Lettering typographic features (#3466)

* add svg font to layers extension which saves glyph annotations into the glyph name
---------
Co-authored-by: Claudine

lib/extensions/__init__.py

@@ -40,6 +40,7 @@ from .lettering_force_lock_stitches import LetteringForceLockStitches
 from .lettering_generate_json import LetteringGenerateJson
 from .lettering_remove_kerning import LetteringRemoveKerning
 from .lettering_set_color_sort_index import LetteringSetColorSortIndex
+from .lettering_svg_font_to_layers import LetteringSvgFontToLayers
 from .letters_to_font import LettersToFont
 from .object_commands import ObjectCommands
 from .object_commands_toggle_visibility import ObjectCommandsToggleVisibility
@@ -112,6 +113,7 @@ __all__ = extensions = [About,
                         LetteringGenerateJson,
                         LetteringRemoveKerning,
                         LetteringSetColorSortIndex,
+                        LetteringSvgFontToLayers,
                         LettersToFont,
                         ObjectCommands,
                         ObjectCommandsToggleVisibility,

lib/extensions/lettering_svg_font_to_layers.py

@@ -0,0 +1,117 @@
+#!/usr/bin/env python3
+# coding=utf-8
+#
+# Copyright (C) 2011 Felipe Correa da Silva Sanches <juca@members.fsf.org>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+#
+# Adapted for the inkstitch lettering module to allow glyph annotations for characters
+# in specific positions or settings. Changes: see git history
+"""Extension for converting svg fonts to layers"""
+
+from inkex import Layer, PathElement, errormsg
+
+from .base import InkstitchExtension
+
+
+class LetteringSvgFontToLayers(InkstitchExtension):
+    """Convert an svg font to layers"""
+
+    def add_arguments(self, pars):
+        pars.add_argument(
+            "--count",
+            type=int,
+            default=30,
+            help="Stop making layers after this number of glyphs.",
+        )
+
+    def flip_cordinate_system(self, elem, emsize, baseline):
+        """Scale and translate the element's path, returns the path object"""
+        path = elem.path
+        path.scale(1, -1, inplace=True)
+        path.translate(0, int(emsize) - int(baseline), inplace=True)
+        return path
+
+    def effect(self):
+        # Current code only reads the first svgfont instance
+        font = self.svg.defs.findone("svg:font")
+        if font is None:
+            return errormsg("There are no svg fonts")
+        # setwidth = font.get("horiz-adv-x")
+        baseline = font.get("horiz-origin-y")
+        if baseline is None:
+            baseline = 0
+
+        guidebase = self.svg.viewbox_height - baseline
+
+        fontface = font.findone("svg:font-face")
+
+        emsize = fontface.get("units-per-em")
+
+        # TODO: should we guarantee that <svg:font horiz-adv-x> equals <svg:font-face units-per-em> ?
+        caps = int(fontface.get("cap-height", 0))
+        xheight = int(fontface.get("x-height", 0))
+        ascender = int(fontface.get("ascent", 0))
+        descender = int(fontface.get("descent", 0))
+
+        self.svg.set("width", emsize)
+        self.svg.namedview.add_guide(guidebase, True, "baseline")
+        self.svg.namedview.add_guide(guidebase - ascender, True, "ascender")
+        self.svg.namedview.add_guide(guidebase - caps, True, "caps")
+        self.svg.namedview.add_guide(guidebase - xheight, True, "xheight")
+        self.svg.namedview.add_guide(guidebase + descender, True, "decender")
+
+        count = 0
+        for glyph in font.findall("svg:glyph"):
+            hide_layer = count != 0
+            self.convert_glyph_to_layer(glyph, emsize, baseline, hide_layer=hide_layer)
+            count += 1
+            if count >= self.options.count:
+                break
+
+    def convert_glyph_to_layer(self, glyph, emsize, baseline, hide_layer):
+        unicode_char = glyph.get("unicode")
+
+        glyph_name = glyph.get("glyph-name").split('.')
+        if unicode_char is None:
+            if len(glyph_name) == 2:
+                unicode_char = glyph_name[0]
+            else:
+                return
+
+        typographic_feature = ''
+        if len(glyph_name) == 2:
+            typographic_feature = glyph_name[1]
+        else:
+            arabic_form = glyph.get('arabic-form', None)
+            if arabic_form is not None and len(arabic_form) > 4:
+                typographic_feature = arabic_form[:4]
+        if typographic_feature:
+            typographic_feature = f".{typographic_feature}"
+
+        layer = self.svg.add(Layer.new(f"GlyphLayer-{unicode_char}{typographic_feature}"))
+
+        # glyph layers (except the first one) are innitially hidden
+        if hide_layer:
+            layer.style["display"] = "none"
+
+        # Using curve description in d attribute of svg:glyph
+        path = layer.add(PathElement())
+        path.path = self.flip_cordinate_system(glyph, emsize, baseline)
+
+
+if __name__ == "__main__":
+    LetteringSvgFontToLayers().run()

lib/gui/edit_json/main_panel.py

@@ -237,16 +237,29 @@ class LetteringEditJsonPanel(wx.Panel):
         self.horiz_adv_x = self.font.horiz_adv_x
 
         kerning_combinations = combinations_with_replacement(self.glyphs, 2)
-        self.kerning_combinations = [''.join(combination) for combination in kerning_combinations]
-        self.kerning_combinations.extend([combination[1] + combination[0] for combination in self.kerning_combinations])
+        self.kerning_combinations = [' '.join(combination) for combination in kerning_combinations]
+        self.kerning_combinations.extend([f'{combination[1]} {combination[0]}' for combination in kerning_combinations])
         self.kerning_combinations = list(set(self.kerning_combinations))
         self.kerning_combinations.sort()
 
+        self.update_legacy_kerning_pairs()
         self.update_settings()
         self.update_kerning_list()
         self.update_glyph_list()
         self.update_preview()
 
+    def update_legacy_kerning_pairs(self):
+        new_list = defaultdict(list)
+        for kerning_pair, value in self.kerning_pairs.items():
+            if " " in kerning_pair:
+                # legacy kerning pairs do not use a space
+                return
+            if len(kerning_pair) < 2:
+                continue
+            pair = f'{kerning_pair[0]} {kerning_pair[1]}'
+            new_list[pair] = value
+        self.kerning_pairs = new_list
+
     def update_settings(self):
         # reset font_meta
         self.font_meta = defaultdict(list)
@@ -305,7 +318,8 @@ class LetteringEditJsonPanel(wx.Panel):
         kerning_list.AppendColumn("New kerning", width=wx.LIST_AUTOSIZE_USEHEADER)
         for kerning_pair in self.kerning_combinations:
             if self.font_meta['text_direction'] == 'rtl':
-                kerning_pair = kerning_pair[::-1]
+                pair = kerning_pair.split()
+                kerning_pair = ' '.join(pair[::-1])
             index = kerning_list.InsertItem(kerning_list.GetItemCount(), kerning_pair)
             # kerning_list.SetItem(index, 0, kerning_pair)
             kerning_list.SetItem(index, 1, str(self.kerning_pairs.get(kerning_pair, 0.0)))
@@ -373,43 +387,59 @@ class LetteringEditJsonPanel(wx.Panel):
         if self.last_notebook_selection == 3:
             text = self.get_active_glyph()
         else:
-            text = self.get_active_kerning_pair()
+            kerning = self.get_active_kerning_pair()
+            kerning = kerning.split()
+            text = ''.join(kerning)
+            if self.font_meta['text_direction'] == 'rtl':
+                text = ''.join(kerning[::-1])
         if not text:
             return
 
-        text = self.text_before + text + self.text_after
-        if self.font_meta['text_direction'] == 'rtl':
-            text = text[::-1]
-
-        self._render_text(text)
+        position_x = self._render_text(self.text_before, 0, True)
+        position_x = self._render_text(text, position_x, False)
+        self._render_text(self.text_after, position_x, True)
 
         if self.default_variant.variant == FontVariant.RIGHT_TO_LEFT:
             self.layer[:] = reversed(self.layer)
             for group in self.layer:
                 group[:] = reversed(group)
 
-    def _render_text(self, text):
-        last_character = None
-        position_x = 0
-        for character in text:
-            glyph = self.default_variant[character]
-            if character == " " or (glyph is None and self.font_meta['default_glyph'] == " "):
-                position_x += self.font_meta['horiz_adv_x_space']
-                last_character = None
-            else:
-                if glyph is None:
-                    glyph = self.default_variant[self.font_meta['default_glyph']]
+    def _render_text(self, text, position_x, use_character_position):
+        words = text.split()
+        for i, word in enumerate(words):
+            glyphs = []
+            skip = []
+            previous_is_binding = False
+            for i, character in enumerate(word):
+                if i in skip:
+                    continue
+                if use_character_position:
+                    glyph, glyph_len, previous_is_binding = self.default_variant.get_next_glyph(word, i, previous_is_binding)
+                else:
+                    glyph, glyph_len = self.default_variant.get_glyph(character, word[i:])
+                glyphs.append(glyph)
+                skip = list(range(i, i+glyph_len))
 
-                if glyph is not None:
-                    position_x, last_character = self._render_glyph(glyph, position_x, character, last_character)
+            last_character = None
+            for glyph in glyphs:
+                if glyph is None:
+                    position_x += self.font_meta['horiz_adv_x_space']
+                    last_character = None
+                    continue
+
+                position_x = self._render_glyph(glyph, position_x, glyph.name, last_character)
+                last_character = glyph.name
+            position_x += self.font_meta['horiz_adv_x_space']
+        position_x -= self.font_meta['horiz_adv_x_space']
+        return position_x
 
     def _render_glyph(self, glyph, position_x, character, last_character):
         node = deepcopy(glyph.node)
         if last_character is not None:
             if self.font_meta['text_direction'] != 'rtl':
-                position_x += glyph.min_x - self.kerning_pairs.get(last_character + character, 0)
+                position_x += glyph.min_x - self.kerning_pairs.get(f'{last_character} {character}', 0)
             else:
-                position_x += glyph.min_x - self.kerning_pairs.get(character + last_character, 0)
+                position_x += glyph.min_x - self.kerning_pairs.get(f'{character} {last_character}', 0)
 
         transform = f"translate({position_x}, 0)"
         node.set('transform', transform)
@@ -427,7 +457,7 @@ class LetteringEditJsonPanel(wx.Panel):
         # because this is not unique it will be overwritten by inkscape when inserted into the document
         node.set("id", "glyph")
         self.layer.add(node)
-        return position_x, character
+        return position_x
 
     def render_stitch_plan(self):
         stitch_groups = []

lib/gui/edit_json/settings_panel.py

@@ -97,7 +97,7 @@ class FontInfo(wx.Panel):
         )
 
         default_variant_label = wx.StaticText(self, label=_("Default Variant"))
-        self.default_variant = wx.Choice(self, choices=[_("→"), _("←"), _("↓"), ("↑")])
+        self.default_variant = wx.Choice(self, choices=["→", "←", "↓", "↑"])
         self.default_variant.Bind(wx.EVT_CHOICE, self.parent.on_default_variant_change)
 
         text_direction_label = wx.StaticText(self, label=_("Text direction"))

lib/gui/lettering/main_panel.py

@@ -15,7 +15,7 @@ from ...i18n import _
 from ...lettering import FontError, get_font_list
 from ...lettering.categories import FONT_CATEGORIES
 from ...stitch_plan import stitch_groups_to_stitch_plan
-from ...svg.tags import INKSCAPE_LABEL, INKSTITCH_LETTERING
+from ...svg.tags import INKSTITCH_LETTERING
 from ...utils import DotDict, cache
 from ...utils.threading import ExitThread, check_stop_flag
 from .. import PresetsPanel, PreviewRenderer, info_dialog
@@ -292,15 +292,11 @@ class LetteringPanel(wx.Panel):
 
         del self.group[:]
 
-        destination_group = inkex.Group(attrib={
-            # L10N The user has chosen to scale the text by some percentage
-            # (50%, 200%, etc).  If you need to use the percentage symbol,
-            # make sure to double it (%%).
-            INKSCAPE_LABEL: _("Text scale") + f' {self.settings.scale}%'
-        })
+        destination_group = inkex.Group()
         self.group.append(destination_group)
 
         font = self.fonts.get(self.options_panel.font_chooser.GetValue(), self.default_font)
+        destination_group.label = f"{font.name} {_('scale')} {self.settings.scale}%"
         try:
             font.render_text(
                 self.settings.text, destination_group, back_and_forth=self.settings.back_and_forth,

lib/gui/lettering_font_sample.py

@@ -3,9 +3,11 @@
 # Copyright (c) 2023 Authors
 # Licensed under the GNU GPL version 3.0 or later.  See the file LICENSE for details.
 
+from copy import deepcopy
+
 import wx
 import wx.adv
-from inkex import errormsg
+from inkex import Group, errormsg
 
 from ..i18n import _
 from ..lettering import get_font_list
@@ -20,6 +22,8 @@ class FontSampleFrame(wx.Frame):
         self.SetWindowStyle(wx.FRAME_FLOAT_ON_PARENT | wx.DEFAULT_FRAME_STYLE)
 
         self.fonts = None
+        self.font = None
+        self.font_variant = None
 
         self.main_panel = wx.Panel(self, wx.ID_ANY)
 
@@ -124,14 +128,14 @@ class FontSampleFrame(wx.Frame):
                 self.font_chooser.Append(font.marked_custom_font_name)
 
     def on_font_changed(self, event=None):
-        font = self.fonts.get(self.font_chooser.GetValue(), list(self.fonts.values())[0].marked_custom_font_name)
-        self.scale_spinner.SetRange(int(font.min_scale * 100), int(font.max_scale * 100))
+        self.font = self.fonts.get(self.font_chooser.GetValue(), list(self.fonts.values())[0].marked_custom_font_name)
+        self.scale_spinner.SetRange(int(self.font.min_scale * 100), int(self.font.max_scale * 100))
         # font._load_variants()
         self.direction.Clear()
-        for variant in font.has_variants():
+        for variant in self.font.has_variants():
             self.direction.Append(variant)
         self.direction.SetSelection(0)
-        if font.sortable:
+        if self.font.sortable:
             self.color_sort_label.Enable()
             self.color_sort_checkbox.Enable()
         else:
@@ -143,19 +147,16 @@ class FontSampleFrame(wx.Frame):
         self.layer.transform.add_scale(self.scale_spinner.GetValue() / 100)
         scale = self.layer.transform.a
 
-        # set font
-        font = self.fonts.get(self.font_chooser.GetValue())
-        if font is None:
+        if self.font is None:
             self.GetTopLevelParent().Close()
             return
 
         # parameters
         line_width = self.max_line_width.GetValue()
         direction = self.direction.GetValue()
-        color_sort = self.sortable(font)
 
-        font._load_variants()
-        font_variant = font.variants[direction]
+        self.font._load_variants()
+        self.font_variant = self.font.variants[direction]
 
         # setup lines of text
         text = ''
@@ -164,33 +165,32 @@ class FontSampleFrame(wx.Frame):
         printed_warning = False
         update_glyphlist_warning = _(
             "The glyphlist for this font seems to be outdated.\n\n"
-            "Please update the glyph list for %s:\n"
-            "open Extensions > Ink/Stitch > Font Management > Edit JSON "
-            "select this font and apply. No other changes necessary."
-            % font.marked_custom_font_name
-        )
+            "Please update the glyph list for {font_name}:\n"
+            "* Open Extensions > Ink/Stitch > Font Management > Edit JSON\n"
+            "* Select this font and apply."
+        ).format(font_name=self.font.marked_custom_font_name)
 
-        self.duplicate_warning(font)
+        self.duplicate_warning()
 
         # font variant glyph list length falls short if a single quote sign is available
         # let's add it in the length comparison
-        if len(set(font.available_glyphs)) != len(font_variant.glyphs):
+        if len(set(self.font.available_glyphs)) != len(self.font_variant.glyphs):
             errormsg(update_glyphlist_warning)
             printed_warning = True
 
-        for glyph in font.available_glyphs:
-            glyph_obj = font_variant[glyph]
+        for glyph in self.font.available_glyphs:
+            glyph_obj = self.font_variant[glyph]
             if glyph_obj is None:
                 if not printed_warning:
                     errormsg(update_glyphlist_warning)
                 printed_warning = True
                 continue
             if last_glyph is not None:
-                width_to_add = (glyph_obj.min_x - font.kerning_pairs.get(last_glyph + glyph, 0)) * scale
+                width_to_add = (glyph_obj.min_x - self.font.kerning_pairs.get(f'{last_glyph} {glyph}', 0)) * scale
                 width += width_to_add
 
             try:
-                width_to_add = (font.horiz_adv_x.get(glyph, font.horiz_adv_x_default) - glyph_obj.min_x) * scale
+                width_to_add = (self.font.horiz_adv_x.get(glyph, self.font.horiz_adv_x_default) - glyph_obj.min_x) * scale
             except TypeError:
                 width_to_add = glyph_obj.width
 
@@ -203,24 +203,84 @@ class FontSampleFrame(wx.Frame):
             text += glyph
             width += width_to_add
 
-        # render text and close
-        font.render_text(text, self.layer, variant=direction, back_and_forth=False, color_sort=color_sort)
+        self._render_text(text)
+
         self.GetTopLevelParent().Close()
 
-    def sortable(self, font):
+    def sortable(self):
         color_sort = self.color_sort_checkbox.GetValue()
-        if color_sort and not font.sortable:
+        if color_sort and not self.font.sortable:
             color_sort = False
         return color_sort
 
-    def duplicate_warning(self, font):
+    def duplicate_warning(self):
         # warn about duplicated glyphs
-        if len(set(font.available_glyphs)) != len(font.available_glyphs):
+        if len(set(self.font.available_glyphs)) != len(self.font.available_glyphs):
             duplicated_glyphs = " ".join(
-                [glyph for glyph in set(font.available_glyphs) if font.available_glyphs.count(glyph) > 1]
+                [glyph for glyph in set(self.font.available_glyphs) if self.font.available_glyphs.count(glyph) > 1]
             )
             errormsg(_("Found duplicated glyphs in font file: {duplicated_glyphs}").format(duplicated_glyphs=duplicated_glyphs))
 
+    def _render_text(self, text):
+        lines = text.splitlines()
+        position = {'x': 0, 'y': 0}
+        for line in lines:
+            group = Group()
+            group.label = line
+            group.set("inkstitch:letter-group", "line")
+            glyphs = []
+            skip = []
+            for i, character in enumerate(line):
+                if i in skip:
+                    continue
+                default_variant = self.font.variants[self.font.json_default_variant]
+                glyph, glyph_len = default_variant.get_glyph(character, line[i:])
+                glyphs.append(glyph)
+                skip = list(range(i, i+glyph_len))
+
+            last_character = None
+            for glyph in glyphs:
+                if glyph is None:
+                    position['x'] += self.font.horiz_adv_x_space
+                    last_character = None
+                    continue
+
+                position = self._render_glyph(group, glyph, position, glyph.name, last_character)
+                last_character = glyph.name
+            self.layer.add(group)
+            position['x'] = 0
+            position['y'] += self.font.leading
+
+        if self.sortable():
+            self.font.do_color_sort(self.layer, 1)
+
+    def _render_glyph(self, group, glyph, position, character, last_character):
+        node = deepcopy(glyph.node)
+        if last_character is not None:
+            if self.font.text_direction != 'rtl':
+                position['x'] += glyph.min_x - self.font.kerning_pairs.get(f'{last_character} {character}', 0)
+            else:
+                position['x'] += glyph.min_x - self.font.kerning_pairs.get(f'{character} {last_character}', 0)
+
+        transform = f"translate({position['x']}, {position['y']})"
+        node.set('transform', transform)
+
+        horiz_adv_x_default = self.font.horiz_adv_x_default
+        if horiz_adv_x_default is None:
+            horiz_adv_x_default = glyph.width + glyph.min_x
+
+        position['x'] += self.font.horiz_adv_x.get(character, horiz_adv_x_default) - glyph.min_x
+
+        self.font._update_commands(node, glyph)
+        self.font._update_clips(group, node, glyph)
+
+        # this is used to recognize a glyph layer later in the process
+        # because this is not unique it will be overwritten by inkscape when inserted into the document
+        node.set("id", "glyph")
+        node.set("inkstitch:letter-group", "glyph")
+        group.add(node)
+        return position
+
     def cancel(self, event):
         self.GetTopLevelParent().Close()
 

lib/lettering/font.py

@@ -324,41 +324,70 @@ class Font(object):
 
         group = inkex.Group()
         group.label = line
+        if self.text_direction == 'rtl':
+            group.label = line[::-1]
         group.set("inkstitch:letter-group", "line")
         last_character = None
 
         words = line.split(" ")
         for word in words:
+
             word_group = inkex.Group()
-            word_group.label = word
+            label = word
+            if self.text_direction == 'rtl':
+                label = word[::-1]
+            word_group.label = label
             word_group.set("inkstitch:letter-group", "word")
 
-            for character in word:
-                if self.letter_case == "upper":
-                    character = character.upper()
-                elif self.letter_case == "lower":
-                    character = character.lower()
+            if self.text_direction == 'rtl':
+                glyphs = self._get_word_glyphs(glyph_set, word[::-1])
+                glyphs = glyphs[::-1]
+            else:
+                glyphs = self._get_word_glyphs(glyph_set, word)
 
-                glyph = glyph_set[character]
-
-                if glyph is None and self.default_glyph == " ":
+            last_character = None
+            for glyph in glyphs:
+                if glyph is None:
                     position.x += self.word_spacing
                     last_character = None
-                else:
-                    if glyph is None:
-                        glyph = glyph_set[self.default_glyph]
-
-                    if glyph is not None:
-                        node = self._render_glyph(destination_group, glyph, position, character, last_character)
-                        word_group.append(node)
-
-                    last_character = character
-            position.x += self.word_spacing
-            last_character = None
+                    continue
+                node = self._render_glyph(destination_group, glyph, position, glyph.name, last_character)
+                word_group.append(node)
+                last_character = glyph.name
             group.append(word_group)
-
+            position.x += self.word_spacing
         return group
 
+    def _get_word_glyphs(self, glyph_set, word):
+        glyphs = []
+        skip = []
+        previous_is_binding = True
+
+        for i, character in enumerate(word):
+            if i in skip:
+                continue
+
+            # forced letter case
+            if self.letter_case == "upper":
+                character = character.upper()
+            elif self.letter_case == "lower":
+                character = character.lower()
+
+            glyph, glyph_len, binding = glyph_set.get_next_glyph(word, i, previous_is_binding)
+            previous_is_binding = binding
+
+            skip = list(range(i, i+glyph_len))
+
+            if glyph is None and self.default_glyph == " ":
+                glyphs.append(None)
+            else:
+                if glyph is None:
+                    glyphs.append(glyph_set[self.default_glyph])
+                if glyph is not None:
+                    glyphs.append(glyph)
+
+        return glyphs
+
     def _render_glyph(self, destination_group, glyph, position, character, last_character):
         """Render a single glyph.
 
@@ -383,9 +412,17 @@ class Font(object):
         node = deepcopy(glyph.node)
         if last_character is not None:
             if self.text_direction != "rtl":
-                position.x += glyph.min_x - self.kerning_pairs.get(last_character + character, 0)
+                kerning = self.kerning_pairs.get(f'{last_character} {character}', None)
+                if kerning is None:
+                    # legacy kerning without space
+                    kerning = self.kerning_pairs.get(last_character + character, 0)
+                position.x += glyph.min_x - kerning
             else:
-                position.x += glyph.min_x - self.kerning_pairs.get(character + last_character, 0)
+                kerning = self.kerning_pairs.get(f'{character} {last_character}', None)
+                if kerning is None:
+                    # legacy kerning without space
+                    kerning = self.kerning_pairs.get(character + last_character, 0)
+                position.x += glyph.min_x - kerning
 
         transform = "translate(%s, %s)" % position.as_tuple()
         node.set('transform', transform)

lib/lettering/font_info.py

@@ -3,6 +3,8 @@
 # Copyright (c) 2010 Authors
 # Licensed under the GNU GPL version 3.0 or later.  See the file LICENSE for details.
 
+from collections import defaultdict
+
 from fontTools.agl import toUnicode
 from inkex import NSS
 from lxml import etree
@@ -21,11 +23,35 @@ class FontFileInfo(object):
     # horiz_adv_x defines the width of specific letters (distance to next letter)
     def horiz_adv_x(self):
         # In XPath 2.0 we could use ".//svg:glyph/(@unicode|@horiz-adv-x)"
-        xpath = ".//svg:glyph[@unicode and @horiz-adv-x]/@*[name()='unicode' or name()='horiz-adv-x']"
-        hax = self.svg.xpath(xpath, namespaces=NSS)
-        if len(hax) == 0:
+        xpath = ".//svg:glyph"  # [@unicode and @horiz-adv-x and @glyph-name]/@*[name()='unicode' or name()='horiz-adv-x' or name()='glyph-name']"
+        glyph_definitions = self.svg.xpath(xpath, namespaces=NSS)
+        if len(glyph_definitions) == 0:
             return {}
-        return dict(zip(hax[0::2], [float(x) for x in hax[1::2]]))
+
+        horiz_adv_x_dict = defaultdict(list)
+        for glyph in glyph_definitions:
+            unicode_char = glyph.get('unicode', None)
+            if unicode_char is None:
+                continue
+            hax = glyph.get('horiz-adv-x', None)
+            if hax is None:
+                continue
+            else:
+                hax = float(hax)
+
+            glyph_name = glyph.get('glyph-name', None)
+            if glyph_name is not None:
+                glyph_name = glyph_name.split('.')
+                if len(glyph_name) == 2:
+                    typographic_feature = glyph_name[1]
+                    unicode_char += f'.{typographic_feature}'
+                else:
+                    arabic_form = glyph.get('arabic-form', None)
+                    if arabic_form is not None and len(arabic_form) > 4:
+                        typographic_feature = arabic_form[:4]
+                        unicode_char += f'.{typographic_feature}'
+            horiz_adv_x_dict[unicode_char] = hax
+        return horiz_adv_x_dict
 
     # kerning (specific distances of two specified letters)
     def hkern(self):
@@ -54,7 +80,7 @@ class FontFileInfo(object):
         for first, second, key in kern_list:
             for f in first:
                 for s in second:
-                    hkern[f+s] = key
+                    hkern[f'{f} {s}'] = key
         return hkern
 
     def split_glyph_list(self, glyph):
@@ -62,7 +88,7 @@ class FontFileInfo(object):
         if len(glyph) > 1:
             # glyph names need to be converted to unicode
             # we need to take into account, that there can be more than one first/second letter in the very same hkern element
-            # in this case they will be commas separated and each first letter needs to be combined with each next letter
+            # in this case they will be comma separated and each first letter needs to be combined with each next letter
             # e.g. <hkern g1="A,Agrave,Aacute,Acircumflex,Atilde,Adieresis,Amacron,Abreve,Aogonek" g2="T,Tcaron" k="5" />
             glyph_names = glyph.split(",")
             for glyph_name in glyph_names:
@@ -73,11 +99,12 @@ class FontFileInfo(object):
                 separators = [".", "_"]
                 used_separator = False
                 for separator in separators:
+                    if used_separator:
+                        continue
                     glyph_with_separator = glyph_name.split(separator)
                     if len(glyph_with_separator) == 2:
-                        glyphs.append("%s%s%s" % (toUnicode(glyph_with_separator[0]), separator, glyph_with_separator[1]))
+                        glyphs.append(f"{toUnicode(glyph_with_separator[0])}{separator}{glyph_with_separator[1]}")
                         used_separator = True
-                        continue
                 # there is no extra separator
                 if not used_separator:
                     glyphs.append(toUnicode(glyph_name))

lib/lettering/font_variant.py

@@ -5,6 +5,7 @@
 
 import os
 from collections import defaultdict
+from unicodedata import normalize
 
 import inkex
 
@@ -73,7 +74,7 @@ class FontVariant(object):
             for layer in glyph_layers:
                 self._clean_group(layer)
                 layer.attrib[INKSCAPE_LABEL] = layer.attrib[INKSCAPE_LABEL].replace("GlyphLayer-", "", 1)
-                glyph_name = layer.attrib[INKSCAPE_LABEL]
+                glyph_name = normalize('NFKC', layer.attrib[INKSCAPE_LABEL])
                 try:
                     self.glyphs[glyph_name] = Glyph(layer)
                 except (AttributeError, ValueError):
@@ -134,6 +135,93 @@ class FontVariant(object):
 
         return svg
 
+    def glyphs_start_with(self, character):
+        glyph_selection = [glyph_name for glyph_name, glyph_layer in self.glyphs.items() if glyph_name.startswith(character)]
+        return sorted(glyph_selection, key=lambda glyph: (len(glyph.split('.')[0]), len(glyph)), reverse=True)
+
+    def isbinding(self, character):
+        # after  a non binding letter a letter can only be in isol or fina shape.
+        # binding glyph only have  two shapes, isol and fina
+        non_binding_char = ['ا', 'أ', 'ﺇ', 'آ', 'د', 'ذ', 'ر', 'ز', 'و']
+        normalized_non_binding_char = [normalize('NFKC', letter) for letter in non_binding_char]
+        return not (character in normalized_non_binding_char)
+
+    def ispunctuation(self, character):
+        # punctuation sign  are  not considered as part of the word. They onnly have one shape
+        punctuation_signs = ['؟', '،', '.', ',', ';', '.', '!', ':', '؛']
+        normalized_punctuation_signs = [normalize('NFKC', letter) for letter in punctuation_signs]
+        return (character in normalized_punctuation_signs)
+
+    def get_glyph(self, character, word):
+        """
+        Returns the glyph for the given character, searching for combined glyphs first
+        This expects glyph annotations to be within the given word, for example: a.init
+
+        Returns glyph node and length of the glyph name
+        """
+        glyph_selection = self.glyphs_start_with(character)
+        for glyph in glyph_selection:
+            if word.startswith(glyph):
+                return self.glyphs[glyph], len(glyph)
+        return self.glyphs.get(self.default_glyph, None), 1
+
+    def get_next_glyph_shape(self, word, starting, ending, previous_is_binding):
+        # in arabic each letter (or ligature) may have up to 4 different shapes, hence 4 glyphs
+        # this computes the shape of the glyph that represents word[starting:ending+1]
+
+        # punctuation is not really part of the word
+        # they may appear at begining or end of words
+        # computes where the actual word begins and ends up
+        last_char_index = len(word)-1
+        first_char_index = 0
+
+        while self.ispunctuation(word[last_char_index]):
+            last_char_index = last_char_index - 1
+        while self.ispunctuation(word[first_char_index]):
+            first_char_index = first_char_index + 1
+
+        # first glyph is eithher isol or init depending wether it is also the last glyph of the actual word
+        if starting == first_char_index:
+            if not self.isbinding(word[ending]) or len(word) == 1:
+                shape = 'isol'
+            else:
+                shape = 'init'
+        # last glyph  is  final if previous is binding, isol otherwise
+        # a non binding  glyph behaves like the last glyph
+        elif ending == last_char_index or not self.isbinding(word[ending]):
+            if previous_is_binding:
+                shape = 'fina'
+            else:
+                shape = 'isol'
+        # in the middle of the actual word, the shape of a glyph is medi if previous glyph is bendinng,  init otherwise
+        elif previous_is_binding:
+            shape = 'medi'
+        else:
+            shape = 'init'
+
+        return shape
+
+    def get_next_glyph(self, word, i, previous_is_binding):
+        # search for the glyph of word that starts at i,taking  into acount the previous glyph binding status
+
+        # find  all the glyphs in tthe font that start with first letter of the glyph
+        glyph_selection = self.glyphs_start_with(word[i])
+
+        # find the longest glyph that match
+        for glyph in glyph_selection:
+            glyph_name = glyph.split('.')
+            if len(glyph_name) == 2 and glyph_name[1] in ['isol', 'init', 'medi', 'fina']:
+                is_binding = self.isbinding(glyph_name[0][-1])
+                if len(word) < i + len(glyph_name[0]):
+                    continue
+                shape = self.get_next_glyph_shape(word, i, i + len(glyph_name[0]) - 1, previous_is_binding)
+                if glyph_name[1] == shape and word[i:].startswith(glyph_name[0]):
+                    return self.glyphs[glyph], len(glyph_name[0]),  is_binding
+            elif word[i:].startswith(glyph):
+                return self.glyphs[glyph], len(glyph), True
+        # nothing was found
+        return self.glyphs.get(self.default_glyph, None), 1, True
+
     def __getitem__(self, character):
         if character in self.glyphs:
             return self.glyphs[character]

lib/lettering/glyph.py

@@ -5,6 +5,7 @@
 
 from collections import defaultdict
 from copy import copy
+from unicodedata import normalize
 
 from inkex import paths, transforms, units
 
@@ -36,6 +37,9 @@ class Glyph(object):
             this Glyph.  Nested groups are allowed.
         """
 
+        self.name = group.label
+        if len(self.name) > 11:
+            self.name = normalize('NFKC', self.name[11:])
         self._process_baseline(group.getroottree().getroot())
         self.clips = self._process_clips(group)
         self.node = self._process_group(group)

templates/lettering_svg_font_to_layers.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<inkscape-extension translationdomain="inkstitch" xmlns="http://www.inkscape.org/namespace/inkscape/extension">
+  <name>Convert SVG Font to Glyph Layers</name>
+  <id>org.{{ id_inkstitch }}.lettering_svg_font_to_layers</id>
+  <param name="extension" type="string" gui-hidden="true">lettering_svg_font_to_layers</param>
+  <param name="count" type="int" min="1" max="65535" gui-text="Stop after">100</param>
+
+  <effect needs-live-preview="false">
+    <object-type>all</object-type>
+    <icon>{{ icon_path }}inx/font_management.svg</icon>
+    <menu-tip>Converts a svg font to glyph layers</menu-tip>
+    <effects-menu>
+      <submenu name="{{ menu_inkstitch }}" translatable="no">
+        <submenu name="Font Management" />
+      </submenu>
+    </effects-menu>
+  </effect>
+  <script>
+    {{ command_tag | safe }}
+  </script>
+</inkscape-extension>