diff options
Diffstat (limited to 'barcode_gen.py')
| -rw-r--r-- | barcode_gen.py | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/barcode_gen.py b/barcode_gen.py new file mode 100644 index 0000000..dc000bf --- /dev/null +++ b/barcode_gen.py @@ -0,0 +1,120 @@ +#!/usr/bin/env python3 + +import math +import itertools +import textwrap + +import click +from reedmuller import reedmuller + + +class Tag: + """ Helper class to ease creation of SVG. All API functions that create SVG allow you to substitute this with your + own implementation by passing a ``tag`` parameter. """ + + def __init__(self, name, children=None, root=False, **attrs): + if (fill := attrs.get('fill')) and isinstance(fill, tuple): + attrs['fill'], attrs['fill-opacity'] = fill + if (stroke := attrs.get('stroke')) and isinstance(stroke, tuple): + attrs['stroke'], attrs['stroke-opacity'] = stroke + self.name, self.attrs = name, attrs + self.children = children or [] + self.root = root + + def __str__(self): + prefix = '<?xml version="1.0" encoding="utf-8"?>\n' if self.root else '' + opening = ' '.join([self.name] + [f'{key.replace("__", ":").replace("_", "-")}="{value}"' for key, value in self.attrs.items()]) + if self.children: + children = '\n'.join(textwrap.indent(str(c), ' ') for c in self.children) + return f'{prefix}<{opening}>\n{children}\n</{self.name}>' + else: + return f'{prefix}<{opening}/>' + + + @classmethod + def setup_svg(kls, tags, bounds, margin=0, unit='mm', pagecolor='white', inkscape=False): + (min_x, min_y), (max_x, max_y) = bounds + + if margin: + min_x -= margin + min_y -= margin + max_x += margin + max_y += margin + + w, h = max_x - min_x, max_y - min_y + w = 1.0 if math.isclose(w, 0.0) else w + h = 1.0 if math.isclose(h, 0.0) else h + + if inkscape: + tags.insert(0, kls('sodipodi:namedview', [], id='namedview1', pagecolor=pagecolor, + inkscape__document_units=unit)) + namespaces = dict( + xmlns="http://www.w3.org/2000/svg", + xmlns__xlink="http://www.w3.org/1999/xlink", + xmlns__sodipodi='http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd', + xmlns__inkscape='http://www.inkscape.org/namespaces/inkscape') + + else: + namespaces = dict( + xmlns="http://www.w3.org/2000/svg", + xmlns__xlink="http://www.w3.org/1999/xlink") + + return kls('svg', tags, + width=f'{w}{unit}', height=f'{h}{unit}', + viewBox=f'{min_x} {min_y} {w} {h}', + style=f'background-color:{pagecolor}', + **namespaces, + root=True) + + +@click.command() +@click.option('-h', '--height', type=float, default=20, help='Bar height in mm') +@click.option('-t/-n', '--text/--no-text', default=True, help='Whether to add text containing the data under the bar code') +@click.option('-f', '--font', default='sans-serif', help='Font for the text underneath the bar code') +@click.option('-s', '--font-size', type=float, default=10, help='Font size for the text underneath the bar code in points (pt)') +@click.option('-b', '--bar-width', type=float, default=1.0, help='Bar width in mm') +@click.option('-m', '--margin', type=float, default=2.0, help='Margin around bar code in mm') +@click.option('-c', '--color', default='black', help='SVG color for the bar code') +@click.option('--text-color', default=None, help='SVG color for the text (defaults to the bar code\'s color)') +@click.option('--dpi', type=float, default=96, help='DPI value to assume for internal SVG unit conversions') +@click.argument('data') +@click.argument('outfile', type=click.File('w'), default='-') +def cli(data, outfile, height, text, font, font_size, bar_width, margin, color, text_color, dpi): + data = int(data, 16) + text_color = text_color or color + + NUM_BITS = 26 + + data_bits = [bool(data & (1<<i)) for i in range(NUM_BITS)] + data_encoded = itertools.chain(*[ + (a, not a) for a in data_bits + ]) + data_encoded = [True, False, True, False, *data_encoded, False, True, True, False, True] + + bars = 32/2*3 + 2 + width = bars * bar_width + # 1 px = 0.75 pt + pt_to_mm = lambda pt: pt / 0.75 /dpi * 25.4 + font_size = pt_to_mm(font_size) + total_height = height + font_size*2 + + tags = [] + for key, group in itertools.groupby(enumerate(data_encoded), key=lambda x: x[1]): + if key: + group = list(group) + x0, _key = group[0] + w = len(group) + tags.append(Tag('path', stroke=color, stroke_width=w, d=f'M {(x0 + w/2)*bar_width} 0 l 0 {height}')) + + if text: + tags.append(Tag('text', children=[f'{data:07x}'], + x=width/2, y=height + 0.5*font_size, + font_family=font, font_size=f'{font_size:.3f}px', + text_anchor='middle', dominant_baseline='hanging', + fill=text_color)) + + outfile.write(str(Tag.setup_svg(tags, bounds=((0, 0), (width, total_height)), margin=margin))) + + +if __name__ == '__main__': + cli() |