kopia lustrzana https://github.com/inkstitch/inkstitch
131 wiersze
3.5 KiB
Python
131 wiersze
3.5 KiB
Python
import math
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from shapely.geometry import LineString, Point as ShapelyPoint
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def cut(line, distance, normalized=False):
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""" Cuts a LineString in two at a distance from its starting point.
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This is an example in the Shapely documentation.
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"""
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if normalized:
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distance *= line.length
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if distance <= 0.0:
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return [None, line]
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elif distance >= line.length:
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return [line, None]
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coords = list(ShapelyPoint(p) for p in line.coords)
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traveled = 0
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last_point = coords[0]
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for i, p in enumerate(coords[1:], 1):
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traveled += p.distance(last_point)
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last_point = p
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if traveled == distance:
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return [
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LineString(coords[:i + 1]),
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LineString(coords[i:])]
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if traveled > distance:
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cp = line.interpolate(distance)
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return [
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LineString(coords[:i] + [(cp.x, cp.y)]),
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LineString([(cp.x, cp.y)] + coords[i:])]
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def cut_path(points, length):
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"""Return a subsection of at the start of the path that is length units long.
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Given a path denoted by a set of points, walk along it until we've travelled
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the specified length and return a new path up to that point.
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If the original path isn't that long, just return it as is.
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"""
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if len(points) < 2:
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return points
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path = LineString(points)
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subpath, rest = cut(path, length)
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return [Point(*point) for point in subpath.coords]
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def collapse_duplicate_point(geometry):
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if geometry.area < 0.01:
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return geometry.representative_point()
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return geometry
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class Point:
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def __init__(self, x, y):
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self.x = x
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self.y = y
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def __add__(self, other):
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return Point(self.x + other.x, self.y + other.y)
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def __sub__(self, other):
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return Point(self.x - other.x, self.y - other.y)
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def mul(self, scalar):
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return Point(self.x * scalar, self.y * scalar)
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def __mul__(self, other):
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if isinstance(other, Point):
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# dot product
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return self.x * other.x + self.y * other.y
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elif isinstance(other, (int, float)):
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return Point(self.x * other, self.y * other)
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else:
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raise ValueError("cannot multiply Point by %s" % type(other))
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def __neg__(self):
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return self * -1
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def __rmul__(self, other):
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if isinstance(other, (int, float)):
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return self.__mul__(other)
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else:
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raise ValueError("cannot multiply Point by %s" % type(other))
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def __div__(self, other):
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if isinstance(other, (int, float)):
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return self * (1.0 / other)
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else:
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raise ValueError("cannot divide Point by %s" % type(other))
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def __repr__(self):
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return "Point(%s,%s)" % (self.x, self.y)
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def length(self):
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return math.sqrt(math.pow(self.x, 2.0) + math.pow(self.y, 2.0))
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def distance(self, other):
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return (other - self).length()
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def unit(self):
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return self.mul(1.0 / self.length())
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def rotate_left(self):
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return Point(-self.y, self.x)
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def rotate(self, angle):
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return Point(self.x * math.cos(angle) - self.y * math.sin(angle), self.y * math.cos(angle) + self.x * math.sin(angle))
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def as_int(self):
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return Point(int(round(self.x)), int(round(self.y)))
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def as_tuple(self):
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return (self.x, self.y)
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def __cmp__(self, other):
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return cmp(self.as_tuple(), other.as_tuple())
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def __getitem__(self, item):
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return self.as_tuple()[item]
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def __len__(self):
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return 2
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