refactor everything out of lib/__init__.py

31 files changed, 379 insertions, 357 deletions

diff --git a/lib/__init__.py b/lib/__init__.py
index 2c0ee620..e69de29b 100644
--- a/lib/__init__.py
+++ b/lib/__init__.py
@@ -1,298 +0,0 @@
-#!/usr/bin/env python
-# http://www.achatina.de/sewing/main/TECHNICL.HTM
-
-import os
-import sys
-import gettext
-from copy import deepcopy
-import math
-import libembroidery
-from .utils import cache
-from .utils.geometry import Point
-
-import inkex
-import simplepath
-import simplestyle
-import simpletransform
-from bezmisc import bezierlength, beziertatlength, bezierpointatt
-from cspsubdiv import cspsubdiv
-import cubicsuperpath
-from shapely import geometry as shgeo
-
-
-# modern versions of Inkscape use 96 pixels per inch as per the CSS standard
-PIXELS_PER_MM = 96 / 25.4
-
-SVG_PATH_TAG = inkex.addNS('path', 'svg')
-SVG_POLYLINE_TAG = inkex.addNS('polyline', 'svg')
-SVG_DEFS_TAG = inkex.addNS('defs', 'svg')
-SVG_GROUP_TAG = inkex.addNS('g', 'svg')
-INKSCAPE_LABEL = inkex.addNS('label', 'inkscape')
-INKSCAPE_GROUPMODE = inkex.addNS('groupmode', 'inkscape')
-
-EMBROIDERABLE_TAGS = (SVG_PATH_TAG, SVG_POLYLINE_TAG)
-
-dbg = open(os.devnull, "w")
-
-translation = None
-_ = lambda message: message
-
-
-def localize():
-    if getattr(sys, 'frozen', False):
-        # we are in a pyinstaller installation
-        locale_dir = sys._MEIPASS
-    else:
-        locale_dir = os.path.dirname(__file__)
-
-    locale_dir = os.path.join(locale_dir, 'locales')
-
-    global translation, _
-
-    translation = gettext.translation("inkstitch", locale_dir, fallback=True)
-    _ = translation.gettext
-
-localize()
-
-# cribbed from inkscape-silhouette
-def parse_length_with_units( str ):
-
-    '''
-    Parse an SVG value which may or may not have units attached
-    This version is greatly simplified in that it only allows: no units,
-    units of px, mm, and %.  Everything else, it returns None for.
-    There is a more general routine to consider in scour.py if more
-    generality is ever needed.
-    '''
-
-    u = 'px'
-    s = str.strip()
-    if s[-2:] == 'px':
-        s = s[:-2]
-    elif s[-2:] == 'mm':
-        u = 'mm'
-        s = s[:-2]
-    elif s[-2:] == 'pt':
-        u = 'pt'
-        s = s[:-2]
-    elif s[-2:] == 'pc':
-        u = 'pc'
-        s = s[:-2]
-    elif s[-2:] == 'cm':
-        u = 'cm'
-        s = s[:-2]
-    elif s[-2:] == 'in':
-        u = 'in'
-        s = s[:-2]
-    elif s[-1:] == '%':
-        u = '%'
-        s = s[:-1]
-    try:
-        v = float( s )
-    except:
-        raise ValueError(_("parseLengthWithUnits: unknown unit %s") % s)
-
-    return v, u
-
-
-def convert_length(length):
-    value, units = parse_length_with_units(length)
-
-    if not units or units == "px":
-        return value
-
-    if units == 'pt':
-       value /= 72
-       units = 'in'
-
-    if units == 'pc':
-       value /= 6
-       units = 'in'
-
-    if units == 'cm':
-       value *= 10
-       units = 'mm'
-
-    if units == 'mm':
-        value = value / 25.4
-        units = 'in'
-
-    if units == 'in':
-        # modern versions of Inkscape use CSS's 96 pixels per inch.  When you
-        # open an old document, inkscape will add a viewbox for you.
-        return value * 96
-
-    raise ValueError(_("Unknown unit: %s") % units)
-
-
-@cache
-def get_doc_size(svg):
-    doc_width = convert_length(svg.get('width'))
-    doc_height = convert_length(svg.get('height'))
-
-    return doc_width, doc_height
-
-@cache
-def get_viewbox_transform(node):
-    # somewhat cribbed from inkscape-silhouette
-    doc_width, doc_height = get_doc_size(node)
-
-    viewbox = node.get('viewBox').strip().replace(',', ' ').split()
-
-    dx = -float(viewbox[0])
-    dy = -float(viewbox[1])
-    transform = simpletransform.parseTransform("translate(%f, %f)" % (dx, dy))
-
-    try:
-        sx = doc_width / float(viewbox[2])
-        sy = doc_height / float(viewbox[3])
-        scale_transform = simpletransform.parseTransform("scale(%f, %f)" % (sx, sy))
-        transform = simpletransform.composeTransform(transform, scale_transform)
-    except ZeroDivisionError:
-        pass
-
-    return transform
-
-@cache
-def get_stroke_scale(node):
-    doc_width, doc_height = get_doc_size(node)
-    viewbox = node.get('viewBox').strip().replace(',', ' ').split()
-    return  doc_width / float(viewbox[2])
-
-
-class Stitch(Point):
-    def __init__(self, x, y, color=None, jump=False, stop=False, trim=False, no_ties=False):
-        self.x = x
-        self.y = y
-        self.color = color
-        self.jump = jump
-        self.trim = trim
-        self.stop = stop
-        self.no_ties = no_ties
-
-    def __repr__(self):
-        return "Stitch(%s, %s, %s, %s, %s, %s, %s)" % (self.x, self.y, self.color, "JUMP" if self.jump else " ", "TRIM" if self.trim else " ", "STOP" if self.stop else " ", "NO TIES" if self.no_ties else " ")
-
-
-def make_thread(color):
-    thread = libembroidery.EmbThread()
-    thread.color = libembroidery.embColor_make(*color.rgb)
-
-    thread.description = color.name
-    thread.catalogNumber = ""
-
-    return thread
-
-def add_thread(pattern, thread):
-    """Add a thread to a pattern and return the thread's index"""
-
-    libembroidery.embPattern_addThread(pattern, thread)
-
-    return libembroidery.embThreadList_count(pattern.threadList) - 1
-
-def get_flags(stitch):
-    flags = 0
-
-    if stitch.jump:
-        flags |= libembroidery.JUMP
-
-    if stitch.trim:
-        flags |= libembroidery.TRIM
-
-    if stitch.stop:
-        flags |= libembroidery.STOP
-
-    return flags
-
-
-def _string_to_floats(string):
-    floats = string.split(',')
-    return [float(num) for num in floats]
-
-
-def get_origin(svg):
-    # The user can specify the embroidery origin by defining two guides
-    # named "embroidery origin" that intersect.
-
-    namedview = svg.find(inkex.addNS('namedview', 'sodipodi'))
-    all_guides = namedview.findall(inkex.addNS('guide', 'sodipodi'))
-    label_attribute = inkex.addNS('label', 'inkscape')
-    guides = [guide for guide in all_guides
-                    if guide.get(label_attribute, "").startswith("embroidery origin")]
-
-    # document size used below
-    doc_size = list(get_doc_size(svg))
-
-    # convert the size from viewbox-relative to real-world pixels
-    viewbox_transform = get_viewbox_transform(svg)
-    simpletransform.applyTransformToPoint(simpletransform.invertTransform(viewbox_transform), doc_size)
-
-    default = [doc_size[0] / 2.0, doc_size[1] / 2.0]
-    simpletransform.applyTransformToPoint(viewbox_transform, default)
-    default = Point(*default)
-
-    if len(guides) < 2:
-        return default
-
-    # Find out where the guides intersect.  Only pay attention to the first two.
-    guides = guides[:2]
-
-    lines = []
-    for guide in guides:
-        # inkscape's Y axis is reversed from SVG's, and the guide is in inkscape coordinates
-        position = Point(*_string_to_floats(guide.get('position')))
-        position.y = doc_size[1] - position.y
-
-
-        # This one baffles me.  I think inkscape might have gotten the order of
-        # their vector wrong?
-        parts = _string_to_floats(guide.get('orientation'))
-        direction = Point(parts[1], parts[0])
-
-        # We have a theoretically infinite line defined by a point on the line
-        # and a vector direction.  Shapely can only deal in concrete line
-        # segments, so we'll pick points really far in either direction on the
-        # line and call it good enough.
-        lines.append(shgeo.LineString((position + 100000 * direction, position - 100000 * direction)))
-
-    intersection = lines[0].intersection(lines[1])
-
-    if isinstance(intersection, shgeo.Point):
-        origin = [intersection.x, intersection.y]
-        simpletransform.applyTransformToPoint(viewbox_transform, origin)
-        return Point(*origin)
-    else:
-        # Either the two guides are the same line, or they're parallel.
-        return default
-
-
-def write_embroidery_file(file_path, stitch_plan, svg):
-    origin = get_origin(svg)
-
-    pattern = libembroidery.embPattern_create()
-
-    for color_block in stitch_plan:
-        add_thread(pattern, make_thread(color_block.color))
-
-        for stitch in color_block:
-            if stitch.stop and stitch is not color_block.last_stitch:
-                # A STOP stitch that is not at the end of a color block
-                # occurs when the user specified "STOP after".  "STOP" is the
-                # same thing as a color change, and the user will assign a
-                # special color at the machine that tells it to pause after.
-                # We need to add another copy of the same color here so that
-                # the stitches after the STOP are still the same color.
-                add_thread(pattern, make_thread(color_block.color))
-
-            flags = get_flags(stitch)
-            libembroidery.embPattern_addStitchAbs(pattern, stitch.x - origin.x, stitch.y - origin.y, flags, 1)
-
-    libembroidery.embPattern_addStitchAbs(pattern, stitch.x - origin.x, stitch.y - origin.y, libembroidery.END, 1)
-
-    # convert from pixels to millimeters
-    libembroidery.embPattern_scale(pattern, 1/PIXELS_PER_MM)
-
-    # SVG and embroidery disagree on the direction of the Y axis
-    libembroidery.embPattern_flipVertical(pattern)
-
-    libembroidery.embPattern_write(pattern, file_path)
diff --git a/lib/elements/auto_fill.py b/lib/elements/auto_fill.py
index 6eb1f10c..08ae67f7 100644
--- a/lib/elements/auto_fill.py
+++ b/lib/elements/auto_fill.py
@@ -1,10 +1,10 @@
 import math
-from .. import _
-from .element import param, Patch
-from ..utils import cache
-from .fill import Fill
 from shapely import geometry as shgeo
+from ..i18n import _
+from ..utils import cache
 from ..stitches import auto_fill
+from .element import param, Patch
+from .fill import Fill
 
 
 class AutoFill(Fill):
diff --git a/lib/elements/element.py b/lib/elements/element.py
index cfca3782..300136dd 100644
--- a/lib/elements/element.py
+++ b/lib/elements/element.py
@@ -1,9 +1,10 @@
 import sys
 from copy import deepcopy
+from shapely import geometry as shgeo
 
+from ..i18n import _
 from ..utils import cache
-from shapely import geometry as shgeo
-from .. import _, PIXELS_PER_MM, get_viewbox_transform, get_stroke_scale, convert_length
+from ..svg import PIXELS_PER_MM, get_viewbox_transform, convert_length, get_doc_size
 
 # inkscape-provided utilities
 import simpletransform
@@ -11,6 +12,7 @@ import simplestyle
 import cubicsuperpath
 from cspsubdiv import cspsubdiv
 
+
 class Patch:
     """A raw collection of stitches with attached instructions."""
 
@@ -146,6 +148,15 @@ class EmbroideryElement(object):
 
     @property
     @cache
+    def stroke_scale(self):
+        svg = self.node.getroottree().getroot()
+        doc_width, doc_height = get_doc_size(svg)
+        viewbox = svg.get('viewBox', '0 0 %s %s' % (doc_width, doc_height))
+        viewbox = viewbox.strip().replace(',', ' ').split()
+        return  doc_width / float(viewbox[2])
+
+    @property
+    @cache
     def stroke_width(self):
         width = self.get_style("stroke-width")
 
@@ -153,8 +164,7 @@ class EmbroideryElement(object):
             return 1.0
 
         width = convert_length(width)
-
-        return width * get_stroke_scale(self.node.getroottree().getroot())
+        return width * self.stroke_scale
 
     @property
     def path(self):
diff --git a/lib/elements/fill.py b/lib/elements/fill.py
index a74a897d..52a42260 100644
--- a/lib/elements/fill.py
+++ b/lib/elements/fill.py
@@ -1,10 +1,13 @@
-from .. import _, PIXELS_PER_MM
-from .element import param, EmbroideryElement, Patch
-from ..utils import cache
 from shapely import geometry as shgeo
 import math
+
+from .element import param, EmbroideryElement, Patch
+from ..i18n import _
+from ..svg import PIXELS_PER_MM
+from ..utils import cache
 from ..stitches import running_stitch, auto_fill, legacy_fill
 
+
 class Fill(EmbroideryElement):
     element_name = _("Fill")
 
diff --git a/lib/elements/polyline.py b/lib/elements/polyline.py
index 6ded9fd1..5c474237 100644
--- a/lib/elements/polyline.py
+++ b/lib/elements/polyline.py
@@ -1,5 +1,6 @@
-from .. import _, Point
 from .element import param, EmbroideryElement, Patch
+from ..i18n import _
+from ..utils.geometry import Point
 from ..utils import cache
 
 
diff --git a/lib/elements/satin_column.py b/lib/elements/satin_column.py
index d22f5145..3593db64 100644
--- a/lib/elements/satin_column.py
+++ b/lib/elements/satin_column.py
@@ -1,9 +1,9 @@
 from itertools import chain, izip
+from shapely import geometry as shgeo, ops as shops
 
-from .. import _, Point
 from .element import param, EmbroideryElement, Patch
-from ..utils import cache
-from shapely import geometry as shgeo, ops as shops
+from ..i18n import _
+from ..utils import cache, Point
 
 
 class SatinColumn(EmbroideryElement):
diff --git a/lib/elements/stroke.py b/lib/elements/stroke.py
index 360e3744..48662b6d 100644
--- a/lib/elements/stroke.py
+++ b/lib/elements/stroke.py
@@ -1,7 +1,8 @@
 import sys
-from .. import _, Point
+
 from .element import param, EmbroideryElement, Patch
-from ..utils import cache
+from ..i18n import _
+from ..utils import cache, Point
 
 
 warned_about_legacy_running_stitch = False
diff --git a/lib/extensions/base.py b/lib/extensions/base.py
index 91e050eb..ff587ca5 100644
--- a/lib/extensions/base.py
+++ b/lib/extensions/base.py
@@ -3,8 +3,9 @@ import re
 import json
 from copy import deepcopy
 from collections import MutableMapping
+
+from ..svg.tags import *
 from ..elements import AutoFill, Fill, Stroke, SatinColumn, Polyline, EmbroideryElement
-from .. import SVG_POLYLINE_TAG, SVG_GROUP_TAG, SVG_DEFS_TAG, INKSCAPE_GROUPMODE, EMBROIDERABLE_TAGS, PIXELS_PER_MM
 from ..utils import cache
 
 
diff --git a/lib/extensions/embroider.py b/lib/extensions/embroider.py
index 564e96ca..a213be64 100644
--- a/lib/extensions/embroider.py
+++ b/lib/extensions/embroider.py
@@ -1,12 +1,13 @@
 import sys
 import traceback
 import os
-
 import inkex
-from .. import _, PIXELS_PER_MM, write_embroidery_file
+
 from .base import InkstitchExtension
+from ..i18n import _
+from ..output import write_embroidery_file
 from ..stitch_plan import patches_to_stitch_plan
-from ..svg import render_stitch_plan
+from ..svg import render_stitch_plan, PIXELS_PER_MM
 
 
 class Embroider(InkstitchExtension):
diff --git a/lib/extensions/input.py b/lib/extensions/input.py
index bd3db0ed..f8bf5a5d 100644
--- a/lib/extensions/input.py
+++ b/lib/extensions/input.py
@@ -1,17 +1,19 @@
 import os
 from os.path import realpath, dirname, join as path_join
 import sys
+from inkex import etree
+import inkex
 
 # help python find libembroidery when running in a local repo clone
 if getattr(sys, 'frozen', None) is None:
     sys.path.append(realpath(path_join(dirname(__file__), '..', '..')))
 
 from libembroidery import *
-from inkex import etree
-import inkex
-from .. import PIXELS_PER_MM, INKSCAPE_LABEL, _
+
+from ..svg import PIXELS_PER_MM, render_stitch_plan
+from ..svg.tags import INKSCAPE_LABEL
+from ..i18n import _
 from ..stitch_plan import StitchPlan
-from ..svg import render_stitch_plan
 
 
 class Input(object):
diff --git a/lib/extensions/palettes.py b/lib/extensions/palettes.py
index 269dc6dc..f7a6c7a5 100644
--- a/lib/extensions/palettes.py
+++ b/lib/extensions/palettes.py
@@ -10,6 +10,7 @@ import time
 import logging
 import wx
 import inkex
+
 from ..utils import guess_inkscape_config_path
 
 
diff --git a/lib/extensions/params.py b/lib/extensions/params.py
index 881dab49..03a6f3cc 100644
--- a/lib/extensions/params.py
+++ b/lib/extensions/params.py
@@ -13,8 +13,8 @@ from collections import defaultdict
 from functools import partial
 from itertools import groupby
 
-from .. import _
 from .base import InkstitchExtension
+from ..i18n import _
 from ..stitch_plan import patches_to_stitch_plan
 from ..elements import EmbroideryElement, Fill, AutoFill, Stroke, SatinColumn
 from ..utils import save_stderr, restore_stderr
diff --git a/lib/extensions/print_pdf.py b/lib/extensions/print_pdf.py
index 5d462c0f..6450ee7c 100644
--- a/lib/extensions/print_pdf.py
+++ b/lib/extensions/print_pdf.py
@@ -10,22 +10,21 @@ from copy import deepcopy
 import wx
 import appdirs
 import json
-
 import inkex
-from .. import _, PIXELS_PER_MM, SVG_GROUP_TAG, translation as inkstitch_translation
-from .base import InkstitchExtension
-from ..stitch_plan import patches_to_stitch_plan
-from ..svg import render_stitch_plan
-from ..threads import ThreadCatalog
-
 from jinja2 import Environment, FileSystemLoader, select_autoescape
 from datetime import date
 import base64
-
 from flask import Flask, request, Response, send_from_directory, jsonify
 import webbrowser
 import requests
 
+from .base import InkstitchExtension
+from ..i18n import _, translation as inkstitch_translation
+from ..svg import PIXELS_PER_MM, render_stitch_plan
+from ..svg.tags import SVG_GROUP_TAG
+from ..stitch_plan import patches_to_stitch_plan
+from ..threads import ThreadCatalog
+
 
 def datetimeformat(value, format='%Y/%m/%d'):
     return value.strftime(format)
diff --git a/lib/extensions/simulate.py b/lib/extensions/simulate.py
index 75bc62c7..0c372d4d 100644
--- a/lib/extensions/simulate.py
+++ b/lib/extensions/simulate.py
@@ -1,6 +1,7 @@
 import wx
 
 from .base import InkstitchExtension
+from ..i18n import _
 from ..simulator import EmbroiderySimulator
 from ..stitch_plan import patches_to_stitch_plan
 
diff --git a/lib/i18n.py b/lib/i18n.py
new file mode 100644
index 00000000..d20f5d2f
--- /dev/null
+++ b/lib/i18n.py
@@ -0,0 +1,21 @@
+import sys
+import os
+import gettext
+
+_ = translation = None
+
+def localize():
+    if getattr(sys, 'frozen', False):
+        # we are in a pyinstaller installation
+        locale_dir = sys._MEIPASS
+    else:
+        locale_dir = os.path.dirname(__file__)
+
+    locale_dir = os.path.join(locale_dir, 'locales')
+
+    global translation, _
+
+    translation = gettext.translation("inkstitch", locale_dir, fallback=True)
+    _ = translation.gettext
+
+localize()
diff --git a/lib/output.py b/lib/output.py
new file mode 100644
index 00000000..f1651357
--- /dev/null
+++ b/lib/output.py
@@ -0,0 +1,130 @@
+import libembroidery
+import inkex
+import simpletransform
+
+from .utils import Point
+from .svg import PIXELS_PER_MM, get_doc_size, get_viewbox_transform
+
+
+def make_thread(color):
+    thread = libembroidery.EmbThread()
+    thread.color = libembroidery.embColor_make(*color.rgb)
+
+    thread.description = color.name
+    thread.catalogNumber = ""
+
+    return thread
+
+def add_thread(pattern, thread):
+    """Add a thread to a pattern and return the thread's index"""
+
+    libembroidery.embPattern_addThread(pattern, thread)
+
+    return libembroidery.embThreadList_count(pattern.threadList) - 1
+
+def get_flags(stitch):
+    flags = 0
+
+    if stitch.jump:
+        flags |= libembroidery.JUMP
+
+    if stitch.trim:
+        flags |= libembroidery.TRIM
+
+    if stitch.stop:
+        flags |= libembroidery.STOP
+
+    return flags
+
+
+def _string_to_floats(string):
+    floats = string.split(',')
+    return [float(num) for num in floats]
+
+
+def get_origin(svg):
+    # The user can specify the embroidery origin by defining two guides
+    # named "embroidery origin" that intersect.
+
+    namedview = svg.find(inkex.addNS('namedview', 'sodipodi'))
+    all_guides = namedview.findall(inkex.addNS('guide', 'sodipodi'))
+    label_attribute = inkex.addNS('label', 'inkscape')
+    guides = [guide for guide in all_guides
+                    if guide.get(label_attribute, "").startswith("embroidery origin")]
+
+    # document size used below
+    doc_size = list(get_doc_size(svg))
+
+    # convert the size from viewbox-relative to real-world pixels
+    viewbox_transform = get_viewbox_transform(svg)
+    simpletransform.applyTransformToPoint(simpletransform.invertTransform(viewbox_transform), doc_size)
+
+    default = [doc_size[0] / 2.0, doc_size[1] / 2.0]
+    simpletransform.applyTransformToPoint(viewbox_transform, default)
+    default = Point(*default)
+
+    if len(guides) < 2:
+        return default
+
+    # Find out where the guides intersect.  Only pay attention to the first two.
+    guides = guides[:2]
+
+    lines = []
+    for guide in guides:
+        # inkscape's Y axis is reversed from SVG's, and the guide is in inkscape coordinates
+        position = Point(*_string_to_floats(guide.get('position')))
+        position.y = doc_size[1] - position.y
+
+
+        # This one baffles me.  I think inkscape might have gotten the order of
+        # their vector wrong?
+        parts = _string_to_floats(guide.get('orientation'))
+        direction = Point(parts[1], parts[0])
+
+        # We have a theoretically infinite line defined by a point on the line
+        # and a vector direction.  Shapely can only deal in concrete line
+        # segments, so we'll pick points really far in either direction on the
+        # line and call it good enough.
+        lines.append(shgeo.LineString((position + 100000 * direction, position - 100000 * direction)))
+
+    intersection = lines[0].intersection(lines[1])
+
+    if isinstance(intersection, shgeo.Point):
+        origin = [intersection.x, intersection.y]
+        simpletransform.applyTransformToPoint(viewbox_transform, origin)
+        return Point(*origin)
+    else:
+        # Either the two guides are the same line, or they're parallel.
+        return default
+
+
+def write_embroidery_file(file_path, stitch_plan, svg):
+    origin = get_origin(svg)
+
+    pattern = libembroidery.embPattern_create()
+
+    for color_block in stitch_plan:
+        add_thread(pattern, make_thread(color_block.color))
+
+        for stitch in color_block:
+            if stitch.stop and stitch is not color_block.last_stitch:
+                # A STOP stitch that is not at the end of a color block
+                # occurs when the user specified "STOP after".  "STOP" is the
+                # same thing as a color change, and the user will assign a
+                # special color at the machine that tells it to pause after.
+                # We need to add another copy of the same color here so that
+                # the stitches after the STOP are still the same color.
+                add_thread(pattern, make_thread(color_block.color))
+
+            flags = get_flags(stitch)
+            libembroidery.embPattern_addStitchAbs(pattern, stitch.x - origin.x, stitch.y - origin.y, flags, 1)
+
+    libembroidery.embPattern_addStitchAbs(pattern, stitch.x - origin.x, stitch.y - origin.y, libembroidery.END, 1)
+
+    # convert from pixels to millimeters
+    libembroidery.embPattern_scale(pattern, 1/PIXELS_PER_MM)
+
+    # SVG and embroidery disagree on the direction of the Y axis
+    libembroidery.embPattern_flipVertical(pattern)
+
+    libembroidery.embPattern_write(pattern, file_path)
diff --git a/lib/simulator.py b/lib/simulator.py
index cc9442ea..c7e74353 100644
--- a/lib/simulator.py
+++ b/lib/simulator.py
@@ -4,8 +4,7 @@ import wx
 import colorsys
 from itertools import izip
 
-from . import PIXELS_PER_MM
-from .svg import color_block_to_point_lists
+from .svg import PIXELS_PER_MM, color_block_to_point_lists
 
 
 class EmbroiderySimulator(wx.Frame):
diff --git a/lib/stitch_plan/__init__.py b/lib/stitch_plan/__init__.py
index 6c1f418a..791a5f20 100644
--- a/lib/stitch_plan/__init__.py
+++ b/lib/stitch_plan/__init__.py
@@ -1 +1,2 @@
 from stitch_plan import patches_to_stitch_plan, StitchPlan, ColorBlock
+from .stitch import Stitch
diff --git a/lib/stitch_plan/stitch.py b/lib/stitch_plan/stitch.py
new file mode 100644
index 00000000..6a8579c2
--- /dev/null
+++ b/lib/stitch_plan/stitch.py
@@ -0,0 +1,15 @@
+from ..utils.geometry import Point
+
+
+class Stitch(Point):
+    def __init__(self, x, y, color=None, jump=False, stop=False, trim=False, no_ties=False):
+        self.x = x
+        self.y = y
+        self.color = color
+        self.jump = jump
+        self.trim = trim
+        self.stop = stop
+        self.no_ties = no_ties
+
+    def __repr__(self):
+        return "Stitch(%s, %s, %s, %s, %s, %s, %s)" % (self.x, self.y, self.color, "JUMP" if self.jump else " ", "TRIM" if self.trim else " ", "STOP" if self.stop else " ", "NO TIES" if self.no_ties else " ")
diff --git a/lib/stitch_plan/stitch_plan.py b/lib/stitch_plan/stitch_plan.py
index fab87876..570a7645 100644
--- a/lib/stitch_plan/stitch_plan.py
+++ b/lib/stitch_plan/stitch_plan.py
@@ -1,8 +1,9 @@
-from .. import Stitch, PIXELS_PER_MM
-from ..utils.geometry import Point
+from .stitch import Stitch
 from .stop import process_stop
 from .trim import process_trim
 from .ties import add_ties
+from ..svg import PIXELS_PER_MM
+from ..utils.geometry import Point
 from ..threads import ThreadColor
 
 
diff --git a/lib/stitch_plan/ties.py b/lib/stitch_plan/ties.py
index 1207ea51..f9c5b721 100644
--- a/lib/stitch_plan/ties.py
+++ b/lib/stitch_plan/ties.py
@@ -1,7 +1,9 @@
+from copy import deepcopy
+
+from .stitch import Stitch
 from ..utils import cut_path
 from ..stitches import running_stitch
-from .. import Stitch
-from copy import deepcopy
+
 
 def add_tie(stitches, tie_path):
     if stitches[-1].no_ties:
diff --git a/lib/stitches/auto_fill.py b/lib/stitches/auto_fill.py
index 7f265909..518a2812 100644
--- a/lib/stitches/auto_fill.py
+++ b/lib/stitches/auto_fill.py
@@ -1,5 +1,3 @@
-from fill import intersect_region_with_grating, row_num, stitch_row
-from .. import _, PIXELS_PER_MM, Point as InkstitchPoint
 import sys
 import shapely
 import networkx
@@ -7,6 +5,11 @@ import math
 from itertools import groupby
 from collections import deque
 
+from .fill import intersect_region_with_grating, row_num, stitch_row
+from ..i18n import _
+from ..svg import PIXELS_PER_MM
+from ..utils.geometry import Point as InkstitchPoint
+
 
 class MaxQueueLengthExceeded(Exception):
     pass
diff --git a/lib/stitches/fill.py b/lib/stitches/fill.py
index 1b7377b0..14971cb4 100644
--- a/lib/stitches/fill.py
+++ b/lib/stitches/fill.py
@@ -1,9 +1,10 @@
-from .. import PIXELS_PER_MM
-from ..utils import cache, Point as InkstitchPoint
 import shapely
 import math
 import sys
 
+from ..svg import PIXELS_PER_MM
+from ..utils import cache, Point as InkstitchPoint
+
 
 def legacy_fill(shape, angle, row_spacing, end_row_spacing, max_stitch_length, flip, staggers):
     rows_of_segments = intersect_region_with_grating(shape, angle, row_spacing, end_row_spacing, flip)
@@ -242,4 +243,3 @@ def pull_runs(rows, shape, row_spacing):
         count += 1
 
     return runs
-
diff --git a/lib/svg/__init__.py b/lib/svg/__init__.py
new file mode 100644
index 00000000..1895bba4
--- /dev/null
+++ b/lib/svg/__init__.py
@@ -0,0 +1,2 @@
+from .svg import color_block_to_point_lists, render_stitch_plan
+from .units import *
diff --git a/lib/svg.py b/lib/svg/svg.py
index 0728309b..3bc546e7 100644
--- a/lib/svg.py
+++ b/lib/svg/svg.py
@@ -1,5 +1,10 @@
 import simpletransform, simplestyle, inkex
-from . import _, get_viewbox_transform, cache, SVG_GROUP_TAG, INKSCAPE_LABEL, INKSCAPE_GROUPMODE, SVG_PATH_TAG
+
+from .units import get_viewbox_transform
+from .tags import SVG_GROUP_TAG, INKSCAPE_LABEL, INKSCAPE_GROUPMODE, SVG_PATH_TAG
+from ..i18n import _
+from ..utils import cache
+
 
 def color_block_to_point_lists(color_block):
     point_lists = [[]]
diff --git a/lib/svg/tags.py b/lib/svg/tags.py
new file mode 100644
index 00000000..fee59957
--- /dev/null
+++ b/lib/svg/tags.py
@@ -0,0 +1,12 @@
+import inkex
+
+
+SVG_PATH_TAG = inkex.addNS('path', 'svg')
+SVG_POLYLINE_TAG = inkex.addNS('polyline', 'svg')
+SVG_DEFS_TAG = inkex.addNS('defs', 'svg')
+SVG_GROUP_TAG = inkex.addNS('g', 'svg')
+
+INKSCAPE_LABEL = inkex.addNS('label', 'inkscape')
+INKSCAPE_GROUPMODE = inkex.addNS('groupmode', 'inkscape')
+
+EMBROIDERABLE_TAGS = (SVG_PATH_TAG, SVG_POLYLINE_TAG)
diff --git a/lib/svg/units.py b/lib/svg/units.py
new file mode 100644
index 00000000..015da60e
--- /dev/null
+++ b/lib/svg/units.py
@@ -0,0 +1,105 @@
+import simpletransform
+
+from ..utils import cache
+
+# modern versions of Inkscape use 96 pixels per inch as per the CSS standard
+PIXELS_PER_MM = 96 / 25.4
+
+# cribbed from inkscape-silhouette
+def parse_length_with_units( str ):
+
+    '''
+    Parse an SVG value which may or may not have units attached
+    This version is greatly simplified in that it only allows: no units,
+    units of px, mm, and %.  Everything else, it returns None for.
+    There is a more general routine to consider in scour.py if more
+    generality is ever needed.
+    '''
+
+    u = 'px'
+    s = str.strip()
+    if s[-2:] == 'px':
+        s = s[:-2]
+    elif s[-2:] == 'mm':
+        u = 'mm'
+        s = s[:-2]
+    elif s[-2:] == 'pt':
+        u = 'pt'
+        s = s[:-2]
+    elif s[-2:] == 'pc':
+        u = 'pc'
+        s = s[:-2]
+    elif s[-2:] == 'cm':
+        u = 'cm'
+        s = s[:-2]
+    elif s[-2:] == 'in':
+        u = 'in'
+        s = s[:-2]
+    elif s[-1:] == '%':
+        u = '%'
+        s = s[:-1]
+    try:
+        v = float( s )
+    except:
+        raise ValueError(_("parseLengthWithUnits: unknown unit %s") % s)
+
+    return v, u
+
+
+def convert_length(length):
+    value, units = parse_length_with_units(length)
+
+    if not units or units == "px":
+        return value
+
+    if units == 'pt':
+       value /= 72
+       units = 'in'
+
+    if units == 'pc':
+       value /= 6
+       units = 'in'
+
+    if units == 'cm':
+       value *= 10
+       units = 'mm'
+
+    if units == 'mm':
+        value = value / 25.4
+        units = 'in'
+
+    if units == 'in':
+        # modern versions of Inkscape use CSS's 96 pixels per inch.  When you
+        # open an old document, inkscape will add a viewbox for you.
+        return value * 96
+
+    raise ValueError(_("Unknown unit: %s") % units)
+
+
+@cache
+def get_doc_size(svg):
+    doc_width = convert_length(svg.get('width'))
+    doc_height = convert_length(svg.get('height'))
+
+    return doc_width, doc_height
+
+@cache
+def get_viewbox_transform(node):
+    # somewhat cribbed from inkscape-silhouette
+    doc_width, doc_height = get_doc_size(node)
+
+    viewbox = node.get('viewBox').strip().replace(',', ' ').split()
+
+    dx = -float(viewbox[0])
+    dy = -float(viewbox[1])
+    transform = simpletransform.parseTransform("translate(%f, %f)" % (dx, dy))
+
+    try:
+        sx = doc_width / float(viewbox[2])
+        sy = doc_height / float(viewbox[3])
+        scale_transform = simpletransform.parseTransform("scale(%f, %f)" % (sx, sy))
+        transform = simpletransform.composeTransform(transform, scale_transform)
+    except ZeroDivisionError:
+        pass
+
+    return transform
diff --git a/lib/threads/catalog.py b/lib/threads/catalog.py
index cebae4ff..d9981dc6 100644
--- a/lib/threads/catalog.py
+++ b/lib/threads/catalog.py
@@ -3,8 +3,10 @@ from os.path import dirname, realpath
 import sys
 from glob import glob
 from collections import Sequence
+
 from .palette import ThreadPalette
 
+
 class _ThreadCatalog(Sequence):
     """Holds a set of ThreadPalettes."""
 
diff --git a/lib/threads/palette.py b/lib/threads/palette.py
index e1f47c7f..785fb082 100644
--- a/lib/threads/palette.py
+++ b/lib/threads/palette.py
@@ -1,9 +1,10 @@
 from collections import Set
-from .color import ThreadColor
 from colormath.color_objects import sRGBColor, LabColor
 from colormath.color_conversions import convert_color
 from colormath.color_diff import delta_e_cie1994
 
+from .color import ThreadColor
+
 
 def compare_thread_colors(color1, color2):
     # K_L=2 indicates textiles
diff --git a/lib/utils/io.py b/lib/utils/io.py
index e87b9881..be1fdf24 100644
--- a/lib/utils/io.py
+++ b/lib/utils/io.py
@@ -2,6 +2,7 @@ import os
 import sys
 from cStringIO import StringIO
 
+
 def save_stderr():
     # GTK likes to spam stderr, which inkscape will show in a dialog.
     null = open(os.devnull, 'w')
diff --git a/messages.po b/messages.po
index a9fae6ff..7b2ca815 100644
--- a/messages.po
+++ b/messages.po
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PROJECT VERSION\n"
 "Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
-"POT-Creation-Date: 2018-04-29 21:45-0400\n"
+"POT-Creation-Date: 2018-05-01 21:21-0400\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -17,17 +17,6 @@ msgstr ""
 "Content-Transfer-Encoding: 8bit\n"
 "Generated-By: Babel 2.5.3\n"
 
-#, python-format
-msgid "parseLengthWithUnits: unknown unit %s"
-msgstr ""
-
-#, python-format
-msgid "Unknown unit: %s"
-msgstr ""
-
-msgid "Stitch Plan"
-msgstr ""
-
 msgid "Auto-Fill"
 msgstr ""
 
@@ -333,6 +322,17 @@ msgid ""
 "file to lexelby@github."
 msgstr ""
 
+msgid "Stitch Plan"
+msgstr ""
+
+#, python-format
+msgid "parseLengthWithUnits: unknown unit %s"
+msgstr ""
+
+#, python-format
+msgid "Unknown unit: %s"
+msgstr ""
+
 msgid "Color"
 msgstr ""