Rename gerbonara/gerber package to just gerbonara

1 files changed, 887 insertions, 0 deletions

diff --git a/gerbonara/excellon.py b/gerbonara/excellon.py
new file mode 100755
index 0000000..3382ffe
--- /dev/null
+++ b/gerbonara/excellon.py
@@ -0,0 +1,887 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright 2014 Hamilton Kibbe <ham@hamiltonkib.be>
+
+# 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 math
+import operator
+import warnings
+import functools
+import dataclasses
+import re
+from enum import Enum
+from dataclasses import dataclass
+from collections import Counter
+from pathlib import Path
+
+from .cam import CamFile, FileSettings
+from .graphic_objects import Flash, Line, Arc
+from .apertures import ExcellonTool
+from .utils import Inch, MM, to_unit, InterpMode, RegexMatcher
+
+class ExcellonContext:
+    def __init__(self, settings, tools):
+        self.settings = settings
+        self.tools = tools
+        self.mode = None
+        self.current_tool = None
+        self.x, self.y = None, None
+        self.drill_down = False
+
+    def select_tool(self, tool):
+        if self.current_tool != tool:
+            if self.drill_down:
+                yield 'M16' # drill up
+                self.drill_down = False
+
+            self.current_tool = tool
+            yield f'T{self.tools[id(tool)]:02d}'
+
+    def drill_mode(self):
+        if self.mode != ProgramState.DRILLING:
+            self.mode = ProgramState.DRILLING
+            if self.drill_down:
+                yield 'M16' # drill up
+                self.drill_down = False
+            yield 'G05' # drill mode
+
+    def route_mode(self, unit, x, y):
+        x, y = self.settings.unit(x, unit), self.settings.unit(y, unit)
+
+        if self.mode == ProgramState.ROUTING and (self.x, self.y) == (x, y):
+            return # nothing to do
+
+        if self.drill_down:
+            yield 'M16' # drill up
+
+        # route mode
+        yield 'G00' + 'X' + self.settings.write_excellon_value(x) + 'Y' + self.settings.write_excellon_value(y)
+        yield 'M15' # drill down
+        self.drill_down = True
+        self.mode = ProgramState.ROUTING
+        self.x, self.y = x, y
+
+    def set_current_point(self, unit, x, y):
+        self.x, self.y = self.settings.unit(x, unit), self.settings.unit(y, unit)
+
+def parse_allegro_ncparam(data, settings=None):
+    # This function parses data from allegro's nc_param.txt and ncdrill.log files. We have to parse these files because
+    # allegro Excellon files omit crucial information such as the *number format*. nc_param.txt really is the file we
+    # want to parse, but sometimes due to user error it doesn't end up in the gerber package. In this case, we want to
+    # still be able to extract the same information from the human-readable ncdrill.log.
+
+    if settings is None:
+        settings = FileSettings(number_format=(None, None), zeros='leading')
+
+    lz_supp, tz_supp = False, False
+    nf_int, nf_frac = settings.number_format
+    for line in data.splitlines():
+        line = re.sub(r'\s+', ' ', line.strip())
+
+        if (match := re.fullmatch(r'FORMAT ([0-9]+\.[0-9]+)', line)):
+            x, _, y = match[1].partition('.')
+            nf_int, nf_frac = int(x), int(y)
+
+        elif (match := re.fullmatch(r'INTEGER-PLACES ([0-9]+)', line)):
+            nf_int = int(match[1])
+
+        elif (match := re.fullmatch(r'DECIMAL-PLACES ([0-9]+)', line)):
+            nf_frac = int(match[1])
+
+        elif (match := re.fullmatch(r'COORDINATES (ABSOLUTE|.*)', line)):
+            # I have not been able to find a single incremental-notation allegro file. Probably that is for the better.
+            settings.notation = match[1].lower()
+
+        elif (match := re.fullmatch(r'OUTPUT-UNITS (METRIC|ENGLISH|INCHES)', line)):
+            # I have no idea wth is the difference between "ENGLISH" and "INCHES". I think one might just be the one
+            # Allegro uses in footprint files, with the other one being used in gerber exports.
+            settings.unit = MM if match[1] == 'METRIC' else Inch
+
+        elif (match := re.fullmatch(r'SUPPRESS-LEAD-ZEROES (YES|NO)', line)):
+            lz_supp = (match[1] == 'YES')
+
+        elif (match := re.fullmatch(r'SUPPRESS-TRAIL-ZEROES (YES|NO)', line)):
+            tz_supp = (match[1] == 'YES')
+
+    if lz_supp and tz_supp:
+        raise SyntaxError('Allegro Excellon parameters specify both leading and trailing zero suppression. We do not '
+                'know how to parse this. Please raise an issue on our issue tracker and provide an example file.')
+
+    settings.number_format = nf_int, nf_frac
+    settings.zeros = 'leading' if lz_supp else 'trailing'
+    return settings
+
+
+def parse_allegro_logfile(data):
+    found_tools = {}
+    unit = None
+
+    for line in data.splitlines():
+        line = line.strip()
+        line = re.sub(r'\s+', ' ', line)
+
+        if (m := re.match(r'OUTPUT-UNITS (METRIC|ENGLISH|INCHES)', line)):
+            # I have no idea wth is the difference between "ENGLISH" and "INCHES". I think one might just be the one
+            # Allegro uses in footprint files, with the other one being used in gerber exports.
+            unit = MM if m[1] == 'METRIC' else Inch
+
+        elif (m := re.match(r'T(?P<index1>[0-9]+) (?P<index2>[0-9]+)\. (?P<diameter>[0-9/.]+) [0-9. /+-]* (?P<plated>PLATED|NON_PLATED|OPTIONAL) [0-9]+', line)):
+            index1, index2 = int(m['index1']), int(m['index2'])
+            if index1 != index2:
+                return {}
+
+            diameter = float(m['diameter'])
+            if unit == Inch:
+                diameter /= 1000
+            is_plated = None if m['plated'] is None else (m['plated'] in ('PLATED', 'OPTIONAL'))
+            found_tools[index1] = ExcellonTool(diameter=diameter, plated=is_plated, unit=unit)
+    return found_tools
+
+class ExcellonFile(CamFile):
+    def __init__(self, objects=None, comments=None, import_settings=None, original_path=None, generator_hints=None):
+        super().__init__(original_path=original_path)
+        self.objects = objects or []
+        self.comments = comments or []
+        self.import_settings = import_settings
+        self.generator_hints = generator_hints or [] # This is a purely informational goodie from the parser. Use it as you wish.
+
+    def __str__(self):
+        name = f'{self.original_path.name} ' if self.original_path else ''
+        if self.is_plated:
+            plating = 'plated'
+        elif self.is_nonplated:
+            plating = 'nonplated'
+        elif self.is_mixed_plating:
+            plating = 'mixed plating'
+        else:
+            plating = 'unknown plating'
+        return f'<ExcellonFile {name}{plating} with {len(list(self.drills()))} drills, {len(list(self.slots()))} slots using {len(self.drill_sizes())} tools>'
+
+    def __repr__(self):
+        return str(self)
+
+    def __bool__(self):
+        return not self.is_empty
+
+    @property
+    def is_plated(self):
+        return all(obj.plated for obj in self.objects)
+
+    @property
+    def is_nonplated(self):
+        return all(obj.plated == False for obj in self.objects) # False, not None
+
+    @property
+    def is_plating_unknown(self):
+        return all(obj.plated is None for obj in self.objects) # False, not None
+
+    @property
+    def is_mixed_plating(self):
+        return len({obj.plated for obj in self.objects}) > 1
+
+    def append(self, obj_or_comment):
+        if isinstnace(obj_or_comment, str):
+            self.comments.append(obj_or_comment)
+        else:
+            self.objects.append(obj_or_comment)
+
+    def to_gerber(self):
+        apertures = {}
+        out = GerberFile()
+        out.comments = self.comments
+
+        for obj in self.objects:
+            if id(obj.tool) not in apertures:
+                apertures[id(obj.tool)] = CircleAperture(obj.tool.diameter)
+
+            out.objects.append(dataclasses.replace(obj, aperture=apertures[id(obj.tool)]))
+
+        out.apertures = list(apertures.values())
+
+    @property
+    def generator(self):
+        return self.generator_hints[0] if self.generator_hints else None
+
+    def merge(self, other):
+        if other is None:
+            return
+
+        self.objects += other.objects
+        self.comments += other.comments
+        self.generator_hints = None
+        self.import_settings = None
+
+    @classmethod
+    def open(kls, filename, plated=None, settings=None):
+        filename = Path(filename)
+        logfile_tools = None
+    
+        # Parse allegro parameter files.
+        # Prefer nc_param.txt over ncparam.log since the txt is the machine-readable one.
+        if settings is None:
+            for fn in 'nc_param.txt', 'ncdrill.log':
+                if (param_file := filename.parent / fn).is_file():
+                    settings =  parse_allegro_ncparam(param_file.read_text())
+                    warnings.warn(f'Loaded allegro-style excellon settings file {param_file}')
+                    break
+
+            # TODO add try/except aronud this
+            log_file = filename.parent / 'ncdrill.log'
+            if log_file.is_file():
+                logfile_tools = parse_allegro_logfile(log_file.read_text())
+
+        return kls.from_string(filename.read_text(), settings=settings,
+                filename=filename, plated=plated, logfile_tools=logfile_tools)
+
+    @classmethod
+    def from_string(kls, data, settings=None, filename=None, plated=None, logfile_tools=None):
+        parser = ExcellonParser(settings, logfile_tools=logfile_tools)
+        parser.do_parse(data, filename=filename)
+        return kls(objects=parser.objects, comments=parser.comments, import_settings=settings,
+                generator_hints=parser.generator_hints, original_path=filename)
+
+    def _generate_statements(self, settings, drop_comments=True):
+
+        yield '; XNC file generated by gerbonara'
+        if self.comments and not drop_comments:
+            yield '; Comments found in original file:'
+            for comment in self.comments:
+                yield ';' + comment
+
+        yield 'M48'
+        yield 'METRIC' if settings.unit == MM else 'INCH'
+
+        # Build tool index
+        tool_map = { id(obj.tool): obj.tool for obj in self.objects }
+        tools = sorted(tool_map.items(), key=lambda id_tool: (id_tool[1].plated, id_tool[1].diameter, id_tool[1].depth_offset))
+        tools = { tool_id: index for index, (tool_id, _tool) in enumerate(tools, start=1) }
+        # FIXME dedup tools
+
+        mixed_plating = (len({ tool.plated for tool in tool_map.values() }) > 1)
+        if mixed_plating:
+            warnings.warn('Multiple plating values in same file. Will use non-standard Altium comment syntax to indicate hole plating.')
+
+        if tools and max(tools.values()) >= 100:
+            warnings.warn('More than 99 tools defined. Some programs may not like three-digit tool indices.', SyntaxWarning)
+
+        for tool_id, index in tools.items():
+            tool = tool_map[tool_id]
+            if mixed_plating:
+                yield ';TYPE=PLATED' if tool.plated else ';TYPE=NON_PLATED'
+            yield f'T{index:02d}' + tool.to_xnc(settings)
+
+        yield '%'
+
+        ctx = ExcellonContext(settings, tools)
+
+        # Export objects
+        for obj in self.objects:
+            yield from obj.to_xnc(ctx)
+
+        yield 'M30'
+
+    def to_excellon(self, settings=None, drop_comments=True):
+        ''' Export to Excellon format. This function always generates XNC, which is a well-defined subset of Excellon.
+        '''
+        if settings is None:
+            if self.import_settings:
+                settings = self.import_settings.copy()
+            else:
+                settings = FileSettings()
+            settings.zeros = None
+            settings.number_format = (3,5)
+        return '\n'.join(self._generate_statements(settings, drop_comments=drop_comments))
+
+    def save(self, filename, settings=None, drop_comments=True):
+        with open(filename, 'w') as f:
+            f.write(self.to_excellon(settings, drop_comments=drop_comments))
+
+    def offset(self, x=0, y=0, unit=MM):
+        self.objects = [ obj.with_offset(x, y, unit) for obj in self.objects ]
+
+    def rotate(self, angle, cx=0, cy=0, unit=MM):
+        if math.isclose(angle % (2*math.pi), 0):
+            return
+
+        for obj in self.objects:
+            obj.rotate(angle, cx, cy, unit=unit)
+
+    @property
+    def has_mixed_plating(self):
+        return len(set(obj.plated for obj in self.objects)) > 1
+    
+    @property
+    def is_plated(self):
+        return all(obj.plated for obj in self.objects)
+
+    @property
+    def is_nonplated(self):
+        return not any(obj.plated for obj in self.objects)
+
+    @property
+    def is_empty(self):
+        return not self.objects
+
+    def __len__(self):
+        return len(self.objects)
+
+    def split_by_plating(self):
+        plated = ExcellonFile(
+            comments = self.comments.copy(),
+            import_settings = self.import_settings.copy(),
+            objects = [ obj for obj in self.objects if obj.plated ],
+            filename = self.filename)
+
+        nonplated = ExcellonFile(
+            comments = self.comments.copy(),
+            import_settings = self.import_settings.copy(),
+            objects = [ obj for obj in self.objects if not obj.plated ],
+            filename = self.filename)
+
+        return nonplated, plated
+
+    def path_lengths(self, unit):
+        """ Calculate path lengths per tool.
+
+        Returns: dict { tool: float(path length) }
+
+        This function only sums actual cut lengths, and ignores travel lengths that the tool is doing without cutting to
+        get from one object to another. Travel lengths depend on the CAM program's path planning, which highly depends
+        on panelization and other factors. Additionally, an EDA tool will not even attempt to minimize travel distance
+        as that's not its job.
+        """
+        lengths = {}
+        tool = None
+        for obj in sorted(self.objects, key=lambda obj: obj.tool):
+            if tool != obj.tool:
+                tool = obj.tool
+                lengths[tool] = 0
+
+            lengths[tool] += obj.curve_length(unit)
+        return lengths
+
+    def hit_count(self):
+        return Counter(obj.tool for obj in self.objects)
+
+    def drill_sizes(self):
+        return sorted({ obj.tool.diameter for obj in self.objects })
+
+    def drills(self):
+        return (obj for obj in self.objects if isinstance(obj, Flash))
+
+    def slots(self):
+        return (obj for obj in self.objects if not isinstance(obj, Flash))
+
+    @property
+    def bounds(self):
+        if not self.objects:
+            return None
+
+        (x_min, y_min), (x_max, y_max) = self.objects[0].bounding_box()
+        for obj in self.objects:
+            (obj_x_min, obj_y_min), (obj_x_max, obj_y_max) = self.objects[0].bounding_box()
+            x_min, y_min = min(x_min, obj_x_min), min(y_min, obj_y_min)
+            x_max, y_max = max(x_max, obj_x_max), max(y_max, obj_y_max)
+
+        return ((x_min, y_min), (x_max, y_max))
+
+class ProgramState(Enum):
+    HEADER = 0
+    DRILLING = 1
+    ROUTING = 2
+    FINISHED = 3
+
+
+class ExcellonParser(object):
+    def __init__(self, settings=None, logfile_tools=None):
+        # NOTE XNC files do not contain an explicit number format specification, but all values have decimal points.
+        # Thus, we set the default number format to (None, None). If the file does not contain an explicit specification
+        # and FileSettings.parse_gerber_value encounters a number without an explicit decimal point, it will throw a
+        # SyntaxError. In case of e.g. Allegro files where the number format and other options are specified separately
+        # from the excellon file, the caller must pass in an already filled-out FileSettings object.
+        if settings is None:
+            self.settings = FileSettings(number_format=(None, None), zeros='leading')
+        else:
+            self.settings = settings
+        self.program_state = None
+        self.interpolation_mode = InterpMode.LINEAR
+        self.tools = {}
+        self.objects = []
+        self.active_tool = None
+        self.pos = 0, 0
+        self.drill_down = False
+        self.is_plated = None
+        self.comments = []
+        self.generator_hints = []
+        self.lineno = None
+        self.filename = None
+        self.logfile_tools = logfile_tools or {}
+
+    def warn(self, msg):
+        warnings.warn(f'{self.filename}:{self.lineno} "{self.line}": {msg}', SyntaxWarning)
+
+    def do_parse(self, data, filename=None):
+        # filename arg is for error messages
+        self.filename = filename = filename or '<unknown>'
+
+        leftover = None
+        for lineno, line in enumerate(data.splitlines(), start=1):
+            line = line.strip()
+            self.lineno, self.line = lineno, line # for warnings
+
+            if not line:
+                continue
+
+            # Coordinates of G00 and G01 may be on the next line
+            if line == 'G00' or line == 'G01':
+                if leftover:
+                    self.warn('Two consecutive G00/G01 commands without coordinates. Ignoring first.')
+                leftover = line
+                continue
+
+            if leftover:
+                line = leftover + line
+                leftover = None
+
+            if line and self.program_state == ProgramState.FINISHED:
+                self.warn('Commands found following end of program statement.')
+            # TODO check first command in file is "start of header" command.
+
+            try:
+                print(f'{self.settings.number_format} {lineno} "{line}"')
+                if not self.exprs.handle(self, line):
+                    raise ValueError('Unknown excellon statement:', line)
+            except Exception as e:
+                raise SyntaxError(f'{filename}:{lineno} "{line}": {e}') from e
+
+    exprs = RegexMatcher()
+
+    # NOTE: These must be kept before the generic comment handler at the end of this class so they match first.
+    @exprs.match(r';T(?P<index1>[0-9]+) Holesize (?P<index2>[0-9]+)\. = (?P<diameter>[0-9/.]+) Tolerance = \+[0-9/.]+/-[0-9/.]+ (?P<plated>PLATED|NON_PLATED|OPTIONAL) (?P<unit>MILS|MM) Quantity = [0-9]+')
+    def parse_allegro_tooldef(self, match):
+        # NOTE: We ignore the given tolerances here since they are non-standard.
+        self.program_state = ProgramState.HEADER # TODO is this needed? we need a test file.
+        self.generator_hints.append('allegro')
+
+        if (index := int(match['index1'])) != int(match['index2']): # index1 has leading zeros, index2 not.
+            raise SyntaxError('BUG: Allegro excellon tool def has mismatching tool indices. Please file a bug report on our issue tracker and provide this file!')
+
+        if index in self.tools:
+            self.warn('Re-definition of tool index {index}, overwriting old definition.') 
+
+        # NOTE: We map "optionally" plated holes to plated holes for API simplicity. If you hit a case where that's a
+        # problem, please raise an issue on our issue tracker, explain why you need this and provide an example file.
+        is_plated = None if match['plated'] is None else (match['plated'] in ('PLATED', 'OPTIONAL'))
+
+        diameter = float(match['diameter'])
+
+        if match['unit'] == 'MILS':
+            diameter /= 1000
+            unit = Inch
+        else:
+            unit = MM
+
+        if unit != self.settings.unit:
+            self.warn('Allegro Excellon drill file tool definitions in {unit.name}, but file parameters say the '
+                    'file should be in {settings.unit.name}. Please double-check that this is correct, and if it is, '
+                    'please raise an issue on our issue tracker.')
+
+        self.tools[index] = ExcellonTool(diameter=diameter, plated=is_plated, unit=unit)
+
+    # Searching Github I found that EasyEDA has two different variants of the unit specification here.
+    @exprs.match(';Holesize (?P<index>[0-9]+) = (?P<diameter>[.0-9]+) (?P<unit>INCH|inch|METRIC|mm)')
+    def parse_easyeda_tooldef(self, match):
+        unit = Inch if match['unit'].lower() == 'inch' else MM
+        tool = ExcellonTool(diameter=float(match['diameter']), unit=unit, plated=self.is_plated)
+
+        if (index := int(match['index'])) in self.tools:
+            self.warn('Re-definition of tool index {index}, overwriting old definition.') 
+
+        self.tools[index] = tool
+        self.generator_hints.append('easyeda')
+
+    @exprs.match('T([0-9]+)(([A-Z][.0-9]+)+)') # Tool definition: T** with at least one parameter
+    def parse_normal_tooldef(self, match):
+        # We ignore parameters like feed rate or spindle speed that are not used for EDA -> CAM file transfer. This is
+        # not a parser for the type of Excellon files a CAM program sends to the machine.
+
+        if (index := int(match[1])) in self.tools:
+            self.warn('Re-definition of tool index {index}, overwriting old definition.') 
+
+        params = { m[0]: self.settings.parse_gerber_value(m[1:]) for m in re.findall('[BCFHSTZ][.0-9]+', match[2]) }
+
+        self.tools[index] = ExcellonTool(diameter=params.get('C'), depth_offset=params.get('Z'), plated=self.is_plated,
+                unit=self.settings.unit)
+
+        if set(params.keys()) == set('TFSC'):
+            self.generator_hints.append('target3001') # target files look like altium files without the comments
+
+        if len(self.tools) >= 3 and list(self.tools.keys()) == reversed(sorted(self.tools.keys())):
+            self.generator_hints.append('geda')
+
+    @exprs.match('T([0-9]+)')
+    def parse_tool_selection(self, match):
+        index = int(match[1])
+
+        if index == 0: # T0 is used as END marker, just ignore
+            return
+        elif index not in self.tools:
+            if not self.tools and index in self.logfile_tools:
+                # allegro is just wonderful.
+                self.warn(f'Undefined tool index {index} selected. We found an allegro drill log file next to this, so '
+                            'we will use tool definitions from there.')
+                self.active_tool = self.logfile_tools[index]
+
+            else:
+                raise SyntaxError(f'Undefined tool index {index} selected.')
+
+        else:
+            self.active_tool = self.tools[index]
+
+    coord = lambda name, key=None: fr'({name}(?P<{key or name}>[+-]?[0-9]*\.?[0-9]*))?'
+    xy_coord = coord('X') + coord('Y')
+    xyaij_coord = xy_coord + coord('A') + coord('I') + coord('J')
+
+    @exprs.match(r'R(?P<count>[0-9]+)' + xy_coord)
+    def handle_repeat_hole(self, match):
+        if self.program_state == ProgramState.HEADER:
+            return
+
+        dx = int(match['X'] or '0')
+        dy = int(match['Y'] or '0')
+
+        for i in range(int(match['count'])):
+            self.pos = (self.pos[0] + dx, self.pos[1] + dy)
+            # FIXME fix API below
+            if not self.ensure_active_tool():
+                return
+
+            self.objects.append(Flash(*self.pos, self.active_tool, unit=self.settings.unit))
+
+    def header_command(name):
+        def wrap(fun):
+            @functools.wraps(fun)
+            def wrapper(self, *args, **kwargs):
+                nonlocal name
+                if self.program_state is None:
+                    self.warn(f'{name} header statement found before start of header')
+                elif self.program_state != ProgramState.HEADER:
+                    self.warn(f'{name} header statement found after end of header')
+                fun(self, *args, **kwargs)
+            return wrapper
+        return wrap
+
+    @exprs.match('M48')
+    def handle_begin_header(self, match):
+        if self.program_state == ProgramState.HEADER:
+            # It seems that only fritzing puts both a '%' start of header thingy and an M48 statement at the beginning
+            # of the file.
+            self.generator_hints.append('fritzing')
+        elif self.program_state is not None:
+            self.warn(f'M48 "header start" statement found in the middle of the file, currently in {self.program_state}')
+        self.program_state = ProgramState.HEADER
+
+    @exprs.match('M95')
+    @header_command('M95')
+    def handle_end_header(self, match):
+        self.program_state = ProgramState.DRILLING
+
+    @exprs.match('M00')
+    def handle_next_tool(self, match):
+        #FIXME is this correct? Shouldn't this be "end of program"?
+        if self.active_tool:
+            self.active_tool = self.tools[self.tools.index(self.active_tool) + 1]
+
+        else:
+            self.warn('M00 statement found before first tool selection statement.')
+
+    @exprs.match('M15')
+    def handle_drill_down(self, match):
+        self.drill_down = True
+
+    @exprs.match('M16|M17')
+    def handle_drill_up(self, match):
+        self.drill_down = False
+
+
+    @exprs.match('M30')
+    def handle_end_of_program(self, match):
+        if self.program_state in (None, ProgramState.HEADER):
+            self.warn('M30 statement found before end of header.')
+        self.program_state = ProgramState.FINISHED
+        # ignore.
+        # TODO: maybe add warning if this is followed by other commands.
+
+    def do_move(self, match=None, x='X', y='Y'):
+        x = self.settings.parse_gerber_value(match['X'])
+        y = self.settings.parse_gerber_value(match['Y'])
+
+        old_pos = self.pos
+
+        if self.settings.absolute:
+            if x is not None:
+                self.pos = (x, self.pos[1])
+            if y is not None:
+                self.pos = (self.pos[0], y)
+        else: # incremental
+            if x is not None:
+                self.pos = (self.pos[0]+x, self.pos[1])
+            if y is not None:
+                self.pos = (self.pos[0], self.pos[1]+y)
+
+        return old_pos, self.pos
+
+    @exprs.match('G00' + xy_coord)
+    def handle_start_routing(self, match):
+        if self.program_state is None:
+            self.warn('Routing mode command found before header.')
+        self.program_state = ProgramState.ROUTING
+        self.do_move(match)
+
+    @exprs.match('%')
+    def handle_rewind_shorthand(self, match):
+        if self.program_state is None:
+            self.program_state = ProgramState.HEADER
+        elif self.program_state is ProgramState.HEADER:
+            self.program_state = ProgramState.DRILLING
+        # FIXME handle rewind start
+
+    @exprs.match('G05')
+    def handle_drill_mode(self, match):
+        self.drill_down = False
+        self.program_state = ProgramState.DRILLING
+
+    def ensure_active_tool(self):
+        if self.active_tool:
+            return self.active_tool
+        
+        self.warn('Routing command found before first tool definition.')
+        return None
+
+    @exprs.match('(?P<mode>G01|G02|G03)' + xyaij_coord)
+    def handle_linear_mode(self, match):
+        if match['mode'] == 'G01':
+            self.interpolation_mode = InterpMode.LINEAR
+        else:
+            clockwise = (match['mode'] == 'G02')
+            self.interpolation_mode = InterpMode.CIRCULAR_CW if clockwise else InterpMode.CIRCULAR_CCW
+
+        self.do_interpolation(match)
+    
+    def do_interpolation(self, match):
+        x, y, a, i, j = match['X'], match['Y'], match['A'], match['I'], match['J']
+
+        start, end = self.do_move(match)
+
+        if self.program_state != ProgramState.ROUTING:
+            return
+
+        if not self.drill_down or not (match['X'] or match['Y']) or not self.ensure_active_tool():
+            return
+
+        if self.interpolation_mode == InterpMode.LINEAR:
+            if a or i or j:
+                self.warn('A/I/J arc coordinates found in linear mode.')
+
+            self.objects.append(Line(*start, *end, self.active_tool, unit=self.settings.unit))
+
+        else:
+            if (x or y) and not (a or i or j):
+                self.warn('Arc without radius found.')
+
+            clockwise = (self.interpolation_mode == InterpMode.CIRCULAR_CW)
+            
+            if a: # radius given
+                if i or j:
+                    self.warn('Arc without both radius and center specified.')
+
+                # Convert endpoint-radius-endpoint notation to endpoint-center-endpoint notation. We always use the
+                # smaller arc here.
+                # from https://math.stackexchange.com/a/1781546
+                r = settings.parse_gerber_value(a)
+                x1, y1 = start
+                x2, y2 = end
+                dx, dy = (x2-x1)/2, (y2-y1)/2
+                x0, y0 = x1+dx, y1+dy
+                f = math.hypot(dx, dy) / math.sqrt(r**2 - a**2)
+                if clockwise:
+                    cx = x0 + f*dy
+                    cy = y0 - f*dx
+                else:
+                    cx = x0 - f*dy
+                    cy = y0 + f*dx
+                i, j = cx-start[0], cy-start[1]
+
+            else: # explicit center given
+                i = settings.parse_gerber_value(i)
+                j = settings.parse_gerber_value(j)
+
+            self.objects.append(Arc(*start, *end, i, j, True, self.active_tool, unit=self.settings.unit))
+
+    @exprs.match(r'(M71|METRIC|M72|INCH)(,LZ|,TZ)?(,0*\.0*)?')
+    def parse_easyeda_format(self, match):
+        metric = match[1] in ('METRIC', 'M71')
+
+        self.settings.unit = MM if metric else Inch
+
+        if match[2]:
+            self.settings.zeros = 'trailing' if match[2] == ',LZ' else 'leading'
+
+        # Newer EasyEDA exports have this in an altium-like FILE_FORMAT comment instead. Some files even have both.
+        # This is used by newer autodesk eagles, fritzing and diptrace
+        if match[3]:
+            integer, _, fractional = match[3][1:].partition('.')
+            self.settings.number_format = len(integer), len(fractional)
+
+        elif self.settings.number_format == (None, None) and not metric:
+            self.warn('Using implicit number format from bare "INCH" statement. This is normal for Fritzing, Diptrace, Geda and pcb-rnd.')
+            self.settings.number_format = (2,4)
+    
+    @exprs.match('G90')
+    @header_command('G90')
+    def handle_absolute_mode(self, match):
+        self.settings.notation = 'absolute'
+
+    @exprs.match('G93' + xy_coord)
+    def handle_absolute_mode(self, match):
+        if int(match['X'] or 0) != 0 or int(match['Y'] or 0) != 0:
+            # Siemens tooling likes to include a meaningless G93X0Y0 after its header.
+            raise NotImplementedError('G93 zero set command is not supported.')
+        self.generator_hints.append('siemens')
+
+    @exprs.match('ICI,?(ON|OFF)')
+    def handle_incremental_mode(self, match):
+        self.settings.notation = 'absolute' if match[1] == 'OFF' else 'incremental'
+
+    @exprs.match('(FMAT|VER),?([0-9]*)')
+    def handle_command_format(self, match):
+        # We do not support integer/fractional decimals specification via FMAT because that's stupid. If you need this,
+        # please raise an issue on our issue tracker, provide a sample file and tell us where on earth you found that
+        # file.
+        if match[2] not in ('', '2'):
+            raise SyntaxError(f'Unsupported FMAT format version {match["version"]}')
+
+    @exprs.match(r'G40|G41|G42|F[0-9]+')
+    def handle_unhandled(self, match):
+        self.warn(f'{match[0]} excellon command intended for CAM tools found in EDA file.')
+
+    @exprs.match(coord('X', 'x1') + coord('Y', 'y1') + 'G85' + coord('X', 'x2') + coord('Y', 'y2'))
+    def handle_slot_dotted(self, match):
+        self.warn('Weird G85 excellon slot command used. Please raise an issue on our issue tracker and provide this file for testing.')
+        self.do_move(match, 'X1', 'Y1')
+        start, end = self.do_move(match, 'X2', 'Y2')
+        
+        if self.program_state in (ProgramState.DRILLING, ProgramState.HEADER): # FIXME should we realy handle this in header?
+            if self.ensure_active_tool():
+                # We ignore whether a slot is a "routed" G00/G01 slot or a "drilled" G85 slot and export both as routed
+                # slots.
+                self.objects.append(Line(*start, *end, self.active_tool, unit=self.settings.unit))
+
+    @exprs.match(xyaij_coord)
+    def handle_bare_coordinate(self, match):
+        # Yes, drills in the header doesn't follow the specification, but it there are many files like this.
+        if self.program_state in (ProgramState.DRILLING, ProgramState.HEADER):
+            _start, end = self.do_move(match)
+
+            if not self.ensure_active_tool():
+                return
+
+            self.objects.append(Flash(*end, self.active_tool, unit=self.settings.unit))
+
+        elif self.program_state == ProgramState.ROUTING:
+            # Bare coordinates for routing also seem illegal, but Siemens actually uses these.
+            # Example file: siemens/80101_0125_F200_ContourPlated.ncd
+            self.do_interpolation(match)
+
+        else:
+            self.warn('Bare coordinate after end of file')
+
+    @exprs.match(r'; Format\s*: ([0-9]+\.[0-9]+) / (Absolute|Incremental) / (Inch|MM) / (Leading|Trailing)')
+    def parse_siemens_format(self, match):
+        x, _, y = match[1].partition('.')
+        self.settings.number_format = int(x), int(y)
+        # NOTE: Siemens files seem to always contain both this comment and an explicit METRIC/INC statement. However,
+        # the meaning of "leading" and "trailing" is swapped in both: When this comment says leading, we get something
+        # like "INCH,TZ".
+        self.settings.notation = match[2].lower()
+        self.settings.unit = to_unit(match[3])
+        self.settings.zeros = {'Leading': 'trailing', 'Trailing': 'leading'}[match[4]]
+        self.generator_hints.append('siemens')
+
+    @exprs.match('; Contents: (Thru|.*) / (Drill|Mill) / (Plated|Non-Plated)')
+    def parse_siemens_meta(self, match):
+        self.is_plated = (match[3] == 'Plated')
+        self.generator_hints.append('siemens')
+
+    @exprs.match(';FILE_FORMAT=([0-9]:[0-9])')
+    def parse_altium_easyeda_number_format_comment(self, match):
+        # Altium or newer EasyEDA exports
+        x, _, y = match[1].partition(':')
+        self.settings.number_format = int(x), int(y)
+
+    @exprs.match(';Layer: (.*)')
+    def parse_easyeda_layer_name(self, match):
+        # EasyEDA embeds the layer name in a comment. EasyEDA uses separate files for plated/non-plated. The (default?)
+        # layer names are: "Drill PTH", "Drill NPTH"
+        self.is_plated = 'NPTH' not in match[1]
+        self.generator_hints.append('easyeda')
+
+    @exprs.match(';TYPE=(PLATED|NON_PLATED)')
+    def parse_altium_composite_plating_comment(self, match):
+        # These can happen both before a tool definition and before a tool selection statement.
+        # FIXME make sure we do the right thing in both cases.
+        self.is_plated = (match[1] == 'PLATED')
+
+    @exprs.match(';(Layer_Color=[-+0-9a-fA-F]*)')
+    def parse_altium_layer_color(self, match):
+        self.generator_hints.append('altium')
+        self.comments.append(match[1])
+    
+    @exprs.match(';HEADER:')
+    def parse_allegro_start_of_header(self, match):
+        self.program_state = ProgramState.HEADER
+        self.generator_hints.append('allegro')
+
+    @exprs.match(r';GenerationSoftware,Autodesk,EAGLE,.*\*%')
+    def parse_eagle_version_header(self, match):
+        # NOTE: Only newer eagles export drills as XNC files. Older eagles produce an aperture-only gerber file called
+        # "profile.gbr" instead.
+        self.generator_hints.append('eagle')
+
+    @exprs.match(';EasyEDA .*')
+    def parse_easyeda_version_header(self, match):
+        self.generator_hints.append('easyeda')
+
+    @exprs.match(';DRILL .*KiCad .*')
+    def parse_kicad_version_header(self, match):
+        self.generator_hints.append('kicad')
+    
+    @exprs.match(';FORMAT={([-0-9]+:[-0-9]+) ?/ (.*) / (inch|.*) / decimal}')
+    def parse_kicad_number_format_comment(self, match):
+        x, _, y = match[1].partition(':')
+        x = None if x == '-' else int(x)
+        y = None if y == '-' else int(y)
+        self.settings.number_format = x, y
+        self.settings.notation = match[2]
+        self.settings.unit = Inch if match[3] == 'inch' else MM
+
+    @exprs.match(';(.*)')
+    def parse_comment(self, match):
+        self.comments.append(match[1].strip())
+
+        if all(cmt.startswith(marker)
+                for cmt, marker in zip(reversed(self.comments), ['Version', 'Job', 'User', 'Date'])):
+            self.generator_hints.append('siemens')
+