## -*-octave-*-

function [bonds] = \
      rbg2ibg(name,rbonds,rstrokes,rcomponents,port_coord,port_name, \
	      infofile, errorfile)

  rbonds
  rstrokes
  rcomponents
  port_coord
  port_name

  ## Default to no components
  components = [0];

  ## Xfig scaling factor
  scale = 1200.0/2.54546;

  ## Rotation matrix
  rot = [0, -1; 1, 0];

  ## Find number of strokes
  [n_strokes,columns] = size(rstrokes);
  if ((columns ~= 4) & (n_strokes > 0))
    error('Incorrect rstrokes matrix: must have 4 columns');
  endif

  ## Find number of bonds
  [n_bonds,columns] = size(rbonds);
  if ((columns ~= 6) & (n_bonds > 0))
    error('Incorrect rbonds matrix: must have 6 columns');
  endif

  ## Find number of components
  [n_components,columns] = size(rcomponents);

  ## Find number of ports referred to
  [n_ports,columns] = size(port_coord);
  
  ## If port_name empty, make it empty string
  if (length(port_name) == 0)
    port_name="";
  endif
  
  ## Determine coordinates of arrow end of bond and other end
  other_end_1	= rbonds(:,1:2);
  arrow_end	= rbonds(:,3:4);
  other_end_2	= rbonds(:,5:6);

  distance_1	= length2d(other_end_1 - arrow_end);
  distance_2	= length2d(other_end_2 - arrow_end);
  which_end	= (distance_1 > distance_2) * [1, 1];
  one		= ones(size(which_end));
  other_end	= which_end .* other_end_1 + (one - which_end) .* \
      other_end_2;
  arrow_vector	= (which_end .* other_end_2 + (one - which_end) .* \
		   other_end_1) - arrow_end;
  
  ## Locate bond end nearest each port
  ## col 1 of port_near_bond contains a signed bond number (+ for arrow
  ## end)
  ## col 2 of port_near_bond contains the corresponding port index
  port_bond = [];
  for i = 1:n_ports
    near_bond = adjbond(port_coord(i,1:2), arrow_end, other_end);
    [rows,cols] = size(near_bond);
    if (rows > 1)
      error(sprintf ...
	    ("A port is near to more than one bond at coordinates \
	  %g,%g %s\n", ...
	     port_coord(i,1)/scale, port_coord(i,2)/scale, \
	     deblank(port_name(i,:))));
    endif
    
    ## The (signed) bond corresponding to the ith port label
    port_bond(i) = near_bond(1) * sign(1.5 - near_bond(2));
  endfor
  
  port_bond
  ## Now have (signed) bond (port_bond(i)) corresponding to the ith port
  ## Create inverse mapping
  for i = 1:n_bonds
    eval(sprintf('bond_port_head%i = "[]"', i))
    eval(sprintf('bond_port_tail%i = "[]"', i))
  endfor  
  for i = 1:n_ports
    if (port_bond(i) > 0)
      eval(sprintf('bond_port_head%i = "%s"', port_bond(i), \
		   deblank(port_name(i,:))))
    else
      eval(sprintf('bond_port_tail%i = "%s"', -port_bond(i), \
		   deblank(port_name(i,:))))
    endif
  endfor
  
  ## Locate the components at the ends of each bond
  ## col 1 of comp_near_bond contains component nearest to the arrow end
  ## col 2 of comp_near_bond contains component nearest other end
  for i = 1:n_bonds
    comp_near_bond(i,:) = adjcomp(arrow_end(i,:), other_end(i,:), \
				  rcomponents);
    [hc_type, hc_name] = eval([name, '_cmp(comp_near_bond(i,1))']);
    [tc_type, tc_name] = eval([name, '_cmp(comp_near_bond(i,2))']);
  endfor

  ## Deduce causality from the strokes (if any)
  causality = zeros(n_bonds,2);
  if (n_strokes > 0)
    ## Find location of centre and ends of stroke
    stroke_end_1	= [rstrokes(:,1), rstrokes(:,2)];
    stroke_end_2	= [rstrokes(:,3), rstrokes(:,4)];

    stroke_centre	= (stroke_end_1 + stroke_end_2)/2;
    stroke_vector	= (stroke_end_1 - stroke_end_2);
    stroke_length	= length2d(stroke_vector);

    for i = 1:n_strokes
      stroke = [stroke_centre(i,:)
		stroke_end_1(i,:)
		stroke_end_2(i,:)];


      ## Find the nearest bond end
      [index,distance] = adjbond(stroke(1,:),arrow_end,other_end);
      if (distance > (2 * stroke_length(i)))
	info = sprintf('Stroke at (%4.3f,%4.3f) is %4.3f away from the nearest bond\n', ...
		       stroke(1,1)/scale, stroke(1,2)/scale, \
		       distance/scale);
      endif

      ## Bond end coordinates
      j = index(1,1);
      which_end = (index(1,2) == 1);
      bond_end = arrow_end(j,:) * which_end + other_end(j,:) * (1 - \
								which_end);
      
      ## Now decide which bit of the stroke is nearest
      stroke_index = adjbond(bond_end, stroke, zeros(size(stroke)));

      if (stroke_index(1) == 1)	# uni-causal stroke
	causality(j,1:2) = (2 * which_end - 1) * [1, 1];
      else			# bi-causal stroke
	stroke_direction = stroke(1,:) - stroke(stroke_index(1),:);
	flow_side = stroke_direction * arrow_vector(j,:)' > 0;
	causality(j,1+flow_side) = 2 * which_end - 1;
      endif
    endfor
  endif

  ## Return data
  for i = 1:n_bonds
    eval(sprintf("bonds.bond%i.head.component\t= '%s:%s'", i, hc_type, \
		 hc_name));
    eval(sprintf("bonds.bond%i.tail.component\t= '%s:%s'", i, tc_type, \
		 tc_name));
    eval(sprintf("bonds.bond%i.head.ports\t= bond_port_head%i", i, i));
    eval(sprintf("bonds.bond%i.tail.ports\t= bond_port_tail%i", i, i));
  endfor
  
  
  
endfunction

## -*-octave-*-

function write_ibg(system_name,bonds);
  
  fid = fopen([system_name,"_ibg.m"], "w");
  [nbonds, junk] = size(struct_elements(bonds));
  format_hc = "  %s.bonds.b%i.head.component\t= \"%s\";\n";
  format_tc = "  %s.bonds.b%i.tail.component\t= \"%s\";\n";
  format_hp = "  %s.bonds.b%i.head.ports\t= \"%s\";\n";
  format_tp = "  %s.bonds.b%i.tail.ports\t= \"%s\";\n";
  format_ce = "  %s.bonds.b%i.causality.effort\t= \"%s\";\n";
  format_cf = "  %s.bonds.b%i.causality.flow\t= \"%s\";\n";

  fprintf(fid, "## -*-octave-*-\n\n");
  fprintf(fid, "function [%s] = %s_ibg\n\n", system_name, system_name);
  fprintf(fid, "## Intermediate bond graph representation of %s\n", \
	  system_name);

  fprintf(fid, "## Generated by MTT on %s\n", ctime(time));

  for i=1:nbonds
    fprintf(fid, "\n  ## bond %i\n", i);
    fprintf(fid, format_hc, system_name, i, \
	    eval(sprintf("bonds.bond%i.head.component", i)));
    fprintf(fid, format_tc, system_name, i, \
	    eval(sprintf("bonds.bond%i.tail.component", i)));
    fprintf(fid, format_hp, system_name, i, \
	    eval(sprintf("bonds.bond%i.head.ports", i)));
    fprintf(fid, format_tp, system_name, i, \
	    eval(sprintf("bonds.bond%i.tail.ports", i)));
    fprintf(fid, format_ce, system_name, i, "FIXME");
    fprintf(fid, format_cf, system_name, i, "FIXME");
  endfor;

  fprintf(fid, "\nendfunction\n");
  fclose(fid);

endfunction;

#! /bin/sh


     ###################################### 
     ##### Model Transformation Tools #####
     ######################################

# Bourne shell script: rbg2ibg_m
# Based on rbg2abg_m

while [ -n "`echo $1 | grep '^-'`" ]; do
    case $1 in
	-I)
	    info=info;;
	*)
	    echo "$1 is an invalid argument - ignoring" ;;
    esac
    shift
done

# Set up some vars
sys=$1
ibg=${sys}_ibg.m
err=mtt_error.txt
log=rbg2ibg_m.log

# Remove the old log file
rm -f ${ibg}
rm -f ${log}

# Inform user
echo Creating ${ibg}

# Use matrix manipulation to accomplish the transformation
${MATRIX} > ${log} 2> ${err} <<EOF
	name = '$1'
	infofile = fopen('mtt_info.txt', 'w');
	errorfile = fopen('mtt_error.txt', 'w');

	## Interpret the connections from the fig version
	[rbonds,rstrokes,rcomponents,port_coord,port_name,port_list] = $1_rbg;
	[n_ports, junk] = size(port_list);

	## Strip the directional information
	rbonds = rbonds(:,1:6);

	[bonds] = \
	    rbg2ibg(name,rbonds,rstrokes,rcomponents,port_coord,port_name, \
		    infofile,errorfile);

	## Write the intermediate bond graph m-file
	write_ibg(name,bonds);
EOF

# Errors and info
if [ "$info" = "info" ]; then
    cat mtt_info.txt
fi

if mtt_error mtt_error.txt; then
    exit 0
else
    exit 1
fi