charset: divide and append row offset label

[sheet.git] / charset.plp

diff --git a/charset.plp b/charset.plp
index 118658569014cd082cc4f2e532678d6052f78867..73b37407b2ff71ecce5fd84f1d526c8aa823caaa 100644 (file)
--- a/charset.plp
+++ b/charset.plp
@@ -158,12 +158,14 @@ sub range_cell {
 
 for my $row (@request) {
        my $colsize = $row->{cell} && $row->{cell}->{colsize} || 1;
+       my $coldigits = ceil(log($colsize * $cols) / log(16));  # uniform length of hexadecimal header
+       my $rowdiv = 16 ** $coldigits;  # divider of row headers
+
        printf '<div class="section"><table class="glyphs%s">', !$row->{cell} && ' charmap';
        my $title = $row->{set};
        $title .= " <aside>($_)</aside>" for $row->{setnote} // ();
        printf '<caption>%s</caption>', $title;
        print '<col>' x ($cols + 1);
-       my $coldigits = ceil(log($colsize * $cols) / log(16));  # uniform length of hexadecimal header
        for my $section (qw{thead}) {
                print "<$section><tr><th>↱";
                printf '<th>%0*X', $coldigits, $_ * $colsize for 0 .. $cols - 1;
@@ -171,7 +173,18 @@ for my $row (@request) {
        }
        print '<tbody>';
        for my $msb (0 .. ((length($row->{table}) || 256) - 1) / $cols) {
-               printf '<tr><th>%X', ($msb + int($row->{offset} / $cols)) * $cols * $colsize;
+               print '<tr><th>';
+               {
+                       my $rowlabel = ($msb + int($row->{offset} / $cols)) * $cols * $colsize;
+                       if (my $rowmod = $rowlabel % $rowdiv) {
+                               # offset in column units
+                               printf '<small>+%X</small>', $rowmod;
+                       }
+                       else {
+                               # divided row offset
+                               printf '%X', $rowlabel / $rowdiv;
+                       }
+               }
                for my $lsb (0 .. $cols - 1) {
                        my $val = ( ($msb * $cols) + $lsb ) * $colsize;
                        if ($row->{cell}) {