def _process_joint(ln, pln, miter_limit, rounded=False):
up_intersection, ln.upper_join = ln_intersection(pln.upper_edge, ln.upper_edge)
lo_intersection, ln.lower_join = ln_intersection(pln.lower_edge, ln.lower_edge)
if up_intersection and lo_intersection:
pln.upper_v.append(pln.upper_join)
pln.lower_v.append(pln.lower_join)
return
if ln.upper_join == None:
ln.upper_join = ln.upper_edge.start
if ln.lower_join == None:
ln.lower_join = ln.lower_edge.start
ml1 = line_length(ln.lower_edge.start, ln.upper_join)
if rounded:
pass
if rounded and not up_intersection:
ln.upper_join = ln.upper_edge.start
pln.upper_v.append(pln.upper_join)
pln.upper_v.append(pln.upper_edge.end)
#arc to next lines upper-join
base = pln.end
start = pln.upper_edge.end
target = ln.upper_join
dist = (start-base).length()
av = (start - base).normalized()
bv = (target - base).normalized()
start_angle = av.angle()
target_angle = bv.angle()
if start_angle > target_angle:
start_angle -= 2.0 * math.pi
theta = start_angle
pln.lower_v.append(pln.lower_join)
while theta < target_angle:
v = base + (vec2(math.cos(theta), math.sin(theta)) * dist)
pln.upper_v.append(v)
pln.lower_v.append(ln.lower_join)
theta += 0.2
pln.upper_v.append(ln.upper_join)
return
elif ml1 > miter_limit and not up_intersection:
#bevel
ln.upper_join = ln.upper_edge.start
pln.upper_v.append(pln.upper_join)
pln.upper_v.append(pln.upper_edge.end)
pln.upper_v.append(ln.upper_join)
elif not rounded:
pln.upper_v.append(pln.upper_join)
pln.upper_v.append(ln.upper_join)
ml2 = line_length(ln.upper_edge.start, ln.lower_join)
if rounded and not lo_intersection:
ln.lower_join = ln.lower_edge.start
pln.upper_v.append(pln.upper_join)
pln.lower_v.append(pln.lower_join)
#arc to next lines upper-join
base = pln.end
start = pln.lower_edge.end
target = ln.lower_join
dist = (start-base).length()
av = (start - base).normalized()
bv = (target - base).normalized()
start_angle = av.angle()
target_angle = bv.angle()
if start_angle < target_angle:
start_angle += 2.0 * math.pi
theta = start_angle
pln.upper_v.append(ln.upper_join)
while theta > target_angle:
v = base + (vec2(math.cos(theta), math.sin(theta)) * dist)
pln.lower_v.append(v)
pln.upper_v.append(ln.upper_join)
theta -= 0.2
pln.lower_v.append(ln.lower_join)
elif ml2 > miter_limit and not lo_intersection:
#bevel
ln.lower_join = ln.lower_edge.start
pln.lower_v.append(pln.lower_join)
pln.lower_v.append(pln.lower_edge.end)
pln.lower_v.append(ln.lower_join)
else:
pln.lower_v.append(pln.lower_join)
pln.lower_v.append(ln.lower_join)
def calc_polyline(points, w, line_cap='butt', join_type='miter', miter_limit=4, closed=False):
miter_length = w * miter_limit
points = [vec2(p) for p in points]
if closed and points[0] != points[-1]:
points.append(vec2(points[0]))
lines = []
for i in range(len(points) - 1):
lines.append(
LineSegment(points[i], points[i+1], w))
lines[0].upper_join = lines[0].upper_edge.start
lines[0].lower_join = lines[0].lower_edge.start
if line_cap == 'square' and not closed:
ext = lines[0].direction * w * -0.5
lines[0].upper_join = lines[0].upper_join + ext
lines[0].lower_join = lines[0].lower_join + ext
for i in range(1, len(lines)):
ln, pln = lines[i], lines[i-1]
_process_joint(ln, pln, miter_length, join_type=='round')
ll = lines[-1]
lf = lines[0]
if closed:
b_up_int, upper_join = ln_intersection(ll.upper_edge, lf.upper_edge)
b_lo_int, lower_join = ln_intersection(ll.lower_edge, lf.lower_edge)
if upper_join == None: upper_join = ll.upper_edge.end
if lower_join == None: lower_join = ll.lower_edge.end
if line_length(ll.lower_edge.end, upper_join) > miter_length and b_up_int:
#bevel
ll.upper_v.append(ll.upper_join)
ll.upper_v.append(ll.upper_edge.end)
ll.upper_v.append(lf.upper_edge.start)
else:
lf.upper_v[0] = upper_join
ll.upper_v.append(ll.upper_join)
ll.upper_v.append(upper_join)
if line_length(ll.upper_edge.end, lower_join) > miter_length and b_lo_int:
#bevel
ll.lower_v.append(ll.lower_join)
ll.lower_v.append(ll.lower_edge.end)
ll.lower_v.append(lf.lower_edge.start)
else:
lf.lower_v[0] = lower_join
ll.lower_v.append(ll.lower_join)
ll.lower_v.append(lower_join)
else:
if line_cap == 'butt' or line_cap == 'round':
ll.upper_v.append(ll.upper_join)
ll.upper_v.append(ll.upper_edge.end)
ll.lower_v.append(ll.lower_join)
ll.lower_v.append(ll.lower_edge.end)
elif line_cap == 'square':
ext = ll.direction * w*0.5
ll.upper_v.append(ll.upper_join)
ll.upper_v.append(ll.upper_edge.end + ext)
ll.lower_v.append(ll.lower_join)
ll.lower_v.append(ll.lower_edge.end + ext)
return lines
