Create symbols only font directly from sfd template

[why]
The symbol only fonts Symbols-1000-em Nerd Font Complete.ttf
and 2048-em in `NerdFontsSymbolsOnly/` are generated from
some 'almost' empty source fonts, that are assumable in turn generated
from the sfd font descriptions in `src/glyphs/`?

The process is not documented and we have issues in the generated font
(for example the glyph for capital `E` is defined (and empty) #581 #765).

[how]
Use the existing font definitions from `src/glyphs/*.sfd` directly as
source font. That needs a change in font-patcher because the empty
fonts have no glyphs that can be used to orient the scaling upon. In
that case scale on the source font definitions EM.

Then we need patch-em-all to also patch *.sfd fonts.

And finally we need patch-em-all to take a font specific command line
switch for font-patcher (compare 9e2bc9a26 of #723) to instruct it to
create a ttf rather than a sfd font file.

In the sfd file we additionally set the Panose type.
And the UnderlinePosition is adjusted to match the current patched font.

[note]
Also fix wrong glob pattern in patch-em-all `*.[o,t]tf`. The comma is
for sure some leftover from a '{}' shell pattern, that is not used
anymore. (This comment is probably outdated, due to rebasing.)

Signed-off-by: Fini Jastrow <ulf.fini.jastrow@desy.de>

bin/scripts/gotta-patch-em-all-font-patcher!.sh

@@ -6,7 +6,8 @@
 # set -x
 
 # The optional first argument to this script is a filter for the fonts to patch.
-# All font files that start with that filter (and are ttf or otf files) will
+# The filter is a regex (glob "*" is expressed as "[^/]*", see `man 7 glob`)
+# All font files that start with that filter (and are ttf, otf, or sfd files) will
 # be processed only.
 #   Example ./gotta-patch-em-all-font-patcher\!.sh "iosevka"
 #   Process all font files that start with "iosevka"
@@ -37,7 +38,6 @@ res1=$(date +%s)
 parent_dir="${sd}/../../"
 # Set source and target directories
 source_fonts_dir="${sd}/../../src/unpatched-fonts"
-like_mode=''
 like_pattern=''
 complete_variations_per_family=4
 font_typefaces_count=0
@@ -54,12 +54,10 @@ if [ $# -eq 1 ] || [ "$1" != "" ]
 then
   if [[ "${1:0:1}" == "/" ]]
   then
-    like_mode="-ipath"
-    like_pattern="*$1/*.[o,t]tf"
+    like_pattern=".*$1/.*\.\(otf\|ttf\|sfd\)"
     echo "$LINE_PREFIX Parameter given, limiting search and patch to pathname pattern '$1' given"
   else
-    like_mode="-iname"
-    like_pattern="$1*.[o,t]tf"
+    like_pattern=".*/$1[^/]*\.\(otf\|ttf\|sfd\)"
     echo "$LINE_PREFIX Parameter given, limiting search and patch to filename pattern '$1' given"
   fi
 fi
@@ -76,7 +74,7 @@ fi
 source_fonts=()
 while IFS= read -d $'\0' -r file ; do
   source_fonts=("${source_fonts[@]}" "$file")
-done < <(find "$source_fonts_dir" ${like_mode} ${like_pattern} -type f -print0)
+done < <(find "$source_fonts_dir" -iregex ${like_pattern} -type f -print0)
 
 # print total number of source fonts found
 echo "$LINE_PREFIX Total source fonts found: ${#source_fonts[*]}"
@@ -297,7 +295,7 @@ then
       # to follow font naming changed. We can not do this if we patch only
       # some of the source font files in that directory.
       last_source_dir=${current_source_dir}
-      num_to_patch=$(find "${current_source_dir}" ${like_mode} ${like_pattern} -type f | wc -l)
+      num_to_patch=$(find "${current_source_dir}" -iregex ${like_pattern} -type f | wc -l)
       num_existing=$(find "${current_source_dir}" -iname "*.[o,t]tf" -type f | wc -l)
       if [ ${num_to_patch} -eq ${num_existing} ]
       then

font-patcher

@@ -804,6 +804,17 @@ class font_patcher:
                 self.font_dim['xmax'] = xmax
 
         # Calculate font height
+        if self.font_dim['height'] == 0:
+            # This can only happen if the input font is empty
+            # Assume we are using our prepared templates
+            self.font_dim = {
+                'xmin'  : 0,
+                'ymin'  : -self.sourceFont.descent,
+                'xmax'  : self.sourceFont.em,
+                'ymax'  : self.sourceFont.ascent,
+                'width' : self.sourceFont.em,
+                'height': 0,
+            }
         self.font_dim['height'] = abs(self.font_dim['ymin']) + self.font_dim['ymax']
 
 

src/unpatched-fonts/NerdFontsSymbolsOnly/NerdFontsSymbols 1000 EM Nerd Font Complete Blank.sfd

@@ -6,7 +6,7 @@ Weight: Regular
 Copyright: Copyright (c) 2016, Ryan McIntyre
 Version: 001.000
 ItalicAngle: 0
-UnderlinePosition: -100
+UnderlinePosition: -150
 UnderlineWidth: 50
 Ascent: 800
 Descent: 200
@@ -20,12 +20,13 @@ OS2Version: 0
 OS2_WeightWidthSlopeOnly: 0
 OS2_UseTypoMetrics: 1
 CreationTime: 1480466430
-ModificationTime: 1480467813
+ModificationTime: 1646316690
 PfmFamily: 17
 TTFWeight: 400
 TTFWidth: 5
 LineGap: 90
 VLineGap: 0
+Panose: 2 0 5 9 0 0 0 0 0 0
 OS2TypoAscent: 0
 OS2TypoAOffset: 1
 OS2TypoDescent: 0

src/unpatched-fonts/NerdFontsSymbolsOnly/NerdFontsSymbols 2048 EM Nerd Font Complete Blank.sfd

@@ -6,7 +6,7 @@ Weight: Regular
 Copyright: Copyright (c) 2016, Ryan McIntyre
 Version: 001.000
 ItalicAngle: 0
-UnderlinePosition: -204
+UnderlinePosition: -306
 UnderlineWidth: 102
 Ascent: 1638
 Descent: 410
@@ -20,12 +20,13 @@ OS2Version: 0
 OS2_WeightWidthSlopeOnly: 0
 OS2_UseTypoMetrics: 1
 CreationTime: 1480466430
-ModificationTime: 1480467841
+ModificationTime: 1646316690
 PfmFamily: 17
 TTFWeight: 400
 TTFWidth: 5
 LineGap: 184
 VLineGap: 0
+Panose: 2 0 5 9 0 0 0 0 0 0
 OS2TypoAscent: 0
 OS2TypoAOffset: 1
 OS2TypoDescent: 0

src/unpatched-fonts/NerdFontsSymbolsOnly/config.cfg

@@ -0,0 +1 @@
+config_patch_flags="--ext ttf"