gEDA - GPL Electronic Design Automation
 * libgeda - gEDA's library
 * Copyright (C) 1998-2007 Ales Hvezda
 * Copyright (C) 1998-2007 gEDA Contributors (see ChangeLog for details)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111 USA
 */

/*! \file o_arc_basic.c
 *  \brief functions for the arc object
 */

#include <config.h>

#include <stdio.h>
#include <math.h>

#include "libgeda_priv.h"

#ifdef HAVE_LIBDMALLOC
#include <dmalloc.h>
#endif

struct st_arc {
  int x, y; /* world */

  int width;
  int height;

  int start_angle;
  int end_angle;
};

static OBJECT *o_arc_copy(TOPLEVEL *toplevel, OBJECT *o_current);
static void o_arc_recalc(OBJECT *o_current);
static void o_arc_grip_foreach(OBJECT *o,
                               gboolean (*fn)(OBJECT *o,
                                              int grip_x, int grip_y,
                                              enum grip_t whichone,
                                              void *userdata),
                               void *userdata);
static int o_arc_grip_move(OBJECT *o, int whichone, int x, int y);

/*! Default setting for arc draw function. */
void (*arc_draw_func)() = NULL;

/*! \brief Create a minimal consistent-state arc.
 *  \par Function Description
 *  Creates an arc at a given position but does not add it to the object list.
 *
 *  \param [in] toplevel  The TOPLEVEL environment.
 *  \param [in] type      The object type (OBJ_ARC).
 *  \param [in] color     The "main" color of the arc.
 *  \param [in] x         The world X coordinate of the arc's origin.
 *  \param [in] y         The world Y coordinate of the arc's origin.
 *  \return A pointer to the newly created OBJECT.
 */
OBJECT *o_arc_new_at_xy(TOPLEVEL *toplevel, char type, int color, int x, int y)
{
  OBJECT *new_node;
  ARC *arc;

  /* create the object */
  new_node = s_toplevel_new_object(toplevel, type, "arc");
  new_node->color = color;

  arc = g_malloc(sizeof (ARC));
  new_node->arc = arc;

  new_node->arc->x = x;
  new_node->arc->y = y;
  /* Placate valgrind. */
  new_node->arc->width = 0;
  new_node->arc->height = 0;
  new_node->arc->start_angle = 0;
  new_node->arc->end_angle = 0;

  new_node->copy_func = &o_arc_copy;
  new_node->bounds_recalc_func = o_arc_recalc;
  new_node->draw_func = arc_draw_func;
  new_node->psprint_func = &o_arc_print;
  new_node->grip_foreach_func = &o_arc_grip_foreach;
  new_node->grip_move_func = &o_arc_grip_move;

  /* Default init */
  o_set_line_options(new_node, END_NONE, TYPE_SOLID, 0, -1, -1);
  o_set_fill_options(new_node, FILLING_HOLLOW, -1, -1, -1, -1, -1);

  o_arc_recalc(new_node);

  return new_node;
}

/*! \brief
 *  \par Function Description
 *  The function creates a new OBJECT of type arc.
 *
 *  The arc is defined by its center in parameters x and y.
 *  The radius parameter specifies the radius of the arc. The start
 *  angle is given by start_angle and the end angle by end_angle.
 *  The line and fill type of the created arc are set to default.
 *
 *  All dimensions are in world unit, except start_angle and
 *  end_angle in degrees.
 *  
 *  A new object of type OBJECT is allocated. Its type and color
 *  are initilized. The description of the arc characteristics
 *  are stored in a new ARC structure.
 *
 *  Now fixed for world coordinates.
 *
 *  \param [in] toplevel    The TOPLEVEL object.
 *  \param [in] type
 *  \param [in] color
 *  \param [in] x
 *  \param [in] y
 *  \param [in] radius
 *  \param [in] start_angle
 *  \param [in] end_angle
 *  \return
 */
OBJECT *o_arc_new(TOPLEVEL *toplevel,
                  char type, int color,
                  int x, int y, int radius, int start_angle, int end_angle)
{
  OBJECT *new_node;

  new_node = o_arc_new_at_xy(toplevel, type, color, x, y);

  /*! \note
   *  The ARC structure is initialized with the parameters.
   *  A default initialization is performed for the line and
   *  fill type to avoid misunderstanding.
   *
   *  The functions relative to the use of the object are sets.
   */

  /* World coordinates */
  new_node->arc->width  = 2 * radius;
  new_node->arc->height = 2 * radius;

  /* PB : must check the sign of start_angle, end_angle ... */
  if(end_angle < 0) {
    start_angle = start_angle + end_angle;
    end_angle = -end_angle;
  }
  if(start_angle < 0) start_angle = 360 + start_angle;
  
  new_node->arc->start_angle = start_angle;
  new_node->arc->end_angle   = end_angle;

  /* new_node->graphical = arc; eventually */

  return new_node;
}

/*! \brief 
 *  \par Function Description
 *  This function creates a new object representing an arc.
 *
 *  The values of the <B>o_current</B> pointed OBJECT are then copied to the new object.
 *
 *  The arc, the line options are initialized whereas the fill options are
 *  initialized to passive values - as an arc can not be filled.
 *
 *  \param [in] toplevel  The TOPLEVEL object
 *  \param [in] o_current
 *  \return The new OBJECT
 */
static OBJECT *o_arc_copy(TOPLEVEL *toplevel, OBJECT *o_current)
{
  OBJECT *new_obj;
  int color;

  if (o_current->saved_color == -1) {
    color = o_current->color;
  } else {
    color = o_current->saved_color;
  }

  new_obj = o_arc_new (toplevel, OBJ_ARC, color,
                       o_current->arc->x, o_current->arc->y,
                       o_current->arc->width / 2,
                       o_current->arc->start_angle,
                       o_current->arc->end_angle);
  o_set_line_options(new_obj,
                     o_current->line_end, o_current->line_type,
                     o_current->line_width,
                     o_current->line_length, o_current->line_space);
  o_set_fill_options(new_obj, FILLING_HOLLOW, -1, -1, -1, -1, -1);

  return new_obj;
}

/*! \brief
 *  \par Function Description
 *  This function reads a formatted text buffer describing an arc
 *  in the gEDA file format and initializes the corresponding object.
 *  Depending on the version of the file format the data extraction is
 *  performed differently : currently pre-20000704 and 20000704 on one
 *  hand and post-20000704 file format version on the other hand are supported.
 *  The version is specified in string pointed by <B>fileformat_ver</B>.
 *
 *  To get information on the various file formats have a
 *  look to the fileformats.html document.
 *  
 *  The object is initialized with the functions #o_set_line_options() and #o_set_fill_options().
 *  The second one is only used to put initialize unused values for an arc as an arc can not be filled.
 * 
 *  The arc is allocated initialized with the function #o_arc_new().
 * 
 *  A negative or null radius is not allowed.
 *
 *  \param [in] toplevel    The TOPLEVEL object.
 *  \param [in] buf
 *  \param [in] release_ver
 *  \param [in] fileformat_ver
 *  \return
 */
OBJECT *o_arc_read(TOPLEVEL *toplevel, char buf[],
                   unsigned int release_ver, unsigned int fileformat_ver)
{
  OBJECT *new_obj;
  char type; 
  int x1, y1;
  int radius;
  int start_angle, end_angle;
  int color;
  int arc_width, arc_length, arc_space;
  int arc_type;
  int arc_end;

  /*! \note
   *  Depending on the version of the file format used to describe this arc,
   *  the buffer is parsed differently. The unknown parameters of the less
   *  restrictive - the oldest - file format are set to common values
   */
  if(release_ver <= VERSION_20000704) {
    sscanf(buf, "%c %d %d %d %d %d %d", &type,
           &x1, &y1, &radius, &start_angle, &end_angle, &color);

    arc_width = 0;
    arc_end   = END_NONE;
    arc_type  = TYPE_SOLID;
    arc_space = -1;
    arc_length= -1;
  } else {
    sscanf(buf, "%c %d %d %d %d %d %d %d %d %d %d %d", &type,
           &x1, &y1, &radius, &start_angle, &end_angle, &color,
           &arc_width, &arc_end, &arc_type, &arc_length, &arc_space);

  }

  /* Error check */
  if (radius <= 0) {
    s_log_message (_("Found a zero radius arc [ %c %d, %d, %d, %d, %d, %d ]\n"),
                   type, x1, y1, radius, start_angle, end_angle, color);
  }
        
  if (color < 0 || color > MAX_COLORS) {
    s_log_message(_("Found an invalid color [ %s ]\n"), buf);
    s_log_message(_("Setting color to WHITE\n"));
    color = WHITE;
  }

  /* Allocation and initialization */
  new_obj = o_arc_new(toplevel, OBJ_ARC, color,
                      x1, y1, radius, start_angle, end_angle);
  o_set_line_options(new_obj,
                     arc_end, arc_type, arc_width, arc_length,
                     arc_space);
  o_set_fill_options(new_obj, FILLING_HOLLOW, -1, -1, -1, -1, -1);

  return new_obj;
}

/*! \brief
 *  \par Function Description
 *  This function formats a string in the buffer <B>*buff</B> to describe
 *  the arc object <B>*object</B>.
 *  It follows the post-20000704 release file format that handle the
 *  line type and filling options.
 *  A pointer to the new allocated and formated string is returned.
 *  The string must be freed at some point.
 *
 *  \param [in] object
 *  \return
 *
 *  \todo EEK! there is a nasty non-snap bug here!
 *        Basically the center isn't being snapped
 *        in complex objects only it seems...
 */
char *o_arc_save(OBJECT *object)
{
  int color;
  int x, y, radius, start_angle, end_angle;
  int arc_width, arc_length, arc_space;
  char *buf;
  OBJECT_END arc_end;
  OBJECT_TYPE arc_type;

  /* radius, center and angles of the arc */
  radius      = object->arc->width / 2;
  x           = object->arc->x;
  y           = object->arc->y;
  start_angle = object->arc->start_angle;
  end_angle   = object->arc->end_angle;

  /* line type parameters */
  arc_width  = object->line_width;
  arc_end    = object->line_end;
  arc_type   = object->line_type;
  arc_length = object->line_length;
  arc_space  = object->line_space;

  /* Save the right color */
  if (object->saved_color == -1) {
    color = object->color;
  } else {
    color = object->saved_color;
  }

  /* Describe a circle with post-20000704 file format */
  buf = g_strdup_printf("%c %d %d %d %d %d %d %d %d %d %d %d", object->type,
                        x, y, radius, start_angle, end_angle, color,
                        arc_width, arc_end, arc_type, arc_length, arc_space);

  return(buf);
}

/*! \brief
 *  \par Function Description
 *  This function applies a translation of (<B>dx</B>,<B>dy</B>)
 *  to the arc described in <B>*object</B>. <B>dx</B> and <B>dy</B> are in world unit.
 *
 *  \param [in] dx
 *  \param [in] dy
 *  \param [in] object
 */
void o_arc_translate_world(int dx, int dy, OBJECT *object)
{
  if (object == NULL) {
    return;
  }

  /* Do world coords */
  object->arc->x = object->arc->x + dx;
  object->arc->y = object->arc->y + dy;


  /* Recalculate screen coords from new world coords */
  o_arc_recalc(object);
}

/*! \brief
 *  \par Function Description
 *  This function rotates the world coordinates of an arc of an angle
 *  specified by <B>angle</B>. The center of the rotation is given by
 *  (<B>world_centerx</B>,<B>world_centery</B>).
 *
 *  The arc is translated in order to put the center of the rotation
 *  on the origin. The center of the arc is then rotated of the angle
 *  specified by <B>angle</B>. The start angle of the arc is incremented by <B>angle</B>.
 *
 *  The arc is finally back translated to its previous location on the page.
 *
 *  <B>world_centerx</B> and <B>world_centery</B> are in world units, <B>angle</B> is in degrees.
 *
 *  \param [in] world_centerx
 *  \param [in] world_centery
 *  \param [in] angle
 *  \param [in] object
 */
void o_arc_rotate_world(int world_centerx, int world_centery, int angle,
                        OBJECT *object)
{
  int x, y, newx, newy;

  /* translate object to origin */
  object->arc->x -= world_centerx;
  object->arc->y -= world_centery;

  /* get center, and rotate center */
  x = object->arc->x;
  y = object->arc->y;
  if(angle % 90 == 0) {
          rotate_point_90(x, y, angle % 360, &newx, &newy);
  } else {
          rotate_point(x, y, angle % 360, &newx, &newy);
  }
  object->arc->x = newx;
  object->arc->y = newy;

  /* apply rotation to angles */
  object->arc->start_angle = (object->arc->start_angle + angle) % 360;
  /* end_angle is unchanged as it is the sweep of the arc */
  /* object->arc->end_angle = (object->arc->end_angle); */

  /* translate object to its previous place */
  object->arc->x += world_centerx;
  object->arc->y += world_centery;

  /* update the screen coords and the bounding box */
  o_arc_recalc(object);
  
}                                   

/*! \brief Mirror the WORLD coordinates of an ARC.
 *  \par Function Description
 *  This function mirrors the world coordinates of an arc.
 *  The symmetry axis is given by the vertical line going through the point (<B>world_centerx</B>,<B>world_centery</B>).
 *
 *  The arc is translated in order to put the point (<B>world_centerx</B>,<B>world_centery</B>)
 *  on the origin. The center of the arc is then mirrored. The start angle of the arc
 *  and the sweep of the arc are also mirrored.
 *
 *  The arc is finally back translated to its previous location on the page.
 *
 *  \param [in] world_centerx
 *  \param [in] world_centery
 *  \param [in] object
 */
void o_arc_mirror_world(int world_centerx, int world_centery,
                        OBJECT *object)
{
  /* translate object to origin */
  object->arc->x -= world_centerx;
  object->arc->y -= world_centery;

  /* get center, and mirror it (vertical mirror) */
  object->arc->x = -object->arc->x;
  object->arc->y =  object->arc->y;

  /* apply mirror to angles (vertical mirror) */
  object->arc->start_angle = (180 - object->arc->start_angle) % 360;
  /* pb20011125 - start_angle *MUST* be positive */
  if(object->arc->start_angle < 0) object->arc->start_angle += 360;
  object->arc->end_angle = -object->arc->end_angle;
        
  /* translate object back to its previous position */
  object->arc->x += world_centerx;
  object->arc->y += world_centery;

  /* update the screen coords and bounding box */
  o_arc_recalc(object);
}

int o_arc_get_radius(OBJECT const *o_current)
{
  return (o_current->arc->width / 2);
}

int o_arc_get_start_angle(OBJECT const *o_current)
{
  return (o_current->arc->start_angle);
}

int o_arc_get_end_angle(OBJECT const *o_current)
{
  return (o_current->arc->end_angle);
}

void o_arc_set_radius(OBJECT *o_current, int radius)
{
  o_current->arc->width = radius * 2;

  /* update the screen coords and bounding box */
  o_arc_recalc(o_current);
}

void o_arc_set_start_angle(OBJECT *o_current, int angle)
{
  o_current->arc->start_angle = angle;

  /* update the screen coords and bounding box */
  o_arc_recalc(o_current);
}

void o_arc_set_end_angle(OBJECT *o_current, int angle)
{
  o_current->arc->end_angle = angle;

  /* update the screen coords and bounding box */
  o_arc_recalc(o_current);
}

/*! \brief
 *  \par Function Description
 *  This function recalculates internal parameters in screen units
 *  of an object containing an arc. The object is given as parameters <B>o_current</B>.
 *  The calculation is done according to the zoom factor detailed in the <B>toplevel</B>
 *  pointed structure.
 *  It also recalculates the <B>OBJECT</B> specific fields and the bounding box of the arc.
 *  
 *  The bounding box - in world units - is recalculated with the <B>world_get_arc_bounds()</B> function.
 *
 *  \param [in] o_current
 */
static void o_arc_recalc(OBJECT *o_current)
{
  int left, right, top, bottom;
        
  if (o_current->arc == NULL) {
    return;
  }

  /* recalculates the bounding box */
  world_get_arc_bounds(o_current, &left, &top, &right, &bottom);
  o_current->w_left   = left;
  o_current->w_top    = top;
  o_current->w_right  = right;
  o_current->w_bottom = bottom;
  o_current->w_bounds_valid = TRUE;
}

static void o_arc_grip_foreach(OBJECT *o,
                               gboolean (*fn)(OBJECT *o,
                                              int grip_x, int grip_y,
                                              enum grip_t whichone,
                                              void *userdata),
                               void *userdata)
{
  int centerx = o->arc->x;
  int centery = o->arc->y;
  int radius = o->arc->width / 2;
  double start_angle = o->arc->start_angle * M_PI / 180;
  double end_angle = start_angle + o->arc->end_angle * M_PI / 180;

  const GRIP arc_grips[] = {
    {
      .x = centerx,
      .y = centery,
      .whichone = GRIP_ARC_CENTER,
    },
    {
      .x = centerx,
      .y = centery,
      .whichone = GRIP_ARC_RADIUS,
    },
    {
      .x = centerx + radius * cos(start_angle),
      .y = centery + radius * sin(start_angle),
      .whichone = GRIP_START_ANGLE,
    },
    {
      .x = centerx + radius * cos(end_angle),
      .y = centery + radius * sin(end_angle),
      .whichone = GRIP_END_ANGLE,
    },
    { .whichone = GRIP_NONE }
  };

  s_basic_grip_foreach_helper(o, arc_grips, fn, userdata);
}

static int o_arc_grip_move(OBJECT *o, int whichone, int x, int y)
{
  int retval = whichone;

  switch (whichone) {
    double radius, theta, r_cos_theta, r_sin_theta;
  case GRIP_NONE:
    o->arc->x = x;
    o->arc->y = y;
    o->arc->width = 0;
    o->arc->height = 0;
    o->arc->start_angle = 0;
    o->arc->end_angle = 180;
    retval = GRIP_ARC_RADIUS;
    break;

  case GRIP_ARC_CENTER:
    o->arc->x = x;
    o->arc->y = y;
    retval = GRIP_ARC_RADIUS;
    break;
  case GRIP_ARC_RADIUS:
    r_cos_theta = x - o->arc->x;
    r_sin_theta = y - o->arc->y;
    radius = sqrt(r_cos_theta*r_cos_theta + r_sin_theta*r_sin_theta);
    o->arc->width = o->arc->height = rint(radius * 2);
    retval = GRIP_START_ANGLE;
    break;
  case GRIP_START_ANGLE:
  case GRIP_END_ANGLE:
    r_cos_theta = x - o->arc->x;
    r_sin_theta = y - o->arc->y;
    radius = sqrt(r_cos_theta*r_cos_theta + r_sin_theta*r_sin_theta);
    theta = atan2(r_sin_theta / radius, r_cos_theta / radius);
    if (theta < 0) {
      theta += 2*M_PI;
    }
    theta *= 180 / M_PI;
    switch (whichone) {
    case GRIP_START_ANGLE:
      o->arc->start_angle = rint(theta);
      retval = GRIP_END_ANGLE;
      break;
    case GRIP_END_ANGLE:
      theta -= o->arc->start_angle;
      if (theta < 0) {
        theta += 360;
      }
      o->arc->end_angle = rint(theta);
      retval = GRIP_NONE;
      break;
    }
    break;
  }

  o_arc_recalc(o);

  return retval;
}

/*! \brief
 *  \par Function Description
 *  This function calculates the smallest rectangle the arc can be drawn into.
 *  The <B>OBJECT</B> pointed by object is assumed to be an arc.
 *  The <B>left</B>, <B>top</B>, <B>right</B> and <B>bottom</B> pointed integers define
 *  this rectangle at the end of the function. It is expressed in world units.
 *  The process is divided into two steps : the first step is to calculate the
 *  coordinates of the two ends of the arc and the coordinates of the center.
 *  They forms a first rectangle but (depending on the start angle and the
 *  sweep of the arc) not the right.
 *
 *  \param [in]  toplevel  The TOPLEVEL object.
 *  \param [in]  object
 *  \param [out] left
 *  \param [out] top
 *  \param [out] right
 *  \param [out] bottom
 */
void world_get_arc_bounds(OBJECT *object, int *left,
                          int *top, int *right, int *bottom)
{
  int x1, y1, x2, y2, x3, y3;
  int radius, start_angle, end_angle;
  int i, angle;
  int halfwidth;

  halfwidth = object->line_width / 2;

  radius      = object->arc->width / 2;
  start_angle = object->arc->start_angle % 360;
  end_angle   = object->arc->end_angle   % 360;

  x1 = object->arc->x;
  y1 = object->arc->y;
  x2 = x1 + radius * cos(start_angle * M_PI / 180);
  y2 = y1 + radius * sin(start_angle * M_PI / 180);
  x3 = x1 + radius * cos((start_angle + end_angle) * M_PI / 180);
  y3 = y1 + radius * sin((start_angle + end_angle) * M_PI / 180);

  *left   = (x1 < x2) ? ((x1 < x3) ? x1 : x3) : ((x2 < x3) ? x2 : x3);
  *right  = (x1 > x2) ? ((x1 > x3) ? x1 : x3) : ((x2 > x3) ? x2 : x3);
  *bottom = (y1 > y2) ? ((y1 > y3) ? y1 : y3) : ((y2 > y3) ? y2 : y3);
  *top    = (y1 < y2) ? ((y1 < y3) ? y1 : y3) : ((y2 < y3) ? y2 : y3);

  /*! \note
   *  The previous rectangle is extended to the final one
   *  by checking whether the arc is over a main axis (vertical or horizontal).
   *  If so, the rectangle is extended in these directions.
   *
   *  In the mirror mode, the sweep angle is negative. To get a
   *  CCW arc before this calculation we have to move the 
   *  start angle to the end angle and reverse the sweep angle.
   */
  if (end_angle < 0) {
    start_angle = (start_angle + end_angle + 360) % 360;
    end_angle = -end_angle;
  }
  angle = ((int) (start_angle / 90)) * 90;
  for(i = 0; i < 4; i++) {
    angle = angle + 90;
    if(angle < start_angle + end_angle) {
      if(angle % 360 == 0)   *right  = x1 + radius;
      if(angle % 360 == 90)  *bottom = y1 + radius;
      if(angle % 360 == 180) *left   = x1 - radius;
      if(angle % 360 == 270) *top    = y1 - radius;
    } else {
      break;
    }
  }

  /* This isn't strictly correct, but a 1st order approximation */
  *left   -= halfwidth;
  *top    -= halfwidth;
  *right  += halfwidth;
  *bottom += halfwidth;

}


/*! \brief
 *  \par Function Description
 *  This function writes in a postscript file the arc described by
 *  the <B>o_current</B> pointed object.
 *  The postscript resulting file is described by the <B>fp</B> file pointer.
 *  
 *  Parameters of the arc are extracted from object pointed by <B>o_current</B>
 *  and formatted to suit future calls to specialized arc printing functions.
 *
 *  \param [in] toplevel  The TOPLEVEL object.
 *  \param [in] fp         The postscript document to print to.
 *  \param [in] o_current
 */
void o_arc_print(TOPLEVEL *toplevel, FILE *fp, OBJECT *o_current,
                 double scale, int unicode_count, gunichar *unicode_table)
{
  int x, y, radius, start_angle, end_angle;
  int color;
  int arc_width, space, length;
  void (*outl_func)(TOPLEVEL *toplevel, FILE *fp,
                    int x, int y, int radius,
                    int angle1, int angle2,
                    int color,
                    int arc_width, int length, int space) = NULL;

  if (o_current == NULL) {
    printf("got null in o_arc_print\n");
    return;
  }
        
  x      = o_current->arc->x;
  y      = o_current->arc->y;
  radius = o_current->arc->width / 2;
  start_angle = o_current->arc->start_angle;
  end_angle   = o_current->arc->end_angle;
  color  = o_current->color;

  /*! \note
   *  Depending on the type of the line for this particular arc, the
   *  appropriate function is chosen among #o_arc_print_solid(),
   *  #o_arc_print_dotted(), #o_arc_print_dashed(), #o_arc_print_center() and #o_arc_print_phantom().
   *
   *  The needed parameters for each of these types are extracted from the <B>o_current</B> object.
   *  Depending on the type, unused parameters are set to -1.
   *  
   *  In the eventuality of a length and/or space null, the arc is printed solid to avoid and
   *  endless loop produced by other functions.
   */

#if 0  /* was causing arcs which are solid to be much thinner compared to */
  /* lines, boxes, also of zero width */
  if (o_current->line_width > 0) {
    arc_width = o_current->line_width;
  } else {
    arc_width = 1;
  }
#endif
  arc_width = o_current->line_width;    /* Added instead of above */
  if(arc_width <=2) {
    if(toplevel->line_style == THICK) {
      arc_width=LINE_WIDTH;
    } else {
      arc_width=2;
    }
  }

  length = o_current->line_length;
  space  = o_current->line_space;
        
  switch(o_current->line_type) {
    case(TYPE_SOLID):
      length = -1; space = -1;
      outl_func = o_arc_print_solid;
      break;
                        
    case(TYPE_DOTTED):
      length = -1;
      outl_func = o_arc_print_dotted;
      break;
                        
    case(TYPE_DASHED):
      outl_func = o_arc_print_dashed;
      break;
                        
    case(TYPE_CENTER):
      outl_func = o_arc_print_center;
      break;
                        
    case(TYPE_PHANTOM):
      outl_func = o_arc_print_phantom;
      break;
                        
    case(TYPE_ERASE):
      /* Unused for now, print it solid */
      length = -1; space = -1;
      outl_func = o_arc_print_solid;
      break;
  }

  if((space == 0) || (length == 0)) {
    length = -1; space = -1;
    outl_func = o_arc_print_solid;
  }

  (*outl_func)(toplevel, fp,
               x, y, radius,
               start_angle, end_angle,
               color, arc_width, length, space);
}


/*! \brief
 *  \par Function Description
 *  This function prints an arc when a solid line type is required.
 *  The arc is defined by its center in <B>x</B> and <B>y</B>, its radius
 *  in <B>radius</B> and the start and end angles of the arc on the circle.
 *  The postscript file is defined by the file pointer <B>fp</B>.
 *
 *  The parameters <B>length</B> and <B>space</B> are ignored
 *  whereas <B>arc_width</B> specifies the width of the printed line.
 *
 *  All dimensions are in mils, except <B>angle1</B> and <B>angle2</B> in degrees.
 *
 *  \param [in] toplevel  The TOPLEVEL object.
 *  \param [in] fp         FILE pointer to postscript document.
 *  \param [in] x
 *  \param [in] y
 *  \param [in] radius
 *  \param [in] angle1
 *  \param [in] angle2
 *  \param [in] color
 *  \param [in] arc_width
 *  \param [in] length
 *  \param [in] space
 */
void o_arc_print_solid(TOPLEVEL *toplevel, FILE *fp,
                       int x, int y, int radius,
                       int angle1, int angle2,
                       int color,
                       int arc_width, int length, int space)
{
  if (toplevel->print_color) {
    f_print_set_color(fp, color);
  }

  /* PB/AVH inverting angle2 if < 0 and changing angle1 accordingly */
  if (angle2 < 0) {
    angle1 = angle1 + angle2;
    angle2 = -angle2;
  }

  fprintf(fp, "%d %d %d %d %d %d darc\n",
          x,y, radius, angle1, angle1 + angle2,
          arc_width);

}

/*! \brief
 *  \par Function Description
 *  This function prints an arc when a dotted line type is required.
 *  The arc is defined by its center in <B>x</B> and <B>y</B>, its
 *  radius in <B>radius</B> and the start and end angles of the arc on the circle.
 *  The postscript file is defined by the file pointer <B>fp</B>.
 *  The parameter <B>length</B> is ignored whereas <B>arc_width</B> specifies
 *  the diameter of the dots of the printed line and <B>space</B> the distance
 *  between two dots.
 *  
 *  A negative value for <B>space</B> leads to an endless loop.
 *
 *  All dimensions are in mils, except <B>angle1</B> and <B>angle2</B> in degrees.
 *
 *  The function sets the color the line will be printed with.
 * 
 *  \param [in] toplevel  The TOPLEVEL object.
 *  \param [in] fp         FILE pointer to postscript document.
 *  \param [in] x
 *  \param [in] y
 *  \param [in] radius
 *  \param [in] angle1
 *  \param [in] angle2
 *  \param [in] color
 *  \param [in] arc_width
 *  \param [in] length
 *  \param [in] space
 */
void o_arc_print_dotted(TOPLEVEL *toplevel, FILE *fp,
                        int x, int y, int radius,
                        int angle1, int angle2,
                        int color,                                 
                        int arc_width, int length, int space)
{
  int da, d;


  if (toplevel->print_color) {
    f_print_set_color(fp, color);
  }

  /*! \note
   *  Depending on the radius of the arc, the <B>space</B> parameter is
   *  changed into a small angle <B>da</B>.
   *  Starting from <B>angle1</B> - the start angle - the dots are printed
   *  along the arc by increments of this new angle.
   *
   *  As <B>da</B> is rounded as an integer, it can take a null value which
   *  will make the function enter an endless loop. In such a case, the arc
   *  is printed solid. The <B>da</B> variable should never be negative
   *  except if <B>space</B> is negative.
   */

  /* Inverting angle2 if < 0 and changing angle1 accordingly */
  /* the loop test assume that da > 0 */
  if (angle2 < 0) {
    angle1 = angle1 + angle2;
    angle2 = -angle2;
  }
  da = (int) ((space * 180) / (M_PI * ((double) radius)));

        /* If da or db too small for arc to be displayed as dotted,
           draw a solid arc */
  if (da <= 0) {
    o_arc_print_solid(toplevel, fp,
                      x, y, radius,
                      angle1, angle2,
                      color,
                      arc_width, length, space);
    return;
  }

  fprintf(fp,"[");
  d = angle1;
  while (d < (angle2 + angle1)) {
    /*xa = ((double) x) + ((double) radius) * cos(d * M_PI / 180);
    ya = ((double) y) + ((double) radius) * sin(d * M_PI / 180);
    */
    fprintf(fp,"[%d] ",d);

    d = d + da;
  }
  fprintf(fp,"] %d %d %d %d dashedarc %% dotted\n",
          x,y, radius, arc_width);
}

/*! \brief
 *  \par Function Description
 *  This function prints an arc when a dashed line type is required.
 *  The arc is defined by its center in <B>x</B> and <B>y</B>, its radius
 *  in <B>radius</B> and the start and end angles of the arc on the circle.
 *  The postscript file is defined by the file pointer <B>fp</B>.
 *  The parameter <B>arc_width</B> specifies the diameter of the dots of the printed line.
 *
 *  A negative value for <B>space</B> or <B>length</B> leads to an endless loop.
 *
 *  All dimensions are in mils, except <B>angle1</B> and <B>angle2</B> in degrees.
 *
 *  The function sets the color the line will be printed with.
 *
 *  \param [in] toplevel  The TOPLEVEL object.
 *  \param [in] fp         FILE pointer to postscript document.
 *  \param [in] x
 *  \param [in] y
 *  \param [in] radius
 *  \param [in] angle1
 *  \param [in] angle2
 *  \param [in] color
 *  \param [in] arc_width
 *  \param [in] length
 *  \param [in] space
 */
void o_arc_print_dashed(TOPLEVEL *toplevel, FILE *fp,
                        int x, int y, int radius,
                        int angle1, int angle2,
                        int color,                                 
                        int arc_width, int length, int space)
{
  int da, db, a1, d;

  if (toplevel->print_color) {
    f_print_set_color(fp, color);
  }
  
  /*! \note
   *  Depending on the radius of the arc, the <B>space</B> (resp. <B>length</B>)
   *  parameter is changed into a small angle <B>da</B> (resp. <B>db</B>).
   *  Starting from <B>angle1</B> - the start angle - the dashes are printed
   *  along the arc by increments of these new angles.
   *
   *  As <B>da</B> (resp. <B>db</B>) is rounded as an integer, it can take a
   *  null value which will make the function enter an endless loop. In such a case,
   *  the arc is printed solid. The <B>da</B> (resp. <B>db</B>) variable should never
   *  be negative except if <B>space</B> (resp. <B>length</B>) is negative.
   *
   *  It prints as many dashes of length <B>length</B> as possible.
   */

  /* Inverting angle2 if < 0 and changing angle1 accordingly */
  /* the loop test assume that da > 0 */
  if (angle2 < 0) {
    angle1 = angle1 + angle2;
    angle2 = -angle2;
  }
  da = (int) ((length * 180) / (M_PI * ((double) radius)));
  db = (int) ((space  * 180) / (M_PI * ((double) radius)));

  /* If da or db too small for arc to be displayed as dotted,
           draw a solid arc */
  if ((da <= 0) || (db <= 0)) {
    o_arc_print_solid(toplevel, fp,
                      x, y, radius, 
                      angle1, angle2,
                      color,
                      arc_width, length, space);
    return;
  }
  
  fprintf(fp,"[");
  d = angle1;
  while ((d + da + db) < (angle1 + angle2)) {
    a1 = d;
    d = d + da;

    fprintf(fp,"[%d %d] ",
            a1, a1+da);

    d = d + db;
  }
  /*! \note
   *  When the above condition is no more satisfied, then it is not
   *  possible to print a dash of length <B>length</B> and the following <B>space</B>.
   *  However it may be possible to print the complete dash or a shorter one.
   */

  if ((d + da) < (angle1 + angle2)) {
    a1 = d;
  } else {
    a1 = d;
  }

  fprintf(fp,"[%d %d] ",
          a1, a1+da);


  fprintf(fp,"] %d %d %d %d dashedarc %% dashed\n",
          x,y, radius, arc_width);
}

/*! \brief
 *  \par Function Description
 *  This function prints an arc when a centered line type is required.
 *  The arc is defined by its center in <B>x</B> and <B>y</B>, its radius in
 *  <B>radius</B> and the start and end angles of the arc on the circle.
 *  The postscript file is defined by the file pointer <B>fp</B>.
 *  The parameter <B>arc_width</B> specifies the diameter of the dots and the width of the dashes of the printed line.
 *
 *  A negative value for <B>space</B> or <B>length</B> leads to an endless loop.
 *
 *  All dimensions are in mils, except <B>angle1</B> and <B>angle2</B> in degrees.
 *
 *  The function sets the color in which the line will be printed with.
 *
 *  \param [in] toplevel  The TOPLEVEL object.
 *  \param [in] fp         FILE pointer to postscript document.
 *  \param [in] x
 *  \param [in] y
 *  \param [in] radius
 *  \param [in] angle1
 *  \param [in] angle2
 *  \param [in] color
 *  \param [in] arc_width
 *  \param [in] length
 *  \param [in] space
 */
void o_arc_print_center(TOPLEVEL *toplevel, FILE *fp,
                        int x, int y, int radius, 
                        int angle1, int angle2,
                        int color,                                 
                        int arc_width, int length, int space)
{
  int da, db, a1, d;

  if (toplevel->print_color) {
    f_print_set_color(fp, color);
  }

  /*! \note
   *  Depending on the radius of the arc, the <B>space</B> (resp. <B>length</B>)
   *  parameter is changed into a small angle <B>da</B> (resp. <B>db</B>).
   *  Starting from <B>angle1</B> - the start angle - the dashes are printed
   *  along the arc by increments of these new angles.
   *
   *  As <B>da</B> (resp. <B>db</B>) is rounded as an integer, it can take a null
   *  value which will make the function enter an endless loop. In such a case,
   *  the arc is printed solid. The <B>da</B> (resp. <B>db</B>) variable should never
   *  be negative except if <B>space</B> (resp. <B>length</B>) is negative.
   *
   *  It prints as many sets of dash-dot as possible.
   */

  /* Inverting angle2 if < 0 and changing angle1 accordingly */
  /* the loop test assume that da > 0 */
  if (angle2 < 0) {
    angle1 = angle1 + angle2;
    angle2 = -angle2;
  }

  da = (int) ((length * 180) / (M_PI * ((double) radius)));
  db = (int) ((space  * 180) / (M_PI * ((double) radius)));

  /* If da or db too small to be displayed, draw an arc */
  if ((da <= 0) || (db <= 0)) {
    o_arc_print_solid(toplevel, fp,
                      x, y, radius,
                      angle1, angle2,
                      color,
                      arc_width, length, space);
    return;
  }
  
  fprintf(fp, "[");
  d = angle1;
  while ((d + da + 2 * db) < (angle1 + angle2)) {
    a1 = d;
    d = d + da;
    fprintf(fp,"[%d %d] ",(int) a1, (int) a1 + da);
    
    d = d + db;
    /*
      xa = ((double) x) + ((double) radius) * cos(d * (M_PI / 180));
      ya = ((double) y) + ((double) radius) * sin(d * (M_PI / 180));
    */
    fprintf(fp,"[%d] ",d);
    d = d + db;
  }
  /*! \note
   *  When the above condition is no more satisfied, then it is not
   *  possible to print a dash of length <B>length</B>. However two cases are possible :
   *  <DL>
   *      <DT>*</DT><DD>it is possible to print the dash and the dot
   *      <DT>*</DT><DD>it is possible to print the dash or a part of the original dash
   *  </DL>
   */
  
  a1 = d;

  d = d + da;
  
  fprintf(fp,"[%d %d] ",(int) a1, (int) a1 + da);

  if ((d + db) < (angle1 + angle2)) {
    /*
      xa = ((double) x) + ((double) radius) * cos(d * (M_PI / 180));
      ya = ((double) y) + ((double) radius) * sin(d * (M_PI / 180));
    */
    fprintf(fp,"[%d] ",d);
  }
  
  fprintf(fp,"] %d %d %d %d dashedarc %% center\n",
          x,y, radius, arc_width);
}

/*! \note
 *  A dot is represented by a filled circle. Position of the circle is (<B>xa</B>, <B>ya</B>)
 *  and its radius is the <B>arc_width</B> parameter.
 */

/*! \brief
 *  \par Function Description
 *  This function prints an arc when a phantom line type is required.
 *  The arc is defined by its center in <B>x</B> and <B>y</B>, its radius
 *  in <B>radius</B> and the start and end angles of the arc on the circle.
 *  The postscript file is defined by the file pointer <B>fp</B>.
 *  The parameter <B>arc_width</B> specifies the diameter of the dots and the width of the dashes of the printed line.
 *
 *  A negative value for <B>space</B> or <B>length</B> leads to an endless loop.
 *
 *  All dimensions are in mils, except <B>angle1</B> and <B>angle2</B> in degrees.
 *
 * The function sets the color in which the line will be printed with.
 *
 *  \param [in] toplevel  The TOPLEVEL object.
 *  \param [in] fp         FILE pointer to postscript document.
 *  \param [in] x
 *  \param [in] y
 *  \param [in] radius
 *  \param [in] angle1
 *  \param [in] angle2
 *  \param [in] color
 *  \param [in] arc_width
 *  \param [in] length
 *  \param [in] space
 */
void o_arc_print_phantom(TOPLEVEL *toplevel, FILE *fp,
                         int x, int y, int radius,
                         int angle1, int angle2,
                         int color,
                         int arc_width, int length, int space)
{
  int da, db, a1, d;

  if (toplevel->print_color) {
    f_print_set_color(fp, color);
  }

  /*! \note
   *  Depending on the radius of the arc, the <B>space</B> (resp. <B>length</B>)
   *  parameter is changed into a small angle <B>da</B> (resp. <B>db</B>).
   *  Starting from <B>angle1</B> - the start angle - the dashes are printed
   *  along the arc by increments of these new angles.
   *
   *  As <B>da</B> (resp. <B>db</B>) is rounded as an integer, it can take a
   *  null value which will make the function enter an endless loop. In such
   *  a case, the arc is printed solid. The <B>da</B> (resp. <B>db</B>) variable
   *  should never be negative except if <B>space</B> (resp. <B>length</B>) is negative.
   *
   *  It prints as many sets of dash-dot-dot as possible.
   */

  /* Inverting angle2 if < 0 and changing angle1 accordingly */
  /* the loop test assume that da > 0 */
  if (angle2 < 0) {
    angle1 = angle1 + angle2;
    angle2 = -angle2;
  }
  da = (int) ((length * 180) / (((double) radius) * M_PI));
  db = (int) ((space  * 180) / (((double) radius) * M_PI));
  
  /* If da or db too small for arc to be displayed as dotted,
     draw a solid arc */
  if ((da <= 0) || (db <= 0)) {
    o_arc_print_solid(toplevel, fp,
                      x, y, radius,
                      angle1, angle2,
                      color,                                              
                      arc_width, length, space);
    return;
  }
  
  fprintf(fp,"[");
  
  d = angle1;
  while ((d + da + 3 * db) < (angle1 + angle2)) {
    a1 = d;
    d = d + da;
    
    fprintf(fp,"[%d %d] ",(int) a1, (int) a1 + da);
    
    d = d + db;
    /*
      xa = ((double) x) + ((double) radius) * cos(d * (M_PI / 180));
      ya = ((double) y) + ((double) radius) * sin(d * (M_PI / 180));
    */
    fprintf(fp,"[%d] ",d);
    
    d = d + db;
    
    /*
      xa = ((double) x) + ((double) radius) * cos(d * (M_PI / 180));
      ya = ((double) y) + ((double) radius) * sin(d * (M_PI / 180));
    */
    fprintf(fp,"[%d] ",d);
    
    d = d + db;
  }

  /*! \note
   *  When the above condition is no more satisfied, then it is not
   *  possible to print a dash of length <B>length</B>.
   *  However three cases are possible :
   *  <DL>
   *    <DT>*</DT><DD>it is possible to print a dash and a dot and a dot
   *    <DT>*</DT><DD>it is possible to print a dash and a dot
   *    <DT>*</DT><DD>it is possible to print the dash or a part of the original dash
   *  </DL>
   */

  a1 = d;
  d = d + da;
  
  fprintf(fp,"[%d %d] ",(int) a1, (int) a1 + da);
  
  if ((d + db) < (angle1 + angle2)) {
    d = d + db;
    
    /*
      xa = ((double) x) + ((double) radius) * cos(d * (M_PI / 180));
      ya = ((double) y) + ((double) radius) * sin(d * (M_PI / 180));
    */
    fprintf(fp,"[%d] ",d);
  }
  
  if ((d + db) < (angle1 + angle2)) {
    d = d + db;
    
    /*
      xa = ((double) x) + ((double) radius) * cos(d * (M_PI / 180));
      ya = ((double) y) + ((double) radius) * sin(d * (M_PI / 180));
    */
    
    fprintf(fp,"[%d] ",d);
  }
  
  fprintf(fp,"] %d %d %d %d dashedarc %% phantom\n",
          x,y, radius, arc_width);
}

/*! \brief Calculates the distance between the given point and the closest
 * point on the perimeter of the arc.
 *
 *  \param [in] arc the arc of the OBJECT
 *  \param [in] x The x coordinate of the given point.
 *  \param [in] y The y coordinate of the given point.
 *  \return The shortest distance from the object to the point. With an
 *  invalid parameter, this function returns G_MAXDOUBLE.
 */
gdouble o_arc_shortest_distance(ARC const *arc, gint x, gint y)
{
  gdouble radius;
  gdouble shortest_distance;

  if (arc == NULL) {
    g_critical("o_arc_shortest_distance(): arc == NULL\n");
    return G_MAXDOUBLE;
  }

  radius = ((gdouble) arc->width) / 2.0;

  if ( o_arc_within_sweep(arc, x, y) ) {
    gdouble distance_to_center;
    gdouble dx;
    gdouble dy;

    dx = ((gdouble) x) - ((gdouble) arc->x);
    dy = ((gdouble) y) - ((gdouble) arc->y);

    distance_to_center = sqrt((dx*dx) + (dy*dy));

    shortest_distance = fabs(distance_to_center - radius);
  }
  else {
    gdouble angle;
    gdouble distance_to_end0;
    gdouble distance_to_end1;
    gdouble dx;
    gdouble dy;

    angle = G_PI * ((gdouble) arc->start_angle ) / 180;

    dx = ((gdouble) x) - radius*cos(angle) - ((gdouble) arc->x);
    dy = ((gdouble) y) - radius*sin(angle) - ((gdouble) arc->y);

    distance_to_end0 = sqrt((dx*dx) + (dy*dy));

    angle += G_PI * ((gdouble) arc->end_angle ) / 180;

    dx = ((gdouble) x) - radius*cos(angle) - ((gdouble) arc->x);
    dy = ((gdouble) y) - radius*sin(angle) - ((gdouble) arc->y);

    distance_to_end1 = sqrt((dx*dx) + (dy*dy));

    shortest_distance = min(distance_to_end0, distance_to_end1);
  }

  return shortest_distance;
}

/*! \brief Determines if a point lies within the sweep of the arc.
 *
 *  \param [in] arc The arc of object
 *  \param [in] x The x coordinate of the given point.
 *  \param [in] y The y coordinate of the given point.
 *  \return TRUE if the point lies within the sweep of the arc.
 *  FALSE if the point lies outside the sweep of the arc. With an 
 *  invalid parameter, this function returns FALSE.
 */
gboolean o_arc_within_sweep(ARC const *arc, gint x, gint y)
{
  gdouble a0;
  gdouble a1;
  gdouble angle;
  gdouble dx;
  gdouble dy;

  if (arc == NULL) {
    g_critical("o_arc_within_sweep(): arc == NULL\n");
    return FALSE;
  }

  dx = ((gdouble) x) - ((gdouble) arc->x);
  dy = ((gdouble) y) - ((gdouble) arc->y);

  angle = 180 * atan2(dy, dx) / G_PI;

  a0 = (gdouble) arc->start_angle;
  a1 = ((gdouble) arc->end_angle) + a0;

  while (angle < a0) {
    angle+=360;
  }

  return (angle < a1);
}