# Copyright (c) P.J.Gawthrop, 1996.

###############################################################
## Version control history
###############################################################
## $Id$
## $Log$
## Revision 1.16  1996/12/30 20:00:29  peterg
## Fixed bent-bond bug.
## NB unfixed problems:
## 1. xfig writes multi line fields if more than about 5 segments.
## 2. rbg2abg takes a multi-segment bond as a straignt line between the
## end points - so computation of stroke and arrow directions may be
## iffy.
##
## Revision 1.15  1996/12/30 19:23:35  peterg
##  Allows for bent bonds - ie bonds with more than 2 line segments.
##
## Revision 1.14  1996/12/21 19:47:53  peterg
## Changed \* to \\*
##
## Revision 1.13  1996/12/21 19:47:23  peterg

# as follows:
#
# Bonds are firm (not dashed etc) polylines with n line segments - 
#  fig represents this by  a firstline record where
#    field 1 = 2 (always 2)
#    field 2 = 1 (polyline)
#    field 3 = 0 (style is a firm line)
#    field 7 = 0 (depth is zero [top level])
#    field 14 = 0 (no forward arrow)
#    field 15 = 0 (backward arrow) 
#    field 16 = Number of point in line (points=segments+1)
#  a data field starting with a tab followed by  points (x,y) cordinates
#
#
# Strokes are polylines with 1 line segment and and no arrow 

function process_text() {
# The text string is field 14 onwards
  str = $14; 
  for (i=15; i<=NF; i++) {
    str = sprintf("%s %s", str, $i)
      }

# The depth is field 4
  depth = $4; 

# It is terminated by /001 - so delete this termination
  str = substr(str,1,length(str)-4);

# A component string contains only alphanumeric  _ and :
  isa_plain_component = match(str, component_regexp)==0;
# It must also be specified at depth 0
  isa_plain_component = isa_plain_component && (depth==0);

# A port is an integer within [] and no alpha characters
  isa_port = (match(str, port_regexp)>0)&&(match(str, nonport_regexp)==0);
# It must also be specified at depth 0
  isa_port = isa_port && (depth==0);

# A port component is SS followed by : followed by a port string
  isa_port_component = 0;
  if (match(str, delimiter)) {
    split(str,a,delimiter);
    isa_port_component = (exact_match(a[1], "SS"))&&
      (match(a[2], port_regexp)>0)
      }
# It must also be specified at depth 0
  isa_port_component = isa_port_component && (depth==0);
    

# A component is a plain or a port component
  isa_component = isa_plain_component||isa_port_component;

# Coordinates in fields 12 & 13
  x_coord = $12;
  y_coord = $13;

  first_line = (data_line==0)&&(NF>min_line_length);

#Process firstline
  if (first_line) {
    object = $1;
    sub_type = $2;
    style = $3;
    zero_depth = (($7==0)&&(object=polyline)) || (($4==0)&&(object=text));
    f_arrow = ($14==1)&&(object=polyline);
    b_arrow = ($15==1)&&(object=polyline);
    arrow = f_arrow||b_arrow;
    arg_count = 0;
  }

#Process text
  if (object==text) {
    process_text()
      }

# Process bond
  if ( \
(data_line)&& \
(data_line)&& zero_depth &&\
       (object==polyline)&& \
       (sub_type==sub_polyline)&& \
       (style==firm_style) \
       ) {
    process_bond()
      }