summaryrefslogtreecommitdiff
path: root/gerbonara/layers.py
blob: a1c854ab5d45b4ff8a99f410e712a65fae19c232 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
#! /usr/bin/env python
# -*- coding: utf-8 -*-
#
# Copyright 2014 Hamilton Kibbe <ham@hamiltonkib.be>
# Copyright 2022 Jan Götte <code@jaseg.de>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

import os
import io
import sys
import re
import warnings
import copy
import bisect
import textwrap
import itertools
from collections import namedtuple
from pathlib import Path
from zipfile import ZipFile, is_zipfile
import tempfile

from .excellon import ExcellonFile, parse_allegro_ncparam, parse_allegro_logfile
from .rs274x import GerberFile
from .ipc356 import Netlist
from .cam import FileSettings, LazyCamFile
from .layer_rules import MATCH_RULES
from .utils import sum_bounds, setup_svg, MM, Tag
from . import graphic_objects as go
from . import graphic_primitives as gp


STANDARD_LAYERS = [
        'mechanical outline',
        'top copper',
        'top mask',
        'top silk',
        'top paste',
        'bottom copper',
        'bottom mask',
        'bottom silk',
        'bottom paste',
        ]

DEFAULT_COLORS = {
        'copper': '#cccccc',
        'mask': '#004200bf',
        'paste': '#999999',
        'silk': '#e0e0e0',
        'drill': '#303030',
        'outline': '#F0C000',
    }

class NamingScheme:
    kicad = {
    'top copper':           '{board_name}-F.Cu.gbr',
    'top mask':             '{board_name}-F.Mask.gbr',
    'top silk':             '{board_name}-F.SilkS.gbr',
    'top paste':            '{board_name}-F.Paste.gbr',
    'bottom copper':        '{board_name}-B.Cu.gbr',
    'bottom mask':          '{board_name}-B.Mask.gbr',
    'bottom silk':          '{board_name}-B.SilkS.gbr',
    'bottom paste':         '{board_name}-B.Paste.gbr',
    'inner copper':         '{board_name}-In{layer_number}.Cu.gbr',
    'mechanical outline':   '{board_name}-Edge.Cuts.gbr',
    'unknown drill':        '{board_name}.drl',
    'plated drill':         '{board_name}.plated.drl',
    'nonplated drill':      '{board_name}.nonplated.drl',
    'other netlist':        '{board_name}.d356',
    }

    altium = {
    'top copper':           '{board_name}.gtl',
    'top mask':             '{board_name}.gts',
    'top silk':             '{board_name}.gto',
    'top paste':            '{board_name}.gtp',
    'bottom copper':        '{board_name}.gbl',
    'bottom mask':          '{board_name}.gbs',
    'bottom silk':          '{board_name}.gbo',
    'bottom paste':         '{board_name}.gbp',
    'inner copper':         '{board_name}.gp{layer_number}',
    'mechanical outline':   '{board_name}.gko',
    'unknown drill':        '{board_name}.drl',
    'plated drill':         '{board_name}.plated.drl',
    'nonplated drill':      '{board_name}.nonplated.drl',
    }



def match_files(filenames):
    matches = {}
    for generator, rules in MATCH_RULES.items():
        gen = {}
        matches[generator] = gen
        for layer, regex in rules.items():
            for fn in filenames:
                if (m := re.fullmatch(regex, fn.name, re.IGNORECASE)):
                    if layer == 'inner copper':
                        target = 'inner_' + ''.join(e or '' for e in m.groups()) + ' copper'
                    else:
                        target = layer
                    gen[target] = gen.get(target, []) + [fn]
    return matches


def best_match(filenames):
    matches = match_files(filenames)
    matches = sorted(matches.items(), key=lambda pair: len(pair[1]))
    generator, files = matches[-1]
    return generator, files


def identify_file(data):
    if 'M48' in data:
        return 'excellon'

    if 'G90' in data and ';LEADER:' in data: # yet another allegro special case
        return 'excellon'

    if 'FSLAX' in data or 'FSTAX' in data:
        return 'gerber'

    if 'UNITS CUST' in data:
        return 'ipc356'

    return None


def common_prefix(l):
    out = []
    for cand in l:
        score = lambda n: sum(elem.startswith(cand[:n]) for elem in l)
        baseline = score(1)
        if len(l) - baseline > 5:
            continue
        for n in range(len(cand) if '.' not in cand else cand.index('.')+1, 2, -1):
            if len(l) - score(n) < 5:
                break
        out.append(cand[:n-1])
 
    if not out:
        return ''
 
    return sorted(out, key=len)[-1]

def do_autoguess(filenames):
    prefix = common_prefix([f.name for f in filenames])

    matches = {}
    for f in filenames:
        name = layername_autoguesser(f.name[len(prefix):] if f.name.startswith(prefix) else f.name)
        if name != 'unknown unknown':
            matches[name] = matches.get(name, []) + [f]

    inner_layers = [ m for m in matches if 'inner' in m ]
    if len(inner_layers) >= 2 and 'copper top' not in matches and 'copper bottom' not in matches:
        if 'inner_01 copper' in matches:
            warnings.warn('Could not find copper layer. Re-assigning outermost inner layers to top/bottom copper.')
            matches['top copper'] = matches.pop('inner_01 copper')
            last_inner = sorted(inner_layers, key=lambda name: int(name.partition(' ')[0].partition('_')[2]))[-1]
            matches['bottom copper'] = matches.pop(last_inner)

    return matches


def layername_autoguesser(fn):
    fn, _, ext = fn.lower().rpartition('.')
    
    if ext in ('log', 'err', 'fdl', 'py', 'sh', 'md', 'rst', 'zip', 'pdf', 'svg', 'ps', 'png', 'jpg', 'bmp'):
        return 'unknown unknown'

    side, use = 'unknown', 'unknown'
    if re.search('top|front|pri?m?(ary)?', fn):
        side = 'top'
        use = 'copper'

    if re.search('bot(tom)?|back|sec(ondary)?', fn):
        side = 'bottom'
        use = 'copper'

    if re.search('silks?(creen)?|symbol', fn):
        use = 'silk'

    elif re.search('(solder)?paste|metalmask', fn):
        use = 'paste'

    elif re.search('(solder)?(mask|resist)', fn):
        use = 'mask'

    elif re.search('drill|rout?e?', fn):
        use = 'drill'
        side = 'unknown'

        if re.search(r'np(th|lt)?|(non|un)\W*plated|(non|un)\Wgalv', fn):
            side = 'nonplated'

        elif re.search('pth|plated|galv|plt', fn):
            side = 'plated'

    elif (m := re.search(r'(la?y?e?r?|in(ner)?|conduct(or|ive)?)\W*(?P<num>[0-9]+)', fn)):
        use = 'copper'
        side = f'inner_{int(m["num"]):02d}'

    elif re.search('film', fn):
        use = 'copper'

    elif re.search('out(line)?', fn):
        use = 'outline'
        side = 'mechanical'

    elif 'ipc' in fn and '356' in fn:
        use = 'netlist'
        side = 'other'

    elif 'netlist' in fn:
        use = 'netlist'
        side = 'other'

    if side == 'unknown':
        if re.search(r'[^a-z0-9]a', fn):
            side = 'top'
        elif re.search(r'[^a-z0-9]b', fn):
            side = 'bottom'

    return f'{side} {use}'


class LayerStack:
    def __init__(self, graphic_layers, drill_layers, netlist=None, board_name=None, original_path=None, was_zipped=False, generator=None):
        self.graphic_layers = graphic_layers
        self.drill_layers = drill_layers
        self.board_name = board_name
        self.netlist = netlist
        self.original_path = original_path
        self.was_zipped = was_zipped
        self.generator = generator

    @classmethod
    def open(kls, path, board_name=None, lazy=False, overrides=None, autoguess=True):
        if str(path) == '-':
            data_io = io.BytesIO(sys.stdin.buffer.read())
            return kls.from_zip_data(data_io, original_path='<stdin>', board_name=board_name, lazy=lazy)

        path = Path(path)
        if path.is_dir():
            return kls.open_dir(path, board_name=board_name, lazy=lazy, overrides=overrides, autoguess=autoguess)
        elif path.suffix.lower() == '.zip' or is_zipfile(path):
            return kls.open_zip(path, board_name=board_name, lazy=lazy, overrides=overrides, autoguess=autoguess)
        else:
            return kls.from_files([path], board_name=board_name, lazy=lazy, overrides=overrides, autoguess=autoguess)

    @classmethod
    def open_zip(kls, file, original_path=None, board_name=None, lazy=False, overrides=None, autoguess=True):
        tmpdir = tempfile.TemporaryDirectory()
        tmp_indir = Path(tmpdir.name) / 'input'
        tmp_indir.mkdir()

        with ZipFile(file) as f:
            f.extractall(path=tmp_indir)

        inst = kls.open_dir(tmp_indir, board_name=board_name, lazy=lazy)
        inst.tmpdir = tmpdir
        inst.original_path = Path(original_path or file)
        inst.was_zipped = True
        return inst

    @classmethod
    def open_dir(kls, directory, board_name=None, lazy=False, overrides=None, autoguess=True):

        directory = Path(directory)
        if not directory.is_dir():
            raise FileNotFoundError(f'{directory} is not a directory')

        files = [ path for path in directory.glob('**/*') if path.is_file() ]
        return kls.from_files(files, board_name=board_name, lazy=lazy, original_path=directory, overrides=overrides,
                              autoguess=autoguess)
        inst.original_path = directory
        return inst

    @classmethod
    def from_files(kls, files, board_name=None, lazy=False, original_path=None, was_zipped=False, overrides=None,
                   autoguess=True):
        if autoguess:
            generator, filemap = best_match(files)
        else:
            generator, filemap = 'custom', {}
        all_generator_hints = set()

        if overrides:
            for fn in files:
                for expr, layer in overrides.items():
                    if re.fullmatch(expr, fn.name):
                        if layer == 'ignore':
                            for entries in filemap.values():
                                if fn in entries:
                                    entries.remove(fn)
                        else:
                            if layer in filemap and fn in filemap[layer]:
                                filemap[layer].remove(fn)
                            filemap[layer] = filemap.get(layer, []) + [fn]

        if sum(len(files) for files in filemap.values()) < 6:
            warnings.warn('Ambiguous gerber filenames. Trying last-resort autoguesser.')
            generator = None
            filemap = do_autoguess(files)
            if len(filemap) < 6:
                raise ValueError('Cannot figure out gerber file mapping. Partial map is: ', filemap)

        excellon_settings, external_tools = None, None
        if generator == 'geda':
            # geda is written by geniuses who waste no bytes of unnecessary output so it doesn't actually include the
            # number format in files that use imperial units. Unfortunately it also doesn't include any hints that the
            # file was generated by geda, so we have to guess by context whether this is just geda being geda or
            # potential user error.
            excellon_settings = FileSettings(number_format=(2, 4))

        elif generator == 'allegro':
            # Allegro puts information that is absolutely vital for parsing its excellon files... into another file,
            # next to the actual excellon file. Despite pretty much everyone else having figured out a way to put that
            # info into the excellon file itself, even if only as a comment.
            if 'excellon params' in filemap:
                excellon_settings = parse_allegro_ncparam(filemap['excellon params'][0].read_text())
                for file in filemap['excellon params']:
                    if (external_tools := parse_allegro_logfile(file.read_text())):
                        break
                del filemap['excellon params']
            # Ignore if we can't find the param file -- maybe the user has convinced Allegro to actually put this
            # information into a comment, or maybe they have made Allegro just use decimal points like XNC does.

            filemap = do_autoguess([ f for files in filemap.values() for f in files ])
            if len(filemap) < 6:
                raise SystemError('Cannot figure out gerber file mapping')
            # FIXME use layer metadata from comments and ipc file if available

        elif generator == 'zuken':
            filemap = do_autoguess([ f for files in filemap.values() for f in files ])
            if len(filemap) < 6:
                raise SystemError('Cannot figure out gerber file mapping')
            # FIXME use layer metadata from comments and ipc file if available

        elif generator == 'altium':
            if 'mechanical outline' in filemap:
                # Use lowest-numbered mechanical layer as outline, ignore others.
                mechs = {}
                for layer in filemap['mechanical outline']:
                    if layer.name.lower().endswith('gko'):
                        filemap['mechanical outline'] = [layer]
                        break

                    if (m := re.match(r'.*\.gm([0-9]+)', layer.name, re.IGNORECASE)):
                        mechs[int(m[1])] = layer
                    else:
                        break
                else:
                    filemap['mechanical outline'] = [sorted(mechs.items(), key=lambda x: x[0])[0][1]]

        else:
            excellon_settings = None

        ambiguous = [ f'{key} ({", ".join(x.name for x in value)})' for key, value in filemap.items() if len(value) > 1 and not 'drill' in key ]
        if ambiguous:
            raise SystemError(f'Ambiguous layer names: {", ".join(ambiguous)}')

        drill_layers = []
        netlist = None
        layers = {} # { tuple(key.split()): None for key in STANDARD_LAYERS }
        for key, paths in filemap.items():
            if len(paths) > 1 and not 'drill' in key:
                raise ValueError(f'Multiple matching files found for {key} layer: {", ".join(value)}')

            for path in paths:
                id_result = identify_file(path.read_text())

                if 'netlist' in key:
                    layer = LazyCamFile(Netlist, path)

                elif ('outline' in key or 'drill' in key) and id_result != 'gerber':
                    if id_result is None:
                        # Since e.g. altium uses ".txt" as the extension for its drill files, we have to assume the
                        # current file might not be a drill file after all.
                        continue

                    if 'nonplated' in key:
                        plated = False
                    elif 'plated' in key:
                        plated = True
                    else:
                        plated = None
                    layer = LazyCamFile(ExcellonFile, path, plated=plated, settings=excellon_settings, external_tools=external_tools)
                else:

                    layer = LazyCamFile(GerberFile, path)

                if not lazy:
                    layer = layer.instance

                if key == 'mechanical outline':
                    layers['mechanical', 'outline'] = layer

                elif 'drill' in key:
                    drill_layers.append(layer)

                elif 'netlist' in key:
                    if netlist:
                        warnings.warn(f'Found multiple netlist files, using only first one. Have: {netlist.original_path.name}, got {path.name}')
                    else:
                        netlist = layer

                else:
                    side, _, use = key.partition(' ')
                    layers[(side, use)] = layer

                if not lazy:
                    hints = set(layer.generator_hints) | { generator }
                    all_generator_hints |= hints
                    if len(hints) > 1:
                        warnings.warn('File identification returned ambiguous results. Please raise an issue on the '
                                'gerbonara tracker and if possible please provide these input files for reference.')

        if not board_name:
            board_name = common_prefix([l.original_path.name for l in layers.values() if l is not None])
            board_name = re.sub(r'^\W+', '', board_name)
            board_name = re.sub(r'\W+$', '', board_name)

        return kls(layers, drill_layers, netlist, board_name=board_name,
                original_path=original_path, was_zipped=was_zipped, generator=[*all_generator_hints, None][0])

    def save_to_zipfile(self, path, naming_scheme={}, overwrite_existing=True, prefix=''):
        if path.is_file():
            if overwrite_existing:
                path.unlink()
            else:
                raise ValueError('output zip file already exists and overwrite_existing is False')

        with ZipFile(path, 'w') as le_zip:
            for path, layer in self._save_files_iter(naming_scheme=naming_scheme):
                with le_zip.open(prefix + str(path), 'w') as out:
                    out.write(layer.instance.write_to_bytes())

    def save_to_directory(self, path, naming_scheme={}, overwrite_existing=True,
                          gerber_settings=None, excellon_settings=None):
        outdir = Path(path)
        outdir.mkdir(parents=True, exist_ok=overwrite_existing)

        for path, layer in self._save_files_iter(naming_scheme=naming_scheme):
            out = outdir / path
            if out.exists() and not overwrite_existing:
                raise SystemError(f'Path exists but overwrite_existing is False: {out}')
            layer.instance.save(out)

    def _save_files_iter(self, naming_scheme={}):
        def get_name(layer_type, layer):
            nonlocal naming_scheme

            if (m := re.match('inner_([0-9]+) copper', layer_type)):
                layer_type = 'inner copper'
                num = int(m[1])
            else:
                num = None

            if layer_type in naming_scheme:
                path = naming_scheme[layer_type].format(layer_number=num, board_name=self.board_name)
            elif layer.original_path:
                path = layer.original_path.name
            else:
                path = f'{self.board_name}-{layer_type.replace(" ", "_")}.gbr'

            return path

        for (side, use), layer in self.graphic_layers.items():
            yield get_name(f'{side} {use}', layer), layer

        #self.normalize_drill_layers()

        if self.drill_pth is not None:
            yield get_name('plated drill', self.drill_pth), self.drill_pth
        if self.drill_npth is not None:
            yield get_name('nonplated drill', self.drill_npth), self.drill_npth
        if self.drill_unknown is not None:
            yield get_name('unknown drill', self.drill_unknown), self.drill_unknown

        if self.netlist:
            yield get_name('other netlist', self.netlist), self.netlist

    def __str__(self):
        names = [ f'{side} {use}' for side, use in self.graphic_layers ]
        return f'<LayerStack {self.board_name} [{", ".join(names)}] and {len(self.drill_layers)} drill layers>'

    def __repr__(self):
        return str(self)

    def to_svg(self, margin=0, arg_unit=MM, svg_unit=MM, force_bounds=None, tag=Tag, page_bg="white"):
        if force_bounds:
            bounds = svg_unit.convert_bounds_from(arg_unit, force_bounds)
        else:
            bounds = self.bounding_box(svg_unit, default=((0, 0), (0, 0)))
        
        tags = []
        for (side, use), layer in self.graphic_layers.items():
            tags.append(tag('g', list(layer.svg_objects(svg_unit=svg_unit, fg='black', bg="white", tag=Tag)),
                id=f'l-{side}-{use}'))

        for i, layer in enumerate(self.drill_layers):
            tags.append(tag('g', list(layer.svg_objects(svg_unit=svg_unit, fg='black', bg="white", tag=Tag)),
                id=f'l-drill-{i}'))

        return setup_svg(tags, bounds, margin=margin, arg_unit=arg_unit, svg_unit=svg_unit, pagecolor=page_bg, tag=tag)

    def to_pretty_svg(self, side='top', margin=0, arg_unit=MM, svg_unit=MM, force_bounds=None, tag=Tag, inkscape=False, colors=None):
        if colors is None:
            colors = DEFAULT_COLORS

        colors_alpha = {}
        for layer, color in colors.items():
            if isinstance(color, str):
                if re.match(r'#[0-9a-fA-F]{8}', color):
                    colors_alpha[layer] = (color[:-2], int(color[-2:], 16)/255)
                else:
                    colors_alpha[layer] = (color, 1)
            else:
                colors_alpha[layer] = color

        if force_bounds:
            bounds = svg_unit.convert_bounds_from(arg_unit, force_bounds)
        else:
            bounds = self.board_bounds(unit=svg_unit, default=((0, 0), (0, 0)))
        
        filter_defs = []

        for layer, (color, alpha) in colors_alpha.items():
            filter_defs.append(textwrap.dedent(f'''
                <filter id="f-{layer}">
                <feFlood result="flood-black" flood-color="black" flood-opacity="1"/>
                <feFlood result="flood-green" flood-color="{color}"/>
                <feBlend in="SourceGraphic" in2="flood-black" result="overlay" mode="normal"/>
                <feBlend in="overlay" in2="flood-green" result="colored" mode="multiply"/>
                <feColorMatrix in="overlay" type="matrix" result="alphaOut" values="0 0 0 0 0
                0 0 0 0 0
                0 0 0 0 0
                {alpha} 0 0 0 0"/>
                <feComposite in="colored" in2="alphaOut" operator="in"/>
                </filter>'''.strip()))

        inkscape_attrs = lambda label: dict(inkscape__groupmode='layer', inkscape__label=label) if inkscape else {}
        
        layers = []
        for use in ['copper', 'mask', 'silk', 'paste']:
            if (side, use) not in self:
                warnings.warn(f'Layer "{side} {use}" not found. Found layers: {", ".join(side + " " + use for side, use in self.graphic_layers)}')
                continue

            layer = self[(side, use)]
            fg, bg = ('white', 'black') if use != 'mask' else ('black', 'white')
            objects = list(layer.instance.svg_objects(svg_unit=svg_unit, fg=fg, bg=bg, tag=Tag))
            if use == 'mask':
                objects.insert(0, tag('path', id='outline-path', d=self.outline_svg_d(unit=svg_unit), style='fill:white'))
            layers.append(tag('g', objects, id=f'l-{side}-{use}', filter=f'url(#f-{use})', **inkscape_attrs(f'{side} {use}')))

        for i, layer in enumerate(self.drill_layers):
            layers.append(tag('g', list(layer.instance.svg_objects(svg_unit=svg_unit, fg='white', bg='black', tag=Tag)),
                id=f'l-drill-{i}', filter=f'url(#f-drill)', **inkscape_attrs(f'drill-{i}')))

        if self.outline:
            layers.append(tag('g', list(self.outline.instance.svg_objects(svg_unit=svg_unit, fg='white', bg='black', tag=Tag)),
                id=f'l-outline-{i}', **inkscape_attrs(f'outline-{i}')))

        layer_group = tag('g', layers, transform=f'translate(0 {bounds[0][1] + bounds[1][1]}) scale(1 -1)')
        tags = [tag('defs', filter_defs), layer_group]
        return setup_svg(tags, bounds, margin=margin, arg_unit=arg_unit, svg_unit=svg_unit, pagecolor="white", tag=tag, inkscape=inkscape)

    def bounding_box(self, unit=MM, default=None):
        return sum_bounds(( layer.bounding_box(unit, default=default)
            for layer in itertools.chain(self.graphic_layers.values(), self.drill_layers) ), default=default)


    def board_bounds(self, unit=MM, default=None):
        if self.outline:
            return self.outline.instance.bounding_box(unit=unit, default=default)
        else:
            return self.bounding_box(unit=unit, default=default)

    def offset(self, x=0, y=0, unit=MM):
        for layer in itertools.chain(self.graphic_layers.values(), self.drill_layers):
            layer.offset(x, y, unit=unit)

    def rotate(self, angle, cx=0, cy=0, unit=MM):
        for layer in itertools.chain(self.graphic_layers.values(), self.drill_layers):
            layer.rotate(angle, cx, cy, unit=unit)

    def scale(self, factor, unit=MM):
        for layer in itertools.chain(self.graphic_layers.values(), self.drill_layers):
            layer.scale(factor)

    def merge_drill_layers(self):
        target = ExcellonFile(comments=['Drill files merged by gerbonara'])

        for layer in self.drill_layers:
            if isinstance(layer, GerberFile):
                layer = layer.to_excellon()

            target.merge(layer)

        self.drill_pth = self.drill_npth = None
        self.drill_unknown = target

    def normalize_drill_layers(self):
        # TODO: maybe also separate into drill and route?
        drill_pth, drill_npth, drill_aux = [], [], []

        for layer in self.drill_layers:
            if isinstance(layer, GerberFile):
                layer = layer.to_excellon()

            if layer.is_plated:
                drill_pth.append(layer)
            elif layer.is_nonplated:
                drill_pth.append(layer)
            else:
                drill_aux.append(layer)
        
        pth_out, *rest = drill_pth or [ExcellonFile()]
        for layer in rest:
            pth_out.merge(layer)

        npth_out, *rest = drill_npth or [ExcellonFile()]
        for layer in rest:
            npth_out.merge(layer)

        unknown_out = ExcellonFile()
        for layer in drill_aux:
            for obj in layer.objects:
                if obj.plated is None:
                    unknown_out.append(obj)
                elif obj.plated:
                    pth_out.append(obj)
                else:
                    npth_out.append(obj)

        self.drill_pth, self.drill_npth = pth_out, npth_out
        self.drill_unknown = unknown_out if unknown_out else None
        self._drill_layers = []

    @property
    def drill_layers(self):
        if self._drill_layers:
            return self._drill_layers
        if self.drill_pth or self.drill_npth or self.drill_unknown:
            return [self.drill_pth, self.drill_npth, self.drill_unknown]
        return []

    @drill_layers.setter
    def drill_layers(self, value):
        self._drill_layers = value
        self.drill_pth = self.drill_npth = self.drill_unknown = None

    def __len__(self):
        return len(self.layers)

    def get(self, index, default=None):
        if self.contains(key):
            return self[key]
        else:
            return default

    def __contains__(self, index):
        if isinstance(index, str):
            side, _, use = index.partition(' ')
            return (side, use) in self.layers

        elif isinstance(index, tuple):
            return index in self.graphic_layers

        return index < len(self.copper_layers)

    def __getitem__(self, index):
        if isinstance(index, str):
            side, _, use = index.partition(' ')
            return self.graphic_layers[(side, use)]

        elif isinstance(index, tuple):
            return self.graphic_layers[index]

        return self.copper_layers[index]

    @property
    def copper_layers(self):
        copper_layers = [ ((side, use), layer) for (side, use), layer in self.graphic_layers.items() if use == 'copper' ]

        def sort_layername(val):
            (side, use), _layer = val
            if side == 'top':
                return -1
            if side == 'bottom':
                return 1e99
            assert side.startswith('inner_')
            return int(side[len('inner_'):])

        return [ layer for _key, layer in sorted(copper_layers, key=sort_layername) ]

    @property
    def top_side(self):
        return { key: self[key] for key in ('top copper', 'top mask', 'top silk', 'top paste', 'mechanical outline') }

    @property
    def bottom_side(self):
        return { key: self[key] for key in ('bottom copper', 'bottom mask', 'bottom silk', 'bottom paste', 'mechanical outline') }

    @property
    def outline(self):
        return self['mechanical outline']

    def outline_svg_d(self, tol=0.01, unit=MM):
        chains = self.outline_polygons(tol, unit)
        polys = []
        for chain in chains:
            outline = [ (chain[0].x1, chain[0].y1), *((elem.x2, elem.y2) for elem in chain) ]
            arcs = [ (elem.clockwise, (elem.cx, elem.cy)) if isinstance(elem, gp.Arc) else None for elem in chain ]
            poly = gp.ArcPoly(outline=outline, arc_centers=arcs)
            polys.append(' '.join(poly.path_d()) + ' Z')
        return ' '.join(polys)

    def outline_polygons(self, tol=0.01, unit=MM):
        polygons = []
        lines = [ obj.as_primitive(unit) for obj in self.outline.instance.objects if isinstance(obj, (go.Line, go.Arc)) ]

        by_x = sorted([ (obj.x1, obj) for obj in lines ] + [ (obj.x2, obj) for obj in lines ], key=lambda x: x[0])
        dist_sq = lambda x1, y1, x2, y2: (x2-x1)**2 + (y2-y1)**2

        joins = {}
        for cur in lines:
            for i, (x, y) in enumerate([(cur.x1, cur.y1), (cur.x2, cur.y2)]):
                x_left  = bisect.bisect_left (by_x, x, key=lambda elem: elem[0] + tol)
                x_right = bisect.bisect_right(by_x, x, key=lambda elem: elem[0] - tol)
                selected = { elem for elem_x, elem in by_x[x_left:x_right] if elem != cur }

                if not selected:
                    continue # loose end

                nearest = sorted(selected, key=lambda elem: min(dist_sq(elem.x1, elem.y1, x, y), dist_sq(elem.x2, elem.y2, x, y)))[0]

                d1, d2 = dist_sq(nearest.x1, nearest.y1, x, y), dist_sq(nearest.x2, nearest.y2, x, y)
                j = 0 if d1 < d2 else 1

                if (nearest, j) in joins and joins[(nearest, j)] != (cur, i):
                    raise ValueError(f'Error: three-way intersection of {(nearest, j)}; {(cur, i)}; and {joins[(nearest, j)]}')

                if (cur, i) in joins and joins[(cur, i)] != (nearest, j):
                    raise ValueError(f'Error: three-way intersection of {(nearest, j)}; {(cur, i)}; and {joins[(nearest, j)]}')

                joins[(cur, i)] = (nearest, j)
                joins[(nearest, j)] = (cur, i)

        def flip_if(obj, i):
            if i:
                c = copy.copy(obj)
                c.flip()
                return c
            else:
                return obj

        while joins:
            (first, i), (cur, j) = joins.popitem()
            del joins[(cur, j)]
            l = [ flip_if(first, not i), flip_if(cur, j) ]
            while cur != first and (cur, not j) in joins:
                cur, j = joins.pop((cur, not j))
                del joins[(cur, j)]
                l.append(flip_if(cur, j))
            yield l


    def _merge_layer(self, target, source):
        if source is None:
            return
        
        if self[target] is None:
            self[target] = source

        else:
            self[target].merge(source)

    def merge(self, other):
        all_keys = set(self.graphic_layers.keys()) | set(other.graphic_layers.keys())
        exclude = { tuple(key.split()) for key in STANDARD_LAYERS }
        all_keys = { key for key in all_keys if key not in exclude }
        if all_keys:
            warnings.warn('Cannot merge unknown layer types: {" ".join(all_keys)}')

        for side in 'top', 'bottom':
            for use in 'copper', 'mask', 'silk', 'paste':
                if (side, use) in other:
                    self._merge_layer((side, use), other[side, use])

        our_inner, their_inner = self.copper_layers[1:-1], other.copper_layers[1:-1]

        if bool(our_inner) != bool(their_inner):
            warnings.warn('Merging board without inner layers into board with inner layers, inner layers will be empty on first board.')

        elif our_inner and their_inner:
            warnings.warn('Merging boards with different inner layer counts. Will fill inner layers starting at core.')

        diff = len(our_inner) - len(their_inner)
        their_inner = ([None] * max(0, diff//2)) + their_inner + ([None] * max(0, diff//2))
        our_inner = ([None] * max(0, -diff//2)) + their_inner + ([None] * max(0, -diff//2))

        new_inner = []
        for ours, theirs in zip(our_inner, their_inner):
            if ours is None:
                new_inner.append(theirs)
            elif theirs is None:
                new_inner.append(ours)
            else:
                ours.merge(theirs)
                new_inner.append(ours)

        for i, layer in enumerate(new_inner, start=1):
            self[f'inner_{i} copper'] = layer

        self._merge_layer('mechanical outline', other['mechanical outline'])

        self.normalize_drill_layers()
        other.normalize_drill_layers()

        self.drill_pth.merge(other.drill_pth)
        self.drill_npth.merge(other.drill_npth)
        self.drill_unknown.merge(other.drill_unknown)

        if self.netlist:
            self.netlist.merge(other.netlist)
        else:
            self.netlist = other.netlist