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Overview
Comment:Enhancements to the bubble diagram generator.
Timelines: family | ancestors | bubble-diagrams
Files: files | file ages | folders
SHA1:4dc85d10941b24c932ff9f6d344288ffd135abbe
User & Date: drh 2014-02-02 22:43:16
Context
2014-02-02
22:43
Enhancements to the bubble diagram generator. Leaf check-in: 4dc85d1094 user: drh tags: bubble-diagrams
2014-01-30
20:55
Fix an error in the table-or-subquery syntax diagram. check-in: a467d7a4b8 user: drh tags: trunk
Changes
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Changes to art/syntax/bubble-generator.tcl.

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set font1 {Helvetica 16 bold}     ;# default token font
set font2 {GillSans 14 bold}      ;# default variable font
set RADIUS 9                      ;# default turn radius
set HSEP 17                       ;# horizontal separation
set VSEP 9                        ;# vertical separation
set DPI 80                       ;# dots per inch

















# Draw a right-hand turn around.  Approximately a ")"
#
proc draw_right_turnback {tag x y0 y1} {
  global RADIUS
  if {$y0 + 2*$RADIUS < $y1} {
    set xr0 [expr {$x-$RADIUS}]
................................................................................
  } elseif {[regexp {^[a-z]} $txt]} {
    set font $::font2
    set istoken 0
  } else {
    set font $::font1
    set istoken 1
  }
  set id1 [.c create text 0 0 -anchor c -text $txt -font $font -tags $tag]
  foreach {x0 y0 x1 y1} [.c bbox $id1] break
  set h [expr {$y1-$y0+2}]
  set rad [expr {($h+1)/2}]
  set top [expr {$y0-2}]
  set btm [expr {$y1}]
  set fudge [expr {int(3*$istoken + [string length $txt]*1.4)}]
#puts "fudge($txt)=$fudge"
  set left [expr {$x0+$fudge}]
  set right [expr {$x1-$fudge}]
  if {$left>$right} {
    set left [expr {($x0+$x1)/2}]
    set right $left
  }
  set tag2 x$tagcnt-box
  set tags [list $tag $tag2]
  if {$istoken} {
    .c create arc [expr {$left-$rad}] $top [expr {$left+$rad}] $btm \
         -width 2 -start 90 -extent 180 -style arc -tags $tags
    .c create arc [expr {$right-$rad}] $top [expr {$right+$rad}] $btm \
         -width 2 -start -90 -extent 180 -style arc -tags $tags
    if {$left<$right} {
      .c create line $left $top $right $top -width 2 -tags $tags
      .c create line $left $btm $right $btm -width 2 -tags $tags
    }
  } else {
    .c create rect $left $top $right $btm -width 2 -tags $tags
  }
  foreach {x0 y0 x1 y1} [.c bbox $tag2] break
  set width [expr {$x1-$x0}]
  .c move $tag [expr {-$x0}] 0

  # Entry is always 0 0
  # Return:  TAG EXIT_X EXIT_Y
  #
  return [list $tag $width 0]
}

................................................................................
  set exx 0
  set exy 0
  foreach term $lx {
    set m [draw_diagram $term]
    foreach {t texx texy} $m break
    if {$exx>0} {
      set xn [expr {$exx+$sep}]
      .c move $t $xn $exy
      .c create line [expr {$exx-1}] $exy $xn $exy \
         -tags $tag -width 2 -arrow last
      set exx [expr {$xn+$texx}]
    } else {
      set exx $texx
    }
    set exy $texy
    .c addtag $tag withtag $t
    .c dtag $t $t
  }
  if {$exx==0} {	
    set exx [expr {$sep*2}]
    .c create line 0 0 $sep 0 -width 2 -tags $tag -arrow last
    .c create line $sep 0 $exx 0 -width 2 -tags $tag
    set exx $sep
  }
................................................................................
  foreach term $lb {
    set m [draw_diagram $term]
    foreach {t texx texy} $m break
    foreach {tx0 ty0 tx1 ty1} [.c bbox $t] break
    set w [expr {$tx1-$tx0}]
    if {$exx>0} {
      set xn [expr {$exx+$sep}]
      .c move $t $xn 0
      .c create line $exx $exy $xn $exy -tags $tag -width 2 -arrow first
      set exx [expr {$xn+$texx}]
    } else {
      set exx $texx
    }
    set exy $texy
    .c addtag $tag withtag $t
    .c dtag $t $t
  }
  if {$exx==0} {
    .c create line 0 0 $sep 0 -width 2 -tags $tag
    set exx $sep
  }
  return [list $tag $exx $exy]
}
................................................................................
      if {$bypass_y>0} {
         set mid_y [expr {($bypass_y+$RADIUS+$back_y)/2}]
         .c create line $bypass_x $bypass_y $bypass_x $mid_y \
            -width 2 -tags $tag -arrow last
         .c create line $bypass_x $mid_y $bypass_x [expr {$back_y+$RADIUS}] \
             -tags $tag -width 2
      }
      .c move $t $enter_x $enter_y
      set e2 [expr {$exit_x + $sep}]
      .c create line $exit_x $exit_y $e2 $exit_y \
            -width 2 -tags $tag
      draw_right_turnback $tag $e2 $exit_y $back_y
      set e3 [expr {$enter_x-$sep}]
      set bypass_x [expr {$e3-$RADIUS}]
      set emid [expr {($e2+$e3)/2}]
................................................................................
      set r2 [expr {($enter_y - $back_y)/2.0}]
      draw_left_turnback $tag $e3 $back_y $enter_y down
      .c create line $e3 $enter_y $enter_x $enter_y \
                 -arrow last -width 2 -tags $tag
      set exit_x [expr {$enter_x + $exx}]
      set exit_y [expr {$enter_y + $exy}]
    }
    .c addtag $tag withtag $t
    .c dtag $t $t
    set btm [lindex [.c bbox $tag] 3]
    incr i
  }
  if {$bypass} {
    set fwd_y [expr {$btm + $sep + 1}]
    set mid_y [expr {($next_bypass_y+$RADIUS+$fwd_y)/2}]
    set descender_x [expr {$exit_x+$RADIUS}]
................................................................................
  foreach {ft fexx fexy} [draw_diagram $forward] break
  foreach {fx0 fy0 fx1 fy1} [.c bbox $ft] break
  set fw [expr {$fx1-$fx0}]
  foreach {bt bexx bexy} [draw_backwards_line $back] break
  foreach {bx0 by0 bx1 by1} [.c bbox $bt] break
  set bw [expr {$bx1-$bx0}]
  set dy [expr {$fy1 - $by0 + $vsep}]
  .c move $bt 0 $dy
  set biny $dy
  set bexy [expr {$dy+$bexy}]
  set by0 [expr {$dy+$by0}]
  set by1 [expr {$dy+$by1}]

  if {$fw>$bw} {
    if {$fexx<$fw && $fexx>=$bw} {
      set dx [expr {($fexx-$bw)/2}]
      .c move $bt $dx 0
      set bexx [expr {$dx+$bexx}]
      .c create line 0 $biny $dx $biny -width 2 -tags $bt
      .c create line $bexx $bexy $fexx $bexy -width 2 -tags $bt -arrow first
      set mxx $fexx
    } else {
      set dx [expr {($fw-$bw)/2}]
      .c move $bt $dx 0
      set bexx [expr {$dx+$bexx}]
      .c create line 0 $biny $dx $biny -width 2 -tags $bt
      .c create line $bexx $bexy $fx1 $bexy -width 2 -tags $bt -arrow first
      set mxx $fexx
    }
  } elseif {$bw>$fw} {
    set dx [expr {($bw-$fw)/2}]
    .c move $ft $dx 0
    set fexx [expr {$dx+$fexx}]
    .c create line 0 0 $dx $fexy -width 2 -tags $ft -arrow last
    .c create line $fexx $fexy $bx1 $fexy -width 2 -tags $ft
    set mxx $bexx
  }
  .c addtag $tag withtag $bt
  .c addtag $tag withtag $ft
  .c dtag $bt $bt
  .c dtag $ft $ft
  .c move $tag $sep 0
  set mxx [expr {$mxx+$sep}]
  .c create line 0 0 $sep 0 -width 2 -tags $tag
  draw_left_turnback $tag $sep 0 $biny up
  draw_right_turnback $tag $mxx $fexy $bexy
  foreach {x0 y0 x1 y1} [.c bbox $tag] break
  set exit_x [expr {$mxx+$::RADIUS}]
  .c create line $mxx $fexy $exit_x $fexy -width 2 -tags $tag
................................................................................
  foreach {ft fexx fexy} [draw_diagram $forward] break
  foreach {fx0 fy0 fx1 fy1} [.c bbox $ft] break
  set fw [expr {$fx1-$fx0}]
  foreach {bt bexx bexy} [draw_backwards_line $back] break
  foreach {bx0 by0 bx1 by1} [.c bbox $bt] break
  set bw [expr {$bx1-$bx0}]
  set dy [expr {-($by1 - $fy0 + $vsep)}]
  .c move $bt 0 $dy
  set biny $dy
  set bexy [expr {$dy+$bexy}]
  set by0 [expr {$dy+$by0}]
  set by1 [expr {$dy+$by1}]

  if {$fw>$bw} {
    set dx [expr {($fw-$bw)/2}]
    .c move $bt $dx 0
    set bexx [expr {$dx+$bexx}]
    .c create line 0 $biny $dx $biny -width 2 -tags $bt
    .c create line $bexx $bexy $fx1 $bexy -width 2 -tags $bt -arrow first
    set mxx $fexx
  } elseif {$bw>$fw} {
    set dx [expr {($bw-$fw)/2}]
    .c move $ft $dx 0
    set fexx [expr {$dx+$fexx}]
    .c create line 0 0 $dx $fexy -width 2 -tags $ft
    .c create line $fexx $fexy $bx1 $fexy -width 2 -tags $ft
    set mxx $bexx
  }
  .c addtag $tag withtag $bt
  .c addtag $tag withtag $ft
  .c dtag $bt $bt
  .c dtag $ft $ft
  .c move $tag $sep 0
  set mxx [expr {$mxx+$sep}]
  .c create line 0 0 $sep 0 -width 2 -tags $tag
  draw_left_turnback $tag $sep 0 $biny down
  draw_right_turnback $tag $mxx $fexy $bexy
  foreach {x0 y0 x1 y1} [.c bbox $tag] break
  .c create line $mxx $fexy $x1 $fexy -width 2 -tags $tag
  return [list $tag $x1 $fexy]
................................................................................

  for {set i 0} {$i<$n} {incr i} {
    foreach {t texx texy} $m($i) break
    foreach {tx0 ty0 tx1 ty1} [.c bbox $t] break
    set w [expr {$tx1-$tx0}]
    set dx [expr {($mxw-$w)/2 + $x2}]
    if {$w>10 && $dx>$x2+10} {set dx [expr {$x2+10}]}
    .c move $t $dx 0
    set texx [expr {$texx+$dx}]
    set m($i) [list $t $texx $texy]
    foreach {tx0 ty0 tx1 ty1} [.c bbox $t] break
    if {$i==0} {
      if {$dx>$x2} {set ax last} {set ax none}
      .c create line 0 0 $dx 0 -width 2 -tags $tag -arrow $ax
      .c create line $texx $texy [expr {$x5+1}] $texy -width 2 -tags $tag
................................................................................
      set exy $texy
      .c create arc -$sep 0 $sep [expr {$sep*2}] \
         -width 2 -start 90 -extent -90 -tags $tag -style arc
      set btm $ty1
    } else {
      set dy [expr {$btm - $ty0 + $vsep}]
      if {$dy<2*$sep} {set dy [expr {2*$sep}]}
      .c move $t 0 $dy
      set texy [expr {$texy+$dy}]
      if {$dx>$x2} {
        .c create line $x2 $dy $dx $dy -width 2 -tags $tag -arrow last
        if {$dx<$xc-2} {set ax last} {set ax none}
        .c create line $texx $texy $x3 $texy -width 2 -tags $tag -arrow $ax
      }
      set y1 [expr {$dy-2*$sep}]
................................................................................
           -width 2 -start 180 -extent -90 -tags $tag -style arc
        .c create line $x1 [expr {$dy-$sep}] $x1 $sep -width 2 -tags $tag
        .c create line $x4 [expr {$texy-$sep}] $x4 [expr {$exy+$sep}] \
               -width 2 -tags $tag
      }
      set btm [expr {$ty1+$dy}]
    }
    .c addtag $tag withtag $t
    .c dtag $t $t
  }
  return [list $tag $x5 $exy]   
}

proc draw_tail_branch {lx} {
  global tagcnt
  incr tagcnt
................................................................................
  set x1 $sep                     ;# decender 
  set x2 [expr {$sep*2}]          ;# start of choice

  for {set i 0} {$i<$n} {incr i} {
    foreach {t texx texy} $m($i) break
    foreach {tx0 ty0 tx1 ty1} [.c bbox $t] break
    set dx [expr {$x2+10}]
    .c move $t $dx 0
    foreach {tx0 ty0 tx1 ty1} [.c bbox $t] break
    if {$i==0} {
      .c create line 0 0 $dx 0 -width 2 -tags $tag -arrow last
      .c create arc -$sep 0 $sep [expr {$sep*2}] \
         -width 2 -start 90 -extent -90 -tags $tag -style arc
      set btm $ty1
    } else {
      set dy [expr {$btm - $ty0 + $vsep}]
      if {$dy<2*$sep} {set dy [expr {2*$sep}]}
      .c move $t 0 $dy
      if {$dx>$x2} {
        .c create line $x2 $dy $dx $dy -width 2 -tags $tag -arrow last
      }
      set y1 [expr {$dy-2*$sep}]
      .c create arc $x1 $y1 [expr {$x1+2*$sep}] $dy \
          -width 2 -start 180 -extent 90 -style arc -tags $tag
      if {$i==$n-1} {
        .c create line $x1 [expr {$dy-$sep}] $x1 $sep -width 2 -tags $tag
      }
      set btm [expr {$ty1+$dy}]
    }
    .c addtag $tag withtag $t
    .c dtag $t $t
  }
  return [list $tag 0 0]
}

proc draw_diagram {spec} {
  set n [llength $spec]
  if {$n==1} {
................................................................................

proc draw_graph {name spec {do_xv 1}} {
  .c delete all
  wm deiconify .
  wm title . $name
  draw_diagram "line bullet [list $spec] bullet"
  foreach {x0 y0 x1 y1} [.c bbox all] break
  .c move all [expr {2-$x0}] [expr {2-$y0}]
  foreach {x0 y0 x1 y1} [.c bbox all] break
  .c create rect -100 -100 [expr {$x1+100}] [expr {$y1+100}] \
     -fill white -outline white -tags bgrect
  .c lower bgrect
  .c config -width $x1 -height $y1
  update
  .c postscript -file $name.ps -width [expr {$x1+2}] -height [expr {$y1+2}]







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set font1 {Helvetica 16 bold}     ;# default token font
set font2 {GillSans 14 bold}      ;# default variable font
set RADIUS 9                      ;# default turn radius
set HSEP 17                       ;# horizontal separation
set VSEP 9                        ;# vertical separation
set DPI 80                       ;# dots per inch

# Move all widgets with $tag and/or $tag-txt
#
proc move_glyphs {tag dx dy} {
  .c move $tag $dx $dy
  .c move $tag-txt $dx $dy
}

# Change all widgets tagged with $old to $new or with $old-txt to $new-txt
#
proc retag {old new} {
  .c addtag $new withtag $old
  .c addtag $new-txt withtag $old-txt
  .c dtag $old
  .c dtag $old-txt
}

# Draw a right-hand turn around.  Approximately a ")"
#
proc draw_right_turnback {tag x y0 y1} {
  global RADIUS
  if {$y0 + 2*$RADIUS < $y1} {
    set xr0 [expr {$x-$RADIUS}]
................................................................................
  } elseif {[regexp {^[a-z]} $txt]} {
    set font $::font2
    set istoken 0
  } else {
    set font $::font1
    set istoken 1
  }
  set id1 [.c create text 0 0 -anchor c -text $txt -font $font -tags $tag-txt]
  foreach {x0 y0 x1 y1} [.c bbox $id1] break
  set h [expr {$y1-$y0+2}]
  set rad [expr {($h+1)/2}]
  set top [expr {$y0-2}]
  set btm [expr {$y1}]
  set fudge [expr {int(3*$istoken + [string length $txt]*1.4)}]
#puts "fudge($txt)=$fudge"
  set left [expr {$x0+$fudge}]
  set right [expr {$x1-$fudge}]
  if {$left>$right} {
    set left [expr {($x0+$x1)/2}]
    set right $left
  }


  if {$istoken} {
    .c create arc [expr {$left-$rad}] $top [expr {$left+$rad}] $btm \
         -width 2 -start 90 -extent 180 -style arc -tags $tag
    .c create arc [expr {$right-$rad}] $top [expr {$right+$rad}] $btm \
         -width 2 -start -90 -extent 180 -style arc -tags $tag
    if {$left<$right} {
      .c create line $left $top $right $top -width 2 -tags $tag
      .c create line $left $btm $right $btm -width 2 -tags $tag
    }
  } else {
    .c create rect $left $top $right $btm -width 2 -tags $tag
  }
  foreach {x0 y0 x1 y1} [.c bbox $tag] break
  set width [expr {$x1-$x0}]
  move_glyphs $tag [expr {-$x0}] 0

  # Entry is always 0 0
  # Return:  TAG EXIT_X EXIT_Y
  #
  return [list $tag $width 0]
}

................................................................................
  set exx 0
  set exy 0
  foreach term $lx {
    set m [draw_diagram $term]
    foreach {t texx texy} $m break
    if {$exx>0} {
      set xn [expr {$exx+$sep}]
      move_glyphs $t $xn $exy
      .c create line [expr {$exx-1}] $exy $xn $exy \
         -tags $tag -width 2 -arrow last
      set exx [expr {$xn+$texx}]
    } else {
      set exx $texx
    }
    set exy $texy

    retag $t $tag
  }
  if {$exx==0} {	
    set exx [expr {$sep*2}]
    .c create line 0 0 $sep 0 -width 2 -tags $tag -arrow last
    .c create line $sep 0 $exx 0 -width 2 -tags $tag
    set exx $sep
  }
................................................................................
  foreach term $lb {
    set m [draw_diagram $term]
    foreach {t texx texy} $m break
    foreach {tx0 ty0 tx1 ty1} [.c bbox $t] break
    set w [expr {$tx1-$tx0}]
    if {$exx>0} {
      set xn [expr {$exx+$sep}]
      move_glyphs $t $xn 0
      .c create line $exx $exy $xn $exy -tags $tag -width 2 -arrow first
      set exx [expr {$xn+$texx}]
    } else {
      set exx $texx
    }
    set exy $texy

    retag $t $tag
  }
  if {$exx==0} {
    .c create line 0 0 $sep 0 -width 2 -tags $tag
    set exx $sep
  }
  return [list $tag $exx $exy]
}
................................................................................
      if {$bypass_y>0} {
         set mid_y [expr {($bypass_y+$RADIUS+$back_y)/2}]
         .c create line $bypass_x $bypass_y $bypass_x $mid_y \
            -width 2 -tags $tag -arrow last
         .c create line $bypass_x $mid_y $bypass_x [expr {$back_y+$RADIUS}] \
             -tags $tag -width 2
      }
      move_glyphs $t $enter_x $enter_y
      set e2 [expr {$exit_x + $sep}]
      .c create line $exit_x $exit_y $e2 $exit_y \
            -width 2 -tags $tag
      draw_right_turnback $tag $e2 $exit_y $back_y
      set e3 [expr {$enter_x-$sep}]
      set bypass_x [expr {$e3-$RADIUS}]
      set emid [expr {($e2+$e3)/2}]
................................................................................
      set r2 [expr {($enter_y - $back_y)/2.0}]
      draw_left_turnback $tag $e3 $back_y $enter_y down
      .c create line $e3 $enter_y $enter_x $enter_y \
                 -arrow last -width 2 -tags $tag
      set exit_x [expr {$enter_x + $exx}]
      set exit_y [expr {$enter_y + $exy}]
    }

    retag $t $tag
    set btm [lindex [.c bbox $tag] 3]
    incr i
  }
  if {$bypass} {
    set fwd_y [expr {$btm + $sep + 1}]
    set mid_y [expr {($next_bypass_y+$RADIUS+$fwd_y)/2}]
    set descender_x [expr {$exit_x+$RADIUS}]
................................................................................
  foreach {ft fexx fexy} [draw_diagram $forward] break
  foreach {fx0 fy0 fx1 fy1} [.c bbox $ft] break
  set fw [expr {$fx1-$fx0}]
  foreach {bt bexx bexy} [draw_backwards_line $back] break
  foreach {bx0 by0 bx1 by1} [.c bbox $bt] break
  set bw [expr {$bx1-$bx0}]
  set dy [expr {$fy1 - $by0 + $vsep}]
  move_glyphs $bt 0 $dy
  set biny $dy
  set bexy [expr {$dy+$bexy}]
  set by0 [expr {$dy+$by0}]
  set by1 [expr {$dy+$by1}]

  if {$fw>$bw} {
    if {$fexx<$fw && $fexx>=$bw} {
      set dx [expr {($fexx-$bw)/2}]
      move_glyphs $bt $dx 0
      set bexx [expr {$dx+$bexx}]
      .c create line 0 $biny $dx $biny -width 2 -tags $bt
      .c create line $bexx $bexy $fexx $bexy -width 2 -tags $bt -arrow first
      set mxx $fexx
    } else {
      set dx [expr {($fw-$bw)/2}]
      move_glyphs $bt $dx 0
      set bexx [expr {$dx+$bexx}]
      .c create line 0 $biny $dx $biny -width 2 -tags $bt
      .c create line $bexx $bexy $fx1 $bexy -width 2 -tags $bt -arrow first
      set mxx $fexx
    }
  } elseif {$bw>$fw} {
    set dx [expr {($bw-$fw)/2}]
    move_glyphs $ft $dx 0
    set fexx [expr {$dx+$fexx}]
    .c create line 0 0 $dx $fexy -width 2 -tags $ft -arrow last
    .c create line $fexx $fexy $bx1 $fexy -width 2 -tags $ft
    set mxx $bexx
  }


  retag $bt $tag
  retag $ft $tag
  move_glyphs $tag $sep 0
  set mxx [expr {$mxx+$sep}]
  .c create line 0 0 $sep 0 -width 2 -tags $tag
  draw_left_turnback $tag $sep 0 $biny up
  draw_right_turnback $tag $mxx $fexy $bexy
  foreach {x0 y0 x1 y1} [.c bbox $tag] break
  set exit_x [expr {$mxx+$::RADIUS}]
  .c create line $mxx $fexy $exit_x $fexy -width 2 -tags $tag
................................................................................
  foreach {ft fexx fexy} [draw_diagram $forward] break
  foreach {fx0 fy0 fx1 fy1} [.c bbox $ft] break
  set fw [expr {$fx1-$fx0}]
  foreach {bt bexx bexy} [draw_backwards_line $back] break
  foreach {bx0 by0 bx1 by1} [.c bbox $bt] break
  set bw [expr {$bx1-$bx0}]
  set dy [expr {-($by1 - $fy0 + $vsep)}]
  move_glyphs $bt 0 $dy
  set biny $dy
  set bexy [expr {$dy+$bexy}]
  set by0 [expr {$dy+$by0}]
  set by1 [expr {$dy+$by1}]

  if {$fw>$bw} {
    set dx [expr {($fw-$bw)/2}]
    move_glyphs $bt $dx 0
    set bexx [expr {$dx+$bexx}]
    .c create line 0 $biny $dx $biny -width 2 -tags $bt
    .c create line $bexx $bexy $fx1 $bexy -width 2 -tags $bt -arrow first
    set mxx $fexx
  } elseif {$bw>$fw} {
    set dx [expr {($bw-$fw)/2}]
    move_glyphs $ft $dx 0
    set fexx [expr {$dx+$fexx}]
    .c create line 0 0 $dx $fexy -width 2 -tags $ft
    .c create line $fexx $fexy $bx1 $fexy -width 2 -tags $ft
    set mxx $bexx
  }


  retag $bt $tag
  retag $ft $tag
  move_glyphs $tag $sep 0
  set mxx [expr {$mxx+$sep}]
  .c create line 0 0 $sep 0 -width 2 -tags $tag
  draw_left_turnback $tag $sep 0 $biny down
  draw_right_turnback $tag $mxx $fexy $bexy
  foreach {x0 y0 x1 y1} [.c bbox $tag] break
  .c create line $mxx $fexy $x1 $fexy -width 2 -tags $tag
  return [list $tag $x1 $fexy]
................................................................................

  for {set i 0} {$i<$n} {incr i} {
    foreach {t texx texy} $m($i) break
    foreach {tx0 ty0 tx1 ty1} [.c bbox $t] break
    set w [expr {$tx1-$tx0}]
    set dx [expr {($mxw-$w)/2 + $x2}]
    if {$w>10 && $dx>$x2+10} {set dx [expr {$x2+10}]}
    move_glyphs $t $dx 0
    set texx [expr {$texx+$dx}]
    set m($i) [list $t $texx $texy]
    foreach {tx0 ty0 tx1 ty1} [.c bbox $t] break
    if {$i==0} {
      if {$dx>$x2} {set ax last} {set ax none}
      .c create line 0 0 $dx 0 -width 2 -tags $tag -arrow $ax
      .c create line $texx $texy [expr {$x5+1}] $texy -width 2 -tags $tag
................................................................................
      set exy $texy
      .c create arc -$sep 0 $sep [expr {$sep*2}] \
         -width 2 -start 90 -extent -90 -tags $tag -style arc
      set btm $ty1
    } else {
      set dy [expr {$btm - $ty0 + $vsep}]
      if {$dy<2*$sep} {set dy [expr {2*$sep}]}
      move_glyphs $t 0 $dy
      set texy [expr {$texy+$dy}]
      if {$dx>$x2} {
        .c create line $x2 $dy $dx $dy -width 2 -tags $tag -arrow last
        if {$dx<$xc-2} {set ax last} {set ax none}
        .c create line $texx $texy $x3 $texy -width 2 -tags $tag -arrow $ax
      }
      set y1 [expr {$dy-2*$sep}]
................................................................................
           -width 2 -start 180 -extent -90 -tags $tag -style arc
        .c create line $x1 [expr {$dy-$sep}] $x1 $sep -width 2 -tags $tag
        .c create line $x4 [expr {$texy-$sep}] $x4 [expr {$exy+$sep}] \
               -width 2 -tags $tag
      }
      set btm [expr {$ty1+$dy}]
    }

    retag $t $tag
  }
  return [list $tag $x5 $exy]   
}

proc draw_tail_branch {lx} {
  global tagcnt
  incr tagcnt
................................................................................
  set x1 $sep                     ;# decender 
  set x2 [expr {$sep*2}]          ;# start of choice

  for {set i 0} {$i<$n} {incr i} {
    foreach {t texx texy} $m($i) break
    foreach {tx0 ty0 tx1 ty1} [.c bbox $t] break
    set dx [expr {$x2+10}]
    move_glyphs $t $dx 0
    foreach {tx0 ty0 tx1 ty1} [.c bbox $t] break
    if {$i==0} {
      .c create line 0 0 $dx 0 -width 2 -tags $tag -arrow last
      .c create arc -$sep 0 $sep [expr {$sep*2}] \
         -width 2 -start 90 -extent -90 -tags $tag -style arc
      set btm $ty1
    } else {
      set dy [expr {$btm - $ty0 + $vsep}]
      if {$dy<2*$sep} {set dy [expr {2*$sep}]}
      move_glyphs $t 0 $dy
      if {$dx>$x2} {
        .c create line $x2 $dy $dx $dy -width 2 -tags $tag -arrow last
      }
      set y1 [expr {$dy-2*$sep}]
      .c create arc $x1 $y1 [expr {$x1+2*$sep}] $dy \
          -width 2 -start 180 -extent 90 -style arc -tags $tag
      if {$i==$n-1} {
        .c create line $x1 [expr {$dy-$sep}] $x1 $sep -width 2 -tags $tag
      }
      set btm [expr {$ty1+$dy}]
    }

    retag $t $tag
  }
  return [list $tag 0 0]
}

proc draw_diagram {spec} {
  set n [llength $spec]
  if {$n==1} {
................................................................................

proc draw_graph {name spec {do_xv 1}} {
  .c delete all
  wm deiconify .
  wm title . $name
  draw_diagram "line bullet [list $spec] bullet"
  foreach {x0 y0 x1 y1} [.c bbox all] break
  move_glyphs all [expr {2-$x0}] [expr {2-$y0}]
  foreach {x0 y0 x1 y1} [.c bbox all] break
  .c create rect -100 -100 [expr {$x1+100}] [expr {$y1+100}] \
     -fill white -outline white -tags bgrect
  .c lower bgrect
  .c config -width $x1 -height $y1
  update
  .c postscript -file $name.ps -width [expr {$x1+2}] -height [expr {$y1+2}]