def findpath(self, points, curvature=1.0):
"""Constructs a path between the given list of points.
Interpolates the list of points and determines
a smooth bezier path betweem them.
The curvature parameter offers some control on
how separate segments are stitched together:
from straight angles to smooth curves.
Curvature is only useful if the path has more than three points.
"""
# The list of points consists of Point objects,
# but it shouldn't crash on something straightforward
# as someone supplying a list of (x,y)-tuples.
for i, pt in enumerate(points):
if type(pt) == TupleType:
points[i] = Point(pt[0], pt[1])
if len(points) == 0:
return None
if len(points) == 1:
path = self.BezierPath(None)
path.moveto(points[0].x, points[0].y)
return path
if len(points) == 2:
path = self.BezierPath(None)
path.moveto(points[0].x, points[0].y)
path.lineto(points[1].x, points[1].y)
return path
# Zero curvature means straight lines.
curvature = max(0, min(1, curvature))
if curvature == 0:
path = self.BezierPath(None)
path.moveto(points[0].x, points[0].y)
for i in range(len(points)):
path.lineto(points[i].x, points[i].y)
return path
curvature = 4 + (1.0 - curvature) * 40
dx = {0: 0, len(points) - 1: 0}
dy = {0: 0, len(points) - 1: 0}
bi = {1: -0.25}
ax = {1: (points[2].x - points[0].x - dx[0]) / 4}
ay = {1: (points[2].y - points[0].y - dy[0]) / 4}
for i in range(2, len(points) - 1):
bi[i] = -1 / (curvature + bi[i - 1])
ax[i] = -(points[i + 1].x - points[i - 1].x - ax[i - 1]) * bi[i]
ay[i] = -(points[i + 1].y - points[i - 1].y - ay[i - 1]) * bi[i]
r = range(1, len(points) - 1)
r.reverse()
for i in r:
dx[i] = ax[i] + dx[i + 1] * bi[i]
dy[i] = ay[i] + dy[i + 1] * bi[i]
path = self.BezierPath(None)
path.moveto(points[0].x, points[0].y)
for i in range(len(points) - 1):
path.curveto(points[i].x + dx[i], points[i].y + dy[i],
points[i + 1].x - dx[i + 1],
points[i + 1].y - dy[i + 1], points[i + 1].x,
points[i + 1].y)
return path
def findpath(self, points, curvature=1.0):
"""Constructs a path between the given list of points.
Interpolates the list of points and determines
a smooth bezier path betweem them.
The curvature parameter offers some control on
how separate segments are stitched together:
from straight angles to smooth curves.
Curvature is only useful if the path has more than three points.
"""
# The list of points consists of Point objects,
# but it shouldn't crash on something straightforward
# as someone supplying a list of (x,y)-tuples.
for i, pt in enumerate(points):
if type(pt) == TupleType:
points[i] = Point(pt[0], pt[1])
if len(points) == 0: return None
if len(points) == 1:
path = self.BezierPath(None)
path.moveto(points[0].x, points[0].y)
return path
if len(points) == 2:
path = self.BezierPath(None)
path.moveto(points[0].x, points[0].y)
path.lineto(points[1].x, points[1].y)
return path
# Zero curvature means straight lines.
curvature = max(0, min(1, curvature))
if curvature == 0:
path = self.BezierPath(None)
path.moveto(points[0].x, points[0].y)
for i in range(len(points)):
path.lineto(points[i].x, points[i].y)
return path
curvature = 4 + (1.0-curvature)*40
dx = {0: 0, len(points)-1: 0}
dy = {0: 0, len(points)-1: 0}
bi = {1: -0.25}
ax = {1: (points[2].x-points[0].x-dx[0]) / 4}
ay = {1: (points[2].y-points[0].y-dy[0]) / 4}
for i in range(2, len(points)-1):
bi[i] = -1 / (curvature + bi[i-1])
ax[i] = -(points[i+1].x-points[i-1].x-ax[i-1]) * bi[i]
ay[i] = -(points[i+1].y-points[i-1].y-ay[i-1]) * bi[i]
r = range(1, len(points)-1)
r.reverse()
for i in r:
dx[i] = ax[i] + dx[i+1] * bi[i]
dy[i] = ay[i] + dy[i+1] * bi[i]
path = self.BezierPath(None)
path.moveto(points[0].x, points[0].y)
for i in range(len(points)-1):
path.curveto(points[i].x + dx[i],
points[i].y + dy[i],
points[i+1].x - dx[i+1],
points[i+1].y - dy[i+1],
points[i+1].x,
points[i+1].y)
return path