Core declares the physics role: Physics_Interface, Rigidbody, Box_Collider #69

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opened 2026-09-05 09:35:07 +00:00 by crowmaki · 0 comments

crowmaki commented

2026-09-05 09:35:07 +00:00

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Part of #67.

What to build

Core declares the physics role and implements none of it, as it does for Backend, Platform and Input. The ABI Surface gains Physics_Interface, the Rigidbody and Box_Collider Component structs, and the enums and ray-hit struct they use; every field is a Boundary Type. The roles file reserves cinnabar.physics/1 and the Schema names cinnabar.rigidbody and cinnabar.box_collider. Body and shape ids are u64 Transient Fields.

The Interface carries set_gravity, gravity, ray_cast, fixed_delta and body_count, each taking self first, shaped so contacts and a character controller can be added later without redesign.

Documentation lands with it: glossary entries for Rigidbody, Collider, Physics Interface, Implicit Static Body and Body User Tag; the Interface entry names Physics as a Core-declared role; a dated note on ADR-0003 records the third role; ADR-0016's heading reads 0016 and its research citation points at something that exists.

Acceptance criteria

The compile-time ABI Surface test passes with the new types and closes over every type they name.
With no physics Plugin listed, acquiring the Physics Interface reports not found and both Schema names report absent.
Rigidbody has body type (Static, Kinematic, Dynamic), initial linear velocity, gravity scale, and transient body ids; Box_Collider has half extents, friction, restitution, density and a transient shape id.
Glossary, ADR-0003 note, and ADR-0016 fixes are in place.

Blocked by

None (can start immediately).

## Parent Part of #67. ## What to build Core declares the physics role and implements none of it, as it does for Backend, Platform and Input. The ABI Surface gains `Physics_Interface`, the `Rigidbody` and `Box_Collider` Component structs, and the enums and ray-hit struct they use; every field is a Boundary Type. The roles file reserves `cinnabar.physics/1` and the Schema names `cinnabar.rigidbody` and `cinnabar.box_collider`. Body and shape ids are `u64` Transient Fields. The Interface carries `set_gravity`, `gravity`, `ray_cast`, `fixed_delta` and `body_count`, each taking `self` first, shaped so contacts and a character controller can be added later without redesign. Documentation lands with it: glossary entries for Rigidbody, Collider, Physics Interface, Implicit Static Body and Body User Tag; the Interface entry names Physics as a Core-declared role; a dated note on ADR-0003 records the third role; ADR-0016's heading reads 0016 and its research citation points at something that exists. ## Acceptance criteria - [ ] The compile-time ABI Surface test passes with the new types and closes over every type they name. - [ ] With no physics Plugin listed, acquiring the Physics Interface reports not found and both Schema names report absent. - [ ] `Rigidbody` has body type (Static, Kinematic, Dynamic), initial linear velocity, gravity scale, and transient body ids; `Box_Collider` has half extents, friction, restitution, density and a transient shape id. - [ ] Glossary, ADR-0003 note, and ADR-0016 fixes are in place. ## Blocked by - None (can start immediately).

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2026-09-05 09:35:07 +00:00

crowmaki referenced this issue

2026-09-05 09:36:49 +00:00

A cube falls onto a plane: the box3d Plugin, Rigidbody and Box_Collider lifecycle, and the fixed step #71

crowmaki referenced this issue from a commit

2026-09-06 23:32:49 +00:00

Core declares the physics role: Physics_Interface, Rigidbody, Box_Collider (#69)

crowmaki referenced this issue from a pull request that will close it,

2026-09-06 23:32:59 +00:00