def update(self):
"""Update the rotation of the label to always be pointing to the camera.
"""
context = Context.get_instance()
c_pos = context.camera.position
direction = Vec(c_pos.x, c_pos.y, c_pos.z, 1)
direction.norm()
z_axis = Vec(0, 0, 1)
# Find the angle between the camera and the health bar, then rotate it.
# NOTE: also scaling and tranlsation are applied here.
angle = math.acos(z_axis.dot(direction))
t = self.node.transform
t.identity()
t.translate(self.translation)
t.rotate(Vec(1, 0, 0), angle)
t.scale(self.scale)
def update(self, dt):
"""Updates the health bar.
:param dt: Time delta from last update.
:type dt: float
"""
context = Context.get_instance()
c_pos = context.camera.position
direction = Vec(c_pos.x, c_pos.y, c_pos.z, 1)
direction.norm()
z_axis = Vec(0, 0, 1)
# Find the angle between the camera and the health bar, then rotate it.
angle = math.acos(z_axis.dot(direction))
t = self[Renderable].transform
t.identity()
t.translate(Vec(-self.w / 2, self.y_offset, 0))
t.rotate(Vec(1, 0, 0), angle)
def in_triangle(point, triangle):
"""Checks if a specified point is inside a triangle using the barycenter
technique.
:param point: The point to be checked
:type point: list
:param triangle: The triangle
:type triangle: list
:returns: True if the point is inside the triangle.
:rtype: bool
"""
A, B, C = map(lambda t: Vec(*t), triangle)
P = Vec(*point)
u = B - A
v = C - A
w = P - A
vxw = v.cross(w)
vxu = v.cross(u)
if vxw.dot(vxu) < 0:
return False
uxw = u.cross(w)
uxv = u.cross(v)
if uxw.dot(uxv) < 0:
return False
denom = uxv.mag()
r = vxw.mag() / denom
t = uxw.mag() / denom
return (r + t <= 1)
def is_degenerate(triangle):
"""Checks if the triangle is degenerate.
:param triangle: The triangle to be checked.
:type triangle: list
:returns: Wether the triangle is degenerate or not
:rtype: bool
"""
A, B, C = map(lambda t: Vec(*t), triangle)
u = B - A
v = C - A
uxv = u.cross(v)
return uxv.mag() == 0
