import sys

from direct.showbase.ShowBase import ShowBase

from panda3d.core import VBase3
from panda3d.bullet import BulletWorld
from panda3d.bullet import BulletRigidBodyNode
from panda3d.bullet import BulletSphereShape
from panda3d.bullet import BulletDebugNode


# Basic setup
s = ShowBase()
s.disable_mouse()
s.accept('escape', sys.exit)
s.cam.set_pos(0, -10, 0)


# Physics
bullet_world = BulletWorld()
def run_physics(task):
    bullet_world.do_physics(globalClock.getDt())
    return task.cont
s.task_mgr.add(run_physics, sort=1)
# Debug visualization
debug_node = BulletDebugNode('Debug')
debug_node.showWireframe(True)
debug_node.showConstraints(True)
debug_node.showBoundingBoxes(False)
debug_node.showNormals(False)
debug_np = s.render.attach_new_node(debug_node)
bullet_world.set_debug_node(debug_node)
debug_np.show()


# A node between the actual object of interest and the root of the scene graph,
# so that we can test whether measurements are taken in node space or world
# space.
in_between = render.attach_new_node('in_between')
in_between.set_hpr(0, 0, 45)


# The object in question
mass = BulletRigidBodyNode()
mass.set_mass(1)
mass.setLinearSleepThreshold(0)
mass.setAngularSleepThreshold(0)
shape = BulletSphereShape(1)
mass.add_shape(shape)
mass_node = in_between.attach_new_node(mass)
bullet_world.attach_rigid_body(mass)
model = s.loader.load_model('models/smiley')
model.reparent_to(mass_node)
# Apply torque with 't'
def add_torque():
    mass.apply_torque_impulse(VBase3(0, 0, 1))
s.accept('t', add_torque)


s.run()