sim-lib-interference-solve

Deterministic CPU f64 reference solving for coherent scalar wave fields.

The crate consumes the checked, dependency-free model and preflight records from sim-lib-interference-core. It stores host results as separate row-major real and imaginary component planes and carries the exact sampling and work evidence that admitted each complete field. Its fail-closed verification suite checks analytic propagation identities, reciprocity, linearity, rigid-motion covariance, global phase, canonical source permutations, the outgoing time sign, and second-order seven-point Helmholtz residual convergence across point, plane, mixed, attenuating, and multi-source fields.

The solver executes a homogeneous, isotropic, three-dimensional scalar free-field model. It does not model polarization, impedance, interfaces, obstacles, or diffraction. Its amplitude-squared projections and detector reductions are normalized observables, not physical intensity, power, or energy.

Scalar projection provides real, imaginary, amplitude, phase, normalized squared magnitude, and instantaneous observations. Phase at or below its declared amplitude floor is represented as a mask, never a number. Reduction uses explicit complex-mean, scalar-area, or squared-magnitude-area detector rules over every source cell exactly once; detail mode refuses a smaller target. Every scalar result carries source and target dimensions, footprint, loss class, source sampling evidence, and mask count.

analyze_fringes accepts only amplitude-like projections and returns deterministic field statistics, strict eight-neighbour node/antinode candidates, and optional Michelson contrast. Every report keeps both its unchanged sampling certificate and its exact projection identity. Contrast is absent when the whole field lies at or below the caller's amplitude floor.

ScenarioBuilder creates bounded two-point, inward counter-propagating plane, progressive-phase line-array, and rectangular discrete-aperture problems. Counts and generated identity storage are checked before allocation. Array/aperture total amplitude is divided equally among elements; certificates report active neighbour spacing in wavelengths. Strict aperture policy refuses spacing above lambda/2, while annotate policy preserves the approximation. The crate has no SIM runtime, tensor, compute-provider, or presentation dependency.