object.cc

早期freebsd实现

  arrow_at_end = at_end;
  aht = a;
}

line_object::line_object(const position &s, const position &e,
			 position *p, int i)
: v(p), n(i), linear_object(s, e)
{
}

void line_object::print()
{
  if (lt.type == line_type::invisible)
    return;
  out->line(strt, v, n, lt);
  if (arrow_at_start)
    draw_arrow(strt, strt-v[0], aht, lt);
  if (arrow_at_end)
    draw_arrow(en, v[n-1] - (n > 1 ? v[n - 2] : strt), aht, lt);
}

void line_object::update_bounding_box(bounding_box *p)
{
  p->encompass(strt);
  for (int i = 0; i < n; i++)
    p->encompass(v[i]);
}

void line_object::move_by(const position &pos)
{
  linear_object::move_by(pos);
  for (int i = 0; i < n; i++)
    v[i] += pos;
}
  
void spline_object::update_bounding_box(bounding_box *p)
{
  p->encompass(strt);
  p->encompass(en);
  /*

  If

  p1 = q1/2 + q2/2
  p2 = q1/6 + q2*5/6
  p3 = q2*5/6 + q3/6
  p4 = q2/2 + q3/2
  [ the points for the Bezier cubic ]

  and

  t = .5

  then

  (1-t)^3*p1 + 3*t*(t - 1)^2*p2 + 3*t^2*(1-t)*p3 + t^3*p4
  [ the equation for the Bezier cubic ]

  = .125*q1 + .75*q2 + .125*q3

  */
  for (int i = 1; i < n; i++)
    p->encompass((i == 1 ? strt : v[i-2])*.125 + v[i-1]*.75 + v[i]*.125);
}

arrow_object::arrow_object(const position &s, const position &e,
			   position *p, int i)
: line_object(s, e, p, i)
{
}

spline_object::spline_object(const position &s, const position &e,
			     position *p, int i)
: line_object(s, e, p, i)
{
}

void spline_object::print()
{
  if (lt.type == line_type::invisible)
    return;
  out->spline(strt, v, n, lt);
  if (arrow_at_start)
    draw_arrow(strt, strt-v[0], aht, lt);
  if (arrow_at_end)
    draw_arrow(en, v[n-1] - (n > 1 ? v[n - 2] : strt), aht, lt);
}

line_object::~line_object()
{
  a_delete v;
}

linear_object *object_spec::make_line(position *curpos, direction *dirp)
{
  static position last_line;
  static int have_last_line = 0;
  *dirp = dir;
  // No need to look at at since `at' attribute sets `from' attribute.
  position startpos = (flags & HAS_FROM) ? from : *curpos;
  if (!(flags & HAS_SEGMENT)) {
    if ((flags & IS_SAME) && (type == LINE_OBJECT || type == ARROW_OBJECT)
	&& have_last_line)
      segment_pos = last_line;
    else 
      switch (dir) {
      case UP_DIRECTION:
	segment_pos.y = segment_height;
	break;
      case DOWN_DIRECTION:
	segment_pos.y = -segment_height;
	break;
      case LEFT_DIRECTION:
	segment_pos.x = -segment_width;
	break;
      case RIGHT_DIRECTION:
	segment_pos.x = segment_width;
	break;
      default:
	assert(0);
      }
  }
  segment_list = new segment(segment_pos, segment_is_absolute, segment_list);
  // reverse the segment_list so that it's in forward order
  segment *old = segment_list;
  segment_list = 0;
  while (old != 0) {
    segment *tem = old->next;
    old->next = segment_list;
    segment_list = old;
    old = tem;
  }
  // Absolutise all movements
  position endpos = startpos;
  int nsegments = 0;
  for (segment *s = segment_list; s; s = s->next, nsegments++)
    if (s->is_absolute)
      endpos = s->pos;
    else {
      endpos += s->pos;
      s->pos = endpos;
      s->is_absolute = 1;	// to avoid confusion
    }
  // handle chop
  line_object *p = 0;
  position *v = new position[nsegments];
  int i = 0;
  for (s = segment_list; s; s = s->next, i++)
    v[i] = s->pos;
  if (flags & IS_DEFAULT_CHOPPED) {
    lookup_variable("circlerad", &start_chop);
    end_chop = start_chop;
    flags |= IS_CHOPPED;
  }
  if (flags & IS_CHOPPED) {
    position start_chop_vec, end_chop_vec;
    if (start_chop != 0.0) {
      start_chop_vec = v[0] - startpos;
      start_chop_vec *= start_chop / hypot(start_chop_vec);
    }
    if (end_chop != 0.0) {
      end_chop_vec = (v[nsegments - 1]
		      - (nsegments > 1 ? v[nsegments - 2] : startpos));
      end_chop_vec *= end_chop / hypot(end_chop_vec);
    }
    startpos += start_chop_vec;
    v[nsegments - 1] -= end_chop_vec;
    endpos -= end_chop_vec;
  }
  switch (type) {
  case SPLINE_OBJECT:
    p = new spline_object(startpos, endpos, v, nsegments);
    break;
  case ARROW_OBJECT:
    p = new arrow_object(startpos, endpos, v, nsegments);
    break;
  case LINE_OBJECT:
    p = new line_object(startpos, endpos, v, nsegments);
    break;
  default:
    assert(0);
  }
  have_last_line = 1;
  last_line = endpos - startpos;
  *curpos = endpos;
  return p;
}

class arc_object : public linear_object {
  int clockwise;
  position cent;
  double rad;
public:
  arc_object(int, const position &, const position &, const position &);
  position origin() { return cent; }
  position center() { return cent; }
  double radius() { return rad; }
  position north();
  position south();
  position east();
  position west();
  position north_east();
  position north_west();
  position south_east();
  position south_west();
  void update_bounding_box(bounding_box *);
  object_type type() { return ARC_OBJECT; }
  void print();
  void move_by(const position &pos);
};

arc_object::arc_object(int cw, const position &s, const position &e,
		       const position &c)
: linear_object(s, e), clockwise(cw), cent(c)
{
  rad = hypot(c - s);
}

void arc_object::move_by(const position &pos)
{
  linear_object::move_by(pos);
  cent += pos;
}

// we get arc corners from the corresponding circle

position arc_object::north()
{
  position result(cent);
  result.y += rad;
  return result;
}

position arc_object::south()
{
  position result(cent);
  result.y -= rad;
  return result;
}

position arc_object::east()
{
  position result(cent);
  result.x += rad;
  return result;
}

position arc_object::west()
{
  position result(cent);
  result.x -= rad;
  return result;
}

position arc_object::north_east()
{
  position result(cent);
  result.x += rad/M_SQRT2;
  result.y += rad/M_SQRT2;
  return result;
}

position arc_object::north_west()
{
  position result(cent);
  result.x -= rad/M_SQRT2;
  result.y += rad/M_SQRT2;
  return result;
}

position arc_object::south_east()
{
  position result(cent);
  result.x += rad/M_SQRT2;
  result.y -= rad/M_SQRT2;
  return result;
}

position arc_object::south_west()
{
  position result(cent);
  result.x -= rad/M_SQRT2;
  result.y -= rad/M_SQRT2;
  return result;
}


void arc_object::print()
{
  if (lt.type == line_type::invisible)
    return;
  if (clockwise)
    out->arc(en, cent, strt, lt);
  else
    out->arc(strt, cent, en, lt);
  if (arrow_at_start) {
    position c = cent - strt;
    draw_arrow(strt,
	       (clockwise ? position(c.y, -c.x) : position(-c.y, c.x)),
	       aht, lt);
  }
  if (arrow_at_end) {
    position e = en - cent;
    draw_arrow(en,
	       (clockwise ? position(e.y, -e.x) : position(-e.y, e.x)),
	       aht, lt);
  }
}

inline double max(double a, double b)
{
  return a > b ? a : b;
}

void arc_object::update_bounding_box(bounding_box *p)
{
  p->encompass(strt);
  p->encompass(en);
  position start_offset = strt - cent;
  if (start_offset.x == 0.0 && start_offset.y == 0.0)
    return;
  position end_offset = en  - cent;
  if (end_offset.x == 0.0 && end_offset.y == 0.0)
    return;
  double start_quad = atan2(start_offset.y, start_offset.x)/(M_PI/2.0);
  double end_quad = atan2(end_offset.y, end_offset.x)/(M_PI/2.0);
  if (clockwise) {
    double temp = start_quad;
    start_quad = end_quad;
    end_quad = temp;
  }
  if (start_quad < 0.0)
    start_quad += 4.0;
  while (end_quad <= start_quad)
    end_quad += 4.0;
  double radius = max(hypot(start_offset), hypot(end_offset));
  for (int q = int(start_quad) + 1; q < end_quad; q++) {
    position offset;
    switch (q % 4) {
    case 0:
      offset.x = radius;
      break;
    case 1:
      offset.y = radius;
      break;
    case 2:
      offset.x = -radius;
      break;
    case 3:
      offset.y = -radius;
      break;
    }
    p->encompass(cent + offset);
  }
}

// We ignore the with attribute. The at attribute always refers to the center.

linear_object *object_spec::make_arc(position *curpos, direction *dirp)
{
  *dirp = dir;
  int cw = (flags & IS_CLOCKWISE) != 0;
  // compute the start
  position startpos;
  if (flags & HAS_FROM)
    startpos = from;
  else
    startpos = *curpos;
  if (!(flags & HAS_RADIUS))
    lookup_variable("arcrad", &radius);
  // compute the end
  position endpos;
  if (flags & HAS_TO)
    endpos = to;
  else {
    position m(radius, radius);
    // Adjust the signs.
    if (cw) {
      if (dir == DOWN_DIRECTION || dir == LEFT_DIRECTION)
	m.x = -m.x;
      if (dir == DOWN_DIRECTION || dir == RIGHT_DIRECTION)
	m.y = -m.y;
      *dirp = direction((dir + 3) % 4);
    }
    else {
      if (dir == UP_DIRECTION || dir == LEFT_DIRECTION)
	m.x = -m.x;
      if (dir == DOWN_DIRECTION || dir == LEFT_DIRECTION)
	m.y = -m.y;
      *dirp = direction((dir + 1) % 4);
    }
    endpos = startpos + m;
  }
  // compute the center
  position centerpos;
  if (flags & HAS_AT)
    centerpos = at;
  else if (startpos == endpos)
    centerpos = startpos;
  else {
    position h = (endpos - startpos)/2.0;
    double d = hypot(h);
    if (radius <= 0)
      radius = .25;
    // make the radius big enough
    while (radius < d)
      radius *= 2.0;
    double alpha = acos(d/radius);
    double theta = atan2(h.y, h.x);
    if (cw)
      theta -= alpha;
    else
      theta += alpha;
    centerpos = position(cos(theta), sin(theta))*radius + startpos;
  }
  arc_object *p = new arc_object(cw, startpos, endpos, centerpos);
  *curpos = endpos;
  return p;
}

graphic_object *object_spec::make_linear(position *curpos, direction *dirp)
{
  linear_object *obj;
  if (type == ARC_OBJECT)
    obj = make_arc(curpos, dirp);
  else
    obj = make_line(curpos, dirp);
  if (type == ARROW_OBJECT
      && (flags & (HAS_LEFT_ARROW_HEAD|HAS_RIGHT_ARROW_HEAD)) == 0)
    flags |= HAS_RIGHT_ARROW_HEAD;
  if (obj && (flags & (HAS_LEFT_ARROW_HEAD|HAS_RIGHT_ARROW_HEAD))) {
    arrow_head_type a;
    int at_start = (flags & HAS_LEFT_ARROW_HEAD) != 0;
    int at_end = (flags & HAS_RIGHT_ARROW_HEAD) != 0;
    if (flags & HAS_HEIGHT)
      a.height = height;
    else
      lookup_variable("arrowht", &a.height);
    if (flags & HAS_WIDTH)
      a.width = width;
    else
      lookup_variable("arrowwid", &a.width);
    double solid;
    lookup_variable("arrowhead", &solid);
    a.solid = solid != 0.0;
    obj->add_arrows(at_start, at_end, a);
  }
  return obj;
}

object *object_spec::make_object(position *curpos, direction *dirp)
{
  graphic_object *obj = 0;
  switch (type) {
  case BLOCK_OBJECT:
    obj = make_block(curpos, dirp);
    break;
  case BOX_OBJECT:
    obj = make_box(curpos, dirp);
    break;
  case TEXT_OBJECT:
    obj = make_text(curpos, dirp);
    break;
  case ELLIPSE_OBJECT:
    obj = make_ellipse(curpos, dirp);
    break;
  case CIRCLE_OBJECT:
    obj = make_circle(curpos, dirp);
    break;
  case MOVE_OBJECT:
    obj = make_move(curpos, dirp);
    break;
  case ARC_OBJECT:
  case LINE_OBJECT:
  case SPLINE_OBJECT:
  case ARROW_OBJECT:
    obj = make_linear(curpos, dirp);
    break;
  case MARK_OBJECT:
  case OTHER_OBJECT:
  default:
    assert(0);
    break;
  }
  if (obj) {
    if (flags & IS_INVISIBLE)
      obj->set_invisible();
    if (text != 0)
      obj->add_text(text, (flags & IS_ALIGNED) != 0);
    if (flags & IS_DOTTED)
      obj->set_dotted(dash_width);
    else if (flags & IS_DASHED)
      obj->set_dashed(dash_width);
    double th;
    if (flags & HAS_THICKNESS)
      th = thickness;
    else
      lookup_variable("linethick", &th);
    obj->set_thickness(th);
    if (flags & (IS_DEFAULT_FILLED|IS_FILLED)) {
      if (flags & IS_DEFAULT_FILLED)
	lookup_variable("fillval", &fill);
      if (fill < 0.0)
	error("bad fill value %1", fill);
      else
	obj->set_fill(fill);
    }
  }
  return obj;
}

struct string_list {
  string_list *next;
  char *str;
  string_list(char *);
  ~string_list();
};

string_list::string_list(char *s)
: next(0), str(s)
{
}

string_list::~string_list()
{
  a_delete str;
}
  
/* A path is used to hold the argument to the with attribute. For example,
`.nw' or `.A.s' or `.A'. The major operation on a path is to take a 
place and follow the path through the place to place within the place.
Note that `.A.B.C.sw' will work. */

path::path(corner c)
: label_list(0), crn(c)
{
}

path::path(char *l, corner c)
: crn(c)
{
  label_list = new string_list(l);
}

path::~path()
{
  while (label_list) {
    string_list *tem = label_list;
    label_list = label_list->next;
    delete tem;
  }
}

void path::append(corner c)
{
  assert(crn == 0);
  crn = c;
}

void path::append(char *s)
{
  for (string_list **p = &label_list; *p; p = &(*p)->next)
    ;
  *p = new string_list(s);
}

// return non-zero for success

int path::follow(const place &pl, place *result) const
{
  const place *p = &pl;
  for (string_list *lb = label_list; lb; lb = lb->next)
    if (p->obj == 0 || (p = p->obj->find_label(lb->str)) == 0) {
      lex_error("object does not contain a place `%1'", lb->str);
      return 0;
    }
  if (crn == 0 || p->obj == 0)
    *result = *p;
  else {
    position pos = ((p->obj)->*(crn))();
    result->x = pos.x;
    result->y = pos.y;
    result->obj = 0;
  }
  return 1;
}

void print_object_list(object *p)
{
  for (; p; p = p->next) {
    p->print();
    p->print_text();
  }
}

void print_picture(object *obj)
{
  bounding_box bb;
  for (object *p = obj; p; p = p->next)
    p->update_bounding_box(&bb);
  double scale;
  lookup_variable("scale", &scale);
  out->start_picture(scale, bb.ll, bb.ur);
  print_object_list(obj);
  out->finish_picture();
}