Rename gerbonara/gerber package to just gerbonara

1 files changed, 237 insertions, 0 deletions

diff --git a/gerbonara/tests/image_support.py b/gerbonara/tests/image_support.py
new file mode 100644
index 0000000..926e91d
--- /dev/null
+++ b/gerbonara/tests/image_support.py
@@ -0,0 +1,237 @@
+import subprocess
+from pathlib import Path
+import tempfile
+import textwrap
+import os
+from functools import total_ordering
+import shutil
+import bs4
+from contextlib import contextmanager
+import hashlib
+
+import numpy as np
+from PIL import Image
+
+cachedir = Path(__file__).parent / 'image_cache'
+cachedir.mkdir(exist_ok=True)
+
+@total_ordering
+class ImageDifference:
+    def __init__(self, value, histogram):
+        self.value = value
+        self.histogram = histogram
+
+    def __float__(self):
+        return float(self.value)
+
+    def __eq__(self, other):
+        return float(self) == float(other)
+
+    def __lt__(self, other):
+        return float(self) < float(other)
+
+    def __str__(self):
+        return str(float(self))
+
+@total_ordering
+class Histogram:
+    def __init__(self, value, size):
+        self.value, self.size = value, size
+
+    def __eq__(self, other):
+        other = np.array(other)
+        other[other == None] = self.value[other == None]
+        return (self.value == other).all()
+
+    def __lt__(self, other):
+        other = np.array(other)
+        other[other == None] = self.value[other == None]
+        return (self.value <= other).all()
+
+    def __getitem__(self, index):
+        return self.value[index]
+
+    def __str__(self):
+        return f'{list(self.value)} size={self.size}'
+
+
+def run_cargo_cmd(cmd, args, **kwargs):
+    if cmd.upper() in os.environ:
+        return subprocess.run([os.environ[cmd.upper()], *args], **kwargs)
+
+    try:
+        return subprocess.run([cmd, *args], **kwargs)
+
+    except FileNotFoundError:
+        return subprocess.run([str(Path.home() / '.cargo' / 'bin' / cmd), *args], **kwargs)
+
+def svg_to_png(in_svg, out_png, dpi=100, bg=None):
+    params = f'{dpi}{bg}'.encode()
+    digest = hashlib.blake2b(Path(in_svg).read_bytes() + params).hexdigest()
+    cachefile = cachedir / f'{digest}.png'
+
+    if not cachefile.is_file():
+        bg = 'black' if bg is None else bg
+        run_cargo_cmd('resvg', ['--background', bg, '--dpi', str(dpi), in_svg, cachefile], check=True, stdout=subprocess.DEVNULL)
+
+    shutil.copy(cachefile, out_png)
+
+to_gerbv_svg_units = lambda val, unit='mm': val*72 if unit == 'inch' else val/25.4*72
+
+def gerbv_export(in_gbr, out_svg, export_format='svg', origin=(0, 0), size=(6, 6), fg='#ffffff', bg='#000000', override_unit_spec=None):
+    params = f'{origin}{size}{fg}{bg}'.encode()
+    digest = hashlib.blake2b(Path(in_gbr).read_bytes() + params).hexdigest()
+    cachefile = cachedir / f'{digest}.svg'
+
+    if not cachefile.is_file():
+        # NOTE: gerbv seems to always export 'clear' polarity apertures as white, irrespective of --foreground, --background
+        # and project file color settings.
+        # TODO: File issue upstream.
+        with tempfile.NamedTemporaryFile('w') as f:
+            if override_unit_spec:
+                units, zeros, digits = override_unit_spec
+                print(f'{Path(in_gbr).name}: overriding excellon unit spec to {units=} {zeros=} {digits=}')
+                units = 0 if units == 'inch' else 1
+                zeros = {None: 0, 'leading': 1, 'trailing': 2}[zeros]
+                unit_spec = textwrap.dedent(f'''(cons 'attribs (list
+                        (list 'autodetect 'Boolean 0)
+                        (list 'zero_suppression 'Enum {zeros})
+                        (list 'units 'Enum {units})
+                        (list 'digits 'Integer {digits})
+                    ))''')
+            else:
+                unit_spec = ''
+
+            r, g, b = int(fg[1:3], 16), int(fg[3:5], 16), int(fg[5:], 16)
+            color = f"(cons 'color #({r*257} {g*257} {b*257}))"
+            f.write(f'''(gerbv-file-version! "2.0A")(define-layer! 0 (cons 'filename "{in_gbr}"){unit_spec}{color})''')
+            f.flush()
+            if override_unit_spec:
+                shutil.copy(f.name, '/tmp/foo.gbv')
+
+            x, y = origin
+            w, h = size
+            cmd = ['gerbv', '-x', export_format,
+                '--border=0',
+                f'--origin={x:.6f}x{y:.6f}', f'--window_inch={w:.6f}x{h:.6f}',
+                f'--background={bg}',
+                f'--foreground={fg}',
+                '-o', str(cachefile), '-p', f.name]
+            subprocess.run(cmd, check=True, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
+    shutil.copy(cachefile, out_svg)
+
+@contextmanager
+def svg_soup(filename):
+    with open(filename, 'r') as f:
+        soup = bs4.BeautifulSoup(f.read(), 'xml')
+
+    yield soup
+
+    with open(filename, 'w') as f:
+        f.write(str(soup))
+
+def cleanup_gerbv_svg(soup):
+    for group in soup.find_all('g'):
+        # gerbv uses Cairo's SVG canvas. Cairo's SVG canvas is kind of broken. It has no support for unit
+        # handling at all, which means the output files just end up being in pixels at 72 dpi. Further, it
+        # seems gerbv's aperture macro rendering interacts poorly with Cairo's SVG export. gerbv renders
+        # aperture macros into a new surface, which for some reason gets clipped by Cairo to the given
+        # canvas size. This is just wrong, so we just nuke the clip path from these SVG groups here.
+        #
+        # Apart from being graphically broken, this additionally causes very bad rendering performance.
+        del group['clip-path']
+
+def gerber_difference(reference, actual, diff_out=None, svg_transform=None, size=(10,10), ref_unit_spec=None):
+    with tempfile.NamedTemporaryFile(suffix='.svg') as act_svg,\
+        tempfile.NamedTemporaryFile(suffix='.svg') as ref_svg:
+
+        gerbv_export(reference, ref_svg.name, size=size, export_format='svg', override_unit_spec=ref_unit_spec)
+        gerbv_export(actual, act_svg.name, size=size, export_format='svg')
+
+        with svg_soup(ref_svg.name) as soup:
+            if svg_transform is not None:
+                soup.find('g', attrs={'id': 'surface1'})['transform'] = svg_transform
+            cleanup_gerbv_svg(soup)
+
+        with svg_soup(act_svg.name) as soup:
+            cleanup_gerbv_svg(soup)
+
+        return svg_difference(ref_svg.name, act_svg.name, diff_out=diff_out)
+
+def gerber_difference_merge(ref1, ref2, actual, diff_out=None, composite_out=None, svg_transform1=None, svg_transform2=None, size=(10,10)):
+    with tempfile.NamedTemporaryFile(suffix='.svg') as act_svg,\
+        tempfile.NamedTemporaryFile(suffix='.svg') as ref1_svg,\
+        tempfile.NamedTemporaryFile(suffix='.svg') as ref2_svg:
+
+        gerbv_export(ref1, ref1_svg.name, size=size, export_format='svg')
+        gerbv_export(ref2, ref2_svg.name, size=size, export_format='svg')
+        gerbv_export(actual, act_svg.name, size=size, export_format='svg')
+
+        with svg_soup(ref1_svg.name) as soup1:
+            if svg_transform1 is not None:
+                soup1.find('g', attrs={'id': 'surface1'})['transform'] = svg_transform1
+            cleanup_gerbv_svg(soup1)
+
+            with svg_soup(ref2_svg.name) as soup2:
+                if svg_transform2 is not None:
+                    soup2.find('g', attrs={'id': 'surface1'})['transform'] = svg_transform2
+                cleanup_gerbv_svg(soup2)
+
+                defs1 = soup1.find('defs')
+                if not defs1:
+                    defs1 = soup1.new_tag('defs')
+                    soup1.find('svg').insert(0, defs1)
+
+                defs2 = soup2.find('defs')
+                if defs2:
+                    defs2 = defs2.extract()
+                    # explicitly convert .contents into list here and below because else bs4 stumbles over itself
+                    # iterating because we modify the tree in the loop body.
+                    for c in list(defs2.contents):
+                        if hasattr(c, 'attrs'):
+                            c['id'] = 'gn-merge-b-' + c.attrs.get('id', str(id(c)))
+                        defs1.append(c)
+
+                for use in soup2.find_all('use', recursive=True):
+                    if (href := use.get('xlink:href', '')).startswith('#'):
+                        use['xlink:href'] = f'#gn-merge-b-{href[1:]}'
+
+                svg1 = soup1.find('svg')
+                for c in list(soup2.find('svg').contents):
+                    if hasattr(c, 'attrs'):
+                        c['id'] = 'gn-merge-b-' + c.attrs.get('id', str(id(c)))
+                    svg1.append(c)
+
+        if composite_out:
+            shutil.copyfile(ref1_svg.name, composite_out)
+
+        with svg_soup(act_svg.name) as soup:
+            cleanup_gerbv_svg(soup)
+
+        return svg_difference(ref1_svg.name, act_svg.name, diff_out=diff_out)
+
+def svg_difference(reference, actual, diff_out=None, background=None):
+    with tempfile.NamedTemporaryFile(suffix='-ref.png') as ref_png,\
+        tempfile.NamedTemporaryFile(suffix='-act.png') as act_png:
+
+        svg_to_png(reference, ref_png.name, bg=background)
+        svg_to_png(actual, act_png.name, bg=background)
+
+        return image_difference(ref_png.name, act_png.name, diff_out=diff_out)
+
+def image_difference(reference, actual, diff_out=None):
+    ref = np.array(Image.open(reference)).astype(float)
+    out = np.array(Image.open(actual)).astype(float)
+
+    ref, out = ref.mean(axis=2), out.mean(axis=2) # convert to grayscale
+    # TODO blur images here before comparison to mitigate aliasing issue
+    delta = np.abs(out - ref).astype(float) / 255
+    if diff_out:
+        Image.fromarray((delta*255).astype(np.uint8), mode='L').save(diff_out)
+
+    hist, _bins = np.histogram(delta, bins=10, range=(0, 1))
+    return (ImageDifference(delta.mean(), hist),
+            ImageDifference(delta.max(), hist),
+            Histogram(hist, out.size))
+
+