def divide_rec(p, l, r, compare):
#base
if r - l == 2:
sort_rec(p, l, r, compare)
guiprim.dist2(p[l], p[l + 1])
update_points(p[l], p[l + 1])
return p[l], p[l + 1]
if r - l == 3:
sort_rec(p, l, r, compare)
d1 = guiprim.dist2(p[l], p[l + 1])
d2 = guiprim.dist2(p[l], p[l + 2])
d3 = guiprim.dist2(p[l + 1], p[l + 2])
if (d1 <= d2 and d1 <= d3):
update_points(p[l], p[l + 1])
return p[l], p[l + 1]
if (d2 <= d1 and d2 <= d3):
update_points(p[l], p[l + 2])
return p[l], p[l + 2]
if (d3 <= d1 and d3 <= d2):
update_points(p[l + 1], p[l + 2])
return p[l + 1], p[l + 2]
# 4 points or more
q = (l + r) // 2
pm = p[q] #median point
p1, p2 = divide_rec(p, l, q, compare)
de = prim.dist2(p1, p2)
p3, p4 = divide_rec(p, q, r, compare)
dr = prim.dist2(p3, p4)
p1, p2 = (p1, p2) if (de <= dr) else (p3, p4)
update_points(p1, p2)
merge(p, l, q, r, compare)
return combine(p, l, r, p1, p2, pm)
def update_points(p1, p2):
global a, b, id, hia, hib
if (a != None and b != None):
if (prim.dist2(p1, p2) >= prim.dist2(a, b)): return
control.freeze_update()
if a != None: a.unhilight(hia)
if b != None: b.unhilight(hib)
if id != None: control.plot_delete(id)
a = p1
b = p2
hia = a.hilight()
hib = b.hilight()
id = a.lineto(b)
control.thaw_update()
control.update()
def q_hull(points):
n = len(points)
if n == 1:
return set(points)
f_ind = 0
for i, pt in enumerate(points):
if pt.y < points[f_ind].y or\
(pt.y == points[f_ind].y and pt.x < points[f_ind].x):
f_ind = i
swap(points, 0, f_ind)
s_ind = 1
for i in range(1, len(points)):
if prim.right(points[0], points[s_ind], points[i]) or\
(prim.collinear(points[0], points[s_ind], points[i]) and\
(prim.dist2(points[0], points[s_ind]) <
prim.dist2(points[0], points[i]))):
s_ind = i
swap(points, n - 1, s_ind)
hull = q_hull_rec(points, 0, n - 1)
for pt in hull:
pt.hilight("blue")
return hull
def __merge(self, startIndex, midIndex, endIndex):
leftCopy = self.pointList[startIndex:midIndex + 1]
rightCopy = self.pointList[midIndex + 1:endIndex + 1]
leftIndex = 0
rightIndex = 0
sortIndex = startIndex
while leftIndex < len(leftCopy) and rightIndex < len(rightCopy):
if not left_on(self.pointList[0], rightCopy[rightIndex],
leftCopy[leftIndex]):
self.pointList[sortIndex] = leftCopy[leftIndex]
leftIndex = leftIndex + 1
elif collinear(self.pointList[0], leftCopy[leftIndex],
rightCopy[rightIndex]):
if dist2(self.pointList[0], leftCopy[leftIndex]) < dist2(
self.pointList[0], rightCopy[rightIndex]):
self.pointList[sortIndex] = leftCopy[leftIndex]
leftIndex = leftIndex + 1
else:
self.pointList[sortIndex] = rightCopy[rightIndex]
rightIndex = rightIndex + 1
else:
self.pointList[sortIndex] = rightCopy[rightIndex]
rightIndex = rightIndex + 1
sortIndex = sortIndex + 1
while leftIndex < len(leftCopy):
self.pointList[sortIndex] = leftCopy[leftIndex]
leftIndex = leftIndex + 1
sortIndex = sortIndex + 1
while rightIndex < len(rightCopy):
self.pointList[sortIndex] = rightCopy[rightIndex]
rightIndex = rightIndex + 1
sortIndex = sortIndex + 1
def Quickhull(P):
'''Recebe uma coleção de pontos P e devolve seu fecho convexo'''
n = len(P)
if n == 1:
return [P[0]]
# encontra primeiro ponto extremo
k = 0
for i in range(n):
# desempata por x
if P[i].y < P[k].y or (P[i].y == P[k].y and P[i].x < P[k].x):
k = i
P[0], P[k] = P[k], P[0]
# encontra extremo consecutivo ao primeiro
i = 1
dist = 0
for j in range(2, n):
if right(P[0], P[i], P[j]):
i = j
# desempata pelo mais distante
elif collinear(P[0], P[i],
P[j]) and dist2(P[0], P[i]) < dist2(P[0], P[j]):
i = j
P[n - 1], P[i] = P[i], P[n - 1]
P[0].lineto(P[n - 1], 'cyan')
control.thaw_update()
control.update()
control.freeze_update()
control.sleep()
quick = quickhull_rec(P, 0, n - 1, Point(P[0].x, P[0].y),
Point(P[n - 1].x, P[n - 1].y))
for p in quick:
p.hilight('yellow')
return quick
def dist2 (a, b): "retorna o quadrado da distancia entre a e b" return prim.dist2(a, b)
def dist2(a, b):
"retorna o quadrado da distancia entre a e b"
return prim.dist2(a, b)
def __distanceWrap(self, i, j):
return dist2(self.pointList[i], self.pointList[j])
def distance_to_origin(origin_point: Point, test_point: Point) -> float:
''' returns the distance of a point to the origin point. '''
return dist2(origin_point, test_point)**0.5
def above(self, l):
"Verifica se o ponto está acima da reta"
prim.dist2(self, self)
return self.y > l.m * self.x + l.b - epsilon
