__docformat__ = "reStructuredText"
import logging
from typing import TYPE_CHECKING, List, Optional, Sequence, Tuple
if TYPE_CHECKING:
from .body import Body
from .space import Space
from ._chipmunk_cffi import ffi
from ._chipmunk_cffi import lib as cp
from ._pickle import PickleMixin, _State
from ._typing_attr import TypingAttrMixing
from .bb import BB
from .contact_point_set import ContactPointSet
from .query_info import PointQueryInfo, SegmentQueryInfo
from .shape_filter import ShapeFilter
from .transform import Transform
from .vec2d import Vec2d
_logger = logging.getLogger(__name__)
[docs]
class Shape(PickleMixin, TypingAttrMixing, object):
"""Base class for all the shapes.
You usually dont want to create instances of this class directly but use
one of the specialized shapes instead (:py:class:`Circle`,
:py:class:`Poly` or :py:class:`Segment`).
All the shapes can be copied and pickled. If you copy/pickle a shape the
body (if any) will also be copied.
"""
_pickle_attrs_init = PickleMixin._pickle_attrs_init + ["body"]
_pickle_attrs_general = PickleMixin._pickle_attrs_general + [
"sensor",
"collision_type",
"filter",
"elasticity",
"friction",
"surface_velocity",
"_hashid",
]
_pickle_attrs_skip = PickleMixin._pickle_attrs_skip + ["mass", "density"]
_space = None # Weak ref to the space holding this body (if any)
_id_counter = 1
[docs]
def __init__(self, shape: "Shape") -> None:
self._shape = shape
self._body: Optional["Body"] = shape.body
def _init(self, body: Optional["Body"], _shape: ffi.CData) -> None:
self._body = body
if body is not None:
body._shapes.add(self)
def shapefree(cp_shape): # type: ignore
_logger.debug("shapefree start %s", cp_shape)
cp_space = cp.cpShapeGetSpace(cp_shape)
if cp_space != ffi.NULL:
_logger.debug("shapefree remove from space %s %s", cp_space, cp_shape)
cp.cpSpaceRemoveShape(cp_space, cp_shape)
_logger.debug("shapefree get body %s", cp_shape)
cp_body = cp.cpShapeGetBody(cp_shape)
if cp_body != ffi.NULL:
_logger.debug("shapefree set body %s", cp_shape)
# print(cp.cpShapeActive2(cp_shape))
cp.cpShapeSetBody(cp_shape, ffi.NULL)
_logger.debug("shapefree free %s", cp_shape)
cp.cpShapeFree(cp_shape)
self._shape = ffi.gc(_shape, shapefree)
self._set_id()
@property
def _id(self) -> int:
"""Unique id of the Shape
.. note::
Experimental API. Likely to change in future major, minor orpoint
releases.
"""
return int(ffi.cast("int", cp.cpShapeGetUserData(self._shape)))
def _set_id(self) -> None:
cp.cpShapeSetUserData(self._shape, ffi.cast("cpDataPointer", Shape._id_counter))
Shape._id_counter += 1
def _get_mass(self) -> float:
return cp.cpShapeGetMass(self._shape)
def _set_mass(self, mass: float) -> None:
cp.cpShapeSetMass(self._shape, mass)
mass = property(
_get_mass,
_set_mass,
doc="""The mass of this shape.
This is useful when you let Pymunk calculate the total mass and inertia
of a body from the shapes attached to it. (Instead of setting the body
mass and inertia directly)
""",
)
def _get_density(self) -> float:
return cp.cpShapeGetDensity(self._shape)
def _set_density(self, density: float) -> None:
cp.cpShapeSetDensity(self._shape, density)
density = property(
_get_density,
_set_density,
doc="""The density of this shape.
This is useful when you let Pymunk calculate the total mass and inertia
of a body from the shapes attached to it. (Instead of setting the body
mass and inertia directly)
""",
)
@property
def moment(self) -> float:
"""The calculated moment of this shape."""
return cp.cpShapeGetMoment(self._shape)
@property
def area(self) -> float:
"""The calculated area of this shape."""
return cp.cpShapeGetArea(self._shape)
@property
def center_of_gravity(self) -> Vec2d:
"""The calculated center of gravity of this shape."""
v = cp.cpShapeGetCenterOfGravity(self._shape)
return Vec2d(v.x, v.y)
def _get_sensor(self) -> bool:
return bool(cp.cpShapeGetSensor(self._shape))
def _set_sensor(self, is_sensor: bool) -> None:
cp.cpShapeSetSensor(self._shape, is_sensor)
sensor = property(
_get_sensor,
_set_sensor,
doc="""A boolean value if this shape is a sensor or not.
Sensors only call collision callbacks, and never generate real
collisions.
""",
)
def _get_collision_type(self) -> int:
return cp.cpShapeGetCollisionType(self._shape)
def _set_collision_type(self, t: int) -> None:
cp.cpShapeSetCollisionType(self._shape, t)
collision_type = property(
_get_collision_type,
_set_collision_type,
doc="""User defined collision type for the shape.
See :py:meth:`Space.add_collision_handler` function for more
information on when to use this property.
""",
)
def _get_filter(self) -> ShapeFilter:
f = cp.cpShapeGetFilter(self._shape)
return ShapeFilter(f.group, f.categories, f.mask)
def _set_filter(self, f: ShapeFilter) -> None:
cp.cpShapeSetFilter(self._shape, f)
filter = property(
_get_filter,
_set_filter,
doc="""Set the collision :py:class:`ShapeFilter` for this shape.
""",
)
def _get_elasticity(self) -> float:
return cp.cpShapeGetElasticity(self._shape)
def _set_elasticity(self, e: float) -> None:
cp.cpShapeSetElasticity(self._shape, e)
elasticity = property(
_get_elasticity,
_set_elasticity,
doc="""Elasticity of the shape.
A value of 0.0 gives no bounce, while a value of 1.0 will give a
'perfect' bounce. However due to inaccuracies in the simulation
using 1.0 or greater is not recommended.
""",
)
def _get_friction(self) -> float:
return cp.cpShapeGetFriction(self._shape)
def _set_friction(self, u: float) -> None:
cp.cpShapeSetFriction(self._shape, u)
friction = property(
_get_friction,
_set_friction,
doc="""Friction coefficient.
Pymunk uses the Coulomb friction model, a value of 0.0 is
frictionless.
A value over 1.0 is perfectly fine.
Some real world example values from Wikipedia (Remember that
it is what looks good that is important, not the exact value).
============== ====== ========
Material Other Friction
============== ====== ========
Aluminium Steel 0.61
Copper Steel 0.53
Brass Steel 0.51
Cast iron Copper 1.05
Cast iron Zinc 0.85
Concrete (wet) Rubber 0.30
Concrete (dry) Rubber 1.0
Concrete Wood 0.62
Copper Glass 0.68
Glass Glass 0.94
Metal Wood 0.5
Polyethene Steel 0.2
Steel Steel 0.80
Steel Teflon 0.04
Teflon (PTFE) Teflon 0.04
Wood Wood 0.4
============== ====== ========
""",
)
def _get_surface_velocity(self) -> Vec2d:
v = cp.cpShapeGetSurfaceVelocity(self._shape)
return Vec2d(v.x, v.y)
def _set_surface_velocity(self, surface_v: Vec2d) -> None:
assert len(surface_v) == 2
cp.cpShapeSetSurfaceVelocity(self._shape, surface_v)
surface_velocity = property(
_get_surface_velocity,
_set_surface_velocity,
doc="""The surface velocity of the object.
Useful for creating conveyor belts or players that move around. This
value is only used when calculating friction, not resolving the
collision.
""",
)
def _get_body(self) -> Optional["Body"]:
return self._body
def _set_body(self, body: Optional["Body"]) -> None:
if self._body is not None:
self._body._shapes.remove(self)
body_body = ffi.NULL if body is None else body._body
cp.cpShapeSetBody(self._shape, body_body)
if body is not None:
body._shapes.add(self)
self._body = body
body = property(
_get_body,
_set_body,
doc="""The body this shape is attached to. Can be set to None to
indicate that this shape doesnt belong to a body.""",
)
[docs]
def update(self, transform: Transform) -> BB:
"""Update, cache and return the bounding box of a shape with an
explicit transformation.
Useful if you have a shape without a body and want to use it for
querying.
"""
_bb = cp.cpShapeUpdate(self._shape, transform)
return BB(_bb.l, _bb.b, _bb.r, _bb.t)
[docs]
def cache_bb(self) -> BB:
"""Update and returns the bounding box of this shape"""
_bb = cp.cpShapeCacheBB(self._shape)
return BB(_bb.l, _bb.b, _bb.r, _bb.t)
@property
def bb(self) -> BB:
"""The bounding box :py:class:`BB` of the shape.
Only guaranteed to be valid after :py:meth:`Shape.cache_bb` or
:py:meth:`Space.step` is called. Moving a body that a shape is
connected to does not update it's bounding box. For shapes used for
queries that aren't attached to bodies, you can also use
:py:meth:`Shape.update`.
"""
_bb = cp.cpShapeGetBB(self._shape)
return BB(_bb.l, _bb.b, _bb.r, _bb.t)
[docs]
def point_query(self, p: Tuple[float, float]) -> PointQueryInfo:
"""Check if the given point lies within the shape.
A negative distance means the point is within the shape.
:return: Tuple of (distance, info)
:rtype: (float, :py:class:`PointQueryInfo`)
"""
assert len(p) == 2
info = ffi.new("cpPointQueryInfo *")
_ = cp.cpShapePointQuery(self._shape, p, info)
ud = int(ffi.cast("int", cp.cpShapeGetUserData(info.shape)))
assert ud == self._id
return PointQueryInfo(
self,
Vec2d(info.point.x, info.point.y),
info.distance,
Vec2d(info.gradient.x, info.gradient.y),
)
[docs]
def segment_query(
self, start: Tuple[float, float], end: Tuple[float, float], radius: float = 0
) -> SegmentQueryInfo:
"""Check if the line segment from start to end intersects the shape.
:rtype: :py:class:`SegmentQueryInfo`
"""
assert len(start) == 2
assert len(end) == 2
info = ffi.new("cpSegmentQueryInfo *")
r = cp.cpShapeSegmentQuery(self._shape, start, end, radius, info)
if r:
ud = int(ffi.cast("int", cp.cpShapeGetUserData(info.shape)))
assert ud == self._id
return SegmentQueryInfo(
self,
Vec2d(info.point.x, info.point.y),
Vec2d(info.normal.x, info.normal.y),
info.alpha,
)
else:
return SegmentQueryInfo(
None,
Vec2d(info.point.x, info.point.y),
Vec2d(info.normal.x, info.normal.y),
info.alpha,
)
[docs]
def shapes_collide(self, b: "Shape") -> ContactPointSet:
"""Get contact information about this shape and shape b.
:rtype: :py:class:`ContactPointSet`
"""
_points = cp.cpShapesCollide(self._shape, b._shape)
return ContactPointSet._from_cp(_points)
@property
def space(self) -> Optional["Space"]:
"""Get the :py:class:`Space` that shape has been added to (or
None).
"""
if self._space is not None:
try:
return self._space._get_self() # ugly hack because of weakref
except ReferenceError:
return None
else:
return None
@property
def _hashid(self) -> int:
return cp.cpShapeGetHashID(self._shape)
@_hashid.setter
def _hashid(self, v: int) -> None:
cp.cpShapeSetHashID(self._shape, v)
def __getstate__(self) -> _State:
"""Return the state of this object
This method allows the usage of the :mod:`copy` and :mod:`pickle`
modules with this class.
"""
d = super(Shape, self).__getstate__()
if self.mass > 0:
d["general"].append(("mass", self.mass))
if self.density > 0:
d["general"].append(("density", self.density))
return d
[docs]
class Circle(Shape):
"""A circle shape defined by a radius
This is the fastest and simplest collision shape
"""
_pickle_attrs_init = Shape._pickle_attrs_init + ["radius", "offset"]
[docs]
def __init__(
self,
body: Optional["Body"],
radius: float,
offset: Tuple[float, float] = (0, 0),
) -> None:
"""body is the body attach the circle to, offset is the offset from the
body's center of gravity in body local coordinates.
It is legal to send in None as body argument to indicate that this
shape is not attached to a body. However, you must attach it to a body
before adding the shape to a space or used for a space shape query.
"""
assert len(offset) == 2
body_body = ffi.NULL if body is None else body._body
_shape = cp.cpCircleShapeNew(body_body, radius, offset)
self._init(body, _shape)
[docs]
def unsafe_set_radius(self, r: float) -> None:
"""Unsafe set the radius of the circle.
.. note::
This change is only picked up as a change to the position
of the shape's surface, but not it's velocity. Changing it will
not result in realistic physical behavior. Only use if you know
what you are doing!
"""
cp.cpCircleShapeSetRadius(self._shape, r)
@property
def radius(self) -> float:
"""The Radius of the circle"""
return cp.cpCircleShapeGetRadius(self._shape)
[docs]
def unsafe_set_offset(self, o: Tuple[float, float]) -> None:
"""Unsafe set the offset of the circle.
.. note::
This change is only picked up as a change to the position
of the shape's surface, but not it's velocity. Changing it will
not result in realistic physical behavior. Only use if you know
what you are doing!
"""
assert len(o) == 2
cp.cpCircleShapeSetOffset(self._shape, o)
@property
def offset(self) -> Vec2d:
"""Offset. (body space coordinates)"""
v = cp.cpCircleShapeGetOffset(self._shape)
return Vec2d(v.x, v.y)
[docs]
class Segment(Shape):
"""A line segment shape between two points
Meant mainly as a static shape. Can be beveled in order to give them a
thickness.
"""
_pickle_attrs_init = Shape._pickle_attrs_init + ["a", "b", "radius"]
[docs]
def __init__(
self,
body: Optional["Body"],
a: Tuple[float, float],
b: Tuple[float, float],
radius: float,
) -> None:
"""Create a Segment
It is legal to send in None as body argument to indicate that this
shape is not attached to a body. However, you must attach it to a body
before adding the shape to a space or used for a space shape query.
:param Body body: The body to attach the segment to
:param a: The first endpoint of the segment
:param b: The second endpoint of the segment
:param float radius: The thickness of the segment
"""
assert len(a) == 2
assert len(b) == 2
body_body = ffi.NULL if body is None else body._body
_shape = cp.cpSegmentShapeNew(body_body, a, b, radius)
self._init(body, _shape)
def _get_a(self) -> Vec2d:
v = cp.cpSegmentShapeGetA(self._shape)
return Vec2d(v.x, v.y)
a = property(_get_a, doc="""The first of the two endpoints for this segment""")
def _get_b(self) -> Vec2d:
v = cp.cpSegmentShapeGetB(self._shape)
return Vec2d(v.x, v.y)
b = property(_get_b, doc="""The second of the two endpoints for this segment""")
[docs]
def unsafe_set_endpoints(
self, a: Tuple[float, float], b: Tuple[float, float]
) -> None:
"""Set the two endpoints for this segment
.. note::
This change is only picked up as a change to the position
of the shape's surface, but not it's velocity. Changing it will
not result in realistic physical behavior. Only use if you know
what you are doing!
"""
assert len(a) == 2
assert len(b) == 2
cp.cpSegmentShapeSetEndpoints(self._shape, a, b)
@property
def normal(self) -> Vec2d:
"""The normal"""
v = cp.cpSegmentShapeGetNormal(self._shape)
return Vec2d(v.x, v.y)
[docs]
def unsafe_set_radius(self, r: float) -> None:
"""Set the radius of the segment
.. note::
This change is only picked up as a change to the position
of the shape's surface, but not it's velocity. Changing it will
not result in realistic physical behavior. Only use if you know
what you are doing!
"""
cp.cpSegmentShapeSetRadius(self._shape, r)
@property
def radius(self) -> float:
"""The radius/thickness of the segment"""
return cp.cpSegmentShapeGetRadius(self._shape)
[docs]
def set_neighbors(
self, prev: Tuple[float, float], next: Tuple[float, float]
) -> None:
"""When you have a number of segment shapes that are all joined
together, things can still collide with the "cracks" between the
segments. By setting the neighbor segment endpoints you can tell
Chipmunk to avoid colliding with the inner parts of the crack.
"""
assert len(prev) == 2
assert len(next) == 2
cp.cpSegmentShapeSetNeighbors(self._shape, prev, next)
[docs]
class Poly(Shape):
"""A convex polygon shape
Slowest, but most flexible collision shape.
"""
[docs]
def __init__(
self,
body: Optional["Body"],
vertices: Sequence[Tuple[float, float]],
transform: Optional[Transform] = None,
radius: float = 0,
) -> None:
"""Create a polygon.
A convex hull will be calculated from the vertexes automatically.
Adding a small radius will bevel the corners and can significantly
reduce problems where the poly gets stuck on seams in your geometry.
It is legal to send in None as body argument to indicate that this
shape is not attached to a body. However, you must attach it to a body
before adding the shape to a space or used for a space shape query.
.. note::
Make sure to put the vertices around (0,0) or the shape might
behave strange.
Either directly place the vertices like the below example:
>>> import pymunk
>>> w, h = 10, 20
>>> vs = [(-w/2,-h/2), (w/2,-h/2), (w/2,h/2), (-w/2,h/2)]
>>> poly_good = pymunk.Poly(None, vs)
>>> print(poly_good.center_of_gravity)
Vec2d(0.0, 0.0)
Or use a transform to move them:
>>> import pymunk
>>> width, height = 10, 20
>>> vs = [(0, 0), (width, 0), (width, height), (0, height)]
>>> poly_bad = pymunk.Poly(None, vs)
>>> print(poly_bad.center_of_gravity)
Vec2d(5.0, 10.0)
>>> t = pymunk.Transform(tx=-width/2, ty=-height/2)
>>> poly_good = pymunk.Poly(None, vs, transform=t)
>>> print(poly_good.center_of_gravity)
Vec2d(0.0, 0.0)
:param Body body: The body to attach the poly to
:param [(float,float)] vertices: Define a convex hull of the polygon
with a counterclockwise winding.
:param Transform transform: Transform will be applied to every vertex.
:param float radius: Set the radius of the poly shape
"""
if transform is None:
transform = Transform.identity()
body_body = ffi.NULL if body is None else body._body
_shape = cp.cpPolyShapeNew(
body_body, len(vertices), vertices, transform, radius
)
self._init(body, _shape)
[docs]
def unsafe_set_radius(self, radius: float) -> None:
"""Unsafe set the radius of the poly.
.. note::
This change is only picked up as a change to the position
of the shape's surface, but not it's velocity. Changing it will
not result in realistic physical behavior. Only use if you know
what you are doing!
"""
cp.cpPolyShapeSetRadius(self._shape, radius)
@property
def radius(self) -> float:
"""The radius of the poly shape.
Extends the poly in all directions with the given radius.
"""
return cp.cpPolyShapeGetRadius(self._shape)
[docs]
@staticmethod
def create_box(
body: Optional["Body"], size: Tuple[float, float] = (10, 10), radius: float = 0
) -> "Poly":
"""Convenience function to create a box given a width and height.
The boxes will always be centered at the center of gravity of the
body you are attaching them to. If you want to create an off-center
box, you will need to use the normal constructor Poly(...).
Adding a small radius will bevel the corners and can significantly
reduce problems where the box gets stuck on seams in your geometry.
:param Body body: The body to attach the poly to
:param size: Size of the box as (width, height)
:type size: (`float, float`)
:param float radius: Radius of poly
:rtype: :py:class:`Poly`
"""
self = Poly.__new__(Poly)
body_body = ffi.NULL if body is None else body._body
_shape = cp.cpBoxShapeNew(body_body, size[0], size[1], radius)
self._init(body, _shape)
return self
[docs]
@staticmethod
def create_box_bb(body: Optional["Body"], bb: BB, radius: float = 0) -> "Poly":
"""Convenience function to create a box shape from a :py:class:`BB`.
The boxes will always be centered at the center of gravity of the
body you are attaching them to. If you want to create an off-center
box, you will need to use the normal constructor Poly(..).
Adding a small radius will bevel the corners and can significantly
reduce problems where the box gets stuck on seams in your geometry.
:param Body body: The body to attach the poly to
:param BB bb: Size of the box
:param float radius: Radius of poly
:rtype: :py:class:`Poly`
"""
self = Poly.__new__(Poly)
body_body = ffi.NULL if body is None else body._body
_shape = cp.cpBoxShapeNew2(body_body, bb, radius)
self._init(body, _shape)
return self
[docs]
def get_vertices(self) -> List[Vec2d]:
"""Get the vertices in local coordinates for the polygon
If you need the vertices in world coordinates then the vertices can be
transformed by adding the body position and each vertex rotated by the
body rotation in the following way::
>>> import pymunk
>>> b = pymunk.Body()
>>> b.position = 1,2
>>> b.angle = 0.5
>>> shape = pymunk.Poly(b, [(0,0), (10,0), (10,10)])
>>> for v in shape.get_vertices():
... x,y = v.rotated(shape.body.angle) + shape.body.position
... (int(x), int(y))
(1, 2)
(9, 6)
(4, 15)
:return: The vertices in local coords
:rtype: [:py:class:`Vec2d`]
"""
verts = []
l = cp.cpPolyShapeGetCount(self._shape)
for i in range(l):
v = cp.cpPolyShapeGetVert(self._shape, i)
verts.append(Vec2d(v.x, v.y))
return verts
[docs]
def unsafe_set_vertices(
self,
vertices: Sequence[Tuple[float, float]],
transform: Optional[Transform] = None,
) -> None:
"""Unsafe set the vertices of the poly.
.. note::
This change is only picked up as a change to the position
of the shape's surface, but not it's velocity. Changing it will
not result in realistic physical behavior. Only use if you know
what you are doing!
"""
if transform is None:
cp.cpPolyShapeSetVertsRaw(self._shape, len(vertices), vertices)
return
cp.cpPolyShapeSetVerts(self._shape, len(vertices), vertices, transform)
def __getstate__(self) -> _State:
"""Return the state of this object
This method allows the usage of the :mod:`copy` and :mod:`pickle`
modules with this class.
"""
d = super(Poly, self).__getstate__()
d["init"].append(("vertices", self.get_vertices()))
d["init"].append(("transform", None))
d["init"].append(("radius", self.radius))
return d
