diff options
Diffstat (limited to 'lib/extensions/convert_to_satin.py')
| -rw-r--r-- | lib/extensions/convert_to_satin.py | 60 |
1 files changed, 39 insertions, 21 deletions
diff --git a/lib/extensions/convert_to_satin.py b/lib/extensions/convert_to_satin.py index 1227b207..e2b287dd 100644 --- a/lib/extensions/convert_to_satin.py +++ b/lib/extensions/convert_to_satin.py @@ -1,16 +1,16 @@ -from copy import deepcopy -from itertools import chain, groupby import math +from itertools import chain, groupby -import inkex -from numpy import diff, sign, setdiff1d import numpy +from numpy import diff, setdiff1d, sign from shapely import geometry as shgeo +import inkex + from ..elements import Stroke from ..i18n import _ -from ..svg import get_correction_transform, PIXELS_PER_MM -from ..svg.tags import SVG_PATH_TAG +from ..svg import PIXELS_PER_MM, get_correction_transform +from ..svg.tags import INKSTITCH_ATTRIBS, SVG_PATH_TAG from ..utils import Point from .base import InkstitchExtension @@ -49,23 +49,31 @@ class ConvertToSatin(InkstitchExtension): # ignore paths with just one point -- they're not visible to the user anyway continue - self.fix_loop(path) + for satin in self.convert_path_to_satins(path, element.stroke_width, style_args, correction_transform, path_style): + parent.insert(index, satin) + index += 1 - try: - rails, rungs = self.path_to_satin(path, element.stroke_width, style_args) - except SelfIntersectionError: - inkex.errormsg( - _("Cannot convert %s to a satin column because it intersects itself. Try breaking it up into multiple paths.") % - element.node.get('id')) + parent.remove(element.node) - # revert any changes we've made - self.document = deepcopy(self.original_document) + def convert_path_to_satins(self, path, stroke_width, style_args, correction_transform, path_style, depth=0): + try: + rails, rungs = self.path_to_satin(path, stroke_width, style_args) + yield self.satin_to_svg_node(rails, rungs, correction_transform, path_style) + except SelfIntersectionError: + # The path intersects itself. Split it in two and try doing the halves + # individually. - return + if depth >= 20: + # At this point we're slicing the path way too small and still + # getting nowhere. Just give up on this section of the path. + return - parent.insert(index, self.satin_to_svg_node(rails, rungs, correction_transform, path_style)) + half = int(len(path) / 2.0) + halves = [path[:half + 1], path[half:]] - parent.remove(element.node) + for path in halves: + for satin in self.convert_path_to_satins(path, stroke_width, style_args, correction_transform, path_style, depth=depth + 1): + yield satin def fix_loop(self, path): if path[0] == path[-1]: @@ -107,13 +115,16 @@ class ConvertToSatin(InkstitchExtension): return args def path_to_satin(self, path, stroke_width, style_args): + if Point(*path[0]).distance(Point(*path[-1])) < 1: + raise SelfIntersectionError() + path = shgeo.LineString(path) left_rail = path.parallel_offset(stroke_width / 2.0, 'left', **style_args) right_rail = path.parallel_offset(stroke_width / 2.0, 'right', **style_args) if not isinstance(left_rail, shgeo.LineString) or \ - not isinstance(right_rail, shgeo.LineString): + not isinstance(right_rail, shgeo.LineString): # If the parallel offsets come out as anything but a LineString, that means the # path intersects itself, when taking its stroke width into consideration. See # the last example for parallel_offset() in the Shapely documentation: @@ -159,6 +170,13 @@ class ConvertToSatin(InkstitchExtension): # The dot product of two vectors is |v1| * |v2| * cos(angle). # These are unit vectors, so their magnitudes are 1. cos_angle_between = prev_direction * direction + + # Clamp to the valid range for a cosine. The above _should_ + # already be in this range, but floating point inaccuracy can + # push it outside the range causing math.acos to throw + # ValueError ("math domain error"). + cos_angle_between = max(-1.0, min(1.0, cos_angle_between)) + angle = abs(math.degrees(math.acos(cos_angle_between))) # Use the square of the angle, measured in degrees. @@ -248,7 +266,7 @@ class ConvertToSatin(InkstitchExtension): # arbitrarily rejects the rung if there was one less than 2 # millimeters before this one. if last_rung_center is not None and \ - (rung_center - last_rung_center).length() < 2 * PIXELS_PER_MM: + (rung_center - last_rung_center).length() < 2 * PIXELS_PER_MM: continue else: last_rung_center = rung_center @@ -292,6 +310,6 @@ class ConvertToSatin(InkstitchExtension): "style": path_style, "transform": correction_transform, "d": d, - "embroider_satin_column": "true", + INKSTITCH_ATTRIBS['satin_column']: "true", } ) |