broken_line documentation.

This glyph draws a straight line whose segment is shifted ('sheared')
up or down. There can be an optional "beak' (two diagonal lines
passing between the main line and its segment).
Either the left or the right side of the main line can be absent.
The line can be of fixed size or extend to take up all available space. In addition to the common options, the following glyph-specific
options are recognized:

  Option      Description                  Default
  ------      -----------                  -------

  -draw_beak Whether to draw the 'beak'.        1

  -shear    Vertical distance between     	5
			the main line and the segment

  -shear_up Whether to shift the segment 	1
				up or down (1 or 0)

  -break 	Width of the break in the line 	8

  -extend  	Whether to extend the line or   1 
			to keep the length fixed (1 or 0) 

  -size  	Total length of the line and   30 
			the break, if extend is 0

  -omit_left	Whether to omit the left	0
			half of the main line

  -omit_right	Whether to omit the right	0
			half of the main line

sub draw_component {

  my $self = shift;
  my $gd = shift;
  my ($x1,$y1,$x2,$y2) = $self->calculate_boundaries(@_);
  
  my $fg = $self->fgcolor;
  my $bg = $self->bgcolor;
  
  my $shear = defined $self->option('shear') ? $self->option('shear') : $self->default_shear();
  my $shear_up = defined $self->option('shear_up') ? $self->option('shear_up') : $self->default_shear_up();
  my $break = defined $self->option('break') ? $self->option('break') : $self->default_break();
  my $draw_beak = defined $self->option('draw_beak') ? $self->option('draw_beak') : $self->default_draw_beak();
  my $extend= defined $self->option('extend') ? $self->option('extend') : $self->default_extend();
  my $size = defined $self->option('size') ? $self->option('size') : $self->default_size();
  my $omit_left = defined $self->option('omit_left') ? $self->option('omit_left') : $self->default_omit_left();
  my $omit_right = defined $self->option('omit_right') ? $self->option('omit_right') : $self->default_omit_right();

  my $midY = ($y1+$y2)/2;
  
  if ($x2-$x1 < $size)
  {
    $gd->line($x1, $midY, $x2, $midY, $bg);
    return;
  }
  
  my $midX = ($x1+$x2)/2;
  
  my $break_start = $midX - $break/2;
  my $break_end = $midX + $break/2;
  
  my ($x11, $x12, $x21, $x22);
  $x12 = $break_start;
  $x21 = $break_end;

  if ($omit_left)
  {
    $break_start = $x1;
    $break_end = $x1+$break;
    $x21 = $break_end;
    $x22 = ($extend ? $x2 : $x21 + $size - $break);
  }
  elsif ($omit_right)
  {
    $x11 = $x1;
    $x12 = ($extend ? $x2 - $break : $x11 + $size - $break);
    $break_end = $x12+$break;
    $break_start = $x12;
  }
  else
  {
    if ($extend)
    {
      $x11 = $x1;
      $x22 = $x2;
    }
    else
    {
      $x11 = $break_start - ($size - $break) / 2;
      $x22 = $break_end + ($size - $break) / 2;
    }
  }
  
  unless ($omit_left)
  {
    $gd->line($x11, $midY, $x12, $midY, $bg);
  }
  
  my $shear_y = ($shear_up ? $midY - $shear : $midY + $shear);
  $gd->line($break_start, $shear_y, $break_end, $shear_y, $fg);
  if ($draw_beak)
  {
    $midX = ($break_start + $break_end) / 2;
    
    my $beak_y1 = $shear_up ? $midY + $shear/2 : $midY - $shear/2;
    my $beak_y2 = $shear_up ? $midY - $shear/2 : $midY + $shear/2;
    
    $gd->line($midX, $beak_y1, $midX-$shear, $beak_y2, $fg);  
    $gd->line($midX, $beak_y1, $midX+$shear, $beak_y2, $fg);  
  }
  
  unless ($omit_right)
  {
    $gd->line($x21, $midY, $x22, $midY, $bg);
  }

}

default_draw_beak	No description	Code
default_shear	No description	Code
default_shear_up	No description	Code
default_break	No description	Code
default_extend	No description	Code
default_size	No description	Code
default_omit_left	No description	Code
default_omit_right	No description	Code
draw_component	No description	Code