def create_arc(length,
curvature,
current_road,
start_s,
hardCode=False,
quad_number=10):
""" Gives the chord line set of points for a curved road"""
plt = [[], []]
anti_clockwise = 1
tangent = Vector(1, 0, 0)
radius = 1 / curvature
end_angle = 0
if (radius > 0):
tangent = tangent.rotate(90)
anti_clockwise = 1
else:
tangent = tangent.rotate(-90)
radius = -1 * radius
anti_clockwise = -1
center = radius * tangent
tangent = tangent.rotate(180)
start_angle = tangent.argument()
end_angle = start_angle + anti_clockwise * 360 * (length /
(2 * math.pi * radius))
angle = start_angle
radius = Vector(radius, 0, 0)
radius = radius.rotate(start_angle)
tot_lane_vertices = []
s = -0.1
for i in range(quad_number + 1):
pt = center + radius
lane_data = current_road.get_lane_data(s + start_s)
current_pt = pt + Vector(0, 0, current_road.get_elevation(s + start_s))
lane_pts = generate_lane_verts(current_pt,
radius.rotate(90 * anti_clockwise),
lane_data, hardCode)
tot_lane_vertices.append(lane_pts)
radius = radius.rotate((end_angle - start_angle) / quad_number)
plt[0].append(pt.x)
plt[1].append(pt.y)
dTheta = (end_angle - start_angle) / quad_number
dTheta = dTheta * 3.14 / 180
s = s + radius.norm() * dTheta
return tot_lane_vertices
