inkstitch/lib/stitches/fill.py

246 wiersze
8.3 KiB
Python

import math
import shapely
from ..svg import PIXELS_PER_MM
from ..utils import cache, Point as InkstitchPoint
def legacy_fill(shape, angle, row_spacing, end_row_spacing, max_stitch_length, flip, staggers, skip_last):
rows_of_segments = intersect_region_with_grating(shape, angle, row_spacing, end_row_spacing, flip)
groups_of_segments = pull_runs(rows_of_segments, shape, row_spacing)
return [section_to_stitches(group, angle, row_spacing, max_stitch_length, staggers, skip_last)
for group in groups_of_segments]
@cache
def east(angle):
# "east" is the name of the direction that is to the right along a row
return InkstitchPoint(1, 0).rotate(-angle)
@cache
def north(angle):
return east(angle).rotate(math.pi / 2)
def row_num(point, angle, row_spacing):
return round((point * north(angle)) / row_spacing)
def adjust_stagger(stitch, angle, row_spacing, max_stitch_length, staggers):
this_row_num = row_num(stitch, angle, row_spacing)
row_stagger = this_row_num % staggers
stagger_offset = (float(row_stagger) / staggers) * max_stitch_length
offset = ((stitch * east(angle)) - stagger_offset) % max_stitch_length
return stitch - offset * east(angle)
def stitch_row(stitches, beg, end, angle, row_spacing, max_stitch_length, staggers, skip_last=False):
# We want our stitches to look like this:
#
# ---*-----------*-----------
# ------*-----------*--------
# ---------*-----------*-----
# ------------*-----------*--
# ---*-----------*-----------
#
# Each successive row of stitches will be staggered, with
# num_staggers rows before the pattern repeats. A value of
# 4 gives a nice fill while hiding the needle holes. The
# first row is offset 0%, the second 25%, the third 50%, and
# the fourth 75%.
#
# Actually, instead of just starting at an offset of 0, we
# can calculate a row's offset relative to the origin. This
# way if we have two abutting fill regions, they'll perfectly
# tile with each other. That's important because we often get
# abutting fill regions from pull_runs().
beg = InkstitchPoint(*beg)
end = InkstitchPoint(*end)
row_direction = (end - beg).unit()
segment_length = (end - beg).length()
# only stitch the first point if it's a reasonable distance away from the
# last stitch
if not stitches or (beg - stitches[-1]).length() > 0.5 * PIXELS_PER_MM:
stitches.append(beg)
first_stitch = adjust_stagger(beg, angle, row_spacing, max_stitch_length, staggers)
# we might have chosen our first stitch just outside this row, so move back in
if (first_stitch - beg) * row_direction < 0:
first_stitch += row_direction * max_stitch_length
offset = (first_stitch - beg).length()
while offset < segment_length:
stitches.append(beg + offset * row_direction)
offset += max_stitch_length
if (end - stitches[-1]).length() > 0.1 * PIXELS_PER_MM and not skip_last:
stitches.append(end)
def intersect_region_with_grating(shape, angle, row_spacing, end_row_spacing=None, flip=False):
# the max line length I'll need to intersect the whole shape is the diagonal
(minx, miny, maxx, maxy) = shape.bounds
upper_left = InkstitchPoint(minx, miny)
lower_right = InkstitchPoint(maxx, maxy)
length = (upper_left - lower_right).length()
half_length = length / 2.0
# Now get a unit vector rotated to the requested angle. I use -angle
# because shapely rotates clockwise, but my geometry textbooks taught
# me to consider angles as counter-clockwise from the X axis.
direction = InkstitchPoint(1, 0).rotate(-angle)
# and get a normal vector
normal = direction.rotate(math.pi / 2)
# I'll start from the center, move in the normal direction some amount,
# and then walk left and right half_length in each direction to create
# a line segment in the grating.
center = InkstitchPoint((minx + maxx) / 2.0, (miny + maxy) / 2.0)
# I need to figure out how far I need to go along the normal to get to
# the edge of the shape. To do that, I'll rotate the bounding box
# angle degrees clockwise and ask for the new bounding box. The max
# and min y tell me how far to go.
_, start, _, end = shapely.affinity.rotate(shape, angle, origin='center', use_radians=True).bounds
# convert start and end to be relative to center (simplifies things later)
start -= center.y
end -= center.y
height = abs(end - start)
# print >> dbg, "grating:", start, end, height, row_spacing, end_row_spacing
# offset start slightly so that rows are always an even multiple of
# row_spacing_px from the origin. This makes it so that abutting
# fill regions at the same angle and spacing always line up nicely.
start -= (start + normal * center) % row_spacing
rows = []
current_row_y = start
while current_row_y < end:
p0 = center + normal * current_row_y + direction * half_length
p1 = center + normal * current_row_y - direction * half_length
endpoints = [p0.as_tuple(), p1.as_tuple()]
grating_line = shapely.geometry.LineString(endpoints)
res = grating_line.intersection(shape)
if (isinstance(res, shapely.geometry.MultiLineString)):
runs = map(lambda line_string: line_string.coords, res.geoms)
else:
if res.is_empty or len(res.coords) == 1:
# ignore if we intersected at a single point or no points
runs = []
else:
runs = [res.coords]
if runs:
runs.sort(key=lambda seg: (InkstitchPoint(*seg[0]) - upper_left).length())
if flip:
runs.reverse()
runs = map(lambda run: tuple(reversed(run)), runs)
rows.append(runs)
if end_row_spacing:
current_row_y += row_spacing + (end_row_spacing - row_spacing) * ((current_row_y - start) / height)
else:
current_row_y += row_spacing
return rows
def section_to_stitches(group_of_segments, angle, row_spacing, max_stitch_length, staggers, skip_last):
stitches = []
swap = False
for segment in group_of_segments:
(beg, end) = segment
if (swap):
(beg, end) = (end, beg)
stitch_row(stitches, beg, end, angle, row_spacing, max_stitch_length, staggers, skip_last)
swap = not swap
return stitches
def make_quadrilateral(segment1, segment2):
return shapely.geometry.Polygon((segment1[0], segment1[1], segment2[1], segment2[0], segment1[0]))
def is_same_run(segment1, segment2, shape, row_spacing):
line1 = shapely.geometry.LineString(segment1)
line2 = shapely.geometry.LineString(segment2)
if line1.distance(line2) > row_spacing * 1.1:
return False
quad = make_quadrilateral(segment1, segment2)
quad_area = quad.area
intersection_area = shape.intersection(quad).area
return (intersection_area / quad_area) >= 0.9
def pull_runs(rows, shape, row_spacing):
# Given a list of rows, each containing a set of line segments,
# break the area up into contiguous patches of line segments.
#
# This is done by repeatedly pulling off the first line segment in
# each row and calling that a shape. We have to be careful to make
# sure that the line segments are part of the same shape. Consider
# the letter "H", with an embroidery angle of 45 degrees. When
# we get to the bottom of the lower left leg, the next row will jump
# over to midway up the lower right leg. We want to stop there and
# start a new patch.
# for row in rows:
# print >> sys.stderr, len(row)
# print >>sys.stderr, "\n".join(str(len(row)) for row in rows)
runs = []
count = 0
while (len(rows) > 0):
run = []
prev = None
for row_num in xrange(len(rows)):
row = rows[row_num]
first, rest = row[0], row[1:]
# TODO: only accept actually adjacent rows here
if prev is not None and not is_same_run(prev, first, shape, row_spacing):
break
run.append(first)
prev = first
rows[row_num] = rest
# print >> sys.stderr, len(run)
runs.append(run)
rows = [r for r in rows if len(r) > 0]
count += 1
return runs