/
forms.py
163 lines (159 loc) · 5.54 KB
/
forms.py
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def b_poly_arc_augmented(op_list, or_list=None):
if or_list == None:
r2_list = [0] * len(op_list)
else:
r2_list = or_list[:]
assert len(op_list) == len(r2_list), \
"Number of points and radii not the same"
# remove overlapping adjacent points
p_list, r_list = [], []
for i1, p1 in enumerate(op_list):
i2 = (i1 - 1)
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)
# invert radius
for i1, p1 in enumerate(p_list):
i0 = (i1 - 1)
p0 = p_list[i0]
i2 = (i1 + 1) % len(p_list)
p2 = p_list[i2]
a = area(p0, p1, p2) / 1000.
if or_list == None:
r_list[i1] = a
else:
if abs(a) < 1:
r_list[i1] = r_list[i1] * abs(a)
if a < 0:
r_list[i1] = -r_list[i1]
# 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, ia 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 = ia
a2, p21, p22 = a_list[i2]
if a1 != None and a2 != None:
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 abs(r1) > abs(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 area(p0, p1, p2):
a = (p1[0] * (p2[1] - p0[1]) +
p2[0] * (p0[1] - p1[1]) +
p0[0] * (p1[1] - p2[1]))
return a