sketch-a-day/2019/sketch_190402a/arcs.py

235 wiersze
7.3 KiB
Python

# -*- coding: utf-8 -*-
ROTATION = {0: 0,
BOTTOM: 0,
DOWN: 0,
1: HALF_PI,
LEFT: HALF_PI,
2: PI,
TOP: PI,
UP: PI,
3: PI + HALF_PI,
RIGHT: PI + HALF_PI,
BOTTOM + RIGHT: 0,
DOWN + RIGHT: 0,
DOWN + LEFT: HALF_PI,
BOTTOM + LEFT: HALF_PI,
TOP + LEFT: PI,
UP + LEFT: PI,
TOP + RIGHT: PI + HALF_PI,
UP + RIGHT: PI + HALF_PI,
}
def quarter_circle(x, y, radius, quadrant):
circle_arc(x, y, radius, ROTATION[quadrant], HALF_PI)
def half_circle(x, y, radius, quadrant):
circle_arc(x, y, radius, ROTATION[quadrant], PI)
def circle_arc(x, y, radius, start_ang, sweep_ang):
arc(x, y, radius * 2, radius * 2, start_ang, start_ang + sweep_ang)
def poly_arc(x, y, radius, start_ang, sweep_ang, num_points=2):
angle = sweep_ang / int(num_points)
a = start_ang
with beginShape():
while a <= start_ang + sweep_ang:
sx = x + cos(a) * radius
sy = y + sin(a) * radius
vertex(sx, sy)
a += angle
def arc_poly(x, y, d, _, start_ang, end_ang, num_points=5):
sweep_ang = end_ang - start_ang
angle = sweep_ang / int(num_points)
a = start_ang
with beginShape():
while a <= end_ang:
sx = x + cos(a) * d / 2
sy = y + sin(a) * d / 2
vertex(sx, sy)
a += angle
def bar(x1, y1, x2, y2, thickness=None, shorter=0, ends=(1, 1)):
"""
O código para fazer as barras, dois pares (x, y),
um parâmetro de encurtamento: shorter
"""
L = dist(x1, y1, x2, y2)
if not thickness:
thickness = 10
with pushMatrix():
translate(x1, y1)
angle = atan2(x1 - x2, y2 - y1)
rotate(angle)
offset = shorter / 2
line(thickness / 2, offset, thickness / 2, L - offset)
line(-thickness / 2, offset, -thickness / 2, L - offset)
if ends[0]:
half_circle(0, offset, thickness / 2, UP)
if ends[1]:
half_circle(0, L - offset, thickness / 2, DOWN)
def var_bar(p1x, p1y, p2x, p2y, r1, r2=None):
if r2 is None:
r2 = r1
#line(p1x, p1y, p2x, p2y)
d = dist(p1x, p1y, p2x, p2y)
ri = r1 - r2
if d > abs(ri):
rid = (r1 - r2) / d
if rid > 1:
rid = 1
if rid < -1:
rid = -1
beta = asin(rid) + HALF_PI
with pushMatrix():
translate(p1x, p1y)
angle = atan2(p1x - p2x, p2y - p1y)
rotate(angle + HALF_PI)
x1 = cos(beta) * r1
y1 = sin(beta) * r1
x2 = cos(beta) * r2
y2 = sin(beta) * r2
#print((d, beta, ri, x1, y1, x2, y2))
with pushStyle():
noStroke()
beginShape()
vertex(-x1, -y1)
vertex(d - x2, -y2)
vertex(d, 0)
vertex(d - x2, +y2)
vertex(-x1, +y1)
vertex(0, 0)
endShape(CLOSE)
line(-x1, -y1, d - x2, -y2)
line(-x1, +y1, d - x2, +y2)
arc(0, 0, r1 * 2, r1 * 2,
-beta - PI, beta - PI)
arc(d, 0, r2 * 2, r2 * 2,
beta - PI, PI - beta)
else:
ellipse(p1x, p1y, r1 * 2, r1 * 2)
ellipse(p2x, p2y, r2 * 2, r2 * 2)
def 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)
if not open_poly:
with pushStyle():
noStroke()
beginShape()
for p0, p1 in zip(p_list, [p_list[-1]] + p_list[:-1]):
m = (PVector(p0.x, p0.y) + PVector(p1.x, p1.y)) / 2
vertex(m.x, m.y)
endShape(CLOSE)
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 = (PVector(p0.x, p0.y) + PVector(p1.x, p1.y)) / 2
m2 = (PVector(p2.x, p2.y) + PVector(p1.x, p1.y)) / 2
roundedCorner(p1, m1, m2, r)
else:
for p0, p1, p2, r in zip(p_list[:-1],
[p_list[-1]] + p_list[:-2],
[p_list[-2]] + [p_list[-1]] + p_list[:-3],
[r_list[-1]] + r_list[:-2]
):
m1 = (PVector(p0.x, p0.y) + PVector(p1.x, p1.y)) / 2
m2 = (PVector(p2.x, p2.y) + PVector(p1.x, p1.y)) / 2
roundedCorner(p1, m1, m2, r)
def roundedCorner(pc, p1, p2, 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.x - dx * factor), (pt.y - dy * factor))
# Vector 1
dx1 = pc.x - p1.x
dy1 = pc.y - p1.y
# Vector 2
dx2 = pc.x - p2.x
dy2 = pc.y - p2.y
# 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.x * 2 - p1Cross.x - p2Cross.x
dy = pc.y * 2 - p1Cross.y - p2Cross.y
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.y - circlePoint.y, p1Cross.x - circlePoint.x)
endAngle = atan2(p2Cross.y - circlePoint.y, p2Cross.x - circlePoint.x)
# Sweep angle
sweepAngle = endAngle - startAngle
# Some additional checks
if sweepAngle < 0:
startAngle, endAngle = endAngle, startAngle
sweepAngle = -sweepAngle
if sweepAngle > PI:
startAngle, endAngle = endAngle, startAngle
sweepAngle = TWO_PI - sweepAngle
# Draw result using graphics
# noStroke()
with pushStyle():
noStroke()
beginShape()
vertex(p1.x, p1.y)
vertex(p1Cross.x, p1Cross.y)
vertex(p2Cross.x, p2Cross.y)
vertex(p2.x, p2.y)
endShape(CLOSE)
line(p1.x, p1.y, p1Cross.x, p1Cross.y)
line(p2.x, p2.y, p2Cross.x, p2Cross.y)
arc(circlePoint.x, circlePoint.y, 2 * max_r, 2 * max_r,
startAngle, startAngle + sweepAngle, OPEN)