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stepanalyser/.venv/lib/python3.12/site-packages/ezdxf/math/_construct.py
Christian Anetzberger a197de9456 initial
2026-01-22 20:23:51 +01:00

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Python

# Copyright (c) 2011-2024, Manfred Moitzi
# License: MIT License
# These are the pure Python implementations of the Cython accelerated
# construction tools: ezdxf/acc/construct.pyx
from __future__ import annotations
from typing import Iterable, Sequence, Optional, TYPE_CHECKING
import math
# The pure Python implementation can't import from ._ctypes or ezdxf.math!
from ._vector import Vec2, Vec3
if TYPE_CHECKING:
from ezdxf.math import UVec
TOLERANCE = 1e-10
RAD_ABS_TOL = 1e-15
DEG_ABS_TOL = 1e-13
def has_clockwise_orientation(vertices: Iterable[UVec]) -> bool:
"""Returns ``True`` if the given 2D `vertices` have clockwise orientation.
Ignores the z-axis of all vertices.
Args:
vertices: iterable of :class:`Vec2` compatible objects
Raises:
ValueError: less than 3 vertices
"""
vertices = Vec2.list(vertices)
if len(vertices) < 3:
raise ValueError("At least 3 vertices required.")
# close polygon:
if not vertices[0].isclose(vertices[-1]):
vertices.append(vertices[0])
return (
sum(
(p2.x - p1.x) * (p2.y + p1.y)
for p1, p2 in zip(vertices, vertices[1:])
)
> 0.0
)
def intersection_line_line_2d(
line1: Sequence[Vec2],
line2: Sequence[Vec2],
virtual=True,
abs_tol=TOLERANCE,
) -> Optional[Vec2]:
"""
Compute the intersection of two lines in the xy-plane.
Args:
line1: start- and end point of first line to test
e.g. ((x1, y1), (x2, y2)).
line2: start- and end point of second line to test
e.g. ((x3, y3), (x4, y4)).
virtual: ``True`` returns any intersection point, ``False`` returns
only real intersection points.
abs_tol: tolerance for intersection test.
Returns:
``None`` if there is no intersection point (parallel lines) or
intersection point as :class:`Vec2`
"""
# Algorithm based on: http://paulbourke.net/geometry/pointlineplane/
# chapter: Intersection point of two line segments in 2 dimensions
s1, s2 = line1 # the subject line
c1, c2 = line2 # the clipping line
s1x = s1.x
s1y = s1.y
s2x = s2.x
s2y = s2.y
c1x = c1.x
c1y = c1.y
c2x = c2.x
c2y = c2.y
den = (c2y - c1y) * (s2x - s1x) - (c2x - c1x) * (s2y - s1y)
if math.fabs(den) <= abs_tol:
return None
us = ((c2x - c1x) * (s1y - c1y) - (c2y - c1y) * (s1x - c1x)) / den
intersection_point = Vec2(s1x + us * (s2x - s1x), s1y + us * (s2y - s1y))
if virtual:
return intersection_point
# 0 = intersection point is the start point of the line
# 1 = intersection point is the end point of the line
# otherwise: linear interpolation
lwr = 0.0 # tolerances required?
upr = 1.0 # tolerances required?
if lwr <= us <= upr: # intersection point is on the subject line
uc = ((s2x - s1x) * (s1y - c1y) - (s2y - s1y) * (s1x - c1x)) / den
if lwr <= uc <= upr: # intersection point is on the clipping line
return intersection_point
return None
def _determinant(v1, v2, v3) -> float:
"""Returns determinant."""
e11, e12, e13 = v1
e21, e22, e23 = v2
e31, e32, e33 = v3
return (
e11 * e22 * e33
+ e12 * e23 * e31
+ e13 * e21 * e32
- e13 * e22 * e31
- e11 * e23 * e32
- e12 * e21 * e33
)
def intersection_ray_ray_3d(
ray1: Sequence[Vec3], ray2: Sequence[Vec3], abs_tol=TOLERANCE
) -> Sequence[Vec3]:
"""
Calculate intersection of two 3D rays, returns a 0-tuple for parallel rays,
a 1-tuple for intersecting rays and a 2-tuple for not intersecting and not
parallel rays with points of the closest approach on each ray.
Args:
ray1: first ray as tuple of two points as :class:`Vec3` objects
ray2: second ray as tuple of two points as :class:`Vec3` objects
abs_tol: absolute tolerance for comparisons
"""
# source: http://www.realtimerendering.com/intersections.html#I304
o1, p1 = ray1
d1 = (p1 - o1).normalize()
o2, p2 = ray2
d2 = (p2 - o2).normalize()
d1xd2 = d1.cross(d2)
denominator = d1xd2.magnitude_square
if denominator <= abs_tol:
# ray1 is parallel to ray2
return tuple()
else:
o2_o1 = o2 - o1
det1 = _determinant(o2_o1, d2, d1xd2)
det2 = _determinant(o2_o1, d1, d1xd2)
p1 = o1 + d1 * (det1 / denominator)
p2 = o2 + d2 * (det2 / denominator)
if p1.isclose(p2, abs_tol=abs_tol):
# ray1 and ray2 have an intersection point
return (p1,)
else:
# ray1 and ray2 do not have an intersection point,
# p1 and p2 are the points of closest approach on each ray
return p1, p2
def arc_angle_span_deg(start: float, end: float) -> float:
"""Returns the counter-clockwise angle span from `start` to `end` in degrees.
Returns the angle span in the range of [0, 360], 360 is a full circle.
Full circle handling is a special case, because normalization of angles
which describe a full circle would return 0 if treated as regular angles.
e.g. (0, 360) → 360, (0, -360) → 360, (180, -180) → 360.
Input angles with the same value always return 0 by definition: (0, 0) → 0,
(-180, -180) → 0, (360, 360) → 0.
"""
# Input values are equal, returns 0 by definition:
if math.isclose(start, end, abs_tol=DEG_ABS_TOL):
return 0.0
# Normalized start- and end angles are equal, but input values are
# different, returns 360 by definition:
start %= 360.0
if math.isclose(start, end % 360.0, abs_tol=DEG_ABS_TOL):
return 360.0
# Special treatment for end angle == 360 deg:
if not math.isclose(end, 360.0, abs_tol=DEG_ABS_TOL):
end %= 360.0
if end < start:
end += 360.0
return end - start
def arc_angle_span_rad(start: float, end: float) -> float:
"""Returns the counter-clockwise angle span from `start` to `end` in radians.
Returns the angle span in the range of [0, 2π], 2π is a full circle.
Full circle handling is a special case, because normalization of angles
which describe a full circle would return 0 if treated as regular angles.
e.g. (0, 2π) → 2π, (0, -2π) → 2π, (π, -π) → 2π.
Input angles with the same value always return 0 by definition: (0, 0) → 0,
(-π, -π) → 0, (2π, 2π) → 0.
"""
tau = math.tau
# Input values are equal, returns 0 by definition:
if math.isclose(start, end, abs_tol=RAD_ABS_TOL):
return 0.0
# Normalized start- and end angles are equal, but input values are
# different, returns 360 by definition:
start %= tau
if math.isclose(start, end % tau, abs_tol=RAD_ABS_TOL):
return tau
# Special treatment for end angle == 2π:
if not math.isclose(end, tau, abs_tol=RAD_ABS_TOL):
end %= tau
if end < start:
end += tau
return end - start
def is_point_in_polygon_2d(
point: Vec2, polygon: list[Vec2], abs_tol=TOLERANCE
) -> int:
"""
Test if `point` is inside `polygon`. Returns +1 for inside, 0 for on the
boundary and -1 for outside.
Supports convex and concave polygons with clockwise or counter-clockwise oriented
polygon vertices. Does not raise an exception for degenerated polygons.
Args:
point: 2D point to test as :class:`Vec2`
polygon: list of 2D points as :class:`Vec2`
abs_tol: tolerance for distance check
Returns:
+1 for inside, 0 for on the boundary, -1 for outside
"""
# Source: http://www.faqs.org/faqs/graphics/algorithms-faq/
# Subject 2.03: How do I find if a point lies within a polygon?
# polygon: the Cython implementation needs a list as input to be fast!
assert isinstance(polygon, list)
if len(polygon) < 3: # empty polygon
return -1
if polygon[0].isclose(polygon[-1]): # open polygon is required
polygon = polygon[:-1]
if len(polygon) < 3:
return -1
x = point.x
y = point.y
inside = False
x1, y1 = polygon[-1]
for x2, y2 in polygon:
# is point on polygon boundary line:
# is point in x-range of line
a, b = (x2, x1) if x2 < x1 else (x1, x2)
if a <= x <= b:
# is point in y-range of line
c, d = (y2, y1) if y2 < y1 else (y1, y2)
if (c <= y <= d) and abs(
(y2 - y1) * x - (x2 - x1) * y + (x2 * y1 - y2 * x1)
) <= abs_tol:
return 0 # on boundary line
if ((y1 <= y < y2) or (y2 <= y < y1)) and (
x < (x2 - x1) * (y - y1) / (y2 - y1) + x1
):
inside = not inside
x1 = x2
y1 = y2
if inside:
return 1 # inside polygon
else:
return -1 # outside polygon
# Values stored in GeoData RSS tag are not precise enough to match
# control calculation at epsg.io:
# Semi Major Axis: 6.37814e+06
# Semi Minor Axis: 6.35675e+06
WGS84_SEMI_MAJOR_AXIS = 6378137
WGS84_SEMI_MINOR_AXIS = 6356752.3142
WGS84_ELLIPSOID_ECCENTRIC = 0.08181919092890624
# WGS84_ELLIPSOID_ECCENTRIC = math.sqrt(
# 1.0 - WGS84_SEMI_MINOR_AXIS**2 / WGS84_SEMI_MAJOR_AXIS**2
# )
CONST_E2 = 1.3591409142295225 # math.e / 2.0
CONST_PI_2 = 1.5707963267948966 # math.pi / 2.0
CONST_PI_4 = 0.7853981633974483 # math.pi / 4.0
def gps_to_world_mercator(longitude: float, latitude: float) -> tuple[float, float]:
"""Transform GPS (long/lat) to World Mercator.
Transform WGS84 `EPSG:4326 <https://epsg.io/4326>`_ location given as
latitude and longitude in decimal degrees as used by GPS into World Mercator
cartesian 2D coordinates in meters `EPSG:3395 <https://epsg.io/3395>`_.
Args:
longitude: represents the longitude value (East-West) in decimal degrees
latitude: represents the latitude value (North-South) in decimal degrees.
.. versionadded:: 1.3.0
"""
# From: https://epsg.io/4326
# EPSG:4326 WGS84 - World Geodetic System 1984, used in GPS
# To: https://epsg.io/3395
# EPSG:3395 - World Mercator
# Source: https://gis.stackexchange.com/questions/259121/transformation-functions-for-epsg3395-projection-vs-epsg3857
longitude = math.radians(longitude) # east
latitude = math.radians(latitude) # north
a = WGS84_SEMI_MAJOR_AXIS
e = WGS84_ELLIPSOID_ECCENTRIC
e_sin_lat = math.sin(latitude) * e
c = math.pow((1.0 - e_sin_lat) / (1.0 + e_sin_lat), e / 2.0) # 7-7 p.44
y = a * math.log(math.tan(CONST_PI_4 + latitude / 2.0) * c) # 7-7 p.44
x = a * longitude
return x, y
def world_mercator_to_gps(x: float, y: float, tol: float = 1e-6) -> tuple[float, float]:
"""Transform World Mercator to GPS.
Transform WGS84 World Mercator `EPSG:3395 <https://epsg.io/3395>`_
location given as cartesian 2D coordinates x, y in meters into WGS84 decimal
degrees as longitude and latitude `EPSG:4326 <https://epsg.io/4326>`_ as
used by GPS.
Args:
x: coordinate WGS84 World Mercator
y: coordinate WGS84 World Mercator
tol: accuracy for latitude calculation
.. versionadded:: 1.3.0
"""
# From: https://epsg.io/3395
# EPSG:3395 - World Mercator
# To: https://epsg.io/4326
# EPSG:4326 WGS84 - World Geodetic System 1984, used in GPS
# Source: Map Projections - A Working Manual
# https://pubs.usgs.gov/pp/1395/report.pdf
a = WGS84_SEMI_MAJOR_AXIS
e = WGS84_ELLIPSOID_ECCENTRIC
e2 = e / 2.0
pi2 = CONST_PI_2
t = math.e ** (-y / a) # 7-10 p.44
latitude_ = pi2 - 2.0 * math.atan(t) # 7-11 p.45
while True:
e_sin_lat = math.sin(latitude_) * e
latitude = pi2 - 2.0 * math.atan(
t * ((1.0 - e_sin_lat) / (1.0 + e_sin_lat)) ** e2
) # 7-9 p.44
if abs(latitude - latitude_) < tol:
break
latitude_ = latitude
longitude = x / a # 7-12 p.45
return math.degrees(longitude), math.degrees(latitude)