def normalVertex2D(vprev, v, vnext):
vec1 = vec.subtract(v, vprev)
vec1 = vec.unitize(vec1)
vec2 = vec.subtract(vnext, v)
vec2 = vec.unitize(vec2)
n = vec.add(vec1, vec2)
n = vec.scale(n, 0.5)
n = vec.rot2D90(n)
#t=n.x
#n.x=-n.y
#n.y=t
return n
def normalEdge2D(vprev, v):
vec1 = vec.subtract(v, vprev)
vec1 = vec.unitize(vec1)
return vec.rot2D90(vec1)
def normalEdge2DNonUnified(vprev, v):
vec1 = vec.subtract(v, vprev)
return vec.rot2D90(vec1)