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# File 'lib/mittsu/math/spline.rb', line 22
def point(k)
point = (@points.length - 1) * k
int_point = point.floor
weight = point - int_point
@c[0] = int_point.zero? ? int_point : int_point - 1
@c[1] = int_point
@c[2] = int_point > @points.length - 1 ? @points.length - 1 : int_point + 1
@c[3] = int_point > @points.length - 3 ? @points.length - 1 : int_point + 2
pa = @points[c[0]]
pb = @points[c[1]]
pc = @points[c[2]]
pd = @points[c[3]]
w2 = weight * weight
w3 = weight * w2
v3.x = interpolate(pa.x, pb.x, pc.x, pd.x, weight, w2, w3)
v3.y = interpolate(pa.y, pb.y, pc.y, pd.y, weight, w2, w3)
v3.z = interpolate(pa.z, pb.z, pc.z, pd.z, weight, w2, w3)
v3
end
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