def nearestOn2(self, points, closed=False, radius=R_M, height=None):
'''Locate the point on a polygon (with great circle arcs
joining consecutive points) closest to this point.
If this point is within the extent of any great circle
arc, the closest point is on that arc. Otherwise,
the closest is the nearest of the arc's end points.
@param points: The polygon points (L{LatLon}[]).
@keyword closed: Optionally, close the polygon (C{bool}).
@keyword radius: Optional, mean earth radius (C{meter}).
@keyword height: Optional height, overriding the mean height
for a point within the arc (C{meter}).
@return: 2-Tuple (closest, distance) of the closest point
(L{LatLon}) on the polygon and the distance to
that point from the given point in C{meter}, same
units of B{C{radius}}.
@raise TypeError: Some B{C{points}} are not C{LatLon}.
@raise ValueError: No B{C{points}}.
'''
n, points = self.points2(points, closed=closed)
i, m = _imdex2(closed, n)
c = p2 = points[i]
d = self.distanceTo(c, radius=radius)
for i in range(m, n):
p1, p2 = p2, points[i]
p = self.nearestOn(p1, p2, height=height)
t = self.distanceTo(p, radius=radius)
if t < d:
c, d = p, t
return c, d
def _rads(n, points, closed): # angular edge lengths in radians
i, m = _imdex2(closed, n)
v1 = points[i].toNvector()
for i in range(m, n):
v2 = points[i].toNvector()
yield v1.angleTo(v2)
v1 = v2
def _rads(n, points, closed): # angular edge lengths in radians
i, m = _imdex2(closed, n)
a1, b1 = points[i].to2ab()
for i in range(m, n):
a2, b2 = points[i].to2ab()
db, b2 = unrollPI(b1, b2, wrap=wrap)
yield haversine_(a2, a1, db)
a1, b1 = a2, b2
def clipCS3(points,
lowerleft,
upperright,
closed=False,
inull=False): # MCCABE 25
'''Clip a path against a rectangular clip box using the
U{Cohen-Sutherland
<http://WikiPedia.org/wiki/Cohen-Sutherland_algorithm>} algorithm.
@param points: The points (C{LatLon}[]).
@param lowerleft: Bottom-left corner of the clip box (C{LatLon}).
@param upperright: Top-right corner of the clip box (C{LatLon}).
@keyword closed: Optionally, close the path (C{bool}).
@keyword inull: Optionally, include null edges if inside (C{bool}).
@return: Yield a 3-tuple (start, end, index) for each edge
of the clipped path with the start and end points
C{LatLon} of the portion of the edge inside or on the
clip box and the index C{int} of the edge in the
original path.
@raise ValueError: The I{lowerleft} corner is not below and/or
not to the left of the I{upperright} corner.
'''
cs = _CS(lowerleft, upperright)
n, points = points2(points, closed=closed)
i, m = _imdex2(closed, n)
cmbp = cs.code4(points[i])
for i in range(m, n):
c1, m1, b1, p1 = cmbp
c2, m2, b2, p2 = cmbp = cs.code4(points[i])
if c1 & c2: # edge outside
continue
if not cs.edge(p1, p2):
if inull: # null edge
if not c1:
yield p1, p1, i
elif not c2:
yield p2, p2, i
continue
for _ in range(5):
if c1: # clip p1
c1, m1, b1, p1 = m1(b1, p1)
elif c2: # clip p2
c2, m2, b2, p2 = m2(b2, p2)
else: # inside
if inull or _neq(p1, p2):
yield p1, p2, i
break
if c1 & c2: # edge outside
break
else: # should never get here
raise AssertionError('clipCS3.for_')
