1 files changed, 124 insertions, 0 deletions
diff --git a/src/silfont/scripts/psfsubset.py b/src/silfont/scripts/psfsubset.py
new file mode 100644
index 0000000..da9c4e6
--- /dev/null
+++ b/src/silfont/scripts/psfsubset.py
@@ -0,0 +1,124 @@
+#!/usr/bin/env python3
+__doc__ = '''Subset an existing UFO based on a csv or text list of glyph names or USVs to keep.
+'''
+__url__ = 'https://github.com/silnrsi/pysilfont'
+__copyright__ = 'Copyright (c) 2018-2023 SIL International (https://www.sil.org)'
+__license__ = 'Released under the MIT License (https://opensource.org/licenses/MIT)'
+__author__ = 'Bob Hallissy'
+
+from silfont.core import execute
+from xml.etree import ElementTree as ET
+import re
+
+argspec = [
+    ('ifont',{'help': 'Input font file'}, {'type': 'infont'}),
+    ('ofont',{'help': 'Output font file','nargs': '?' }, {'type': 'outfont'}),
+    ('-i','--input',{'help': 'Input csv file'}, {'type': 'incsv'}),
+    ('--header', {'help': 'Column header for glyph list', 'default': 'glyph_name'}, {}),
+    ('--filter', {'help': 'Column header for filter status', 'default': None}, {}),
+    ('-l','--log',{'help': 'Log file'}, {'type': 'outfile', 'def': '_subset.log'})]
+
+def doit(args) :
+    font = args.ifont
+    incsv = args.input
+    logger = args.logger
+    deflayer = font.deflayer
+
+    # Create mappings to find glyph name from decimal usv:
+    dusv2gname = {int(ucode.hex, 16): gname for gname in deflayer for ucode in deflayer[gname]['unicode']}
+
+    # check for headers in the csv
+    fl = incsv.firstline
+    if fl is None: logger.log("Empty input file", "S")
+    numfields = len(fl)
+    if numfields == 1 and args.header not in fl:
+        dataCol = 0       # Default for plain csv
+    elif numfields >= 1:  # Must have headers
+        try:
+            dataCol = fl.index(args.header)
+        except ValueError as e:
+            logger.log(f'Missing csv header field: {e}', 'S')
+        except Exception as e:
+            logger.log(f'Error reading csv header field: {e}', 'S')
+        if args.filter:
+            try:
+                filterCol = fl.index(args.filter)
+            except ValueError as e:
+                logger.log(f'Missing csv filter field: {e}', 'S')
+            except Exception as e:
+                logger.log(f'Error reading csv filter field: {e}', 'S')
+        next(incsv.reader, None)  # Skip first line with headers in
+    else:
+        logger.log("Invalid csv file", "S")
+
+    # From the csv, assemble a list of glyphs to process:
+    toProcess = set()
+    usvRE = re.compile('[0-9a-f]{4,6}$',re.IGNORECASE)   # matches 4-6 digit hex
+    for r in incsv:
+        if args.filter:
+            filterstatus = r[filterCol].strip()
+            if filterstatus != "Y":
+                continue
+        gname = r[dataCol].strip()
+        if usvRE.match(gname):
+            # data is USV, not glyph name
+            dusv = int(gname,16)
+            if dusv in dusv2gname:
+                toProcess.add(dusv2gname[dusv])
+                continue
+            # The USV wasn't in the font... try it as a glyph name
+        if gname not in deflayer:
+            logger.log("Glyph '%s' not in font; line %d ignored" % (gname, incsv.line_num), 'W')
+            continue
+        toProcess.add(gname)
+
+    # Generate a complete list of glyphs to keep:
+    toKeep = set()
+    while len(toProcess):
+        gname = toProcess.pop()   # retrieves a random item from the set
+        if gname in toKeep:
+            continue    # Already processed this one
+        toKeep.add(gname)
+        
+        # If it has any components we haven't already processed, add them to the toProcess list
+        for component in deflayer[gname].etree.findall('./outline/component[@base]'):
+            cname = component.get('base')
+            if cname not in toKeep:
+                toProcess.add(cname)
+
+    # Generate a complete list of glyphs to delete:
+    toDelete = set(deflayer).difference(toKeep)
+
+    # Remove any glyphs not in the toKeep set
+    for gname in toDelete:
+        logger.log("Deleting " + gname, "V")
+        deflayer.delGlyph(gname)
+    assert len(deflayer) == len(toKeep), "len(deflayer) != len(toKeep)"
+    logger.log("Retained %d glyphs, deleted %d glyphs." % (len(toKeep), len(toDelete)), "P")
+
+    # Clean up and rebuild sort orders
+    libexists = True if "lib" in font.__dict__ else False
+    for orderName in ('public.glyphOrder', 'com.schriftgestaltung.glyphOrder'):
+        if libexists and orderName in font.lib:
+            glyphOrder = font.lib.getval(orderName)  # This is an array
+            array = ET.Element("array")
+            for gname in glyphOrder:
+                if gname in toKeep:
+                    ET.SubElement(array, "string").text = gname
+            font.lib.setelem(orderName, array)
+
+    # Clean up and rebuild psnames
+    if libexists and 'public.postscriptNames' in font.lib:
+        psnames = font.lib.getval('public.postscriptNames')  # This is a dict keyed by glyphnames
+        dict = ET.Element("dict")
+        for gname in psnames:
+            if gname in toKeep:
+                ET.SubElement(dict, "key").text = gname
+                ET.SubElement(dict, "string").text = psnames[gname]
+        font.lib.setelem("public.postscriptNames", dict)
+
+    return font
+
+def cmd() : execute("UFO",doit,argspec) 
+
+if __name__ == "__main__": cmd()