def polygonEnvelope(polygon):
# 多边形的顶点序列
partList = polygon.partList
# 两个顶点
rt = Point()
lb = Point()
rt.x = lb.x = partList[0][0].x
rt.y = lb.y = partList[0][0].y
for i in range(len(partList)):
for k in range(len(partList[i])):
if partList[i][k].x < lb.x:
lb.x = partList[i][k].x
if partList[i][k].x > rt.x:
rt.x = partList[i][k].x
if partList[i][k].y < lb.y:
lb.y = partList[i][k].y
if partList[i][k].y > rt.y:
rt.y = partList[i][k].y
envelope = Envelope()
envelope.rtPoint = rt
envelope.lbPoint = lb
return envelope
def getEnvelopeGravity(envelopeList):
#
rtPoint = Point()
lbPoint = Point()
rtPoint.x = lbPoint.x = envelopeList[0].rtPoint.x
rtPoint.y = lbPoint.y = envelopeList[0].lbPoint.y
for envelope in envelopeList:
rt = envelope.rtPoint
lb = envelope.lbPoint
if lb.x < lbPoint.x:
lbPoint.x = lb.x
if lb.y < lbPoint.y:
lbPoint.y = lb.y
if rt.x > rtPoint.x:
rtPoint.x = rt.x
if rt.y > rtPoint.y:
rtPoint.y = rt.y
envelope = Envelope()
envelope.lbPoint = lbPoint
envelope.rtPoint = rtPoint
gravity = Point()
gravity.x = (rtPoint.x + lbPoint.x) / 2
gravity.y = (rtPoint.y + lbPoint.y) / 2
return gravity, envelope
pass