kopia lustrzana https://github.com/villares/sketch-a-day
200 wiersze
6.3 KiB
Python
200 wiersze
6.3 KiB
Python
# Alexandre B A Villares - https://abav.lugaralgum.com/sketch-a-day
|
|
# Circ-circ tangents on a poly using Bezier approximation of arcs
|
|
|
|
pts = []
|
|
rds = [30, 70, 50]
|
|
dragged_pt = -1
|
|
|
|
def setup():
|
|
size(500, 500)
|
|
pts.append((250, 150))
|
|
|
|
pts.append((250 + 100 * cos(PI / 6.0),
|
|
250 + 100 * sin(PI / 6.0)))
|
|
pts.append((250 - 100 * cos(PI / 6.0),
|
|
250 + 100 * sin(PI / 6.0)))
|
|
|
|
def draw():
|
|
background(200)
|
|
fill(255, 100)
|
|
b_poly_arc_augmented(pts, rds)
|
|
fill(0, 0, 100)
|
|
for pt in pts:
|
|
ellipse(pt[0], pt[1], 10, 10)
|
|
|
|
|
|
def mouseWheel(E):
|
|
global r, d
|
|
for i, pt in enumerate(pts):
|
|
if dist(mouseX, mouseY, pt[0], pt[1]) < 10:
|
|
rds[i] += 5 * E.getAmount()
|
|
|
|
def mousePressed():
|
|
global dragged_pt
|
|
for i, pt in enumerate(pts):
|
|
if dist(mouseX, mouseY, pt[0], pt[1]) < 10:
|
|
dragged_pt = i
|
|
break
|
|
|
|
def mouseDragged():
|
|
if dragged_pt >= 0:
|
|
pts[dragged_pt] = mouseX, mouseY
|
|
|
|
def mouseReleased():
|
|
global dragged_pt
|
|
dragged_pt = -1
|
|
|
|
def b_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
|
|
if r2 < 0:
|
|
a2 = a2 - TWO_PI
|
|
b_arc(p2[0], p2[1], r2 * 2, r2 * 2, start, a2, mode=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 b_arc(cx, cy, w, h, start_angle, end_angle, mode=0):
|
|
"""
|
|
A bezier approximation of an arc
|
|
using the same signature as the original Processing arc()
|
|
mode: 0 "normal" arc, using beginShape() and endShape()
|
|
1 "middle" used in recursive call of smaller arcs
|
|
2 "naked" like normal, but without beginShape() and endShape()
|
|
for use inside a larger PShape
|
|
"""
|
|
theta = end_angle - start_angle
|
|
# Compute raw Bezier coordinates.
|
|
if mode != 1 or abs(theta) < HALF_PI:
|
|
x0 = cos(theta / 2.0)
|
|
y0 = sin(theta / 2.0)
|
|
x3 = x0
|
|
y3 = 0 - y0
|
|
x1 = (4.0 - x0) / 3.0
|
|
if y0 != 0:
|
|
y1 = ((1.0 - x0) * (3.0 - x0)) / (3.0 * y0) # y0 != 0...
|
|
else:
|
|
y1 = 0
|
|
x2 = x1
|
|
y2 = 0 - y1
|
|
# Compute rotationally-offset Bezier coordinates, using:
|
|
# x' = cos(angle) * x - sin(angle) * y
|
|
# y' = sin(angle) * x + cos(angle) * y
|
|
bezAng = start_angle + theta / 2.0
|
|
cBezAng = cos(bezAng)
|
|
sBezAng = sin(bezAng)
|
|
rx0 = cBezAng * x0 - sBezAng * y0
|
|
ry0 = sBezAng * x0 + cBezAng * y0
|
|
rx1 = cBezAng * x1 - sBezAng * y1
|
|
ry1 = sBezAng * x1 + cBezAng * y1
|
|
rx2 = cBezAng * x2 - sBezAng * y2
|
|
ry2 = sBezAng * x2 + cBezAng * y2
|
|
rx3 = cBezAng * x3 - sBezAng * y3
|
|
ry3 = sBezAng * x3 + cBezAng * y3
|
|
# Compute scaled and translated Bezier coordinates.
|
|
rx, ry = w / 2.0, h / 2.0
|
|
px0 = cx + rx * rx0
|
|
py0 = cy + ry * ry0
|
|
px1 = cx + rx * rx1
|
|
py1 = cy + ry * ry1
|
|
px2 = cx + rx * rx2
|
|
py2 = cy + ry * ry2
|
|
px3 = cx + rx * rx3
|
|
py3 = cy + ry * ry3
|
|
# Debug points... comment this out!
|
|
# stroke(0)
|
|
# ellipse(px3, py3, 15, 15)
|
|
# ellipse(px0, py0, 5, 5)
|
|
# Drawing
|
|
if mode == 0: # 'normal' arc (not 'middle' nor 'naked')
|
|
beginShape()
|
|
if mode != 1: # if not 'middle'
|
|
vertex(px3, py3)
|
|
if abs(theta) < HALF_PI:
|
|
bezierVertex(px2, py2, px1, py1, px0, py0)
|
|
else:
|
|
# to avoid distortion, break into 2 smaller arcs
|
|
b_arc(cx, cy, w, h, start_angle, end_angle - theta / 2.0, mode=1)
|
|
b_arc(cx, cy, w, h, start_angle + theta / 2.0, end_angle, mode=1)
|
|
if mode == 0: # end of a 'normal' arc
|
|
endShape()
|
|
|
|
|
|
def settings():
|
|
from os import path
|
|
global SKETCH_NAME
|
|
SKETCH_NAME = path.basename(sketchPath())
|
|
OUTPUT = ".png"
|
|
println(
|
|
"""
|
|
|
|
|
|
[{0}](https://github.com/villares/sketch-a-day/tree/master/{2}/{0}) [[Py.Processing](https://villares.github.io/como-instalar-o-processing-modo-python/index-EN)]
|
|
""".format(SKETCH_NAME, OUTPUT, year())
|
|
)
|