sketch-a-day/2019/sketch_190604a/c_polys.py

202 wiersze
7.2 KiB
Python

# -*- coding: utf-8 -*-
def c_poly_arc_augmented(op_list, or_list):
assert len(op_list) == len(or_list), \
"Number of points and radii not the same"
# remove overlapping adjacent points
p_list, r_list, r2_list = [], [], or_list[:]
for i1, p1 in enumerate(op_list):
i2 = (i1 + 1) % len(op_list)
p2, r2, r1 = op_list[i2], r2_list[i2], r2_list[i1]
if dist(p1[0], p1[1], p2[0], p2[1]) > 1: # or p1 != p2:
p_list.append(p1)
r_list.append(r1)
else:
r2_list[i2] = min(r1, r2)
# reduce radius that won't fit
for i1, p1 in enumerate(p_list):
i2 = (i1 + 1) % len(p_list)
p2, r2, r1 = p_list[i2], r_list[i2], r_list[i1]
r_list[i1], r_list[i2] = reduce_radius(p1, p2, r1, r2)
# calculate the tangents
a_list = []
for i1, p1 in enumerate(p_list):
i2 = (i1 + 1) % len(p_list)
p2, r2, r1 = p_list[i2], r_list[i2], r_list[i1]
a = circ_circ_tangent(p1, p2, r1, r2)
a_list.append(a)
# draw
beginShape()
for i1, _ in enumerate(a_list):
i2 = (i1 + 1) % len(a_list)
p1, p2, r1, r2 = p_list[i1], p_list[i2], r_list[i1], r_list[i2]
a1, p11, p12 = a_list[i1]
a2, p21, p22 = a_list[i2]
if a1 and a2:
start = a1 if a1 < a2 else a1 - TWO_PI
c_arc(p2[0], p2[1], r2 * 2, r2 * 2, start, a2, arc_type=2)
else:
# when the the segment is smaller than the diference between
# radius, circ_circ_tangent won't renturn the angle
# ellipse(p2[0], p2[1], r2 * 2, r2 * 2) # debug
if a1:
vertex(p12[0], p12[1])
if a2:
vertex(p21[0], p21[1])
endShape(CLOSE)
def reduce_radius(p1, p2, r1, r2):
d = dist(p1[0], p1[1], p2[0], p2[1])
ri = abs(r1 - r2)
if d - ri < 0:
if r1 > r2:
r1 = map(d, ri + 1, 0, r1, r2)
else:
r2 = map(d, ri + 1, 0, r2, r1)
return(r1, r2)
def circ_circ_tangent(p1, p2, r1, r2):
d = dist(p1[0], p1[1], p2[0], p2[1])
ri = r1 - r2
line_angle = atan2(p1[0] - p2[0], p2[1] - p1[1])
if d - abs(ri) > 0:
theta = asin(ri / float(d))
x1 = -cos(line_angle + theta) * r1
y1 = -sin(line_angle + theta) * r1
x2 = -cos(line_angle + theta) * r2
y2 = -sin(line_angle + theta) * r2
return (line_angle + theta,
(p1[0] - x1, p1[1] - y1),
(p2[0] - x2, p2[1] - y2))
else:
return (None,
(p1[0], p1[1]),
(p2[0], p2[1]))
def c_poly_filleted(p_list, r_list=None, open_poly=False):
"""
draws a 'filleted' polygon with variable radius
dependent on roundedCorner()
"""
if not r_list:
r_list = [0] * len(p_list)
assert len(p_list) == len(r_list), \
"Number of points and radii not the same"
strokeJoin(ROUND)
beginShape()
for p0, p1, p2, r in zip(p_list,
[p_list[-1]] + p_list[:-1],
[p_list[-2]] + [p_list[-1]] + p_list[:-2],
[r_list[-1]] + r_list[:-1]
):
m1 = (p0[0] + p1[0]) / 2, (p0[1] + p1[1]) / 2
m2 = (p2[0] + p1[0]) / 2, (p2[1] + p1[1]) / 2
b_roundedCorner(p1, m1, m2, r)
endShape(CLOSE)
def b_roundedCorner(pc, p2, p1, r):
"""
Based on Stackoverflow C# rounded corner post
https://stackoverflow.com/questions/24771828/algorithm-for-creating-rounded-corners-in-a-polygon
"""
def GetProportionPoint(pt, segment, L, dx, dy):
factor = float(segment) / L if L != 0 else segment
return PVector((pt[0] - dx * factor), (pt[1] - dy * factor))
# Vector 1
dx1 = pc[0] - p1[0]
dy1 = pc[1] - p1[1]
# Vector 2
dx2 = pc[0] - p2[0]
dy2 = pc[1] - p2[1]
# Angle between vector 1 and vector 2 divided by 2
angle = (atan2(dy1, dx1) - atan2(dy2, dx2)) / 2
# The length of segment between angular point and the
# points of intersection with the circle of a given radius
tng = abs(tan(angle))
segment = r / tng if tng != 0 else r
# Check the segment
length1 = sqrt(dx1 * dx1 + dy1 * dy1)
length2 = sqrt(dx2 * dx2 + dy2 * dy2)
min_len = min(length1, length2)
if segment > min_len:
segment = min_len
max_r = min_len * abs(tan(angle))
else:
max_r = r
# Points of intersection are calculated by the proportion between
# length of vector and the length of the segment.
p1Cross = GetProportionPoint(pc, segment, length1, dx1, dy1)
p2Cross = GetProportionPoint(pc, segment, length2, dx2, dy2)
# Calculation of the coordinates of the circle
# center by the addition of angular vectors.
dx = pc[0] * 2 - p1Cross[0] - p2Cross[0]
dy = pc[1] * 2 - p1Cross[1] - p2Cross[1]
L = sqrt(dx * dx + dy * dy)
d = sqrt(segment * segment + max_r * max_r)
circlePoint = GetProportionPoint(pc, d, L, dx, dy)
# StartAngle and EndAngle of arc
startAngle = atan2(p1Cross[1] - circlePoint[1],
p1Cross[0] - circlePoint[0])
endAngle = atan2(p2Cross[1] - circlePoint[1],
p2Cross[0] - circlePoint[0])
# Sweep angle
sweepAngle = endAngle - startAngle
# Some additional checks
A, B = False, False
if sweepAngle < 0:
A = True
startAngle, endAngle = endAngle, startAngle
sweepAngle = -sweepAngle
# ellipse(pc[0], pc[1], 15, 15) # debug
if sweepAngle > PI:
B = True
startAngle, endAngle = endAngle, startAngle
sweepAngle = TWO_PI - sweepAngle
# ellipse(pc[0], pc[1], 25, 25) # debug
if (A and not B) or (B and not A):
startAngle, endAngle = endAngle, startAngle
sweepAngle = -sweepAngle
# ellipse(pc[0], pc[1], 5, 5) # debug
c_arc(circlePoint[0], circlePoint[1], 2 * max_r, 2 * max_r,
startAngle, startAngle + sweepAngle, arc_type=2)
def c_arc(cx, cy, w, h, startAngle, endAngle, arc_type=0, num_points=None):
"""
A poly approximation of an arc
using the same signature as the original Processing arc()
arc_type: 0 "normal" arc, using beginShape() and endShape()
2 "naked" like normal, but without beginShape() and endShape()
for use inside a larger PShape
"""
if not num_points:
num_points = 12
sweepAngle = endAngle - startAngle
if arc_type == 0:
beginShape()
if sweepAngle < 0:
startAngle, endAngle = endAngle, startAngle
sweepAngle = -sweepAngle
angle = sweepAngle / int(num_points)
a = endAngle
while a >= startAngle:
sx = cx + cos(a) * w / 2.
sy = cy + sin(a) * h / 2.
vertex(sx, sy)
a -= angle
elif sweepAngle > 0:
angle = sweepAngle / int(num_points)
a = startAngle
while a <= endAngle:
sx = cx + cos(a) * w / 2.
sy = cy + sin(a) * h / 2.
vertex(sx, sy)
a += angle
else:
sx = cx + cos(startAngle) * w / 2.
sy = cy + sin(startAngle) * h / 2.
vertex(sx, sy)
if arc_type == 0:
endShape()