# Source code for pymunk.shapes

    __version__ = "$Id$"
    __docformat__ = "reStructuredText"

    from . import _chipmunk_cffi
    cp = _chipmunk_cffi.lib
    ffi = _chipmunk_cffi.ffi

    from .transform import Transform
    from .shape_filter import ShapeFilter
    from .bb import BB
    from .query_info import PointQueryInfo, SegmentQueryInfo
    from .contact_point_set import ContactPointSet
    from .vec2d import Vec2d

    class Shape(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.
        """

        _space = None # Weak ref to the space holding this body (if any)

        _shapeid_counter = 1

        def __init__(self, shape=None):
            self._shape = shape
            self._body = shape.body

        def _get_shapeid(self):
            return cp.cpShapeGetUserData(self._shape)
        def _set_shapeid(self):
            cp.cpShapeSetUserData(self._shape, ffi.cast("cpDataPointer", Shape._shapeid_counter))
            Shape._shapeid_counter += 1

        def _get_sensor(self):
            return cp.cpShapeGetSensor(self._shape)
        def _set_sensor(self, is_sensor):
            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):
            return cp.cpShapeGetCollisionType(self._shape)
        def _set_collision_type(self, t):
            cp.cpShapeSetCollisionType(self._shape, t)
        collision_type = property(_get_collision_type, _set_collision_type,
            doc="""User defined collision type for the shape.

            See add_collisionpair_func function for more information on when to
            use this property.
            """)

        def _get_filter(self):
            f = cp.cpShapeGetFilter(self._shape)
            return ShapeFilter(f.group, f.categories, f.mask)
        def _set_filter(self, f):
            cp.cpShapeSetFilter(self._shape, f)
        filter = property(_get_filter, _set_filter,
            doc="""Set the collision filter for this shape.""")

        def _get_elasticity(self):
            return cp.cpShapeGetElasticity(self._shape)
        def _set_elasticity(self, e):
            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):
            return cp.cpShapeGetFriction(self._shape)
        def _set_friction(self, u):
            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):
            return Vec2d(cp.cpShapeGetSurfaceVelocity(self._shape))
        def _set_surface_velocity(self, surface_v):
            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):
            return self._body
        def _set_body(self, body):
            if self._body != 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 != 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.""")

        def update(self, transform):
            """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)

        def cache_bb(self):
            """Update and returns the bouding box of this shape"""
            return BB(cp.cpShapeCacheBB(self._shape))

        def _get_bb(self):
            return BB(cp.cpShapeGetBB(self._shape))

        bb = property(_get_bb, doc="""The bounding box of the shape.

        Only guaranteed to be valid after Shape.cache_bb() or 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 Shape.update().
        """)

        def point_query(self, p):
            """Check if the given point lies within the shape."""
            info = ffi.new("cpPointQueryInfo *")
            distance = cp.cpShapePointQuery(self._shape, p, info)
            return PointQueryInfo(self, Vec2d(info.point), info.distance, Vec2d(info.gradient))
            ud = cp.cpShapeGetUserData(info.shape)
            assert ud == self._get_shapeid()
            x = PointQueryInfo(self, info.point, info.distance, info.gradient)
            return distance, x

        def segment_query(self, start, end, radius=0):
            """Check if the line segment from start to end intersects the shape.
            """
            info = ffi.new("cpSegmentQueryInfo *")
            r = cp.cpShapeSegmentQuery(self._shape, start, end, radius, info)
            if r:
                ud = cp.cpShapeGetUserData(info.shape)
                assert ud == self._get_shapeid()
                return SegmentQueryInfo(self, Vec2d(info.point), Vec2d(info.normal), info.alpha)
            else:
                return SegmentQueryInfo(None, Vec2d(info.point), Vec2d(info.normal), info.alpha)

        def shapes_collide(self, b):
            """Get contact information about this shape and shape b.

            Returns ContactPointSet
            """
            _points = cp.cpShapesCollide(self._shape, b._shape)
            return ContactPointSet._from_cp(_points)

        def _get_space(self):
            if self._space != None:
                return self._space._get_self() #ugly hack because of weakref
            else:
                return None
        space = property(_get_space,
            doc="""Get the Space that shape has been added to (or None).""")

    class Circle(Shape):
        """A circle shape defined by a radius

        This is the fastest and simplest collision shape
        """
        def __init__(self, body, radius, offset = (0, 0)):
            """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.
            """

            self._body = body
            body_body = ffi.NULL if body is None else body._body
            if body != None:
                body._shapes.add(self)

            self._shape = ffi.gc(
                cp.cpCircleShapeNew(body_body, radius, offset), cp.cpShapeFree)
            self._set_shapeid()

        def unsafe_set_radius(self, r):
            """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)

        def _get_radius(self):
            return cp.cpCircleShapeGetRadius(self._shape)
        radius = property(_get_radius, doc="""The Radius of the circle""")

        def unsafe_set_offset(self, o):
            """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!
            """
            cp.cpCircleShapeSetOffset(self._shape, o)

        def _get_offset (self):
            return Vec2d(cp.cpCircleShapeGetOffset(self._shape))
        offset = property(_get_offset, doc="""Offset. (body space coordinates)""")

    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.

        It is legal to send in None as body argument to indicate that this
        shape is not attached to a body.
        """
        def __init__(self, body, a, b, radius):
            """Create a Segment

            :Parameters:
                body : `Body`
                    The body to attach the segment to
                a : (x,y) or `Vec2d`
                    The first endpoint of the segment
                b : (x,y) or `Vec2d`
                    The second endpoint of the segment
                radius : float
                    The thickness of the segment
            """
            self._body = body
            body_body = ffi.NULL if body is None else body._body
            if body != None:
                body._shapes.add(self)

            self._shape = ffi.gc(
                cp.cpSegmentShapeNew(body_body, a, b, radius), cp.cpShapeFree)
            self._set_shapeid()

        def _get_a(self):
            return Vec2d(cp.cpSegmentShapeGetA(self._shape))
        a = property(_get_a,
            doc="""The first of the two endpoints for this segment""")

        def _get_b(self):
            return Vec2d(cp.cpSegmentShapeGetB(self._shape))
        b = property(_get_b,
            doc="""The second of the two endpoints for this segment""")

        def unsafe_set_endpoints(self, a, b):
            """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!
            """
            cp.cpSegmentShapeSetEndpoints(self._shape, a, b)

        def _get_normal(self):
            return Vec2d(cp.cpSegmentShapeGetNormal(self._shape))
        normal = property(_get_normal,
            doc="""The normal""")

        def unsafe_set_radius(self, r):
            """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)
        def _get_radius(self):
            return cp.cpSegmentShapeGetRadius(self._shape)
        radius = property(_get_radius,
            doc="""The radius/thickness of the segment""")

        def set_neighbors(self, prev, next):
            """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.
            """
            cp.cpSegmentShapeSetNeighbors(self._shape, prev, next)

    class Poly(Shape):
        """A convex polygon shape

        Slowest, but most flexible collision shape.

        It is legal to send in None as body argument to indicate that this
        shape is not attached to a body.
        """

        def __init__(self, body, vertices, transform=None, radius=0):
            """Create a polygon.

                A convex hull will be calculated from the vertexes automatically.

                body : `Body`
                    The body to attach the poly to
                vertices : [(x,y)] or [`Vec2d`]
                    Define a convex hull of the polygon with a counterclockwise
                    winding.
                transform : `Transform`
                    Transform will be applied to every vertex.
                radius : int
                    Set the radius of the poly shape. Adding a small radius will
                    bevel the corners and can significantly reduce problems where
                    the poly gets stuck on seams in your geometry.
            """

            self._body = body

            body_body = ffi.NULL if body is None else body._body
            if body != None:
                body._shapes.add(self)

            if transform == None:
                transform = Transform.identity()

            s = cp.cpPolyShapeNew(body_body, len(vertices), vertices, transform, radius)
            self._shape = ffi.gc(s, cp.cpShapeFree)
            self._set_shapeid()

        def unsafe_set_radius(self, radius):
            """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)

        def _get_radius(self):
            return cp.cpPolyShapeGetRadius(self._shape)
        radius = property(_get_radius,
            doc="""The radius of the poly shape. Extends the poly in all
            directions with the given radius""")

        @staticmethod
        def create_box(body, size=(10,10), radius=0):
            """Convenience function to create a box.

            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(...).

                body : `Body`
                    The body to attach the poly to
                size : `(w,h)` or `Vec2d` or `BB`
                    Size of the box
                radius : `float`
                    Adding a small radius will bevel the corners and can
                    significantly reduce problems where the box gets stuck on
                    seams in your geometry.

            """

            self = Poly.__new__(Poly)

            self._body = body

            body_body = ffi.NULL if body is None else body._body
            if body != None:
                body._shapes.add(self)

            if isinstance(size, BB):
                self._shape = ffi.gc(
                    cp.cpBoxShapeNew2(body_body, size._bb[0], radius),
                    cp.cpShapeFree)
            else:
                self._shape = ffi.gc(
                    cp.cpBoxShapeNew(body_body, size[0], size[1], radius),
                    cp.cpShapeFree)

            self._set_shapeid()

            return self

        def get_vertices(self):
            """Get the vertices in local coordinates for the polygon

            :return: [`Vec2d`] in local coords
            """
            verts = []
            l = cp.cpPolyShapeGetCount(self._shape)
            for i in range(l):
                verts.append(Vec2d(cp.cpPolyShapeGetVert(self._shape, i)))
            return verts

        def unsafe_set_vertices(self, vertices, transform=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 == None:
                cp.cpPolyShapeSetVertsRaw(self._shape, len(vertices), vertices)
                return

            cp.cpPolyShapeSetVerts(self._shape, len(vertices), vertices, transform)