import math


def squareVerts(a,t,res):
    """Get the vertices of the interpolation square."""
    invRes = 1/res
    aB = math.trunc(a*invRes)/invRes
    aT = math.ceil(a*invRes)/invRes
    if aT == aB:
        aT += res#1.0
    tB = math.trunc(t*invRes)/invRes
    tT = math.ceil(t*invRes)/invRes
    if tT == tB:
        tT += res#1.0
    return [[aB, aT], [tB, tT]]