tidied up OO

1 files changed, 91 insertions, 92 deletions

diff --git a/challenge-165/james-smith/perl/SVG.pm b/challenge-165/james-smith/perl/SVG.pm
index 9a9ca6b77b..7e8c413244 100644
--- a/challenge-165/james-smith/perl/SVG.pm
+++ b/challenge-165/james-smith/perl/SVG.pm
@@ -4,13 +4,16 @@ use feature qw(say);
 use Data::Dumper qw(Dumper);
 use Const::Fast qw(const);
 
-const my $DEFAULT_CONFIG => { 'margin' => 40, 'max_w' => 960, 'max_h' => 540,
-                       'color' => '#000',  'stroke' => 3,
-                       'fill' => '#ccc',   'radius' => 10,
-                       'border' => '#000', 'bg' => '#eee' };
+## -----------------------------------
+## Constants - configuration & SVG templates...
+## -----------------------------------
+
+const my %DEFAULT_CONFIG => ( 'margin' => 40, 'max_w' => 960, 'max_h' => 540, 'color' => '#000',  'stroke' => 3,
+                              'fill' => '#ccc',   'radius' => 10, 'border' => '#000', 'bg' => '#eee' );
 const my $LINE_TEMPLATE  => '<line x1="%s" y1="%s" x2="%s" y2="%s" />';
 const my $POINT_TEMPLATE => '<circle cx="%s" cy="%s" r="%s" />';
-const my $SVG_TEMPLATE   => '<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+const my $SVG_TEMPLATE   =>
+'<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
 <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
 <svg height="%s" width="%s" viewBox="%s %s %s %s" xmlns="http://www.w3.org/2000/svg" xmlns:svg="http://www.w3.org/2000/svg"
   xmlns:xlink="http://www.w3.org/1999/xlink">
@@ -24,131 +27,127 @@ const my $SVG_TEMPLATE   => '<?xml version="1.0" encoding="UTF-8" standalone="ye
 </svg>';
 
 
+## -----------------------------------
+## Constructor
+## -----------------------------------
+
 sub new {
   my ( $class, $config ) = @_;
   my $self = {
-    'config' => { %{$DEFAULT_CONFIG}, %{$config} },
-    'points' => [],
-    'lines'  => [],
-    'min_x'  => undef,
-    'max_x'  => undef,
-    'min_y'  => undef,
-    'max_y'  => undef,
-    'width'  => undef,
-    'height'  => undef,
-    'scale'  => undef,
+    'config' => { %DEFAULT_CONFIG },
+    'points' => [], 'lines'  => [], 'range'  => [], 'size' => [],
+    'scale'  => 1,
   };
   bless $self, $class;
-  $self;
+  $self->update_config( %{$config} )
+       ->set_range( 0, 0, $self->max_w, $self->max_h )
+       ->set_size(  $self->max_w, $self->max_h )
 }
 
+## -----------------------------------
+## Getters....
+## -----------------------------------
+
+sub min_x   {   $_[0]{'range'}[0]       }     sub min_y   {   $_[0]{'range'}[1]       }
+sub max_x   {   $_[0]{'range'}[2]       }     sub max_y   {   $_[0]{'range'}[3]       }
+sub width   {   $_[0]{'size'}[0]        }     sub height  {   $_[0]{'size'}[1]        }
+sub points  { @{$_[0]{'points'}}        }     sub lines   { @{$_[0]{'lines'}}         }
+sub scale   {   $_[0]{'scale'}          }     sub config  {   $_[0]{'config'}{$_[1]}  }
+sub margin  {   $_[0]->config('margin') }
+sub max_w   {   $_[0]->config('max_w')  }     sub max_h   {   $_[0]->config('max_h')  }
+sub color   {   $_[0]->config('color')  }     sub stroke  {   $_[0]->config('stroke') }
+sub fill    {   $_[0]->config('fill')   }     sub radius  {   $_[0]->config('radius') }
+sub border  {   $_[0]->config('border') }     sub bg      {   $_[0]->config('bg')     }
+
+## -----------------------------------
+## Setters..
+## -----------------------------------
+
+sub add_point  { my( $self, @coord         ) = @_; push @{$self->{'points'}}, [@coord];     $self }
+sub add_points { my( $self, @points        ) = @_; push @{$self->{'points'}},  @points;     $self }
+sub add_line   { my( $self, @coord         ) = @_; push @{$self->{'lines'}},  [@coord];     $self }
+sub add_lines  { my( $self, @lines         ) = @_; push @{$self->{'lines'}},   @lines;      $self }
+sub set_size   { my( $self, $w, $h         ) = @_; $self->{'size'}  = [ $w, $h ];           $self }
+sub set_range  { my( $self, $l, $b, $r, $t ) = @_; $self->{'range'} = [ $l, $b, $r, $t ];   $self }
+sub set_scale  { my( $self, $scale         ) = @_; $self->{'scale'} = $scale;               $self }
+
+sub update_config { my( $self, %pars ) = @_;
+  ( exists $self->{'config'}{$_} ) && ( $self->{'config'}{$_} = $pars{$_} ) for keys %pars; $self }
+
+## --------------------------------------------------------
+## The real code - no direct references to the $self hash!
+## --------------------------------------------------------
+
 sub load_data {
   my( $self, $fn, @t ) = @_;
   local $/ = undef;
   open my $ifh, '<', $fn;
-    4 == (@t = split /,/) ? ( push @{$self->{'lines'}},  [@t] )       ## Length 4 - line
-  : 2 == @t               ? ( push @{$self->{'points'}}, [@t] )       ## Length 2 - point
-  :                         ( warn "input error: $_" )                ## o/w error
+    4 == (@t = split /,/) ? ( $self->add_line(  @t ) )     ## Length 4 - line
+  : 2 == @t               ? ( $self->add_point( @t ) )     ## Length 2 - point
+  :                         ( warn "input error: $_" )     ## o/w error
     for grep { /\S/ } split /\s+/, <$ifh>;
   close $ifh;
   $self;
 }
 
-sub add_points {
-  my( $self, @points ) = @_;
-  push @{$self->{'points'}}, @points;
-  $self;
-}
-
-sub add_lines {
-  my( $self, @lines ) = @_;
-  push @{$self->{'lines'}}, @lines;
-  $self;
-}
-
-sub get_range {
+sub compute_range {
   my $self = shift;
+  my( $min_x,$min_y ) = my( $max_x,$max_y ) = @{ $self->points ? ($self->points)[0] : ($self->lines)[0] };
 
-  ## rather than having a special cast as the first part of the loop, we start with the
-  ## values for the first point (or start of line if no points)
-  my( $min_x,$min_y ) = my( $max_x,$max_y ) = @{$self->{'points'}} ? @{$self->{'points'}[1]} : @{$self->{'lines'}[0]};
-
-  ## Compute the range of all points. We comma separate conditions so we only need one postfix for
-  ## We use ($c)&&($a=?) to mimic if($c) { $a=? } so we can use the postfix loop...
-  ## Note we unravel the two ends of the line by mapping the each line ($_) to $_ + the last two values $_.
   ($_->[0]<$min_x)&&($min_x=$_->[0]), ($_->[0]>$max_x)&&($max_x=$_->[0]),
   ($_->[1]<$min_y)&&($min_y=$_->[1]), ($_->[1]>$max_y)&&($max_y=$_->[1])
-    for @{$self->{'points'}}, map {($_,[$_->[2],$_->[3]])} @{$self->{'lines'}||[]};
-  ( $self->{'min_x'}, $self->{'max_x'}, $self->{'min_y'}, $self->{'max_y'} ) = ( $min_x, $max_x, $min_y, $max_y );
-  $self;
-}
+    for $self->points, map { ($_,  [$_->[2],$_->[3]]) } $self->lines;
 
-sub best_fit {
-  my $self = shift;
-  my $sx = my $sy = my $sxy = my $sxx = 0, my $n = @{$self->{'points'}};
-  $sx += $_->[0], $sxy += $_->[0]*$_->[1], $sy += $_->[1], $sxx += $_->[0]*$_->[0] for @{$self->{'points'}};
-  return $sx/$n unless $n*$sxx - $sx*$sx;
-  my $b = ( $n*$sxy-$sx*$sy ) / ( $n*$sxx - $sx*$sx );
-  ( ($sy-$b*$sx)/$n, $b );
+  $self->set_range( $min_x, $min_y, $max_x, $max_y );
 }
 
 sub add_line_of_best_fit {
   my $self = shift;
-  my ($a,$b) = $self->best_fit;
-  my ( $min_x,           $max_x,           $min_y,           $max_y,           $extn                       ) =
-     ( $self->{'min_x'}, $self->{'max_x'}, $self->{'min_y'}, $self->{'max_y'}, $self->{'config'}{'margin'} );
-  ## special case of a vertical line
-  $self->add_lines( [ $a, $min_y - $extn, $a, $max_y + $extn] ), return $self unless defined $b;
-
-  ## Normal case - get y coprdinates of end points, adjust if outside the box...
-  my $l_y = $a + $b * ($min_x - $extn);
-  my $r_y = $a + $b * ($max_x + $extn);
-  my $l_x = $l_y < $min_y - $extn ? ( ( $l_y = $min_y - $extn ) - $a)/$b
-          : $l_y > $max_y + $extn ? ( ( $l_y = $max_y + $extn ) - $a)/$b : $min_x - $extn;
-  my $r_x = $r_y < $min_y - $extn ? ( ( $r_y = $min_y - $extn ) - $a)/$b
-          : $r_y > $max_y + $extn ? ( ( $r_y = $max_y + $extn ) - $a)/$b : $max_x + $extn;
-  $self->add_lines( [ $l_x, $l_y, $r_x, $r_y ] );
+  my $sx = my $sy = my $sxy = my $sxx = 0, my $n = $self->points;
+
+  $sx += $_->[0], $sxy += $_->[0]*$_->[1], $sy += $_->[1], $sxx += $_->[0]*$_->[0] for $self->points;
+
+  return $self->add_line( $sx/$n, $self->min_y - $self->margin, $sx/$n, $self->max_y + $self->margin )
+    unless $n*$sxx - $sx*$sx; ## special case of a vertical line
+
+  my $b = ( $n*$sxy-$sx*$sy ) / ( $n*$sxx - $sx*$sx ); my $a = ($sy-$b*$sx)/$n;
+  my ( $l, $r, $d, $t ) = ( $self->min_x - $self->margin, $self->max_x + $self->margin,
+       $self->min_y - $self->margin, $self->max_y + $self->margin );
+
+  my $l_y = $a + $b * $l;
+  my $r_y = $a + $b * $r;
+  my $l_x = $l_y < $d ? ( ( $l_y = $d ) - $a)/$b : $l_y > $t ? ( ( $l_y = $t ) - $a)/$b : $l;
+  my $r_x = $r_y < $d ? ( ( $r_y = $d ) - $a)/$b : $r_y > $t ? ( ( $r_y = $t ) - $a)/$b : $r;
+
+  $self->add_line( $l_x, $l_y, $r_x, $r_y );
 }
 
 sub calculate_image_size {
   my $self = shift;
-  my $margin = $self->{'config'}{'margin'};
 
-  ## Adjust height and width so it fits the size from the self->{'config'}ig.
-  my($W,$H,$width,$height) = ($self->{'config'}{'max_w'},$self->{'config'}{'max_h'},
-                              $self->{'max_x'}-$self->{'min_x'}+2*$margin,$self->{'max_y'}-$self->{'min_y'}+2*$margin);
+  my($W,$H,$width,$height) = ( $self->max_w, $self->max_h,
+    $self->max_x-$self->min_x+2*$self->margin,$self->max_y-$self->min_y+2*$self->margin);
   ( $width/$height > $W/$H ) ? ( $H = $height/$width*$W ) : ( $W = $width/$height*$H );
-  ## Calculate the scale factor so that we keep spots/lines the same size irrespective of the ranges.
-  ( $self->{'width'}, $self->{'height'}, $self->{'scale'} ) = ( $W, $H, $width/$W );
-  $self;
-}
 
-sub render_with_best_fit {
-  my $self = shift;
-  return $self->get_range()->add_line_of_best_fit()->_render();
+  $self->set_size( $W, $H )->set_scale( $width / $W );
 }
 
-sub render {
-  my $self = shift;
-  return $self->get_range()->_render();
-}
+sub render_with_best_fit { shift->compute_range->add_line_of_best_fit->_render }
+sub render {               shift->compute_range->_render                       }
 
 sub _render {
   my $self = shift;
-  $self->calculate_image_size();                  ## Given max height/width work out the dimensions of image and the scale factor.
-  my $margin = $self->{'config'}{'margin'};       ## Get margin...
-  sprintf $SVG_TEMPLATE,
-    $self->{'height'}, $self->{'width'},  $self->{'min_x'} - $margin, $self->{'min_y'} - $margin,
-                                          $self->{'max_x'} - $self->{'min_x'} + 2 * $margin,
-                                          $self->{'max_y'} - $self->{'min_y'} + 2 * $margin,
-    $self->{'config'}{'border'}, $self->{'scale'}, $self->{'config'}{'bg'}, $self->{'min_x'} - $margin, $self->{'min_y'} - $margin,
-                                          $self->{'max_x'} - $self->{'min_x'} + 2 * $margin,
-                                          $self->{'max_y'} - $self->{'min_y'} + 2 * $margin,
-    $self->{'config'}{'color'}, $self->{'config'}{'stroke'} * $self->{'scale'},
-      join( qq(\n    ), map { sprintf $LINE_TEMPLATE,   @{$_} } @{$self->{'lines'}} ), ## lines
-    $self->{'config'}{'fill'}, join( qq(\n    ),
-      map { sprintf $POINT_TEMPLATE,  @{$_}, $self->{'config'}{'radius'}*$self->{'scale'}  } @{$self->{'points'}}   )  ## points
 
+  $self->calculate_image_size;    ## Given max height/width work out the dimensions of image and the scale factor.
+  my $margin = $self->margin;     ## Get margin...
+
+  sprintf $SVG_TEMPLATE,
+    $self->height, $self->width, $self->min_x - $margin, $self->min_y - $margin,
+                   $self->max_x - $self->min_x + 2 * $margin, $self->max_y - $self->min_y + 2 * $margin,
+    $self->border, $self->scale, $self->bg, $self->min_x - $margin, $self->min_y - $margin,
+                   $self->max_x - $self->min_x + 2 * $margin, $self->max_y - $self->min_y + 2 * $margin,
+    $self->color, $self->stroke * $self->scale, join( qq(\n    ), map { sprintf $LINE_TEMPLATE, @{$_} } $self->lines ), ## lines
+    $self->fill, join( qq(\n    ), map { sprintf $POINT_TEMPLATE, @{$_}, $self->radius*$self->scale  } $self->points )  ## points
 }
 
 1;