Fill underlay inset (#108)

* interim commit

* implement underlay inset

* more refactoring
pull/114/head
Lex Neva 2018-03-01 19:39:44 -05:00 zatwierdzone przez GitHub
rodzic a7817fb1d3
commit 2ddc013c76
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@ -36,7 +36,7 @@ from pprint import pformat
import inkstitch
from inkstitch import _, cache, dbg, param, EmbroideryElement, get_nodes, SVG_POLYLINE_TAG, SVG_GROUP_TAG, PIXELS_PER_MM, get_viewbox_transform
from inkstitch.stitches import running_stitch
from inkstitch.stitches import running_stitch, auto_fill, legacy_fill
from inkstitch.utils import cut_path
class Fill(EmbroideryElement):
@ -120,257 +120,21 @@ class Fill(EmbroideryElement):
# print >> sys.stderr, "polygon valid:", polygon.is_valid
return polygon
@cache
def east(self, angle):
# "east" is the name of the direction that is to the right along a row
return inkstitch.Point(1, 0).rotate(-angle)
@cache
def north(self, angle):
return self.east(angle).rotate(math.pi / 2)
def row_num(self, point, angle, row_spacing):
return round((point * self.north(angle)) / row_spacing)
def adjust_stagger(self, stitch, angle, row_spacing, max_stitch_length):
row_num = self.row_num(stitch, angle, row_spacing)
row_stagger = row_num % self.staggers
stagger_offset = (float(row_stagger) / self.staggers) * max_stitch_length
offset = ((stitch * self.east(angle)) - stagger_offset) % max_stitch_length
return stitch - offset * self.east(angle)
def intersect_region_with_grating(self, angle=None, row_spacing=None, end_row_spacing=None):
if angle is None:
angle = self.angle
if row_spacing is None:
row_spacing = self.row_spacing
if end_row_spacing is None:
end_row_spacing = self.end_row_spacing
# the max line length I'll need to intersect the whole shape is the diagonal
(minx, miny, maxx, maxy) = self.shape.bounds
upper_left = inkstitch.Point(minx, miny)
lower_right = inkstitch.Point(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 = inkstitch.Point(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 = inkstitch.Point((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 = affinity.rotate(self.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 = shgeo.LineString(endpoints)
res = grating_line.intersection(self.shape)
if (isinstance(res, shgeo.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: (inkstitch.Point(*seg[0]) - upper_left).length())
if self.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 make_quadrilateral(self, segment1, segment2):
return shgeo.Polygon((segment1[0], segment1[1], segment2[1], segment2[0], segment1[0]))
def is_same_run(self, segment1, segment2):
if shgeo.LineString(segment1).distance(shgeo.LineString(segment2)) > self.row_spacing * 1.1:
return False
quad = self.make_quadrilateral(segment1, segment2)
quad_area = quad.area
intersection_area = self.shape.intersection(quad).area
return (intersection_area / quad_area) >= 0.9
def pull_runs(self, rows):
# 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 self.is_same_run(prev, first):
break
run.append(first)
prev = first
rows[row_num] = rest
# print >> sys.stderr, len(run)
runs.append(run)
rows = [row for row in rows if len(row) > 0]
count += 1
return runs
def stitch_row(self, patch, beg, end, angle, row_spacing, max_stitch_length):
# 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 = inkstitch.Point(*beg)
end = inkstitch.Point(*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 patch.stitches or (beg - patch.stitches[-1]).length() > 0.5 * PIXELS_PER_MM:
patch.add_stitch(beg)
first_stitch = self.adjust_stagger(beg, angle, row_spacing, max_stitch_length)
# 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:
patch.add_stitch(beg + offset * row_direction)
offset += max_stitch_length
if (end - patch.stitches[-1]).length() > 0.1 * PIXELS_PER_MM:
patch.add_stitch(end)
def section_to_patch(self, group_of_segments, angle=None, row_spacing=None, max_stitch_length=None):
if max_stitch_length is None:
max_stitch_length = self.max_stitch_length
if row_spacing is None:
row_spacing = self.row_spacing
if angle is None:
angle = self.angle
# print >> sys.stderr, len(groups_of_segments)
patch = Patch(color=self.color)
first_segment = True
swap = False
last_end = None
for segment in group_of_segments:
(beg, end) = segment
if (swap):
(beg, end) = (end, beg)
self.stitch_row(patch, beg, end, angle, row_spacing, max_stitch_length)
swap = not swap
return patch
def to_patches(self, last_patch):
rows_of_segments = self.intersect_region_with_grating()
groups_of_segments = self.pull_runs(rows_of_segments)
stitch_lists = legacy_fill(self.shape,
self.angle,
self.row_spacing,
self.end_row_spacing,
self.max_stitch_length,
self.flip,
self.staggers)
return [Patch(stitches=stitch_list, color=self.color) for stitch_list in stitch_lists]
return [self.section_to_patch(group) for group in groups_of_segments]
rows_of_segments = fill.intersect_region_with_grating(self.shape, self.angle, self.row_spacing, self.end_row_spacing, self.flip)
groups_of_segments = fill.pull_runs(rows_of_segments)
return [fill.section_to_patch(group) for group in groups_of_segments]
class MaxQueueLengthExceeded(Exception):
pass
class AutoFill(Fill):
element_name = _("Auto-Fill")
@ -427,462 +191,50 @@ class AutoFill(Fill):
def fill_underlay_max_stitch_length(self):
return self.get_float_param("fill_underlay_max_stitch_length_mm") or self.max_stitch_length
def which_outline(self, coords):
"""return the index of the outline on which the point resides
Index 0 is the outer boundary of the fill region. 1+ are the
outlines of the holes.
"""
# I'd use an intersection check, but floating point errors make it
# fail sometimes.
point = shgeo.Point(*coords)
outlines = list(enumerate(self.shape.boundary))
closest = min(outlines, key=lambda (index, outline): outline.distance(point))
return closest[0]
def project(self, coords, outline_index):
"""project the point onto the specified outline
This returns the distance along the outline at which the point resides.
"""
return self.shape.boundary.project(shgeo.Point(*coords))
def build_graph(self, segments, angle, row_spacing):
"""build a graph representation of the grating segments
This function builds a specialized graph (as in graph theory) that will
help us determine a stitching path. The idea comes from this paper:
http://www.sciencedirect.com/science/article/pii/S0925772100000158
The goal is to build a graph that we know must have an Eulerian Path.
An Eulerian Path is a path from edge to edge in the graph that visits
every edge exactly once and ends at the node it started at. Algorithms
exist to build such a path, and we'll use Hierholzer's algorithm.
A graph must have an Eulerian Path if every node in the graph has an
even number of edges touching it. Our goal here is to build a graph
that will have this property.
Based on the paper linked above, we'll build the graph as follows:
* nodes are the endpoints of the grating segments, where they meet
with the outer outline of the region the outlines of the interior
holes in the region.
* edges are:
* each section of the outer and inner outlines of the region,
between nodes
* double every other edge in the outer and inner hole outlines
Doubling up on some of the edges seems as if it will just mean we have
to stitch those spots twice. This may be true, but it also ensures
that every node has 4 edges touching it, ensuring that a valid stitch
path must exist.
"""
graph = networkx.MultiGraph()
# First, add the grating segments as edges. We'll use the coordinates
# of the endpoints as nodes, which networkx will add automatically.
for segment in segments:
# networkx allows us to label nodes with arbitrary data. We'll
# mark this one as a grating segment.
graph.add_edge(*segment, key="segment")
for node in graph.nodes():
outline_index = self.which_outline(node)
outline_projection = self.project(node, outline_index)
# Tag each node with its index and projection.
graph.add_node(node, index=outline_index, projection=outline_projection)
nodes = list(graph.nodes(data=True)) # returns a list of tuples: [(node, {data}), (node, {data}) ...]
nodes.sort(key=lambda node: (node[1]['index'], node[1]['projection']))
for outline_index, nodes in groupby(nodes, key=lambda node: node[1]['index']):
nodes = [ node for node, data in nodes ]
# heuristic: change the order I visit the nodes in the outline if necessary.
# If the start and endpoints are in the same row, I can't tell which row
# I should treat it as being in.
for i in xrange(len(nodes)):
row0 = self.row_num(inkstitch.Point(*nodes[0]), angle, row_spacing)
row1 = self.row_num(inkstitch.Point(*nodes[1]), angle, row_spacing)
if row0 == row1:
nodes = nodes[1:] + [nodes[0]]
else:
break
# heuristic: it's useful to try to keep the duplicated edges in the same rows.
# this prevents the BFS from having to search a ton of edges.
row_num = min(row0, row1)
if row_num % 2 == 0:
edge_set = 0
else:
edge_set = 1
#print >> sys.stderr, outline_index, "es", edge_set, "rn", row_num, inkstitch.Point(*nodes[0]) * self.north(angle), inkstitch.Point(*nodes[1]) * self.north(angle)
# add an edge between each successive node
for i, (node1, node2) in enumerate(zip(nodes, nodes[1:] + [nodes[0]])):
graph.add_edge(node1, node2, key="outline")
# duplicate edges contained in every other row (exactly half
# will be duplicated)
row_num = min(self.row_num(inkstitch.Point(*node1), angle, row_spacing),
self.row_num(inkstitch.Point(*node2), angle, row_spacing))
# duplicate every other edge around this outline
if i % 2 == edge_set:
graph.add_edge(node1, node2, key="extra")
if not networkx.is_eulerian(graph):
raise Exception(_("Unable to autofill. This most often happens because your shape is made up of multiple sections that aren't connected."))
return graph
def node_list_to_edge_list(self, node_list):
return zip(node_list[:-1], node_list[1:])
def bfs_for_loop(self, graph, starting_node, max_queue_length=2000):
to_search = deque()
to_search.appendleft(([starting_node], set(), 0))
while to_search:
if len(to_search) > max_queue_length:
raise MaxQueueLengthExceeded()
path, visited_edges, visited_segments = to_search.pop()
ending_node = path[-1]
# get a list of neighbors paired with the key of the edge I can follow to get there
neighbors = [
(node, key)
for node, adj in graph.adj[ending_node].iteritems()
for key in adj
]
# heuristic: try grating segments first
neighbors.sort(key=lambda (dest, key): key == "segment", reverse=True)
for next_node, key in neighbors:
# skip if I've already followed this edge
edge = (tuple(sorted((ending_node, next_node))), key)
if edge in visited_edges:
continue
new_path = path + [next_node]
if key == "segment":
new_visited_segments = visited_segments + 1
else:
new_visited_segments = visited_segments
if next_node == starting_node:
# ignore trivial loops (down and back a doubled edge)
if len(new_path) > 3:
return self.node_list_to_edge_list(new_path), new_visited_segments
new_visited_edges = visited_edges.copy()
new_visited_edges.add(edge)
to_search.appendleft((new_path, new_visited_edges, new_visited_segments))
def find_loop(self, graph, starting_nodes):
"""find a loop in the graph that is connected to the existing path
Start at a candidate node and search through edges to find a path
back to that node. We'll use a breadth-first search (BFS) in order to
find the shortest available loop.
In most cases, the BFS should not need to search far to find a loop.
The queue should stay relatively short.
An added heuristic will be used: if the BFS queue's length becomes
too long, we'll abort and try a different starting point. Due to
the way we've set up the graph, there's bound to be a better choice
somewhere else.
"""
#loop = self.simple_loop(graph, starting_nodes[-2])
#if loop:
# print >> sys.stderr, "simple_loop success"
# starting_nodes.pop()
# starting_nodes.pop()
# return loop
loop = None
retry = []
max_queue_length = 2000
while not loop:
while not loop and starting_nodes:
starting_node = starting_nodes.pop()
#print >> sys.stderr, "find loop from", starting_node
try:
# Note: if bfs_for_loop() returns None, no loop can be
# constructed from the starting_node (because the
# necessary edges have already been consumed). In that
# case we discard that node and try the next.
loop = self.bfs_for_loop(graph, starting_node, max_queue_length)
if not loop:
print >> dbg, "failed on", starting_node
dbg.flush()
except MaxQueueLengthExceeded:
print >> dbg, "gave up on", starting_node
dbg.flush()
# We're giving up on this node for now. We could try
# this node again later, so add it to the bottm of the
# stack.
retry.append(starting_node)
# Darn, couldn't find a loop. Try harder.
starting_nodes.extendleft(retry)
max_queue_length *= 2
starting_nodes.extendleft(retry)
return loop
def insert_loop(self, path, loop):
"""insert a sub-loop into an existing path
The path will be a series of edges describing a path through the graph
that ends where it starts. The loop will be similar, and its starting
point will be somewhere along the path.
Insert the loop into the path, resulting in a longer path.
Both the path and the loop will be a list of edges specified as a
start and end point. The points will be specified in order, such
that they will look like this:
((p1, p2), (p2, p3), (p3, p4) ... (pn, p1))
path will be modified in place.
"""
loop_start = loop[0][0]
for i, (start, end) in enumerate(path):
if start == loop_start:
break
path[i:i] = loop
def find_stitch_path(self, graph, segments):
"""find a path that visits every grating segment exactly once
Theoretically, we just need to find an Eulerian Path in the graph.
However, we don't actually care whether every single edge is visited.
The edges on the outline of the region are only there to help us get
from one grating segment to the next.
We'll build a "cycle" (a path that ends where it starts) using
Hierholzer's algorithm. We'll stop once we've visited every grating
segment.
Hierholzer's algorithm says to select an arbitrary starting node at
each step. In order to produce a reasonable stitch path, we'll select
the vertex carefully such that we get back-and-forth traversal like
mowing a lawn.
To do this, we'll use a simple heuristic: try to start from nodes in
the order of most-recently-visited first.
"""
original_graph = graph
graph = graph.copy()
num_segments = len(segments)
segments_visited = 0
nodes_visited = deque()
# start with a simple loop: down one segment and then back along the
# outer border to the starting point.
path = [segments[0], list(reversed(segments[0]))]
graph.remove_edges_from(path)
segments_visited += 1
nodes_visited.extend(segments[0])
while segments_visited < num_segments:
result = self.find_loop(graph, nodes_visited)
if not result:
print >> sys.stderr, _("Unexpected error while generating fill stitches. Please send your SVG file to lexelby@github.")
break
loop, segments = result
print >> dbg, "found loop:", loop
dbg.flush()
segments_visited += segments
nodes_visited += [edge[0] for edge in loop]
graph.remove_edges_from(loop)
self.insert_loop(path, loop)
#if segments_visited >= 12:
# break
# Now we have a loop that covers every grating segment. It returns to
# where it started, which is unnecessary, so we'll snip the last bit off.
#while original_graph.has_edge(*path[-1], key="outline"):
# path.pop()
return path
def collapse_sequential_outline_edges(self, graph, path):
"""collapse sequential edges that fall on the same outline
When the path follows multiple edges along the outline of the region,
replace those edges with the starting and ending points. We'll use
these to stitch along the outline later on.
"""
start_of_run = None
new_path = []
for edge in path:
if graph.has_edge(*edge, key="segment"):
if start_of_run:
# close off the last run
new_path.append((start_of_run, edge[0]))
start_of_run = None
new_path.append(edge)
else:
if not start_of_run:
start_of_run = edge[0]
if start_of_run:
# if we were still in a run, close it off
new_path.append((start_of_run, edge[1]))
return new_path
def outline_distance(self, outline, p1, p2):
# how far around the outline (and in what direction) do I need to go
# to get from p1 to p2?
p1_projection = outline.project(shgeo.Point(p1))
p2_projection = outline.project(shgeo.Point(p2))
distance = p2_projection - p1_projection
if abs(distance) > self.outline_length / 2.0:
# if we'd have to go more than halfway around, it's faster to go
# the other way
if distance < 0:
return distance + self.outline_length
elif distance > 0:
return distance - self.outline_length
else:
# this ought not happen, but just for completeness, return 0 if
# p1 and p0 are the same point
return 0
@property
@param('fill_underlay_inset_mm', _('Inset'), unit='mm', group=_('AutoFill Underlay'), type='float', default=0)
def fill_underlay_inset(self):
return self.get_float_param('fill_underlay_inset_mm', 0)
@property
def underlay_shape(self):
if self.fill_underlay_inset:
shape = self.shape.buffer(-self.fill_underlay_inset)
if not isinstance(shape, shgeo.MultiPolygon):
shape = shgeo.MultiPolygon([shape])
return shape
else:
return distance
def connect_points(self, patch, start, end):
outline_index = self.which_outline(start)
outline = self.shape.boundary[outline_index]
pos = outline.project(shgeo.Point(start))
distance = self.outline_distance(outline, start, end)
stitches = abs(int(distance / self.running_stitch_length))
direction = math.copysign(1.0, distance)
one_stitch = self.running_stitch_length * direction
print >> dbg, "connect_points:", outline_index, start, end, distance, stitches, direction
dbg.flush()
patch.add_stitch(inkstitch.Point(*start))
for i in xrange(stitches):
pos = (pos + one_stitch) % self.outline_length
patch.add_stitch(inkstitch.Point(*outline.interpolate(pos).coords[0]))
end = inkstitch.Point(*end)
if (end - patch.stitches[-1]).length() > 0.1 * PIXELS_PER_MM:
patch.add_stitch(end)
print >> dbg, "end connect_points"
dbg.flush()
def path_to_patch(self, graph, path, angle, row_spacing, max_stitch_length):
path = self.collapse_sequential_outline_edges(graph, path)
patch = Patch(color=self.color)
#patch.add_stitch(inkstitch.Point(*path[0][0]))
#for edge in path:
# patch.add_stitch(inkstitch.Point(*edge[1]))
for edge in path:
if graph.has_edge(*edge, key="segment"):
self.stitch_row(patch, edge[0], edge[1], angle, row_spacing, max_stitch_length)
else:
self.connect_points(patch, *edge)
return patch
def do_auto_fill(self, angle, row_spacing, max_stitch_length, starting_point=None):
patches = []
print >> dbg, "start do_auto_fill"
dbg.flush()
rows_of_segments = self.intersect_region_with_grating(angle, row_spacing)
segments = [segment for row in rows_of_segments for segment in row]
graph = self.build_graph(segments, angle, row_spacing)
path = self.find_stitch_path(graph, segments)
if starting_point:
patch = Patch(self.color)
self.connect_points(patch, starting_point, path[0][0])
patches.append(patch)
patches.append(self.path_to_patch(graph, path, angle, row_spacing, max_stitch_length))
print >> dbg, "end do_auto_fill"
dbg.flush()
return patches
return self.shape
def to_patches(self, last_patch):
patches = []
stitches = []
if last_patch is None:
starting_point = None
else:
nearest_point = self.outline.interpolate(self.outline.project(shgeo.Point(last_patch.stitches[-1])))
starting_point = inkstitch.Point(*nearest_point.coords[0])
starting_point = last_patch.stitches[-1]
if self.fill_underlay:
patches.extend(self.do_auto_fill(self.fill_underlay_angle, self.fill_underlay_row_spacing, self.fill_underlay_max_stitch_length, starting_point))
starting_point = patches[-1].stitches[-1]
stitches.extend(auto_fill(self.underlay_shape,
self.fill_underlay_angle,
self.fill_underlay_row_spacing,
self.fill_underlay_row_spacing,
self.fill_underlay_max_stitch_length,
self.running_stitch_length,
self.staggers,
starting_point))
starting_point = stitches[-1]
patches.extend(self.do_auto_fill(self.angle, self.row_spacing, self.max_stitch_length, starting_point))
stitches.extend(auto_fill(self.shape,
self.angle,
self.row_spacing,
self.end_row_spacing,
self.max_stitch_length,
self.running_stitch_length,
self.staggers,
starting_point))
print >> dbg, "end AutoFill.to_patches"
dbg.flush()
return patches
return [Patch(stitches=stitches, color=self.color)]
class Stroke(EmbroideryElement):

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@ -1 +1,3 @@
from running_stitch import *
from auto_fill import auto_fill
from fill import legacy_fill

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from fill import intersect_region_with_grating, row_num, stitch_row
from .. import _, PIXELS_PER_MM, Point as InkstitchPoint
import sys
import shapely
import networkx
import math
from itertools import groupby
from collections import deque
class MaxQueueLengthExceeded(Exception):
pass
def auto_fill(shape, angle, row_spacing, end_row_spacing, max_stitch_length, running_stitch_length, staggers, starting_point=None):
stitches = []
rows_of_segments = intersect_region_with_grating(shape, angle, row_spacing, end_row_spacing)
segments = [segment for row in rows_of_segments for segment in row]
graph = build_graph(shape, segments, angle, row_spacing)
path = find_stitch_path(graph, segments)
if starting_point:
stitches.extend(connect_points(shape, starting_point, path[0][0], running_stitch_length))
stitches.extend(path_to_stitches(graph, path, shape, angle, row_spacing, max_stitch_length, running_stitch_length, staggers))
return stitches
def which_outline(shape, coords):
"""return the index of the outline on which the point resides
Index 0 is the outer boundary of the fill region. 1+ are the
outlines of the holes.
"""
# I'd use an intersection check, but floating point errors make it
# fail sometimes.
point = shapely.geometry.Point(*coords)
outlines = enumerate(list(shape.boundary))
closest = min(outlines, key=lambda (index, outline): outline.distance(point))
return closest[0]
def project(shape, coords, outline_index):
"""project the point onto the specified outline
This returns the distance along the outline at which the point resides.
"""
outline = list(shape.boundary)[outline_index]
return outline.project(shapely.geometry.Point(*coords))
def build_graph(shape, segments, angle, row_spacing):
"""build a graph representation of the grating segments
This function builds a specialized graph (as in graph theory) that will
help us determine a stitching path. The idea comes from this paper:
http://www.sciencedirect.com/science/article/pii/S0925772100000158
The goal is to build a graph that we know must have an Eulerian Path.
An Eulerian Path is a path from edge to edge in the graph that visits
every edge exactly once and ends at the node it started at. Algorithms
exist to build such a path, and we'll use Hierholzer's algorithm.
A graph must have an Eulerian Path if every node in the graph has an
even number of edges touching it. Our goal here is to build a graph
that will have this property.
Based on the paper linked above, we'll build the graph as follows:
* nodes are the endpoints of the grating segments, where they meet
with the outer outline of the region the outlines of the interior
holes in the region.
* edges are:
* each section of the outer and inner outlines of the region,
between nodes
* double every other edge in the outer and inner hole outlines
Doubling up on some of the edges seems as if it will just mean we have
to stitch those spots twice. This may be true, but it also ensures
that every node has 4 edges touching it, ensuring that a valid stitch
path must exist.
"""
graph = networkx.MultiGraph()
# First, add the grating segments as edges. We'll use the coordinates
# of the endpoints as nodes, which networkx will add automatically.
for segment in segments:
# networkx allows us to label nodes with arbitrary data. We'll
# mark this one as a grating segment.
graph.add_edge(*segment, key="segment")
for node in graph.nodes():
outline_index = which_outline(shape, node)
outline_projection = project(shape, node, outline_index)
# Tag each node with its index and projection.
graph.add_node(node, index=outline_index, projection=outline_projection)
nodes = list(graph.nodes(data=True)) # returns a list of tuples: [(node, {data}), (node, {data}) ...]
nodes.sort(key=lambda node: (node[1]['index'], node[1]['projection']))
for outline_index, nodes in groupby(nodes, key=lambda node: node[1]['index']):
nodes = [ node for node, data in nodes ]
# heuristic: change the order I visit the nodes in the outline if necessary.
# If the start and endpoints are in the same row, I can't tell which row
# I should treat it as being in.
for i in xrange(len(nodes)):
row0 = row_num(InkstitchPoint(*nodes[0]), angle, row_spacing)
row1 = row_num(InkstitchPoint(*nodes[1]), angle, row_spacing)
if row0 == row1:
nodes = nodes[1:] + [nodes[0]]
else:
break
# heuristic: it's useful to try to keep the duplicated edges in the same rows.
# this prevents the BFS from having to search a ton of edges.
min_row_num = min(row0, row1)
if min_row_num % 2 == 0:
edge_set = 0
else:
edge_set = 1
#print >> sys.stderr, outline_index, "es", edge_set, "rn", row_num, inkstitch.Point(*nodes[0]) * self.north(angle), inkstitch.Point(*nodes[1]) * self.north(angle)
# add an edge between each successive node
for i, (node1, node2) in enumerate(zip(nodes, nodes[1:] + [nodes[0]])):
graph.add_edge(node1, node2, key="outline")
# duplicate every other edge around this outline
if i % 2 == edge_set:
graph.add_edge(node1, node2, key="extra")
if not networkx.is_eulerian(graph):
raise Exception(_("Unable to autofill. This most often happens because your shape is made up of multiple sections that aren't connected."))
return graph
def node_list_to_edge_list(node_list):
return zip(node_list[:-1], node_list[1:])
def bfs_for_loop(graph, starting_node, max_queue_length=2000):
to_search = deque()
to_search.appendleft(([starting_node], set(), 0))
while to_search:
if len(to_search) > max_queue_length:
raise MaxQueueLengthExceeded()
path, visited_edges, visited_segments = to_search.pop()
ending_node = path[-1]
# get a list of neighbors paired with the key of the edge I can follow to get there
neighbors = [
(node, key)
for node, adj in graph.adj[ending_node].iteritems()
for key in adj
]
# heuristic: try grating segments first
neighbors.sort(key=lambda (dest, key): key == "segment", reverse=True)
for next_node, key in neighbors:
# skip if I've already followed this edge
edge = (tuple(sorted((ending_node, next_node))), key)
if edge in visited_edges:
continue
new_path = path + [next_node]
if key == "segment":
new_visited_segments = visited_segments + 1
else:
new_visited_segments = visited_segments
if next_node == starting_node:
# ignore trivial loops (down and back a doubled edge)
if len(new_path) > 3:
return node_list_to_edge_list(new_path), new_visited_segments
new_visited_edges = visited_edges.copy()
new_visited_edges.add(edge)
to_search.appendleft((new_path, new_visited_edges, new_visited_segments))
def find_loop(graph, starting_nodes):
"""find a loop in the graph that is connected to the existing path
Start at a candidate node and search through edges to find a path
back to that node. We'll use a breadth-first search (BFS) in order to
find the shortest available loop.
In most cases, the BFS should not need to search far to find a loop.
The queue should stay relatively short.
An added heuristic will be used: if the BFS queue's length becomes
too long, we'll abort and try a different starting point. Due to
the way we've set up the graph, there's bound to be a better choice
somewhere else.
"""
#loop = self.simple_loop(graph, starting_nodes[-2])
#if loop:
# print >> sys.stderr, "simple_loop success"
# starting_nodes.pop()
# starting_nodes.pop()
# return loop
loop = None
retry = []
max_queue_length = 2000
while not loop:
while not loop and starting_nodes:
starting_node = starting_nodes.pop()
#print >> sys.stderr, "find loop from", starting_node
try:
# Note: if bfs_for_loop() returns None, no loop can be
# constructed from the starting_node (because the
# necessary edges have already been consumed). In that
# case we discard that node and try the next.
loop = bfs_for_loop(graph, starting_node, max_queue_length)
#if not loop:
#print >> dbg, "failed on", starting_node
#dbg.flush()
except MaxQueueLengthExceeded:
#print >> dbg, "gave up on", starting_node
#dbg.flush()
# We're giving up on this node for now. We could try
# this node again later, so add it to the bottm of the
# stack.
retry.append(starting_node)
# Darn, couldn't find a loop. Try harder.
starting_nodes.extendleft(retry)
max_queue_length *= 2
starting_nodes.extendleft(retry)
return loop
def insert_loop(path, loop):
"""insert a sub-loop into an existing path
The path will be a series of edges describing a path through the graph
that ends where it starts. The loop will be similar, and its starting
point will be somewhere along the path.
Insert the loop into the path, resulting in a longer path.
Both the path and the loop will be a list of edges specified as a
start and end point. The points will be specified in order, such
that they will look like this:
((p1, p2), (p2, p3), (p3, p4) ... (pn, p1))
path will be modified in place.
"""
loop_start = loop[0][0]
for i, (start, end) in enumerate(path):
if start == loop_start:
break
path[i:i] = loop
def find_stitch_path(graph, segments):
"""find a path that visits every grating segment exactly once
Theoretically, we just need to find an Eulerian Path in the graph.
However, we don't actually care whether every single edge is visited.
The edges on the outline of the region are only there to help us get
from one grating segment to the next.
We'll build a "cycle" (a path that ends where it starts) using
Hierholzer's algorithm. We'll stop once we've visited every grating
segment.
Hierholzer's algorithm says to select an arbitrary starting node at
each step. In order to produce a reasonable stitch path, we'll select
the vertex carefully such that we get back-and-forth traversal like
mowing a lawn.
To do this, we'll use a simple heuristic: try to start from nodes in
the order of most-recently-visited first.
"""
original_graph = graph
graph = graph.copy()
num_segments = len(segments)
segments_visited = 0
nodes_visited = deque()
# start with a simple loop: down one segment and then back along the
# outer border to the starting point.
path = [segments[0], list(reversed(segments[0]))]
graph.remove_edges_from(path)
segments_visited += 1
nodes_visited.extend(segments[0])
while segments_visited < num_segments:
result = find_loop(graph, nodes_visited)
if not result:
print >> sys.stderr, _("Unexpected error while generating fill stitches. Please send your SVG file to lexelby@github.")
break
loop, segments = result
#print >> dbg, "found loop:", loop
#dbg.flush()
segments_visited += segments
nodes_visited += [edge[0] for edge in loop]
graph.remove_edges_from(loop)
insert_loop(path, loop)
#if segments_visited >= 12:
# break
# Now we have a loop that covers every grating segment. It returns to
# where it started, which is unnecessary, so we'll snip the last bit off.
#while original_graph.has_edge(*path[-1], key="outline"):
# path.pop()
return path
def collapse_sequential_outline_edges(graph, path):
"""collapse sequential edges that fall on the same outline
When the path follows multiple edges along the outline of the region,
replace those edges with the starting and ending points. We'll use
these to stitch along the outline later on.
"""
start_of_run = None
new_path = []
for edge in path:
if graph.has_edge(*edge, key="segment"):
if start_of_run:
# close off the last run
new_path.append((start_of_run, edge[0]))
start_of_run = None
new_path.append(edge)
else:
if not start_of_run:
start_of_run = edge[0]
if start_of_run:
# if we were still in a run, close it off
new_path.append((start_of_run, edge[1]))
return new_path
def outline_distance(outline, p1, p2):
# how far around the outline (and in what direction) do I need to go
# to get from p1 to p2?
p1_projection = outline.project(shapely.geometry.Point(p1))
p2_projection = outline.project(shapely.geometry.Point(p2))
distance = p2_projection - p1_projection
if abs(distance) > outline.length / 2.0:
# if we'd have to go more than halfway around, it's faster to go
# the other way
if distance < 0:
return distance + outline.length
elif distance > 0:
return distance - outline.length
else:
# this ought not happen, but just for completeness, return 0 if
# p1 and p0 are the same point
return 0
else:
return distance
def connect_points(shape, start, end, running_stitch_length):
outline_index = which_outline(shape, start)
outline = shape.boundary[outline_index]
pos = outline.project(shapely.geometry.Point(start))
distance = outline_distance(outline, start, end)
num_stitches = abs(int(distance / running_stitch_length))
direction = math.copysign(1.0, distance)
one_stitch = running_stitch_length * direction
#print >> dbg, "connect_points:", outline_index, start, end, distance, stitches, direction
#dbg.flush()
stitches = [InkstitchPoint(*start)]
for i in xrange(num_stitches):
pos = (pos + one_stitch) % outline.length
stitches.append(InkstitchPoint(*outline.interpolate(pos).coords[0]))
end = InkstitchPoint(*end)
if (end - stitches[-1]).length() > 0.1 * PIXELS_PER_MM:
stitches.append(end)
#print >> dbg, "end connect_points"
#dbg.flush()
return stitches
def path_to_stitches(graph, path, shape, angle, row_spacing, max_stitch_length, running_stitch_length, staggers):
path = collapse_sequential_outline_edges(graph, path)
stitches = []
for edge in path:
if graph.has_edge(*edge, key="segment"):
stitch_row(stitches, edge[0], edge[1], angle, row_spacing, max_stitch_length, staggers)
else:
stitches.extend(connect_points(shape, edge[0], edge[1], running_stitch_length))
return stitches

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from .. import Point as InkstitchPoint, cache, PIXELS_PER_MM
import shapely
import math
import sys
def legacy_fill(shape, angle, row_spacing, end_row_spacing, max_stitch_length, flip, staggers):
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)
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):
# 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:
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):
stitches = []
first_segment = True
swap = False
last_end = None
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)
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 = [row for row in rows if len(row) > 0]
count += 1
return runs

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@ -8,7 +8,7 @@ msgid ""
msgstr ""
"Project-Id-Version: PACKAGE VERSION\n"
"Report-Msgid-Bugs-To: \n"
"POT-Creation-Date: 2018-02-27 23:14-0500\n"
"POT-Creation-Date: 2018-02-28 20:27-0500\n"
"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
"Language-Team: LANGUAGE <LL@li.org>\n"
@ -62,14 +62,7 @@ msgstr ""
msgid "Max stitch length"
msgstr ""
msgid ""
"Unable to autofill. This most often happens because your shape is made up "
"of multiple sections that aren't connected."
msgstr ""
msgid ""
"Unexpected error while generating fill stitches. Please send your SVG file "
"to lexelby@github."
msgid "Inset"
msgstr ""
msgid "Satin stitch along paths"