def checkPolygons(map):
clean = True
for edge in map.edgeIter():
l, pa = edge.length(), edge.partialArea()
p = Polygon(edge)
p.invalidateProperties()
if abs(l - p.length()) > 1e-6:
print "edge %d: length wrong (was %s, is %s)" % (
edge.label(), l, p.length())
clean = False
if abs(pa - p.partialArea()) > 1e-6:
print "edge %d: partial area wrong (was %s, is %s)" % (
edge.label(), pa, p.partialArea())
clean = False
return clean
def checkPolygons(map):
clean = True
for edge in map.edgeIter():
l, pa = edge.length(), edge.partialArea()
p = Polygon(edge)
p.invalidateProperties()
if abs(l - p.length()) > 1e-6:
print "edge %d: length wrong (was %s, is %s)" % (edge.label(), l,
p.length())
clean = False
if abs(pa - p.partialArea()) > 1e-6:
print "edge %d: partial area wrong (was %s, is %s)" % (
edge.label(), pa, p.partialArea())
clean = False
return clean
def clipPoly(polygon, clipRect, closeAtBorder = None):
"""clipPoly(polygon, clipRect)
Clips away those parts of polygon which are not in clipRect.
Returns a list of polygons (since the polygon may leave clipRect,
enter again, leave, ...). Polygon segments crossing clipRect's
borders are cut, such that the resulting polyons get new endpoints
exactly on the border."""
result = []
# print "clipPoly(%s..%s)" % (clipRect.begin(), clipRect.end())
# print list(polygon)
if closeAtBorder is None:
closeAtBorder = (polygon[0] == polygon[-1])
x1, y1 = clipRect.begin()
x2, y2 = clipRect.end()
part = None
startBorder = None
parts = []
relPos = None
for i, p in enumerate(polygon):
prevRP = relPos
relPos = 0
if p[0] < x1:
relPos |= LEFT
elif p[0] > x2:
relPos |= RIGHT
if p[1] < y1:
relPos |= TOP
elif p[1] > y2:
relPos |= BOTTOM
if relPos: # outside
if not i: # incomplete first segment
continue
if prevRP & relPos:
# complete segment outside
continue
# calculate leaving intersection
diff = polygon[i-1] - p
l = -1.0
if relPos & LEFT:
l = max(l, (x1 - p[0]) / diff[0])
endBorder = LEFT
if relPos & RIGHT:
l = max(l, (x2 - p[0]) / diff[0])
endBorder = RIGHT
if relPos & TOP:
nl = (y1 - p[1]) / diff[1]
if nl > l:
l = nl
endBorder = TOP
if relPos & BOTTOM:
nl = (y2 - p[1]) / diff[1]
if nl > l:
l = nl
endBorder = BOTTOM
ip = p + l * diff
if prevRP:
# segment may cross cliprect, calc. start intersection
pl = 2.0
if prevRP & LEFT:
pl = min(pl, (x1 - p[0]) / diff[0])
startBorder = LEFT
if prevRP & RIGHT:
pl = min(pl, (x2 - p[0]) / diff[0])
startBorder = RIGHT
if prevRP & TOP:
npl = (y1 - p[1]) / diff[1]
if npl < pl:
pl = npl
startBorder = TOP
if prevRP & BOTTOM:
npl = (y2 - p[1]) / diff[1]
if npl < pl:
pl = npl
startBorder = BOTTOM
if pl <= l:
# we never crossed the clipRect
continue
pip = p + pl * diff
part = Polygon([pip, ip])
else:
part.append(ip)
if part.length():
parts.append((startBorder, part, endBorder))
part = None
continue
if not part:
part = Polygon()
if i:
# calculate entering intersection:
diff = polygon[i-1] - p
l = 2.0
if prevRP & LEFT:
l = min(l, (x1 - p[0]) / diff[0])
startBorder = LEFT
if prevRP & RIGHT:
l = min(l, (x2 - p[0]) / diff[0])
startBorder = RIGHT
if prevRP & TOP:
nl = (y1 - p[1]) / diff[1]
if nl < l:
l = nl
startBorder = TOP
if prevRP & BOTTOM:
nl = (y2 - p[1]) / diff[1]
if nl < l:
l = nl
startBorder = BOTTOM
ip = p + l * diff
part.append(ip)
part.append(p)
if part and part.length():
parts.append((startBorder, part, None))
if not parts:
return []
if not polygon.closed():
return [p[1] for p in parts]
# if polygon[0] (== polygon[-1]) is inside clipRect, we may
# need to join the first and last part here:
if parts[0][1][0] == parts[-1][1][-1]:
assert parts[0][0] is None and parts[-1][-1] is None
# polygon is entirely within clipRect:
if len(parts) == 1:
return [parts[0][1]]
parts[-1][1].extend(parts[0][1])
parts[0] = (parts[-1][0], parts[-1][1], parts[0][2])
del parts[-1]
if not closeAtBorder:
return [p[1] for p in parts]
# compose counterclockwise list of intersection points at clip border:
sides = (
([(-p[1][-1][0], p[1], True ) for p in parts if p[2] == TOP] +
[(-p[1][ 0][0], p[1], False) for p in parts if p[0] == TOP]),
([( p[1][-1][1], p[1], True ) for p in parts if p[2] == LEFT] +
[( p[1][ 0][1], p[1], False) for p in parts if p[0] == LEFT]),
([( p[1][-1][0], p[1], True ) for p in parts if p[2] == BOTTOM] +
[( p[1][ 0][0], p[1], False) for p in parts if p[0] == BOTTOM]),
([(-p[1][-1][1], p[1], True ) for p in parts if p[2] == RIGHT] +
[(-p[1][ 0][1], p[1], False) for p in parts if p[0] == RIGHT]))
# counterclockwise list of corner positions:
corners = (clipRect.begin(),
clipRect.begin()+(0, clipRect.size()[1]),
clipRect.end(),
clipRect.begin()+(clipRect.size()[0], 0))
isCCW = polygon.partialArea() > 0
# bookkeeping about mergings (always use the most current polygon)
merged = {}
def mergeRoot(poly):
while True:
result = merged.get(poly, poly)
if result is poly:
break
poly = result
return result
lastPoly = None
prevPoly = None
prevOutside = None
for side, end in zip(sides, corners):
for _, poly, outside in sorted(side):
# assert outside != prevOutside; prevOutside = outside
if outside == isCCW:
prevPoly = poly
else:
if prevPoly == None:
lastPoly = poly
continue
prevPoly = mergeRoot(prevPoly)
if prevPoly == poly:
poly.append(poly[0])
result.append(poly)
else:
prevPoly.extend(poly)
merged[poly] = prevPoly
prevPoly = None
if prevPoly:
mergeRoot(prevPoly).append(end)
if lastPoly:
lastPoly.append(lastPoly[0])
if lastPoly.length():
result.append(lastPoly)
return result
def clipPoly(polygon, clipRect, closeAtBorder=None):
"""clipPoly(polygon, clipRect)
Clips away those parts of polygon which are not in clipRect.
Returns a list of polygons (since the polygon may leave clipRect,
enter again, leave, ...). Polygon segments crossing clipRect's
borders are cut, such that the resulting polyons get new endpoints
exactly on the border."""
result = []
# print "clipPoly(%s..%s)" % (clipRect.begin(), clipRect.end())
# print list(polygon)
if closeAtBorder is None:
closeAtBorder = (polygon[0] == polygon[-1])
x1, y1 = clipRect.begin()
x2, y2 = clipRect.end()
part = None
startBorder = None
parts = []
relPos = None
for i, p in enumerate(polygon):
prevRP = relPos
relPos = 0
if p[0] < x1:
relPos |= LEFT
elif p[0] > x2:
relPos |= RIGHT
if p[1] < y1:
relPos |= TOP
elif p[1] > y2:
relPos |= BOTTOM
if relPos: # outside
if not i: # incomplete first segment
continue
if prevRP & relPos:
# complete segment outside
continue
# calculate leaving intersection
diff = polygon[i - 1] - p
l = -1.0
if relPos & LEFT:
l = max(l, (x1 - p[0]) / diff[0])
endBorder = LEFT
if relPos & RIGHT:
l = max(l, (x2 - p[0]) / diff[0])
endBorder = RIGHT
if relPos & TOP:
nl = (y1 - p[1]) / diff[1]
if nl > l:
l = nl
endBorder = TOP
if relPos & BOTTOM:
nl = (y2 - p[1]) / diff[1]
if nl > l:
l = nl
endBorder = BOTTOM
ip = p + l * diff
if prevRP:
# segment may cross cliprect, calc. start intersection
pl = 2.0
if prevRP & LEFT:
pl = min(pl, (x1 - p[0]) / diff[0])
startBorder = LEFT
if prevRP & RIGHT:
pl = min(pl, (x2 - p[0]) / diff[0])
startBorder = RIGHT
if prevRP & TOP:
npl = (y1 - p[1]) / diff[1]
if npl < pl:
pl = npl
startBorder = TOP
if prevRP & BOTTOM:
npl = (y2 - p[1]) / diff[1]
if npl < pl:
pl = npl
startBorder = BOTTOM
if pl <= l:
# we never crossed the clipRect
continue
pip = p + pl * diff
part = Polygon([pip, ip])
else:
part.append(ip)
if part.length():
parts.append((startBorder, part, endBorder))
part = None
continue
if not part:
part = Polygon()
if i:
# calculate entering intersection:
diff = polygon[i - 1] - p
l = 2.0
if prevRP & LEFT:
l = min(l, (x1 - p[0]) / diff[0])
startBorder = LEFT
if prevRP & RIGHT:
l = min(l, (x2 - p[0]) / diff[0])
startBorder = RIGHT
if prevRP & TOP:
nl = (y1 - p[1]) / diff[1]
if nl < l:
l = nl
startBorder = TOP
if prevRP & BOTTOM:
nl = (y2 - p[1]) / diff[1]
if nl < l:
l = nl
startBorder = BOTTOM
ip = p + l * diff
part.append(ip)
part.append(p)
if part and part.length():
parts.append((startBorder, part, None))
if not parts:
return []
if not polygon.closed():
return [p[1] for p in parts]
# if polygon[0] (== polygon[-1]) is inside clipRect, we may
# need to join the first and last part here:
if parts[0][1][0] == parts[-1][1][-1]:
assert parts[0][0] is None and parts[-1][-1] is None
# polygon is entirely within clipRect:
if len(parts) == 1:
return [parts[0][1]]
parts[-1][1].extend(parts[0][1])
parts[0] = (parts[-1][0], parts[-1][1], parts[0][2])
del parts[-1]
if not closeAtBorder:
return [p[1] for p in parts]
# compose counterclockwise list of intersection points at clip border:
sides = (([(-p[1][-1][0], p[1], True) for p in parts if p[2] == TOP] +
[(-p[1][0][0], p[1], False) for p in parts if p[0] == TOP]),
([(p[1][-1][1], p[1], True) for p in parts if p[2] == LEFT] +
[(p[1][0][1], p[1], False) for p in parts if p[0] == LEFT]),
([(p[1][-1][0], p[1], True) for p in parts if p[2] == BOTTOM] +
[(p[1][0][0], p[1], False) for p in parts if p[0] == BOTTOM]),
([(-p[1][-1][1], p[1], True) for p in parts if p[2] == RIGHT] +
[(-p[1][0][1], p[1], False) for p in parts if p[0] == RIGHT]))
# counterclockwise list of corner positions:
corners = (clipRect.begin(), clipRect.begin() + (0, clipRect.size()[1]),
clipRect.end(), clipRect.begin() + (clipRect.size()[0], 0))
isCCW = polygon.partialArea() > 0
# bookkeeping about mergings (always use the most current polygon)
merged = {}
def mergeRoot(poly):
while True:
result = merged.get(poly, poly)
if result is poly:
break
poly = result
return result
lastPoly = None
prevPoly = None
prevOutside = None
for side, end in zip(sides, corners):
for _, poly, outside in sorted(side):
# assert outside != prevOutside; prevOutside = outside
if outside == isCCW:
prevPoly = poly
else:
if prevPoly == None:
lastPoly = poly
continue
prevPoly = mergeRoot(prevPoly)
if prevPoly == poly:
poly.append(poly[0])
result.append(poly)
else:
prevPoly.extend(poly)
merged[poly] = prevPoly
prevPoly = None
if prevPoly:
mergeRoot(prevPoly).append(end)
if lastPoly:
lastPoly.append(lastPoly[0])
if lastPoly.length():
result.append(lastPoly)
return result
