def init_parameters(self,start_angle, angle, arc_center, quad, ccw, **kwargs):
if arc_center is None:
if isinstance(start_angle, VMobject) and isinstance(angle, VMobject):
self.tmp_center = line_intersection([start_angle.pts(0), start_angle.pts(-1)], [angle.pts(0), angle.pts(-1)])
else:
self.tmp_center = ORIGIN
elif isinstance(arc_center, (int, float)):
if isinstance(start_angle, VMobject):
self.tmp_center = start_angle.point_from_proportion(arc_center)
else:
raise Exception(
"Invalid arc_center"
)
else:
self.tmp_center=arc_center
if isinstance(start_angle, (VMobject)):
start_angle = start_angle.get_direction()
if quad==2 or quad==3:
start_angle = (PI+start_angle)%TAU
if isinstance(angle, (VMobject)):
angle = angle.get_direction()
if quad==3 or quad==4:
angle = (PI+angle)%TAU
if angle <= start_angle:
angle = TAU+angle
angle = angle-start_angle
if not ccw:
angle = -angle
self.start_angle = start_angle
self.angle = angle
def __init__(self, line, line_or_ratio=0, width=0.2, ccw=1, stroke_color=GRAY, reverse=False, *args, **kwargs):
VGroup.__init__(self, **kwargs)
if not isinstance(line, VGroup):
angle = -ccw*PI/2
if reverse:
width = -width
if isinstance(line_or_ratio, (int, float)):
pt0 = line.point_from_proportion(line_or_ratio)
elif isinstance(line_or_ratio, (Mobject)):
pt0 = line_intersection(line, line_or_ratio)
else:
pt0 = line_or_ratio
self.add(SymElbow(line.get_line(1, pt0),
width, ccw).set_color(stroke_color))
def get_arc_center(self):
"""
Looks at the normals to the first two
anchors, and finds their intersection points
"""
# First two anchors and handles
a1, h1, h2, a2 = self.points[:4]
# Tangent vectors
t1 = h1 - a1
t2 = h2 - a2
# Normals
n1 = rotate_vector(t1, TAU / 4)
n2 = rotate_vector(t2, TAU / 4)
try:
return line_intersection(
line1=(a1, a1 + n1),
line2=(a2, a2 + n2),
)
except Exception:
warnings.warn("Can't find Arc center, using ORIGIN instead")
return np.array(ORIGIN)
def get_arc_center(self):
"""
Looks at the normals to the first two
anchors, and finds their intersection points
"""
# First two anchors and handles
a1, h1, h2, a2 = self.points[:4]
# Tangent vectors
t1 = h1 - a1
t2 = h2 - a2
# Normals
n1 = rotate_vector(t1, TAU / 4)
n2 = rotate_vector(t2, TAU / 4)
try:
return line_intersection(
line1=(a1, a1 + n1),
line2=(a2, a2 + n2),
)
except Exception:
warnings.warn("Can't find Arc center, using ORIGIN instead")
return np.array(ORIGIN)
