topology.py 文件源码

def torus_faces(x, y):
    faces = np.empty((x * y, 4), dtype=np.uint32)
    tmp = np.arange(0, x * y)
    faces[:, 0] = tmp
    faces[:, 1] = np.roll(tmp, -y)
    tmp += 1
    tmp.shape = (x, y)
    tmp[:, y - 1] -= y
    tmp.shape = -1
    faces[:, 3] = tmp
    faces[:, 2] = np.roll(tmp, -y)
    faces.shape = -1
    l_total = np.empty(x * y, dtype=np.uint32)
    l_total[:] = 4
    l_start = np.arange(0, (x * y) * 4, 4, dtype=np.uint32)
    return SvPolygon(l_start, l_total, faces)