def angle_arrow(self, path, origin='head'):
''' Compute the two points of the arrow head with the right angle '''
if origin == 'tail':
path = path.toReversed()
length = path.length()
percent = path.percentAtLength(length - 10.0)
src = path.pointAtPercent(percent)
#path.moveTo(path.pointAtPercent(1))
end_point = path.pointAtPercent(1)
#end_point = path.currentPosition()
line = QLineF(src, end_point)
angle = math.acos(line.dx() / (line.length() or 1))
if line.dy() >= 0:
angle = math.pi * 2 - angle
arrow_size = 10.0
arrow_p1 = end_point + QPointF(
math.sin(angle - math.pi / 3) * arrow_size,
math.cos(angle - math.pi / 3) * arrow_size)
arrow_p2 = end_point + QPointF(
math.sin(angle - math.pi + math.pi / 3) * arrow_size,
math.cos(angle - math.pi + math.pi / 3) * arrow_size)
return (arrow_p1, arrow_p2)
def angle_arrow(self, path, origin='head'):
''' Compute the two points of the arrow head with the right angle '''
if origin == 'tail':
path = path.toReversed()
length = path.length()
percent = path.percentAtLength(length - 10.0)
src = path.pointAtPercent(percent)
#path.moveTo(path.pointAtPercent(1))
end_point = path.pointAtPercent(1)
#end_point = path.currentPosition()
line = QLineF(src, end_point)
angle = math.acos(line.dx() / (line.length() or 1))
if line.dy() >= 0:
angle = math.pi * 2 - angle
arrow_size = 10.0
arrow_p1 = end_point + QPointF(
math.sin(angle - math.pi / 3) * arrow_size,
math.cos(angle - math.pi / 3) * arrow_size)
arrow_p2 = end_point + QPointF(
math.sin(angle - math.pi + math.pi / 3) * arrow_size,
math.cos(angle - math.pi + math.pi / 3) * arrow_size)
return (arrow_p1, arrow_p2)
