path: root/gerbonara/cad/kicad/schematic.py

"""
Library for handling KiCad's schematic files (`*.kicad_sch`).
"""

import math
import string
from pathlib import Path
from dataclasses import field, KW_ONLY
from itertools import chain
import re
import fnmatch
import os.path
import warnings

from .sexp import *
from .base_types import *
from .primitives import *
from .symbols import Symbol
from . import graphical_primitives as gr

from .. import primitives as cad_pr

from ... import graphic_primitives as gp
from ... import graphic_objects as go
from ... import apertures as ap
from ...layers import LayerStack
from ...newstroke import Newstroke
from ...utils import MM, rotate_point, Tag, setup_svg
from .schematic_colors import *


KICAD_PAPER_SIZES = {
    'A5': (210,   148),
    'A4': (297,   210),
    'A3': (420,   297),
    'A2': (594,   420),
    'A1': (841,   594),
    'A0': (1189,  841),
    'A': (11*25.4, 8.5*25.4),
    'B': (17*25.4, 11*15.4),
    'C': (22*25.4, 17*25.4),
    'D': (34*25.4, 22*25.4),
    'E': (44*25.4, 34*25.4),
    'USLetter': (11*25.4, 8.5*25.4),
    'USLegal': (14*25.4, 8.5*25.4),
    'USLedger': (17*25.4, 11*25.4),
    }

@sexp_type('path')
class SheetPath:
    path: str = '/'
    page: Named(str) = '1'


@sexp_type('junction')
class Junction:
    at: Rename(XYCoord) = field(default_factory=XYCoord)
    diameter: Named(float) = 0
    color: Color = field(default_factory=lambda: Color(0, 0, 0, 0))
    uuid: UUID = field(default_factory=UUID)

    def bounding_box(self, default=None):
        r = (self.diameter/2 or 0.5)
        return (self.at.x - r, self.at.y - r), (self.at.x + r, self.at.y + r)
    
    def to_svg(self, colorscheme=Colorscheme.KiCad):
        yield Tag('circle', cx=f'{self.at.x:.3f}', cy=f'{self.at.y:.3f}', r=(self.diameter/2 or 0.5),
                   fill=self.color.svg(colorscheme.wire))


@sexp_type('no_connect')
class NoConnect:
    at: Rename(XYCoord) = field(default_factory=XYCoord)
    uuid: UUID = field(default_factory=UUID)

    def bounding_box(self, default=None):
        r = 0.635
        return (self.at.x - r, self.at.y - r), (self.at.x + r, self.at.y + r)

    def to_svg(self, colorscheme=Colorscheme.KiCad):
        r = 0.635
        x, y = self.at.x, self.at.y
        yield Tag('path', d=f'M {x-r:.3f} {y-r:.3f} L {x+r:.3f} {y+r:.3f} M {x-r:.3f} {y+r:.3f} L {x+r:.3f} {y-r:.3f}',
                   fill='none', stroke_width='0.254', stroke=colorscheme.no_connect)


@sexp_type('bus_entry')
class BusEntry:
    at: AtPos = field(default_factory=AtPos)
    size: Rename(XYCoord) = field(default_factory=lambda: XYCoord(2.54, 2.54))
    stroke: Stroke = field(default_factory=Stroke)
    uuid: UUID = field(default_factory=UUID)

    def bounding_box(self, default=None):
        r = math.hypot(self.size.x, self.size.y)
        x1, y1 = self.at.x, self.at.y
        x2, y2 = rotate_point(x1+r, y1+r, self.at.rotation or 0)
        x1, x2 = min(x1, x2), max(x1, x2)
        y1, y2 = min(y1, y2), max(y1, y2)

        r = (self.stroke.width or 0.254) / 2
        return (x1-r, y1-r), (x2+r, y2+r)

    def to_svg(self, colorscheme=Colorscheme.KiCad):
        yield Tag('path', d='M {self.at.x} {self.at.y} l {self.size.x} {self.size.y}',
                   transform=f'rotate({self.at.rotation or 0})',
                   fill='none', stroke=self.stroke.svg_color(colorscheme.bus), width=self.stroke.width or '0.254')


def _polyline_svg(self, default_color):
    da = Dasher(self)
    if len(self.points.xy) < 2:
        warnings.warn(f'Schematic {type(self)} with less than two points')

    p0, *rest = self.points.xy
    da.move(p0.x, p0.y)
    for pn in rest:
        da.line(pn.x, pn.y)

    return da.svg(stroke=self.stroke.svg_color(default_color))


def _polyline_bounds(self):
    x1 = min(pt.x for pt in self.points)
    y1 = min(pt.y for pt in self.points)
    x2 = max(pt.x for pt in self.points)
    y2 = max(pt.y for pt in self.points)

    r = (self.stroke.width or 0.254) / 2
    return (x1-r, y1-r), (x2+r, y2+r)


@sexp_type('wire')
class Wire:
    points: PointList = field(default_factory=PointList)
    stroke: Stroke = field(default_factory=Stroke)
    uuid: UUID = field(default_factory=UUID)

    def bounding_box(self, default=None):
        return _polyline_bounds(self)

    def to_svg(self, colorscheme=Colorscheme.KiCad):
        yield _polyline_svg(self, colorscheme.wire)


@sexp_type('bus')
class Bus:
    points: PointList = field(default_factory=PointList)
    stroke: Stroke = field(default_factory=Stroke)
    uuid: UUID = field(default_factory=UUID)

    def bounding_box(self, default=None):
        return _polyline_bounds(self)

    def to_svg(self, colorscheme=Colorscheme.KiCad):
        yield _polyline_svg(self, colorscheme.bus)


@sexp_type('polyline')
class Polyline:
    points: PointList = field(default_factory=PointList)
    stroke: Stroke = field(default_factory=Stroke)
    uuid: UUID = field(default_factory=UUID)

    def bounding_box(self, default=None):
        return _polyline_bounds(self)

    def to_svg(self, colorscheme=Colorscheme.KiCad):
        yield _polyline_svg(self, colorscheme.lines)


@sexp_type('text')
class Text(TextMixin):
    text: str = ''
    exclude_from_sim: Named(YesNoAtom()) = True
    at: AtPos = field(default_factory=AtPos)
    effects: TextEffect = field(default_factory=TextEffect)
    uuid: UUID = field(default_factory=UUID)

    def to_svg(self, colorscheme=Colorscheme.KiCad):
        yield from TextMixin.to_svg(self, colorscheme.text)


@sexp_type('label')
class LocalLabel(TextMixin):
    text: str = ''
    at: AtPos = field(default_factory=AtPos)
    fields_autoplaced: Wrap(Flag()) = False
    effects: TextEffect = field(default_factory=TextEffect)
    uuid: UUID = field(default_factory=UUID)

    @property
    def _text_offset(self):
        return (0, -2*self.line_width)

    def to_svg(self, colorscheme=Colorscheme.KiCad):
        yield from TextMixin.to_svg(self, colorscheme.labels)


def label_shape_path_d(shape, w, h):
    l, r = {
        Atom.input: '<]',
        Atom.output: '[>',
        Atom.bidirectional: '<>',
        Atom.tri_state: '<>',
        Atom.passive: '[]'}.get(shape, '<]')
    r = h/2

    if l == '[':
        d = f'M {r:.3f} {r:.3f} L 0 {r:.3f} L 0 {-r:.3f} L {r:.3f} {-r:.3f}'
    else:
        d = f'M {r:.3f} {r:.3f} L 0 0 L {r:.3f} {-r:.3f}'

    e = w+r
    d += f' L {e:.3f} {-r:.3f}'

    if l == '[':
        return d + f'L {e+r:.3f} {-r:.3f} L {e+r:.3f} {r:.3f} L {e:.3f} {r:.3f} Z'
    else:
        return d + f'L {e+r:.3f} {0:.3f} L {e:.3f} {r:.3f} Z'


@sexp_type('global_label')
class GlobalLabel(TextMixin):
    text: str = ''
    shape: Named(AtomChoice(Atom.input, Atom.output, Atom.bidirectional, Atom.tri_state, Atom.passive)) = Atom.input
    at: AtPos = field(default_factory=AtPos)
    fields_autoplaced: Wrap(Flag()) = False
    effects: TextEffect = field(default_factory=TextEffect)
    uuid: UUID = field(default_factory=UUID)
    properties: List(Property) = field(default_factory=list)

    def to_svg(self, colorscheme=Colorscheme.KiCad):
        text = super(TextMixin, self).to_svg(colorscheme.labels),
        text.attrs['transform'] = f'translate({self.size*0.6:.3f} 0)'
        (x1, y1), (x2, y2) = self.bounding_box()
        frame = Tag('path', fill='none', stroke_width=0.254, stroke=colorscheme.lines,
            d=label_shape_path_d(self.shape, self.size*0.2 + y2-y1, self.size*1.2 + 0.254))
        yield Tag('g', children=[frame, text])


@sexp_type('hierarchical_label')
class HierarchicalLabel(TextMixin):
    text: str = ''
    shape: Named(AtomChoice(Atom.input, Atom.output, Atom.bidirectional, Atom.tri_state, Atom.passive)) = Atom.input
    at: AtPos = field(default_factory=AtPos)
    fields_autoplaced: Wrap(Flag()) = False
    effects: TextEffect = field(default_factory=TextEffect)
    uuid: UUID = field(default_factory=UUID)

    def to_svg(self, colorscheme=Colorscheme.KiCad):
        text, = TextMixin.to_svg(self, colorscheme.labels),
        text.attrs['transform'] = f'translate({self.size*1.2:.3f} 0)'
        frame = Tag('path', fill='none', stroke_width=0.254, stroke=colorscheme.lines,
            d=label_shape_path_d(self.shape, self.size, self.size))
        yield Tag('g', children=[frame, text])


@sexp_type('pin')
class Pin:
    name: str = '1'
    uuid: UUID = field(default_factory=UUID)


# Suddenly, we're doing syntax like this is yaml or something.
@sexp_type('path')
class SymbolCrosslinkSheet:
    path: str = ''
    reference: Named(str) = ''
    unit: Named(int) = 1


@sexp_type('project')
class SymbolCrosslinkProject:
    project_name: str = ''
    instances: List(SymbolCrosslinkSheet) = field(default_factory=list)


@sexp_type('mirror')
class MirrorFlags:
    x: Flag() = False
    y: Flag() = False


@sexp_type('property')
class DrawnProperty(TextMixin):
    key: str = None
    value: str = None
    at: AtPos = field(default_factory=AtPos)
    hide: Flag() = False
    effects: TextEffect = field(default_factory=TextEffect)
    _: SEXP_END = None
    parent: object = None

    def __after_parse__(self, parent=None):
        self.parent = parent

    # Alias value for text mixin
    @property
    def text(self):
        if self.key == 'Reference' and self.parent.unit > 0:
            return f'{self.value}{string.ascii_uppercase[self.parent.unit-1]}'
        else:
            return self.value

    @text.setter
    def text(self, value):
        self.value = value

    @property
    def default_v_align(self):
        return 'middle'

    @property
    def h_align(self):
        align = self.effects.justify.h_str
        if self.rotation in (90, 270):
            align = {'left': 'right', 'right': 'left'}.get(align, align)
        return align

    @property
    def rotation(self):
        rot = self.at.rotation
        rot += getattr(self.parent.at, 'rotation', 0)
        return rot%360

    @property
    def mirrored(self):
        if hasattr(self.parent, 'mirror'):
            return self.parent.mirror.x, self.parent.mirror.y
        return False, False

    def to_svg(self, colorscheme=Colorscheme.KiCad):
        if not self.hide:
            yield from TextMixin.to_svg(self, colorscheme.values)


@sexp_type('symbol')
class SymbolInstance:
    name: str = None
    lib_name: Named(str) = ''
    lib_id: Named(str) = ''
    at: AtPos = field(default_factory=AtPos)
    mirror: OmitDefault(MirrorFlags) = field(default_factory=MirrorFlags)
    unit: Named(int) = 1
    in_bom: Named(YesNoAtom()) = True
    on_board: Named(YesNoAtom()) = True
    dnp: Named(YesNoAtom()) = True
    fields_autoplaced: Wrap(Flag()) = True
    uuid: UUID = field(default_factory=UUID)
    properties: List(DrawnProperty) = field(default_factory=list)
    # AFAICT this property is completely redundant.
    pins: List(Pin) = field(default_factory=list)
    # AFAICT this property, too,  is completely redundant. It ultimately just lists paths and references of at most
    # three other uses of the same symbol in this schematic.
    instances: Named(List(SymbolCrosslinkProject)) = field(default_factory=list)
    _ : SEXP_END = None
    schematic: object = None

    def __after_parse__(self, parent):
        self.schematic = parent

    @property
    def reference(self):
        return self['Reference'].value

    @reference.setter
    def reference(self, value):
        self['Reference'].value = value

    @property
    def value(self):
        return self['Value'].value

    @value.setter
    def value(self, value):
        self['Value'].value = value

    @property
    def footprint(self):
        return self['Footprint'].value

    @footprint.setter
    def footprint(self, value):
        self['Footprint'].value = value

    def __getitem__(self, key):
        for prop in self.properties:
            if prop.key == key:
                return prop

    @property
    def rotation(self):
        return self.at.rotation

    def to_svg(self, colorscheme=Colorscheme.KiCad):
        children = []
        rot = self.at.rotation

        sym = self.schematic.lookup_symbol(self.lib_name, self.lib_id)

        units = [unit for unit in sym.units if unit.unit_global or unit.unit_index == self.unit]

        at_xform = xform = f'translate({self.at.x:.3f} {self.at.y:.3f})'
        if self.mirror.y:
            xform += f'scale(-1 -1)'
        elif self.mirror.x:
            xform += f'scale(1 1)'
        else:
            xform += f'scale(1 -1)'
        if rot:
            xform += f'rotate({rot})'

        children = [foo for unit in units for elem in unit.graphical_elements for foo in elem.to_svg(colorscheme)]
        yield Tag('g', children=children, transform=xform, fill=colorscheme.fill, stroke=colorscheme.lines)

        children = [foo for unit in units for pin in unit.pins for foo in pin.to_svg(colorscheme, self.mirror, rot)]
        yield Tag('g', children=children, transform=at_xform, fill=colorscheme.fill, stroke=colorscheme.lines)

        for prop in self.properties:
            yield from prop.to_svg(colorscheme)


@sexp_type('path')
class SubsheetCrosslinkSheet:
    path: str = ''
    page: Named(str) = ''


@sexp_type('project')
class SubsheetCrosslinkProject:
    project_name: str = ''
    instances: List(SymbolCrosslinkSheet) = field(default_factory=list)


@sexp_type('pin')
class SubsheetPin:
    name: str = '1'
    shape: AtomChoice(Atom.input, Atom.output, Atom.bidirectional, Atom.tri_state, Atom.passive) = Atom.input
    at: AtPos = field(default_factory=AtPos)
    effects: TextEffect = field(default_factory=TextEffect)
    uuid: UUID = field(default_factory=UUID)
    _ : SEXP_END = None
    subsheet: object = None

    def __after_parse__(self, parent):
        self.subsheet = parent

    def to_svg(self):
        size = self.effects.font.size.y or 1.27
        yield Tag('path', fill='none', d=label_shape_path_d(self.shape, 0, size+0.5),
                  transform=f'translate({self.at.x:.3f} {self.at.y:.3f}) rotate({180-self.at.rotation})')

        lx, ly = self.at.x, self.at.y
        dx, dy = rotate_point(-(size+1), 0, math.radians(self.at.rotation))
        lx += dx
        ly += dy
        frot = self.at.rotation
        h_align = 'right'
        if frot == 180:
            frot = 0
            h_align = 'left'

        font = Newstroke.load()
        yield font.render_svg(self.name,
                              size=size,
                              x0=0,
                              y0=0,
                              h_align=h_align,
                              v_align='middle',
                              rotation=-frot,
                              transform=f'translate({lx:.3f} {ly:.3f})',
                              scale=(1, 1),
                              mirror=(False, False),
                              )

@sexp_type('fill')
class SubsheetFill:
    color: Color = field(default_factory=lambda: Color(0, 0, 0, 0))


@sexp_type('sheet')
class Subsheet:
    at: Rename(XYCoord) = field(default_factory=XYCoord)
    size: Rename(XYCoord) = field(default_factory=lambda: XYCoord(2.54, 2.54))
    fields_autoplaced: Wrap(Flag()) = True
    stroke: Stroke = field(default_factory=Stroke)
    fill: SubsheetFill = field(default_factory=SubsheetFill)
    uuid: UUID = field(default_factory=UUID)
    _properties: List(DrawnProperty) = field(default_factory=list)
    pins: List(SubsheetPin) = field(default_factory=list)
    # AFAICT this is completely redundant, just like the one in SymbolInstance
    instances: Named(List(SubsheetCrosslinkProject)) = field(default_factory=list)
    _ : SEXP_END = None
    sheet_name: object = field(default_factory=lambda: DrawnProperty('Sheetname', ''))
    file_name: object = field(default_factory=lambda: DrawnProperty('Sheetfile', ''))
    schematic: object = None

    def __after_parse__(self, parent):
        self.sheet_name, self.file_name = self._properties
        self.schematic = parent

    def __before_sexp__(self):
        self._properties = [self.sheet_name, self.file_name]

    @property
    def rotation(self):
        return 0

    def open(self, search_dir=None, safe=True):
        if search_dir is None:
            if not self.schematic.original_filename:
                raise FileNotFoundError('No search path given and path of parent schematic unknown')
            else:
                search_dir = Path(self.schematic.original_filename).parent
        else:
            search_dir = Path(search_dir)

        resolved = search_dir / self.file_name.value
        if safe and os.path.commonprefix((search_dir.parts, resolved.parts)) != search_dir.parts:
                raise ValueError('Subsheet path traversal to parent directory attempted in Subsheet.open(..., safe=True)')

        return Schematic.open(resolved)

    def to_svg(self, colorscheme=Colorscheme.KiCad):
        children = []

        for prop in self._properties:
            yield from prop.to_svg(colorscheme)

        yield Tag('rect', x=f'{self.at.x:.3f}', y=f'{self.at.y:.3f}',
                  width=f'{self.size.x:.3f}', height=f'{self.size.y:.3f}',
                  **self.stroke.svg_attrs(colorscheme.lines), fill=self.fill.color.svg(colorscheme.fill))

        children = []
        for pin in self.pins:
            children += pin.to_svg()

        #xform = f'translate({self.at.x:.3f} {self.at.y:.3f})'
        yield Tag('g', children=children, #transform=xform,
                  fill=self.fill.color.svg(colorscheme.fill),
                  **self.stroke.svg_attrs(colorscheme.lines))


@sexp_type('lib_symbols')
class LocalLibrary:
    symbols: List(Symbol) = field(default_factory=list)


SUPPORTED_FILE_FORMAT_VERSIONS = [20230620]
@sexp_type('kicad_sch')
class Schematic:
    _version: Named(int, name='version') = 20230620
    generator: Named(Atom) = Atom.gerbonara
    uuid: UUID = field(default_factory=UUID)
    page_settings: PageSettings = field(default_factory=PageSettings)
    # The doc says this is expected, but eeschema barfs when it's there.
    # path: SheetPath = field(default_factory=SheetPath)
    lib_symbols: LocalLibrary = field(default_factory=list)
    junctions: List(Junction) = field(default_factory=list)
    no_connects: List(NoConnect) = field(default_factory=list)
    bus_entries: List(BusEntry) = field(default_factory=list)
    wires: List(Wire) = field(default_factory=list)
    buses: List(Bus) = field(default_factory=list)
    images: List(gr.Image) = field(default_factory=list)
    polylines: List(Polyline) = field(default_factory=list)
    texts: List(Text) = field(default_factory=list)
    local_labels: List(LocalLabel) = field(default_factory=list)
    global_labels: List(GlobalLabel) = field(default_factory=list)
    hierarchical_labels: List(HierarchicalLabel) = field(default_factory=list)
    symbols: List(SymbolInstance) = field(default_factory=list)
    subsheets: List(Subsheet) = field(default_factory=list)
    sheet_instances: Named(List(SubsheetCrosslinkSheet)) = field(default_factory=list)
    _ : SEXP_END = None
    original_filename: str = None

    @property
    def version(self):
        return self._version

    @version.setter
    def version(self, value):
        if value not in SUPPORTED_FILE_FORMAT_VERSIONS:
            raise FormatError(f'File format version {value} is not supported. Supported versions are {", ".join(map(str, SUPPORTED_FILE_FORMAT_VERSIONS))}.')


    def lookup_symbol(self, lib_name, lib_id):
        key = lib_name or lib_id
        for sym in self.lib_symbols.symbols:
            if sym.name == key or sym.raw_name == key:
                return sym
        raise KeyError(f'Symbol with {lib_name=} {lib_id=} not found')

    def write(self, filename=None):
        with open(filename or self.original_filename, 'w') as f:
            f.write(self.serialize())

    def serialize(self):
        return build_sexp(sexp(type(self), self)[0])

    @classmethod
    def open(kls, pcb_file, *args, **kwargs):
        return kls.load(Path(pcb_file).read_text(), *args, **kwargs, original_filename=pcb_file)

    @classmethod
    def load(kls, data, *args, **kwargs):
        return kls.parse(data, *args, **kwargs)

    @property
    def elements(self):
        yield from self.subsheets
        yield from self.images
        yield from self.polylines
        yield from self.symbols
        yield from self.junctions
        yield from self.no_connects
        yield from self.bus_entries
        yield from self.wires
        yield from self.buses
        yield from self.texts
        yield from self.local_labels
        yield from self.global_labels
        yield from self.hierarchical_labels

    def to_svg(self, colorscheme=Colorscheme.KiCad):
        children = []
        for elem in self.elements:
            children += elem.to_svg(colorscheme)
        w, h = KICAD_PAPER_SIZES[self.page_settings.page_format]
        return setup_svg(children, ((0, 0), (w, h)), pagecolor=colorscheme.background)


    
# From: https://jakevdp.github.io/blog/2012/10/07/xkcd-style-plots-in-matplotlib/
#def xkcd_line(x, y, xlim=None, ylim=None, mag=1.0, f1=30, f2=0.05, f3=15):
def xkcd_line(x, y, xlim=None, ylim=None, mag=1.0, f1=10, f2=0.10, f3=5):
    """
    Mimic a hand-drawn line from (x, y) data

    Parameters
    ----------
    x, y : array_like
        arrays to be modified
    xlim, ylim : data range
        the assumed plot range for the modification.  If not specified,
        they will be guessed from the  data
    mag : float
        magnitude of distortions
    f1, f2, f3 : int, float, int
        filtering parameters.  f1 gives the size of the window, f2 gives
        the high-frequency cutoff, f3 gives the size of the filter
    
    Returns
    -------
    x, y : ndarrays
        The modified lines
    """
    import numpy as np
    from scipy import interpolate, signal

    x = np.asarray(x)
    y = np.asarray(y)
    
    # get limits for rescaling
    if xlim is None:
        xlim = (x.min(), x.max())
    if ylim is None:
        ylim = (y.min(), y.max())

    if xlim[1] == xlim[0]:
        xlim = ylim
        
    if ylim[1] == ylim[0]:
        ylim = xlim

    # scale the data
    x_scaled = (x - xlim[0]) * 1. / (xlim[1] - xlim[0])
    y_scaled = (y - ylim[0]) * 1. / (ylim[1] - ylim[0])

    # compute the total distance along the path
    dx = x_scaled[1:] - x_scaled[:-1]
    dy = y_scaled[1:] - y_scaled[:-1]
    dist_tot = np.sum(np.sqrt(dx * dx + dy * dy))

    # number of interpolated points is proportional to the distance
    Nu = int(50 * dist_tot)
    u = np.arange(-1, Nu + 1) * 1. / (Nu - 1)

    # interpolate curve at sampled points
    k = min(3, len(x) - 1)
    res = interpolate.splprep([x_scaled, y_scaled], s=0, k=k)
    x_int, y_int = interpolate.splev(u, res[0]) 

    # we'll perturb perpendicular to the drawn line
    dx = x_int[2:] - x_int[:-2]
    dy = y_int[2:] - y_int[:-2]
    dist = np.sqrt(dx * dx + dy * dy)

    # create a filtered perturbation
    coeffs = mag * np.random.normal(0, 0.01, len(x_int) - 2)
    b = signal.firwin(f1, f2 * dist_tot, window=('kaiser', f3))
    response = signal.lfilter(b, 1, coeffs)

    x_int[1:-1] += response * dy / dist
    y_int[1:-1] += response * dx / dist

    # un-scale data
    x_int = x_int[1:-1] * (xlim[1] - xlim[0]) + xlim[0]
    y_int = y_int[1:-1] * (ylim[1] - ylim[0]) + ylim[0]
    
    return x_int, y_int

def wonkify(path):
    out = []
    for segment in path.attrs['d'].split('M')[1:]:
        if 'A' in segment:
            out.append(segment)
            continue

        points = segment.split('L')
        if points[-1].rstrip().endswith('Z'):
            closed = True
            points[-1] = points[-1].rstrip()[:-1].rstrip()
            points.append(points[0])
        else:
            closed = False

        pts = []
        lx, ly = None, None
        for pt in points:
            x, y = pt.strip().split()
            x, y = float(x), float(y)
            if (x, y) == (lx, ly):
                continue

            lx, ly = x, y
            pts.append((x, y))

        if len(pts) == 2:
            segs = [pts]

        else:
            seg = [pts[0]]
            segs = [seg]
            for p0, p1, p2 in zip(pts[0::], pts[1::], pts[2::]):
                dx1, dy1 = p1[0] - p0[0], p1[1] - p0[1]
                dx2, dy2 = p2[0] - p1[0], p2[1] - p1[1]
                a1, a2 = math.atan2(dy1, dx1), math.atan2(dy2, dx2)
                da = (a2 - a1 + math.pi) % (2*math.pi) - math.pi
                if abs(da) > math.pi/4:
                    seg.append(p1)
                    seg = [p1, p2]
                    segs.append(seg)
                seg.append(p1)
            seg.append(p2)

        for seg in segs:
            xs, ys = [x for x, y in seg], [y for x, y in seg]
            xs, ys = xkcd_line(xs, ys)
            d = ' L '.join(f'{x:.3f} {y:.3f}' for x, y in zip(xs, ys))
            if closed:
                d += ' Z'
            out.append(d)

    path.attrs['d'] = ' '.join(f'M {seg}' for seg in out)


def postprocess(tag):
    if tag.name == 'path':
        wonkify(tag)
    else:
        for child in tag.children:
            postprocess(child)
    return tag

if __name__ == '__main__':
    import sys
    from ...layers import LayerStack
    from .tmtheme import *
    sch = Schematic.open(sys.argv[1])
    print('Loaded schematic with', len(sch.wires), 'wires and', len(sch.symbols), 'symbols.')
    for subsh in sch.subsheets:
        subsh = subsh.open()
        print('Loaded sub-sheet with', len(subsh.wires), 'wires and', len(subsh.symbols), 'symbols.')

    sch.write('/tmp/test.kicad_sch')
    for p in Path('/tmp').glob('*.tmTheme'):
        cs = TmThemeSchematic(p.read_text())
        Path(f'/tmp/test-{p.stem}.svg').write_text(str(postprocess(sch.to_svg(cs))))
    for p in Path('/tmp').glob('*.sublime-color-scheme'):
        cs = SublimeSchematic(p.read_text())
        Path(f'/tmp/test-{p.stem}.svg').write_text(str(postprocess(sch.to_svg(cs))))