3 Commits
Author SHA1 Message Date
wyj b3f1e837d5 Alcubierre: support superluminal v_s 2026-10-06 02:51:20 -04:00
wyj f7380cbf75 Feat: Rework ray termination into escaped/dark/unresolved/incomplete
Replace the position capture cutoff with a camera-relative dark threshold
shared by every backend, and carry explicit outcome/reason provenance
through the ray, RayPool, adaptive mesh, lens-map and replay paths.

- eval/eval_slab return SpacetimePointStatus; remove SPACETIME_RAY_CAPTURED
  and the Schwarzschild capture radius; decouple observer construction from
  ray position.
- RayEndpoint stores RayOutcome/RayReason plus the last trusted state;
  budget exhaustion is retryable UNRESOLVED, data/integration failures are
  INCOMPLETE.
- Normal dark terminal is L - L0 >= --dark-threshold (default 8), with L0
  taken at the camera event and kept distinct from the worldtube entry
  energy; photon energy and frequency ratio are never reset.
- Implement E/D/U triangle decisions with merged budget retries, persistent
  probe witnesses promoted in place by vertex identity, conformity settling,
  and approximate-black boundary provenance with achieved-scale statistics.
- Add RayPool continuation state and per-ray step budgets.
- Bump lens-map to v2 with explicit end/outcome/reason, approx_black,
  threshold/retry/geometry provenance and per-frame retry counts; reject v1.
- Gate production output on incomplete/error results, overridable with
  --allow-incomplete.
- Update AGENTS.md, the design document and usage docs; add the termination
  oracle and regression coverage.

make -B -j4 BUILD_TYPE=Debug test passes with bit-identical reference HDRs.
2026-10-05 06:22:47 -04:00
wyj 3cbf5ba386 Feat: Add analytic moving Alcubierre spacetime backend
Add a third analytic spacetime provider for the moving Alcubierre warp
bubble, x_s(t) = v_s*t with x_s(0) = 0.  The lab slices stay flat, so
alpha = 1, gamma_ij = delta_ij, beta^x = -v_s f(r_s), and K_ij follows
from the flat spatial metric; the time dependence enters through the
moving shape argument.  The exotic matter is treated as transparent, so
there is no capture: rays are only ACTIVE or ESCAPED, with a bubble-
centered escape radius R + 20/sigma.

Expose --alcubierre-vs, --alcubierre-radius, and --alcubierre-sigma
(|v_s| < 1).  Scale the per-ray step budget with the escape radius and
1/(1-|v_s|) so near-luminal grazing rays still escape, and reject
parameter combinations whose worst-case budget exceeds the cap.  Use a
cancellation-free shape formula for small sigma*R and reject derived
escape radii that overflow.

The regression test covers metric reconstruction, d_beta/K finite
differences, the translation isometry, small-sigma stability, the flat
limit, reflection symmetry, step convergence, and a near-luminal slow
ray.  build.md, usage.md, and README.md document the backend.
2026-10-03 03:09:26 -04:00