Force lock stitches option/extension and some typos (#1471)

1 files changed, 86 insertions, 0 deletions

diff --git a/lib/extensions/lettering_force_lock_stitches.py b/lib/extensions/lettering_force_lock_stitches.py
new file mode 100644
index 00000000..62d7ae14
--- /dev/null
+++ b/lib/extensions/lettering_force_lock_stitches.py
@@ -0,0 +1,86 @@
+# Authors: see git history
+#
+# Copyright (c) 2021 Authors
+# Licensed under the GNU GPL version 3.0 or later.  See the file LICENSE for details.
+
+import inkex
+from shapely.geometry import Point
+
+from ..i18n import _
+from ..svg import PIXELS_PER_MM
+from ..svg.tags import INKSTITCH_ATTRIBS
+from .base import InkstitchExtension
+
+
+class LetteringForceLockStitches(InkstitchExtension):
+    '''
+    This extension helps font creators to add the force lock stitches attribute to the last objects of each glyph
+    Font creators to add forced lock stitches on glyphs with accents / spaces.
+    '''
+
+    def __init__(self, *args, **kwargs):
+        InkstitchExtension.__init__(self, *args, **kwargs)
+        self.arg_parser.add_argument("-a", "--max_distance", type=float, default=3, dest="max_distance")
+        self.arg_parser.add_argument("-i", "--min_distance", type=float, default=1, dest="min_distance")
+        self.arg_parser.add_argument("-l", "--last_element", type=inkex.Boolean, dest="last_element")
+
+    def effect(self):
+        if self.options.max_distance < self.options.min_distance:
+            inkex.errormssg(_("The maximum value is smaller than the minimum value."))
+
+        # Set glyph layers to be visible. We don't want them to be ignored by self.elements
+        self._update_layer_visibility('inline')
+
+        # mark last elements of a glyph
+        xpath = ".//svg:g[@inkscape:groupmode='layer']//svg:path[last()]"
+        last_elements = self.document.xpath(xpath, namespaces=inkex.NSS)
+        for last_element in last_elements:
+            last_element.set('lastglyphelement', str(True))
+
+        # find last point of an element
+        if not self.get_elements():
+            return
+
+        previous_element = None
+        last_stitch = None
+        for element in self.elements:
+            stitch_group = element.to_stitch_groups(None)
+            # if the distance of the last stitch of the previous object to the first stitch of this objects
+            # lies within the user defined distance range, set the force_lock_stitches-attribute.
+            if last_stitch:
+                first_stitch = stitch_group[0].stitches[0]
+                first_stitch = Point(first_stitch.x, first_stitch.y)
+                self._set_force_attribute(first_stitch, last_stitch, previous_element)
+
+            # if this is the last element of a glyph, we don't want to compare it to the next element
+            if element.node.get('lastglyphelement', False):
+                previous_element = None
+                last_stitch = None
+            else:
+                previous_element = element
+                last_stitch = stitch_group[-1].stitches[-1]
+                last_stitch = Point(last_stitch.x, last_stitch.y)
+
+        # remove last element attributes again
+        # set force lock stitches attribute if needed
+        for last_element in last_elements:
+            last_element.attrib.pop('lastglyphelement')
+            if self.options.last_element:
+                last_element.set(INKSTITCH_ATTRIBS['force_lock_stitches'], True)
+
+        # hide glyph layers again
+        self._update_layer_visibility('none')
+
+    def _set_force_attribute(self, first_stitch, last_stitch, previous_element):
+        distance_mm = first_stitch.distance(last_stitch) / PIXELS_PER_MM
+
+        if distance_mm < self.options.max_distance and distance_mm > self.options.min_distance:
+            previous_element.node.set(INKSTITCH_ATTRIBS['force_lock_stitches'], True)
+
+    def _update_layer_visibility(self, display):
+        xpath = ".//svg:g[@inkscape:groupmode='layer']"
+        layers = self.document.xpath(xpath, namespaces=inkex.NSS)
+        for layer in layers:
+            display_style = 'display:%s' % display
+            style = inkex.Style(layer.get('style', '')) + inkex.Style(display_style)
+            layer.set('style', style)