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stepanalyser/.venv/lib/python3.12/site-packages/ezdxf/acc/bezier4p.pyx
Christian Anetzberger a197de9456 initial
2026-01-22 20:23:51 +01:00

372 lines
11 KiB
Cython

# cython: language_level=3
# Copyright (c) 2020-2024 Manfred Moitzi
# License: MIT License
from typing import TYPE_CHECKING, Sequence, Iterable, Iterator
import cython
import warnings
from .vector cimport (
Vec3,
Vec2,
isclose,
v3_add,
v3_mul,
v3_dist,
v3_lerp,
v3_from_angle,
normalize_rad_angle,
)
from .matrix44 cimport Matrix44
from libc.math cimport ceil, tan, M_PI
from .construct import arc_angle_span_deg
if TYPE_CHECKING:
from ezdxf.math import UVec
from ezdxf.math.ellipse import ConstructionEllipse
__all__ = [
'Bezier4P', 'cubic_bezier_arc_parameters',
'cubic_bezier_from_arc', 'cubic_bezier_from_ellipse',
]
cdef extern from "constants.h":
const double ABS_TOL
const double REL_TOL
const double M_TAU
cdef double DEG2RAD = M_PI / 180.0
cdef double RECURSION_LIMIT = 1000
cdef class Bezier4P:
cdef:
FastCubicCurve curve # pyright: ignore
readonly Vec3 start_point
Vec3 cp1
Vec3 cp2
readonly Vec3 end_point
def __cinit__(self, defpoints: Sequence[UVec]):
if not isinstance(defpoints[0], (Vec2, Vec3)):
warnings.warn(
DeprecationWarning,
"Bezier4P requires defpoints of type Vec2 or Vec3 in the future",
)
if len(defpoints) == 4:
self.start_point = Vec3(defpoints[0])
self.cp1 = Vec3(defpoints[1])
self.cp2 = Vec3(defpoints[2])
self.end_point = Vec3(defpoints[3])
self.curve = FastCubicCurve(
self.start_point,
self.cp1,
self.cp2,
self.end_point
)
else:
raise ValueError("Four control points required.")
@property
def control_points(self) -> tuple[Vec3, Vec3, Vec3, Vec3]:
return self.start_point, self.cp1, self.cp2, self.end_point
def __reduce__(self):
return Bezier4P, (self.control_points,)
def point(self, double t) -> Vec3:
if 0.0 <= t <= 1.0:
return self.curve.point(t)
else:
raise ValueError("t not in range [0 to 1]")
def tangent(self, double t) -> Vec3:
if 0.0 <= t <= 1.0:
return self.curve.tangent(t)
else:
raise ValueError("t not in range [0 to 1]")
def approximate(self, int segments) -> list[Vec3]:
cdef double delta_t
cdef int segment
cdef list points = [self.start_point]
if segments < 1:
raise ValueError(segments)
delta_t = 1.0 / segments
for segment in range(1, segments):
points.append(self.curve.point(delta_t * segment))
points.append(self.end_point)
return points
def flattening(self, double distance, int segments = 4) -> list[Vec3]:
cdef double dt = 1.0 / segments
cdef double t0 = 0.0, t1
cdef _Flattening f = _Flattening(self, distance)
cdef Vec3 start_point = self.start_point
cdef Vec3 end_point
while t0 < 1.0:
t1 = t0 + dt
if isclose(t1, 1.0, REL_TOL, ABS_TOL):
end_point = self.end_point
t1 = 1.0
else:
end_point = self.curve.point(t1)
f.reset_recursion_check()
f.flatten(start_point, end_point, t0, t1)
if f.has_recursion_error():
raise RecursionError(
"Bezier4P flattening error, check for very large coordinates"
)
t0 = t1
start_point = end_point
return f.points
def approximated_length(self, segments: int = 128) -> float:
cdef double length = 0.0
cdef bint start_flag = 0
cdef Vec3 prev_point, point
for point in self.approximate(segments):
if start_flag:
length += v3_dist(prev_point, point)
else:
start_flag = 1
prev_point = point
return length
def reverse(self) -> Bezier4P:
return Bezier4P((self.end_point, self.cp2, self.cp1, self.start_point))
def transform(self, Matrix44 m) -> Bezier4P:
return Bezier4P(tuple(m.transform_vertices(self.control_points)))
cdef class _Flattening:
cdef FastCubicCurve curve # pyright: ignore
cdef double distance
cdef list points
cdef int _recursion_level
cdef int _recursion_error
def __cinit__(self, Bezier4P curve, double distance):
self.curve = curve.curve
self.distance = distance
self.points = [curve.start_point]
self._recursion_level = 0
self._recursion_error = 0
cdef has_recursion_error(self):
return self._recursion_error
cdef reset_recursion_check(self):
self._recursion_level = 0
self._recursion_error = 0
cdef flatten(
self,
Vec3 start_point,
Vec3 end_point,
double start_t,
double end_t
):
# Keep in sync with CPython implementation: ezdxf/math/_bezier4p.py
# Test suite: 630a
if self._recursion_level > RECURSION_LIMIT:
self._recursion_error = 1
return
self._recursion_level += 1
cdef double mid_t = (start_t + end_t) * 0.5
cdef Vec3 mid_point = self.curve.point(mid_t)
cdef double d = v3_dist(mid_point, v3_lerp(start_point, end_point, 0.5))
if d < self.distance:
self.points.append(end_point)
else:
self.flatten(start_point, mid_point, start_t, mid_t)
self.flatten(mid_point, end_point, mid_t, end_t)
self._recursion_level -= 1
cdef double DEFAULT_TANGENT_FACTOR = 4.0 / 3.0 # 1.333333333333333333
cdef double OPTIMIZED_TANGENT_FACTOR = 1.3324407374108935
cdef double TANGENT_FACTOR = DEFAULT_TANGENT_FACTOR
@cython.cdivision(True)
def cubic_bezier_arc_parameters(
double start_angle,
double end_angle,
int segments = 1,
) -> Iterator[tuple[Vec3, Vec3, Vec3, Vec3]]:
if segments < 1:
raise ValueError('Invalid argument segments (>= 1).')
cdef double delta_angle = end_angle - start_angle
cdef int arc_count
if delta_angle > 0:
arc_count = <int> ceil(delta_angle / M_PI * 2.0)
if segments > arc_count:
arc_count = segments
else:
raise ValueError('Delta angle from start- to end angle has to be > 0.')
cdef double segment_angle = delta_angle / arc_count
cdef double tangent_length = TANGENT_FACTOR * tan(segment_angle / 4.0)
cdef double angle = start_angle
cdef Vec3 start_point, end_point, cp1, cp2
end_point = v3_from_angle(angle, 1.0)
for _ in range(arc_count):
start_point = end_point
angle += segment_angle
end_point = v3_from_angle(angle, 1.0)
cp1 = Vec3()
cp1.x = start_point.x - start_point.y * tangent_length
cp1.y = start_point.y + start_point.x * tangent_length
cp2 = Vec3()
cp2.x = end_point.x + end_point.y * tangent_length
cp2.y = end_point.y - end_point.x * tangent_length
yield start_point, cp1, cp2, end_point
def cubic_bezier_from_arc(
center = (0, 0),
double radius = 1.0,
double start_angle = 0.0,
double end_angle = 360.0,
int segments = 1
) -> Iterable[Bezier4P]:
cdef Vec3 center_ = Vec3(center)
cdef Vec3 tmp
cdef list res
cdef int i
cdef double angle_span = arc_angle_span_deg(start_angle, end_angle)
if abs(angle_span) < 1e-9:
return
cdef double s = start_angle
start_angle = (s * DEG2RAD) % M_TAU
end_angle = (s + angle_span) * DEG2RAD
while start_angle > end_angle:
end_angle += M_TAU
for control_points in cubic_bezier_arc_parameters(start_angle, end_angle, segments):
res = []
for i in range(4):
tmp = <Vec3> control_points[i]
res.append(v3_add(center_, v3_mul(tmp, radius)))
yield Bezier4P(res)
def cubic_bezier_from_ellipse(
ellipse: ConstructionEllipse,
int segments = 1
) -> Iterator[Bezier4P]:
cdef double param_span = ellipse.param_span
if abs(param_span) < 1e-9:
return
cdef double start_angle = normalize_rad_angle(ellipse.start_param)
cdef double end_angle = start_angle + param_span
while start_angle > end_angle:
end_angle += M_TAU
cdef Vec3 center = Vec3(ellipse.center)
cdef Vec3 x_axis = Vec3(ellipse.major_axis)
cdef Vec3 y_axis = Vec3(ellipse.minor_axis)
cdef Vec3 cp
cdef Vec3 c_res
cdef list res
for control_points in cubic_bezier_arc_parameters(start_angle, end_angle, segments):
res = list()
for i in range(4):
cp = <Vec3> control_points[i]
c_res = v3_add_3(center, v3_mul(x_axis, cp.x), v3_mul(y_axis, cp.y))
res.append(c_res)
yield Bezier4P(res)
cdef Vec3 v3_add_3(Vec3 a, Vec3 b, Vec3 c):
cdef Vec3 result = Vec3()
result.x = a.x + b.x + c.x
result.y = a.y + b.y + c.y
result.z = a.z + b.z + c.z
return result
cdef class FastCubicCurve:
cdef:
double[3] offset
double[3] p1
double[3] p2
double[3] p3
def __cinit__(self, Vec3 p0, Vec3 p1, Vec3 p2, Vec3 p3):
cdef:
double x = p0.x
double y = p0.y
double z = p0.z
self.offset[0] = x
self.offset[1] = y
self.offset[2] = z
# 1st control point (p0) is always (0, 0, 0)
self.p1[0] = p1.x - x
self.p1[1] = p1.y - y
self.p1[2] = p1.z - z
self.p2[0] = p2.x - x
self.p2[1] = p2.y - y
self.p2[2] = p2.z - z
self.p3[0] = p3.x - x
self.p3[1] = p3.y - y
self.p3[2] = p3.z - z
cdef Vec3 point(self, double t):
# 1st control point (p0) is always (0, 0, 0)
# => p0 * a is always (0, 0, 0)
cdef:
Vec3 result = Vec3()
double t2 = t * t
double _1_minus_t = 1.0 - t
# a = (1 - t) ** 3
double b = 3.0 * _1_minus_t * _1_minus_t * t
double c = 3.0 * _1_minus_t * t2
double d = t2 * t
iadd_mul(result, self.p1, b)
iadd_mul(result, self.p2, c)
iadd_mul(result, self.p3, d)
# add offset at last - it is maybe very large
result.x += self.offset[0]
result.y += self.offset[1]
result.z += self.offset[2]
return result
cdef Vec3 tangent(self, double t):
# tangent vector is independent from offset location!
cdef:
Vec3 result = Vec3()
double t2 = t * t
# a = -3 * (1 - t) ** 2
double b = 3.0 * (1.0 - 4.0 * t + 3.0 * t2)
double c = 3.0 * t * (2.0 - 3.0 * t)
double d = 3.0 * t2
iadd_mul(result, self.p1, b)
iadd_mul(result, self.p2, c)
iadd_mul(result, self.p3, d)
return result
cdef void iadd_mul(Vec3 a, double[3] b, double c):
a.x += b[0] * c
a.y += b[1] * c
a.z += b[2] * c