rewrite of autofill to handle arbitrary holes!

pull/5/head
Lex Neva 2017-09-23 01:03:33 +01:00
rodzic a13745e39b
commit 1e86acdc58
1 zmienionych plików z 453 dodań i 137 usunięć

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@ -24,7 +24,8 @@ import os
import subprocess
from copy import deepcopy
import time
from itertools import chain, izip
from itertools import chain, izip, groupby
from collections import deque
import inkex
import simplepath
import simplestyle
@ -37,6 +38,7 @@ import lxml.etree as etree
import shapely.geometry as shgeo
import shapely.affinity as affinity
import shapely.ops
import networkx
from pprint import pformat
import PyEmb
@ -49,7 +51,6 @@ SVG_PATH_TAG = inkex.addNS('path', 'svg')
SVG_DEFS_TAG = inkex.addNS('defs', 'svg')
SVG_GROUP_TAG = inkex.addNS('g', 'svg')
class Param(object):
def __init__(self, name, description, unit=None, values=[], type=None, group=None, inverse=False, default=None):
self.name = name
@ -309,8 +310,11 @@ class Fill(EmbroideryElement):
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 = round((stitch * self.north(angle)) / row_spacing)
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
@ -448,24 +452,7 @@ class Fill(EmbroideryElement):
return runs
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:
def stitch_row(self, patch, beg, end, angle, row_spacing, max_stitch_length):
# We want our stitches to look like this:
#
# ---*-----------*-----------
@ -486,10 +473,6 @@ class Fill(EmbroideryElement):
# tile with each other. That's important because we often get
# abutting fill regions from pull_runs().
(beg, end) = segment
if (swap):
(beg, end) = (end, beg)
beg = PyEmb.Point(*beg)
end = PyEmb.Point(*end)
@ -499,7 +482,7 @@ class Fill(EmbroideryElement):
# only stitch the first point if it's a reasonable distance away from the
# last stitch
if last_end is None or (beg - last_end).length() > 0.5 * self.options.pixels_per_mm:
if not patch.stitches or (beg - patch.stitches[-1]).length() > 0.5 * self.options.pixels_per_mm:
patch.add_stitch(beg)
first_stitch = self.adjust_stagger(beg, angle, row_spacing, max_stitch_length)
@ -517,7 +500,32 @@ class Fill(EmbroideryElement):
if (end - patch.stitches[-1]).length() > 0.1 * self.options.pixels_per_mm:
patch.add_stitch(end)
last_end = 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
@ -529,6 +537,9 @@ class Fill(EmbroideryElement):
return [self.section_to_patch(group) for group in groups_of_segments]
class MaxQueueLengthExceeded(Exception):
pass
class AutoFill(Fill):
@property
@param('auto_fill', 'Automatically routed fill stitching', type='toggle', default=True)
@ -580,116 +591,421 @@ class AutoFill(Fill):
@param('fill_underlay_max_stitch_length_mm', 'Max stitch length', unit='mm', group='AutoFill Underlay', type='float')
@cache
def fill_underlay_max_stitch_length(self):
return self.get_float_param("fill_underlay_max_stitch_length_mm" or self.max_stitch_length)
return self.get_float_param("fill_underlay_max_stitch_length_mm") or self.max_stitch_length
def validate(self):
if len(self.shape.boundary) > 1:
self.fatal("auto-fill: object %s cannot be auto-filled because it has one or more holes. Please disable auto-fill for this object or break it into separate objects without holes." % self.node.get('id'))
def which_outline(self, coords):
"""return the index of the outline on which the point resides
def is_same_run(self, segment1, segment2):
if shgeo.Point(segment1[0]).distance(shgeo.Point(segment2[0])) > self.max_stitch_length:
return False
Index 0 is the outer boundary of the fill region. 1+ are the
outlines of the holes.
"""
if shgeo.Point(segment1[1]).distance(shgeo.Point(segment2[1])) > self.max_stitch_length:
return False
point = shgeo.Point(*coords)
return True
for i, outline in enumerate(self.shape.boundary):
# I'd use an intersection check, but floating point errors make it
# fail sometimes.
if outline.distance(point) < 0.00001:
return i
def perimeter_distance(self, p1, p2):
# how far around the perimeter (and in what direction) do I need to go
# to get from p1 to p2?
def project(self, coords, outline_index):
"""project the point onto the specified outline
p1_projection = self.outline.project(shgeo.Point(p1))
p2_projection = self.outline.project(shgeo.Point(p2))
This returns the distance along the outline at which the point resides.
"""
distance = p2_projection - p1_projection
return self.shape.boundary.project(shgeo.Point(*coords))
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
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 = graph.nodes(data=True)
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.
while True:
row0 = self.row_num(PyEmb.Point(*nodes[0]), angle, row_spacing)
row1 = self.row_num(PyEmb.Point(*nodes[1]), angle, row_spacing)
if row0 == row1:
nodes = nodes[1:] + [nodes[0]]
else:
# this ought not happen, but just for completeness, return 0 if
# p1 and p0 are the same point
return 0
else:
return distance
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, PyEmb.Point(*nodes[0]) * self.north(angle), PyEmb.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(PyEmb.Point(*node1), angle, row_spacing),
self.row_num(PyEmb.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("something went wrong: graph is not eulerian")
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.
"""
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 filling region. Please send your SVG 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
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 connect_points(self, patch, start, end):
outline_index = self.which_outline(start)
outline = self.shape.boundary[outline_index]
start = outline.project(shgeo.Point(*start))
end = outline.project(shgeo.Point(*end))
direction = math.copysign(1.0, end - start)
while (end - start) * direction > 0:
stitch = outline.interpolate(start)
patch.add_stitch(PyEmb.Point(stitch.x, stitch.y))
start += self.running_stitch_length * direction
stitch = outline.interpolate(end)
end = PyEmb.Point(stitch.x, stitch.y)
if (end - patch.stitches[-1]).length() > 0.1 * self.options.pixels_per_mm:
patch.add_stitch(end)
def path_to_patch(self, graph, path, angle, row_spacing, max_stitch_length):
path = self.collapse_sequential_outline_edges(graph, path)
def connect_points(self, p1, p2):
patch = Patch(color=self.color)
#patch.add_stitch(PyEmb.Point(*path[0][0]))
pos = self.outline.project(shgeo.Point(p1))
distance = self.perimeter_distance(p1, p2)
stitches = abs(int(distance / self.running_stitch_length))
#for edge in path:
# patch.add_stitch(PyEmb.Point(*edge[1]))
direction = math.copysign(1.0, distance)
one_stitch = self.running_stitch_length * direction
for i in xrange(stitches):
pos = (pos + one_stitch) % self.outline_length
stitch = PyEmb.Point(*self.outline.interpolate(pos).coords[0])
# if we're moving along the fill direction, adjust the stitch to
# match the fill so it blends in
if patch.stitches:
if abs((stitch - patch.stitches[-1]) * self.north(self.angle)) < 0.01:
new_stitch = self.adjust_stagger(stitch, self.angle, self.row_spacing, self.max_stitch_length)
# don't push the point past the end of this section of the outline
if self.outline.distance(shgeo.Point(new_stitch)) <= 0.01:
stitch = new_stitch
patch.add_stitch(stitch)
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 get_corner_points(self, section):
return section[0][0], section[0][-1], section[-1][0], section[-1][-1]
def nearest_corner(self, section, point):
return min(self.get_corner_points(section),
key=lambda corner: abs(self.perimeter_distance(point, corner)))
def find_nearest_section(self, sections, point):
sections_with_nearest_corner = [(i, self.nearest_corner(section, point))
for i, section in enumerate(sections)]
return min(sections_with_nearest_corner,
key=lambda(section, corner): abs(self.perimeter_distance(point, corner)))
def section_from_corner(self, section, start_corner, angle, row_spacing, max_stitch_length):
if start_corner not in section[0]:
section = list(reversed(section))
if section[0][0] != start_corner:
section = [list(reversed(row)) for row in section]
return self.section_to_patch(section, angle, row_spacing, max_stitch_length)
def do_auto_fill(self, angle, row_spacing, max_stitch_length, starting_point=None):
rows_of_segments = self.intersect_region_with_grating(angle, row_spacing)
sections = self.pull_runs(rows_of_segments)
def visualize_graph(self, graph):
patches = []
last_stitch = starting_point
while sections:
if last_stitch:
section_index, start_corner = self.find_nearest_section(sections, last_stitch)
patches.append(self.connect_points(last_stitch, start_corner))
patches.append(self.section_from_corner(sections.pop(section_index), start_corner, angle, row_spacing, max_stitch_length))
else:
patches.append(self.section_to_patch(sections.pop(0), angle, row_spacing, max_stitch_length))
last_stitch = patches[-1].stitches[-1]
graph = graph.copy()
for start, end, key in graph.edges_iter(keys=True):
if key == "extra":
patch = Patch(color="#FF0000")
patch.add_stitch(PyEmb.Point(*start))
patch.add_stitch(PyEmb.Point(*end))
patches.append(patch)
return patches
def do_auto_fill(self, angle, row_spacing, max_stitch_length, starting_point=None):
patches = []
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)
# snip off the last one because it just unnecessarily returns to the start
path.pop()
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))
return patches
def to_patches(self, last_patch):
print >> dbg, "autofill"
self.validate()
print >> dbg, "autofill", self.max_stitch_length, self.fill_underlay_max_stitch_length
patches = []