Cancelling terms with manim instead TeX - manim

Question

Can you draw diagonal lines/arrows/ whatever looks like youre crossing out cancelling like terms in a math equation in manim?

Answer 1

The closest thing that is defined is Cross, but it is not exactly what you are looking for, I like to use this:
class Cancel(VGroup):
CONFIG = {
"line_kwargs": {"color":RED},
"buff_text": None,
"buff_line": 0.7,
}
def __init__(self,text,texmob=None,**kwargs):
digest_config(self,kwargs)
VGroup.__init__(self,**kwargs)
pre_coord_dl = text.get_corner(DL)
pre_coord_ur = text.get_corner(UR)
reference_line = Line(pre_coord_dl,pre_coord_ur)
reference_unit_vector = reference_line.get_unit_vector()
coord_dl = text.get_corner(DL) - text.get_center() - reference_unit_vector*self.buff_line
coord_ur = text.get_corner(UR) - text.get_center() + reference_unit_vector*self.buff_line
if texmob == None:
line = Line(coord_dl,coord_ur,**self.line_kwargs)
self.add(line)
else:
arrow = Arrow(coord_dl,coord_ur,**self.line_kwargs)
unit_vector = arrow.get_unit_vector()
if self.buff_text == None:
self.buff_text = get_norm((texmob.get_center()-texmob.get_critical_point(unit_vector))/2)*2
texmob.move_to(arrow.get_end()+unit_vector*self.buff_text)
self.add(arrow,texmob)
class CancelTerms(Scene):
def construct(self):
formula = TexMobject("f(x)",height=1)
cancel_formula = Cancel(formula,TexMobject("testa"))
self.add(formula,cancel_formula)