panda3d/tests/pgraph/test_nodepath.py

def test_nodepath_empty():
    """Tests NodePath behavior for empty NodePaths."""
    from panda3d.core import NodePath

    empty = NodePath('np')

    assert empty.get_pos() == (0, 0, 0)
    assert empty.get_hpr() == (0, 0, 0)
    assert empty.get_scale() == (1, 1, 1)

def test_nodepath_parent():
    """Tests NodePath.reparentTo()."""
    from panda3d.core import NodePath

    np1 = NodePath('np')
    np2 = NodePath('np')

    assert np1.parent is None
    assert np2.parent is None

    np1.reparentTo(np2)

    assert np1.parent == np2
    assert np2.parent is None

def test_nodepath_transform_changes():
    """Tests that NodePath applies transform changes to its managed node."""
    from panda3d.core import NodePath

    np = NodePath('np')
    assert np.get_pos() == (0, 0, 0)
    assert np.get_hpr() == (0, 0, 0)
    assert np.get_scale() == (1, 1, 1)

    np.set_pos(1, 2, 3)
    assert np.get_pos() == (1, 2, 3)
    assert np.node().get_transform().get_pos() == (1, 2, 3)

def test_nodepath_transform_composition():
    """Tests that NodePath composes transform states according to the path it holds."""
    from panda3d.core import PandaNode, NodePath, LPoint3, LVector3

    # Create 3 PandaNodes, and give each some interesting transform state:
    node1 = PandaNode('node1')
    node2 = PandaNode('node2')
    node3 = PandaNode('node3')

    node1.set_transform(node1.get_transform().set_pos(LPoint3(0, 0, 1)).set_hpr(LVector3(90, 0, -90)))
    node2.set_transform(node2.get_transform().set_pos(LPoint3(0, 1, 0)).set_hpr(LVector3(180, 180, 0)))
    node3.set_transform(node3.get_transform().set_pos(LPoint3(1, 0, 0)).set_hpr(LVector3(270, 0, 270)))

    # node3 is going to be attached under both node1 and node2 and we will
    # hold a path both ways:
    node1.add_child(node3)
    node2.add_child(node3)

    assert len(node1.children) == 1
    assert len(node2.children) == 1
    assert len(node3.children) == 0
    assert len(node1.parents) == 0
    assert len(node2.parents) == 0
    assert len(node3.parents) == 2

    # np1 is the path to node3 via node1:
    np1 = NodePath(node1).children[0]
    # np2 is the path to node3 via node2:
    np2 = NodePath(node2).children[0]

    # Both should point to node3:
    assert np1.node() == node3
    assert np2.node() == node3

    # However if we ask for the net transform to node3, it should compose:
    assert np1.get_transform(NodePath()) == node1.get_transform().compose(node3.get_transform())
    assert np2.get_transform(NodePath()) == node2.get_transform().compose(node3.get_transform())

    # If we ask for np1 RELATIVE to np2, it should compose like so:
    leg1 = node2.get_transform().compose(node3.get_transform())
    leg2 = node1.get_transform().compose(node3.get_transform())
    relative_transform = leg1.get_inverse().compose(leg2)
    assert np1.get_transform(np2) == relative_transform