btf = 1;

point1 = {-1, 0, 0}
point2 = {1, 0, 0}

point3 = {0, -1, 0}
point4 = {0, 1, 0}

transform all points

if (point1[0] > point2[0]) btf = -btf;
if (point3[1] > point4[1]) btf = -btf;