def getSector(p, dot):
start = 0
end = len(p) - 1
while end - start > 1:
sep = (start + end) // 2
if point_relative(p[0], p[sep], dot) == -1:
start = sep
else:
end = sep
return start, end
def recursion_for_qh_algorithm1(ch, SL, sl, sr):
if len(SL) == 0:
return ch
square = 0
SRnew = []
SLnew = []
max = SL[0]
for i in range(len(SL)):
if square < triangle_area(sl, sr, SL[i]):
square = triangle_area(sl, sr, SL[i])
max = SL[i]
# ch.append(max)
SL.remove(max)
for i in range(len(SL)):
if point_relative(sl, max, SL[i]) != -1:
SLnew.append(SL[i])
if point_relative(max, sr, SL[i]) != -1:
SRnew.append(SL[i])
recursion_for_qh_algorithm1(ch, SLnew, sl, max)
ch.append(max)
recursion_for_qh_algorithm1(ch, SRnew, max, sr)
def is_convex(p):
s = 0
g = 0
n = len(p)
for i in range(n):
k = i + 2
if (i == n - 2):
k = 0
if (i == n - 1):
k = 1
if point_relative(p[i], p[0], p[k]) < 0:
s += 1
if point_relative(p[i], p[0], p[k]) > 0:
g += 1
if i != n - 1:
if point_relative(p[i], p[i + 1], p[k]) < 0:
s += 1
if point_relative(p[i], p[i + 1], p[k]) > 0:
g += 1
if g != 0 and s != 0:
return False
return True
def main_lab1_1():
p1 = Point(random.randint(100, 700), random.randint(100, 700))
p2 = Point(random.randint(100, 700), random.randint(100, 700))
p = Point(random.randint(100, 700), random.randint(100, 700))
point_relative_result = point_relative(p1, p2, p)
if point_relative_result == 0:
print("on line")
else:
if point_relative_result < 0:
print("right")
else:
print("left")
draw_lab1_1(p1, p2, p)
def QH_algorithm(points):
points = points.copy()
sl = min_of_points_of_x(points)
sr = max_of_points_of_x(points)
SL = []
SR = []
square = 0
max = 0
min = 0
SRnew = []
SLnew = []
ch = []
ch.append(sl)
# ch.append(sr)
points.remove(sl)
points.remove(sr)
for i in range(len(points)):
if point_relative(sl, sr, points[i]) != 1:
SR.append(points[i])
else:
SL.append(points[i])
# for i in range(len(SL)):
# if square < triangle_area(sl, sr, SL[i]):
# square = triangle_area(sl, sr, SL[i])
# max = SL[i]
# ch.append(max)
# SL.remove(max)
# for i in range(len(SL)):
# if point_relative(sl, max, SL[i]) != -1:
# SLnew.append(SL[i])
# if point_relative(max, sr, SL[i]) != -1:
# SRnew.append(SL[i])
recursion_for_qh_algorithm1(ch, SL, sl, sr)
ch.append(sr)
recursion_for_qh_algorithm2(ch, SR, sl, sr)
# square = 0
# sl = min_of_points_of_x(points)
# sr = max_of_points_of_x(points)
# for i in range(len(SR)):
# if square < triangle_area(sl, sr, SR[i]):
# square = triangle_area(sl, sr, SR[i])
# min = SR[i]
# ch.append(min)
# SR.remove(min)
# recursion_for_qh_algorithm(ch, SRnew, SLnew, sr, min)
return ch
def is_in_convex(p, dot):
start = 0
end = len(p) - 1
if point_relative(p[0], p[1], dot) != point_relative(p[0], p[1], p[2]) or point_relative(
p[len(p) - 1], p[0], dot) != point_relative(p[len(p) - 1], p[0], p[len(p) - 2]):
return False
while end - start > 1:
sep = (start + end) // 2
if point_relative(p[0], p[sep], dot) == point_relative(p[0], p[sep], p[1]):
end = sep
else:
start = sep
if is_intersection(p[start], p[end], p[0], dot):
return False
else:
return True
def ray_test(p, dot):
S = 0
# plt.scatter(q.x, q.y, marker='.', color='red')
# plt.text(q.x + 0.05, q.y + 0.05, 'q', fontsize="15")
# ray = Line(q, dot)
# ray.drow_line()
i = 0
n = len(p)
if dimensionalTest(p, dot):
q = Point(dimensionalTest(p, dot) - 1, dot.y)
while i < n:
h = i
if i == n - 1:
h = 1
p_tmp = p.copy()
p_tmp.append(p[0])
if is_intersection(q, dot, p_tmp[i], p_tmp[i + 1]):
if point_relative(q, dot, p_tmp[i]) == 0:
if point_relative(q, dot, p_tmp[i + 1]) == 0:
if point_relative(q, dot,
p_tmp[i - 1]) == point_relative(
q, dot, p_tmp[h + 2]):
S += 1
# i = i + 1
else:
if point_relative(q, dot,
p_tmp[i - 1]) == point_relative(
q, dot, p_tmp[i + 1]):
S += 1
else:
S += 1
# i = i + 1
i += 1
if S % 2 == 0:
return False
else:
return True
else:
return False
def dynamic_convex_hull_algorithm(points):
points = points.copy()
ch = []
result = []
for i in range(len(points)):
if i == 0:
ch.append(points[i])
ch_copy = ch.copy()
result.append(ch_copy)
continue
if i == 1:
if points[0] != points[1]:
ch.append(points[1])
ch_copy = ch.copy()
result.append(ch_copy)
continue
if i == 2:
if points[2] == points[0] or points[2] == points[1]:
continue
if points[0] == points[1] and points[0] != points[2]:
ch.append(points[i])
ch_copy = ch.copy()
result.append(ch_copy)
continue
if point_relative(points[0], points[1], points[2]) == 0:
if (points[1].x -
points[0].x) * (points[2].x - points[0].x) + (
points[1].y - points[0].y) * (points[2].y -
points[0].y) < 0:
ch.clear()
ch.append(points[1])
ch.append(points[2])
ch_copy = ch.copy()
result.append(ch_copy)
continue
elif (points[0].x -
points[1].x) * (points[2].x - points[1].x) + (
points[0].y - points[1].y) * (points[2].y -
points[1].y) < 0:
ch.clear()
ch.append(points[0])
ch.append(points[2])
ch_copy = ch.copy()
result.append(ch_copy)
continue
else:
ch.clear()
ch.append(points[0])
ch.append(points[1])
ch_copy = ch.copy()
result.append(ch_copy)
continue
if point_relative(points[0], points[1], points[2]) == 1:
ch.append(points[2])
ch_copy = ch.copy()
result.append(ch_copy)
continue
else:
ch.pop()
ch.append(points[2])
ch.append(points[1])
ch_copy = ch.copy()
result.append(ch_copy)
continue
visible = []
for j in range(len(ch)):
tmp = ch.copy()
tmp.append(tmp[0])
if point_relative(tmp[j], tmp[j + 1], points[i]) == -1:
# if tmp[j] not in visible:
visible.append(tmp[j])
# if tmp[j+1] not in visible:
visible.append(tmp[j + 1])
index = j + 1
if len(visible) == 0:
ch_copy = ch.copy()
result.append(ch_copy)
else:
k = 0
ch.insert(index, points[i])
while k < len(visible) - 1:
if visible.count(visible[k]) == 2:
ch.remove(visible[k])
visible.remove(visible[k])
visible.remove(visible[k])
k += 1
ch_copy = ch.copy()
result.append(ch_copy)
return result