pymunk.batch
Module¶
- The batch module contain functions to efficiently get and set space data in
a batch insteaf of one by one.
Note
This module is highly experimental and will likely change in future Pymunk verisons including major, minor and patch verisons!
To get data out¶
First create space and two bodies.
>>> import pymunk, pymunk.batch
>>> s = pymunk.Space()
>>> b1 = pymunk.Body(1, 1)
>>> b1.position = 1,2
>>> s.add(b1, pymunk.Circle(b1, 4))
>>> b2 = pymunk.Body(1,1)
>>> b2.position = 3,4
>>> s.add(b2, pymunk.Circle(b2, 4))
To get data out first create a Buffer holder object, which is used to reuse the underlying arrays between calls. Then call the batch method. Note that the fields on the body to extract need to be specified explicitly.
>>> data = pymunk.batch.Buffer()
>>> pymunk.batch.get_space_bodies(
... s,
... pymunk.batch.BodyFields.BODY_ID | pymunk.batch.BodyFields.POSITION,
... data,
... )
The data is available in the Buffer object as cffi buffers. One that contains any int data, and one that contains floating point data. You can either use it directly like here, but also pass it in to 3rd parties that implements the buffer protocol like numpy arrays.
>>> list(memoryview(data.int_buf()).cast("P")) == [b1.id, b2.id]
True
>>> list(memoryview(data.float_buf()).cast("d"))
[1.0, 2.0, 3.0, 4.0]
Its also possible to get the arbiters with collision data. Note that we need to call step to run the simulation, and clear the data data buffers first so they can be reused:
>>> s.step(1)
>>> data.clear()
>>> pymunk.batch.get_space_arbiters(
... s,
... pymunk.batch.ArbiterFields.BODY_A_ID | pymunk.batch.ArbiterFields.BODY_B_ID,
... data,
... )
>>> list(memoryview(data.int_buf()).cast("P")) == [b2.id, b1.id]
True
>>> list(memoryview(data.float_buf()).cast("d"))
[]
To set data¶
(see planet.py example)
TODO
- class pymunk.batch.ArbiterFields(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)[source]¶
Bases:
Flag
Flag fields to specify arbiter properties to get.
- ALL = 65535¶
All the fields
- BODY_A_ID¶
pymunk.Body.id
of body A. Value stored in int_buf.
- BODY_B_ID¶
pymunk.Body.id
of body B. Value stored in int_buf.
- CONTACT_COUNT¶
Number of contacts (1 or 2)`. Value stored in int_buf.
- DISTANCE_1¶
pymunk.ContactPoint.distance
of contact 1. Value stored in float_buf.
- DISTANCE_2¶
pymunk.ContactPoint.distance
of contact 2. Value stored in float_buf.
- IS_FIRST_CONTACT¶
pymunk.Arbiter.is_first_contact
. Value (0 or 1) stored in int_buf.
- NORMAL¶
pymunk.Arbiter.normal
. X and Y stored in float_buf.
- POINT_A_1¶
pymunk.ContactPoint.point_a
of contact 1. X and Y stored in float_buf.
- POINT_A_2¶
pymunk.ContactPoint.point_a
of contact 2. X and Y stored in float_buf.
- POINT_B_1¶
pymunk.ContactPoint.point_b
of contact 1. X and Y stored in float_buf.
- POINT_B_2¶
pymunk.ContactPoint.point_b
of contact 2. X and Y stored in float_buf.
- TOTAL_IMPULSE¶
pymunk.Arbiter.total_impulse
. X and Y stored in float_buf.
- TOTAL_KE¶
pymunk.Arbiter.total_ke
. Value stored in float_buf.
- class pymunk.batch.BodyFields(value, names=None, *, module=None, qualname=None, type=None, start=1, boundary=None)[source]¶
Bases:
Flag
Flag fields to specify body properties to get.
- ALL = 65535¶
All the fields
- ANGLE¶
pymunk.Body.angle
. Value stored in float_buf.
- ANGULAR_VELOCITY¶
pymunk.Body.angular_velocity
. Value stored in float_buf
- BODY_ID¶
pymunk.Body.id
. Value stored in int_buf.
- FORCE¶
pymunk.Body.force
. X and Y stored in float_buf.
- POSITION¶
pymunk.Body.position
. X and Y stored in float_buf.
- TORQUE¶
pymunk.Body.torque
. Value stored in float_buf
- VELOCITY¶
pymunk.Body.velocity
. X and Y stored in float_buf.
- class pymunk.batch.Buffer[source]¶
Bases:
object
- clear() None [source]¶
Mark the internal arrays empty (for reuse).
It is more efficient to reuse the BatchedData object and its internal arrays by calling clear, than to create a new object each step.
- float_buf() pymunk._chipmunk.ffi.buffer [source]¶
Return a CFFI buffer object of the floating point data in the internal array.
- int_buf() pymunk._chipmunk.ffi.buffer [source]¶
Return a CFFI buffer object of the integer data in the internal array.
- pymunk.batch.get_space_arbiters(space: Space, fields: ArbiterFields, buffers: Buffer) None [source]¶
Get data for all active arbiters in the space.
Filter out the fields you are interested in with the fields property.
The data is returned in the batched_data buffers.
- pymunk.batch.get_space_bodies(space: Space, fields: BodyFields, buffers: Buffer) None [source]¶
Get data for all bodies in the space.
Filter out the fields you are interested in with the fields property.
The data is returned in the batched_data buffers.