Add original-source.otf generator script

[why]
When we add a custom glyph (or want to update Seti) the process is
rather laborious and we are needed to change the font and the
accompanying `i_seti.sh` in sync.

[how]
We use a data file to map icon (svg) filenames to codepoints and
readable names.

That file is parsed and the font and info file is created (overwritten
in the repo); and could then be easily committed. This can be a CI
workflow.

Having a dedicated mapping file (`icons.tsv`) enables us to have stable
codepoints for the same symbol over time. Changes in codepoint
allocation can be checked in git.

Having the font autogenerated help guarantee that the icons are all
likely scaled. We rescale them all to the same size and mid-position.
That is not needed for font-patcher, because it rescales and shifts
again based on to-be-patched font metrics. But it certainly is better
for a view into the original-source font.

Sizes and position are still roughly equivalent to the hand positioned
glyphs.

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

bin/scripts/generate-original-source.py

@@ -0,0 +1,175 @@
+#!/usr/bin/env python3
+# Nerd Fonts Version: 2.2.2
+# Script Version: 1.0.0
+# Generates original-source.otf from individual glyphs
+#
+# Idea & original code taken from
+# https://github.com/lukas-w/font-logos/blob/v1.0.1/scripts/generate-font.py
+
+import os
+import re
+import fontforge
+import psMat
+
+# Double-quotes required here, for version-bump.sh:
+version = "2.2.2"
+
+start_codepoint = 0xE4FA
+codepoint_shift = 0x0100 # shift introduced by font-patcher
+
+vector_datafile = 'icons.tsv'
+vectorsdir = '../../src/svgs'
+fontfile = 'original-source.otf'
+fontdir = '../../src/glyphs'
+glyphsetfile = 'i_seti.sh'
+glyphsetsdir = 'lib'
+
+def hasGaps(data, start_codepoint):
+    """ Takes a list of integers and checks that it contains no gaps """
+    for i in range(min(data) + 1, max(data)):
+        if not i in data:
+            print("Gap at offset {}".format(i - start_codepoint))
+            return True
+    return False
+
+def iconFileLineOk(parts):
+    """ Check one line for course errors, decide if it shall be skipped """
+    if parts[0].startswith('#'):
+        # Comment lines start with '#'
+        return False
+    if len(parts) != 2 and len(parts) != 3:
+        print('Unexpected data on the line "{}"'.format(line.strip()))
+        return False
+    if int(parts[0]) < 0:
+        print('Offset must be positive on line "{}", ignoring'.format(line.strip()))
+        return False
+    return True
+
+def addLineToData(data, parts, codepoint):
+    """ Add one line to the data. Return (success, is_alias) """
+    ali = False
+    if codepoint in data:
+        data[codepoint][0] += [ parts[1] ]
+        if len(parts) > 2 and data[codepoint][1] != parts[2]:
+            print('Conflicting filename for {}, ignoring {}'.format(codepoint, parts[2]))
+            return False, False
+        ali = True
+    else:
+        data[codepoint] = [[parts[1]], parts[2]]
+    return True, ali
+
+def readIconFile(filename, start_codepoint):
+    """ Read the database with codepoints, names and files """
+    # First line of the file is the header, it is ignored
+    # All other lines are one line for one glyph
+    # Elements in each line are tab separated (any amount consecutive of tabs)
+    # First element is the offset, 2nd is name, 3rd is filename
+    # For aliases the 3rd can be ommited on an additional line
+    data = {}
+    num = 0
+    ali = 0
+    with open(filename, 'r') as f:
+        for line in f.readlines():
+            parts = re.split('\t+', line.strip())
+            if not iconFileLineOk(parts):
+                continue
+            offset = int(parts[0])
+            codepoint = start_codepoint + offset
+            if re.search('[^a-zA-Z0-9_]', parts[1]):
+                print('Invalid characters in name: "{}" replaced by "_"'.format(parts[1]))
+                parts[1] = re.sub('[^a-zA-Z0-9_]', '_', parts[1])
+            added = addLineToData(data, parts, codepoint)
+            if not added[0]:
+                continue
+            num += 1
+            if added[1]:
+                ali += 1
+    print('Read glyph data successfully with {} entries ({} aliases)'.format(num, ali))
+    return (data, num, ali)
+
+def widthFromBB(bb):
+    """ Calculate glyph width from BoundingBox data """
+    return bb[2] - bb[0]
+
+def heightFromBB(bb):
+    """ Calculate glyph height from BoundingBox data """
+    return bb[3] - bb[1]
+
+def calcShift(left1, width1, left2, width2):
+    """ Calculate shift needed to center '2' in '1' """
+    return width1 / 2 + left1 - width2 / 2 - left2
+
+def addIcon(codepoint, name, filename):
+    """ Add one outline file and rescale/move """
+    dBB = [120, 0, 1000-120, 900] # just some nice sizes
+    filename = os.path.join(vectorsdir, filename)
+    glyph = font.createChar(codepoint, name)
+    glyph.importOutlines(filename)
+    gBB = glyph.boundingBox()
+    scale_x = widthFromBB(dBB) / widthFromBB(gBB)
+    scale_y = heightFromBB(dBB) / heightFromBB(gBB)
+    scale = scale_y if scale_y < scale_x else scale_x
+    glyph.transform(psMat.scale(scale, scale))
+    gBB = glyph.boundingBox() # re-get after scaling (rounding errors)
+    glyph.transform(psMat.translate(
+        calcShift(dBB[0], widthFromBB(dBB), gBB[0], widthFromBB(gBB)),
+        calcShift(dBB[1], heightFromBB(dBB), gBB[1], heightFromBB(gBB))))
+    glyph.width = int(dBB[2] + dBB[0])
+    glyph.manualHints = True
+
+def createGlyphInfo(icon_datasets, filepathname, into):
+    """ Write the glyphinfo file """
+    with open(filepathname, 'w', encoding = 'utf8') as f:
+        f.write(u'#!/usr/bin/env bash\n')
+        f.write(intro)
+        f.write(u'# Script Version: (autogenerated)\n')
+        f.write(u'test -n "$__i_seti_loaded" && return || __i_seti_loaded=1\n')
+        for codepoint, data in icon_datasets.items():
+            f.write(u"i='{}' {}=$i\n".format(chr(codepoint),data[0][0]))
+            for alias in data[0][1:]:
+                f.write(u"      {}=${}\n".format(alias, data[0][0]))
+        f.write(u'unset i\n')
+
+
+### Lets go
+
+print('\n[Nerd Fonts]  Glyph collection font generator {}\n'.format(version))
+
+font = fontforge.font()
+font.fontname = 'NerdFontFileTypes-Regular'
+font.fullname = 'Nerd Font File Types Regular'
+font.familyname = 'Nerd Font File Types'
+font.em = 1024
+font.encoding = 'UnicodeFull'
+
+# Add valid space glyph to avoid "unknown character" box on IE11
+glyph = font.createChar(32)
+glyph.width = 200
+
+font.sfntRevision = None # Auto-set (refreshed) by fontforge
+font.version = version
+font.copyright = 'Nerd Fonts'
+font.appendSFNTName('English (US)', 'Version', version)
+font.appendSFNTName('English (US)', 'Vendor URL', 'https://github.com/ryanoasis/nerd-fonts')
+font.appendSFNTName('English (US)', 'Copyright', 'Nerd Fonts')
+
+icon_datasets, _, num_aliases = readIconFile(os.path.join(vectorsdir, vector_datafile), start_codepoint)
+gaps = ' (with gaps)' if hasGaps(icon_datasets.keys(), start_codepoint) else ''
+
+for codepoint, data in icon_datasets.items():
+    addIcon(codepoint, data[0][0], data[1])
+num_icons = len(icon_datasets)
+
+print('Generating {} with {} glyphs'.format(fontfile, num_icons))
+font.generate(os.path.join(fontdir, fontfile))
+
+# We create the font, but ... patch it in on other codepoints :-}
+icon_datasets = { code + codepoint_shift : data for (code, data) in icon_datasets.items() }
+
+intro  = u'# Seti-UI + Custom ({} icons, {} aliases)\n'.format(num_icons, num_aliases)
+intro += u'# Codepoints: {:X}-{:X}{}\n'.format(min(icon_datasets.keys()), max(icon_datasets.keys()), gaps)
+intro += u'# Nerd Fonts Version: {}\n'.format(version)
+
+print('Generating GlyphInfo {}'.format(glyphsetfile))
+createGlyphInfo(icon_datasets, os.path.join(glyphsetsdir, glyphsetfile), intro)
+print('Finished')

src/svgs/icons.tsv

@@ -0,0 +1,77 @@
+# This file defines the codepoints for the individual glyphs in
+# original-source.otf and their names in the CSS and on the cheat
+# sheet (via i_seti.sh).
+#
+# If you add a svg to the directory you need to add also a line here.
+# Keep the numbers consecutive.
+# You can add aliases by adding a new line with the same offset but
+# different name; omit the filename on those lines.
+# Use generate-original-source.py to regenerate the font used to patch.
+#
+# offset	name (in i_seti.sh)			filename (.svg)
+#
+0		i_custom_folder_npm			npm-folder.svg
+1		i_custom_folder_git			git-folder.svg
+1		i_custom_folder_git_branch
+2		i_custom_folder_config			config-folder.svg
+3		i_custom_folder_github			octocat-folder.svg
+4		i_custom_folder_open			open-folder.svg
+5		i_custom_folder				folder.svg
+6		i_seti_stylus				stylus.svg
+7		i_seti_project				project.svg
+8		i_seti_play_arrow			play-arrow.svg
+9		i_seti_sass				sass.svg
+10		i_seti_rails				rails.svg
+11		i_seti_ruby				ruby.svg
+12		i_seti_python				python.svg
+13		i_seti_heroku				heroku.svg
+14		i_seti_php				php.svg
+15		i_seti_markdown				markdown.svg
+16		i_seti_license				license.svg
+17		i_seti_json				less.svg
+17		i_seti_less
+18		i_seti_javascript			javascript.svg
+19		i_seti_image				image.svg
+20		i_seti_html				html.svg
+21		i_seti_mustache				handlebars.svg
+22		i_seti_gulp				gulp.svg
+23		i_seti_grunt				grunt.svg
+24		i_seti_default				file.svg
+24		i_seti_text
+25		i_seti_folder				seti-folder.svg
+26		i_seti_css				css.svg
+27		i_seti_config				config.svg
+28		i_seti_npm				npm.svg
+29		i_seti_home				home.svg
+30		i_seti_ejs				html.svg
+31		i_seti_xml				rss.svg
+32		i_seti_bower				bower.svg
+33		i_seti_coffee				coffeescript.svg
+33		i_seti_cjsx
+34		i_seti_twig				twig.svg
+35		i_custom_cpp				c++.svg
+36		i_custom_c				c.svg
+37		i_seti_haskell				haskell.svg
+38		i_seti_lua				lua.svg
+39		i_indent_line				separator.svg
+39		i_indentation_line
+39		i_indent_dotted_guide
+40		i_seti_karma				karma.svg
+41		i_seti_favicon				favourite.svg
+42		i_seti_julia				julia.svg
+43		i_seti_react				react.svg
+44		i_custom_go				go2.svg
+45		i_seti_go				go.svg
+46		i_seti_typescript			typescript.svg
+47		i_custom_msdos				ms-dos.svg
+48		i_custom_windows			windows.svg
+49		i_custom_vim				vim.svg
+50		i_custom_elm				elm.svg
+51		i_custom_elixir				elixir.svg
+52		i_custom_electron			electron.svg
+53		i_custom_crystal			crystal.svg
+54		i_custom_purescript			purescript.svg
+55		i_custom_puppet				puppet.svg
+56		i_custom_emacs				emacs.svg
+57		i_custom_orgmode			orgmode.svg
+58		i_custom_kotlin				kotlin.svg