def _generate_spiral(self, is_dragging=False):
"""
Generate a spiral curve
"""
_key = ''
_start = Vector(self.pi_nodes[0].point)
_pi = Vector(self.pi_nodes[1].point)
_end = Vector(self.pi_nodes[2].point)
if not self.curve.get('StartRadius') \
or self.curve['StartRadius'] == math.inf:
_key = 'EndRadius'
_end = self.curve['End']
#first curve uses the start point.
#otherwise, calculate a point halfway in between.
if _start.is_end_node:
_start = _pi.sub(
Vector(_pi.sub(_start)).multiply(
_start.distanceToPoint(_pi) / 2.0
)
)
else:
_key = 'StartRadius'
_start = self.curve['Start']
#last curve uses the end point.
#otherwise, calculate a point halfway between.
if _start.is_end_node:
_end = _pi.add(
Vector(_end.sub(_pi)).multiply(
_end.distanceToPoint(_pi) / 2.0)
)
_curve = {
'PI': _pi,
'Start': _start,
'End': _end,
_key: self.curve[_key]
}
_curve = spiral.solve_unk_length(_curve)
#re-render the last known good points if an error occurs
if _curve['TanShort'] <= 0.0 or _curve['TanLong'] <= 0.0:
_curve = self.curve
self.curve = _curve
return spiral.get_points(self.curve)
def extend_two_points(
p1: FreeCAD.Vector,
p2: FreeCAD.Vector,
length: float = 4000,
) -> tuple:
xs = p1.x
xe = p2.x
ys = p1.y
ye = p2.y
delta_x = xe - xs
d = p1.distanceToPoint(p2)
if delta_x == 0:
dx = 0
dy = length
new_start_point = p1.add(FreeCAD.Vector(dx, -dy, 0))
new_d = new_start_point.distanceToPoint(p2)
if new_d > d:
new_end_point = p2.add(FreeCAD.Vector(dx, dy, 0))
else:
new_start_point = p1.add(FreeCAD.Vector(dx, dy, 0))
new_end_point = p2.add(FreeCAD.Vector(dx, -dy, 0))
else:
equation = get_line_equation(p1, p2)
m = (ye - ys) / (xe - xs)
dx = length / math.sqrt(1 + m**2)
x = p2.x + dx
y = eval(equation)
dist = math.sqrt((x - p1.x)**2 + (y - p1.y)**2)
if dist > d:
new_end_point = FreeCAD.Vector(x, y, p2.z)
x = p1.x - dx
y = eval(equation)
new_start_point = FreeCAD.Vector(x, y, p1.z)
else:
x = p2.x - dx
y = eval(equation)
new_end_point = FreeCAD.Vector(x, y, p2.z)
x = p1.x + dx
y = eval(equation)
new_start_point = FreeCAD.Vector(x, y, p1.z)
return new_start_point, new_end_point
