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Arrows really should be filled, not stroked

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This commit is contained in:
Grant Sanderson 2017-08-24 23:10:39 -07:00
parent 97a563abc0
commit 6aac96c734
1 changed files with 36 additions and 2 deletions
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38
topics/geometry.py
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@ -186,6 +186,9 @@ class Arrow(Line):
"buff" : MED_SMALL_BUFF,
"propogate_style_to_family" : False,
"preserve_tip_size_when_scaling" : True,
"normal_vector" : OUT,
"use_rectangular_stem" : True,
"rectangular_stem_width" : 0.05,
}
def __init__(self, *args, **kwargs):
points = map(self.pointify, args)
@ -193,6 +196,8 @@ class Arrow(Line):
args = (points[0]+UP+LEFT, points[0])
Line.__init__(self, *args, **kwargs)
self.add_tip()
if self.use_rectangular_stem and not hasattr(self, "rect"):
self.add_rectangular_stem()
def add_tip(self, add_at_end = True):
tip = VMobject(
@ -207,6 +212,33 @@ class Arrow(Line):
self.add(self.tip)
self.init_colors()
def add_rectangular_stem(self):
self.rect = Rectangle(
stroke_width = 0,
fill_color = self.tip.get_fill_color(),
fill_opacity = self.tip.get_fill_opacity()
)
self.add(self.rect)
self.set_stroke(width = 0)
self.set_rectangular_stem_points()
def set_rectangular_stem_points(self):
start, end = self.get_start_and_end()
vect = end - start
tip_base_points = self.tip.get_anchors()[1:]
tip_base = center_of_mass(tip_base_points)
tbp1, tbp2 = tip_base_points
perp_vect = tbp2 - tbp1
perp_vect /= np.linalg.norm(perp_vect)
width = self.rectangular_stem_width
self.rect.set_points_as_corners([
start + perp_vect*width/2,
tip_base + perp_vect*width/2,
tip_base - perp_vect*width/2,
start - perp_vect*width/2,
])
return self
def set_tip_points(self, tip, add_at_end = True, tip_length = None):
if tip_length is None:
tip_length = self.tip_length
@ -221,7 +253,7 @@ class Arrow(Line):
for index in indices
]
vect = end_point - pre_end_point
perp_vect = np.cross(vect, OUT)
perp_vect = np.cross(vect, self.normal_vector)
for v in vect, perp_vect:
if np.linalg.norm(v) == 0:
v[0] = 1
@ -239,7 +271,7 @@ class Arrow(Line):
def get_end(self):
if hasattr(self, "tip"):
return self.tip.get_anchors()[1]
return self.tip.get_anchors()[0]
else:
return Line.get_end(self)
@ -249,9 +281,11 @@ class Arrow(Line):
def put_start_and_end_on(self, *args, **kwargs):
Line.put_start_and_end_on(self, *args, **kwargs)
self.set_tip_points(self.tip)
self.set_rectangular_stem_points()
def scale(self, scale_factor, **kwargs):
Line.scale(self, scale_factor, **kwargs)
self.set_rectangular_stem_points()
if self.preserve_tip_size_when_scaling:
self.set_tip_points(self.tip)
return self