def setSegmentStartTangent(segment, tangent):
if len(segment.points) == 2:
'''
Convert straight segment to 4-point cubic bezier.
'''
p0, p3 = segment.points
p2 = p0.midpoint(p3)
p1 = p0.plus(tangent.scale(p0.distanceTo(p3) * 0.5))
result = TFSSegment(p0, p1, p2, p3)
elif len(segment.points) == 3:
'''
Update 3-point cubic bezier.
'''
p0, p1, p2 = segment.points
p1 = TFSIntersection.getIntersectPoint(p0,
p0.plus(tangent),
p1,
p2)
result = TFSSegment(p0, p1, p2)
elif len(segment.points) == 4:
'''
Update 4-point cubic bezier.
'''
p0, p1, p2, p3 = segment.points
p1 = p0.plus(tangent.scale(p0.distanceTo(p1)))
result = TFSSegment(p0, p1, p2, p3)
else:
raise Exception('Invalid segment: ' + segment.description())
# print 'updated segment:', segment.description(), 'to:', result.description()
return result
def updateSegment(segment):
startPoint = segment.startPoint()
# startOffset = TFSPoint0()
if segment.startPoint() in selectedPoints:
# startOffset = pointAverage.minus(startPoint)
startPoint = pointAverage
endPoint = segment.endPoint()
# endOffset = TFSPoint0()
if segment.endPoint() in selectedPoints:
# endOffset = pointAverage.minus(endPoint)
endPoint = pointAverage
if startPoint == endPoint:
return None
newPoints = [startPoint,]
if len(segment.points) == 2:
pass
elif len(segment.points) == 3:
if updateControlPoints:
# Preserve the control angles.
controlPoint0 = TFSIntersection.getIntersectPoint(startPoint,
startPoint.plus(segment.startTangent()),
endPoint,
endPoint.plus(segment.endTangent()))
else:
controlPoint0 = segment.points[1]
newPoints += [controlPoint0,]
# offset = startOffset.blend(endOffset)
# controlPoint0 = segment.points[1].plus(offset)
# newPoints += [controlPoint0,]
elif len(segment.points) == 4:
if updateControlPoints:
factor = startPoint.distanceTo(endPoint) / segment.endPointDistance()
controlPoint0 = startPoint.plus(segment.startTangent().scale(segment.startVector().length() * factor))
controlPoint1 = endPoint.plus(segment.endTangent().scale(segment.endVector().length() * -factor))
else:
controlPoint0 = segment.points[1]
controlPoint1 = segment.points[2]
newPoints += [controlPoint0, controlPoint1,]
# controlPoint0 = segment.points[1].plus(startOffset)
# controlPoint1 = segment.points[2].plus(endOffset)
# newPoints += [controlPoint0, controlPoint1,]
else:
raise Exception('Invalid segment: ' + segment.description())
newPoints += [endPoint,]
return TFSSegment(*newPoints)