Measured with Stryker once Solve was actually mutated (21 survivors), most of
them were code that decided nothing:
- The finite-input loops over A and b duplicated the non-finite test on the
accumulated A^T b, which is exactly equivalent (floats cannot overflow a
double product, and NaN/infinity never cancel to a finite value). One check
on each A^T b entry remains.
- The tolerance scale is the gradient at the box point nearest the origin,
computed inline; the max with |A^T b| duplicated it whenever the origin is in
the box, and the scratch vector for it is gone.
- Bound violation is state * gradient, which is zero for a free column; the
three-way ternary duplicated the free-stationarity check.
- The warm-start clamp is Math.Clamp plus a NaN test.
- Workspace slices come off a cursor (Take) instead of hand-summed offsets.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Stryker left the refinement step (removed, negated, or subtracted) unobserved,
and it is unobservable for a reason: refinement with a same-precision residual
does not improve forward error, and Cholesky is backward stable, so the
residual the KKT test reads is already at rounding level. Measured on n=24
problems at cond(A) 1e3..1e6, the solver with and without the step gives the
same iteration counts and the same x error against a Gram-Schmidt QR
reference (both limited by cond(A^T A) * eps).
The refinement pass, its dp buffer and the scratch vector are deleted;
WorkspaceLength returns to 4n^2 + 15n. The doc states where the normal
equations stop being optimal (cost gap below 1e-6 |b|^2 through cond(A) 3e5,
about 2e-5 at 1e6, independent of the scale of A) and that a ridge row beyond
that is the caller's policy.
status is now initialised: the unassigned local made Stryker discard every
mutant inside Solve as a compile error, so 255 mutants were never measured.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
- n=24 fully free problems at cond 1e2/1e3/1e4, and A x 1e6 with unscaled
bounds, converge in at most two iterations (a regression to cap-spinning
fails on the count, not on a clock).
- b = 0 from a far start reaches the optimum instead of the start.
- Warm-start clamp table, free duplicate column gets no step, parallel columns
at absolute scales 1e3 and 1e-3, near-singular free sets confirm once and
stop, near-collinear optimum at A x 1e6, and zero allocation on the invalid,
converged and cap paths (first and second call).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
The working iterate now lives in double inside the workspace (WorkspaceLength
4n^2 + 17n); A, b and the API x stay float and x is converted in at the start
and out at the end. The gradient, the free-stationarity check and the KKT test
all run in the double domain, which removes the float noise floor that made the
free-stationarity re-solve spin to the cap on optimal points (cond >= ~20).
A fixed tolerance is no longer the only stopping rule: after a stationarity
miss or a release, a pass that lowers the double cost by no more than rounding
reports Converged.
The tolerance scale is the larger of the gradient at the origin and at the box
point nearest the origin, so it never depends on the warm start; b = 0 with a
far start is no longer judged converged by its own steepness.
Two clauses were equivalent or unobservable and are deleted: the d <= 0 pivot
test (implied by d <= tol * diag) and the dependent[] exclusion from the
free-stationarity check (the progress rule now terminates it).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
The operator ruled Q6 (a) on 2026-09-29: this branch lands on main before
route continuity cut C1 changes it. What lands is the ten 09-28 commits
that StreamPixels pins at 542ddd3, plus the Soul-gated fixes:
- runtime presence and daemon-health details are bounded by UTF-8 bytes
through one helper, made well formed first, matching the Rust owner's
len() > 512;
- the dead readAuthorityRecordBytes is deleted;
- the TypeScript packages require Node >= 20.
Soul confirmed byte-level wire parity with Idunn's Rust owners on real
Rust-written bundles, including the full write-lease flow. cultnet-ts has
90/90 tests on node:24. Capability-floor split authority, forced active
and the http-only route filter are recorded for C1.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The UTF-8 detail bound calls String.prototype.toWellFormed, which
Node 20 introduced. Node 18 reached end of life in April 2025, and CI
runs Node 24. All four TypeScript packages move together so the family
keeps one floor.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
signed-daemon-health sliced detail at 512 UTF-16 units while the Rust owner
counts bytes, so 300 x "é" failed shape validation. truncateUtf8Bytes now
serves runtime presence and both daemon-health sites, replacing
truncateRuntimePresenceDetail. It makes the string well formed first, so a
lone surrogate becomes U+FFFD instead of invalid UTF-8 in msgpack. The
unsigned payload is extracted as unsignedDaemonHealthPayload so it can be
tested without a socket.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
The Rust owner refuses detail over 512 UTF-8 bytes; TypeScript counted
UTF-16 units, so 300 x "é" was signed and then refused, and a slice inside a
surrogate pair produced invalid UTF-8. One helper,
truncateRuntimePresenceDetail, now cuts on a code point boundary at 512
bytes and serves both the publisher and validateRuntimePresence.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Soul pass 3 confirmed two documentation defects: the F6 search-radius proof
misstated 3 - 2m + 3m^2 at m=1/2 as 2.5 (actual 2.75; true min on [0,1/2] is
8/3 at m=1/3), and both math.cs and design.md cited a fabricated 203.8
chi-square statistic for float-bit hashing that Soul could not reproduce
(6+ seeds scored 7.7-30.9). Corrected the arithmetic and replaced the
unreproducible measurement with what actually pins integer hashing: the
oracle and mirror tests, and the chi-square test's real scope (the hash as
cellular calls it, not the call site itself). No test or code changed.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
EveryMirrorFunctionMatchesCSharpMath's generic random/special-value cases
never happen to hit a point where a radius-2 cell wins (about 3.5e-5 of
points) or an integer point at or past 2^23, so an HLSL mutant of cellular's
search radius, its lower-bound prune, or the removed F2=0 guard could change
cultmath_cellular's real output and still pass this test.
Adds three targeted point cases, reusing CellularAndSminGradTests' own
fixtures so the mirror test does not carry a second copy of the construction:
- the six points from AxisAlignedRadiusTwoOffsets/FindPointRealizingOffset,
each of which realizes a different axis-aligned radius-2 offset as F1 or
F2 in the independent 7x7x7 oracle;
- four integer points at 2^24 (both signs), where distinct cells' jittered
features can round onto the same float32 value, reaching the F2 = 0 guard;
- one exact F1 = F2 tie point, the midpoint of two adjacent cells' feature
points (bit-exact-equidistant from both by construction, no search
needed).
Verified against four HLSL mutants applied to shaders/CultMath.hlsl on
scratch copies (not committed) and reverted after each check:
- `dz < 2` instead of `dz <= 2`: killed by the axis-slice point at
(-56.671272, -67.01973, -79.001).
- `dx` starting at -1 instead of -2: killed by the axis-slice point at
(62, -77.91331, -79.42451).
- pruning against f1 instead of f2: killed by an axis-slice point and both
of the 2^24 integer points (3 mismatches).
- the F2 = 0 guard removed (`grad2 = (p - c2) / f2`, unconditional): killed
by the (2^24, 2^24, 2^24) integer point (NaN vs the guarded zero).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
CellularAndSminGradTests.cs changes for cut 2a-i's pass-2 findings:
- FeaturePoint and the two other independent pcg3d/pcg4d call sites now hash
int3(cell)/int4(int3(cellId), 0) to match production's integer-hashing fix
(previous commit); the oracle would otherwise diverge from cellular() and
every comparison test would fail.
- New JitterAndIdPassAChiSquareUniformityTest: jitter.x/y/z and id each pass
a chi-square uniformity test (16 bins, 15 df, critical value 37.7 at
alpha=0.001) over 200,000 cells. This is the behavioural pin for the
hashing fix; reverting to pcg3d(cell)'s float-bit hash fails it.
- Two false comments corrected to the measured facts: the
NearestFeatureWins test's claim that |component|=2 offsets are "provably
never the true nearest" is false (their lower bound is 1, not sqrt(3); Soul
measured 3 F1 wins in 2,000,000 samples), and SearchReachesEveryAxis...'s
claim of "lower bound is exactly 2" and "zero hits in 3,000,000" is also
false (lower bound is 1; Soul measured about 1 hit in 28,000).
- PrunedSearchIsBitIdentical... renamed to
...BelowTwoToTheTwentyFifth and its comment states that domain explicitly
(design.md, previous commit).
- GradientTolerance split into SminGradientTolerance (2.5e-4f) and
CellularGradientTolerance (1.3e-3f): the two functions have different
curvature (smin_grad is exactly quadratic in a band; cellular's F1/F2 are
real distance fields), so a shared 3e-4 tolerance carried almost no
headroom over either's actual measured noise (re-measured here at 5.3e-4
for smin's old eps, 2.0e-4/2.6e-4 for cellular), not the "~6e-5" the old
comment claimed. smin_grad's eps moves from 0.001f to 0.01f (no truncation
cost there; dilutes float noise 8x) with a matching widened seam-exclusion
band so p +/- eps cannot step across the seam the check at p already
avoided. cellular's eps stays at 0.0005f (a small sweep found it already
near the truncation/noise sweet spot for a real distance field). Both new
tolerances keep >5x headroom over their own measured worst case and both
still die under a 1.01x-scale mutant on the returned gradient — smin down
to 1.0005x, cellular (M9/M16-style, either gradient) down to 1.002x.
- GradientMatchesCentralDifferencesAwayFromTheF1EqualsF2Seam also excludes a
band around F2 = F3 now, not just F1 = F2: the second-nearest feature's
identity swaps there too, a genuine kink the old test could silently hit
(an unfiltered large sample found a 0.78 edge error this way, swamping the
~2e-4 the filtered test actually sees).
- AxisAlignedRadiusTwoOffsets and FindPointRealizingOffset are extracted from
SearchReachesEveryAxisAlignedRadiusTwoSlice as internal fixtures so
HlslSourceCompatibilityTests (next commit) can reuse the same construction
instead of a second copy.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
design.md follow-ups matching the math.cs/HLSL fix in the previous commit:
- The F6 "5x5x5 is exact" argument is rewritten with the corrected near-side
neighbour bound (choose the axis closest to its own boundary, not a fixed
axis), the m <= 1/2 derivation, and the counterexample that showed the old
argument wrong. Same text as the math.cs comment, so the two do not drift.
- "Integer hashing" now states that cellular hashes the winning cell's
integer coordinate, not its float32 bit pattern, and records the measured
chi-square evidence (203.8 over 1,000,000 cells, 15 df, critical value
37.7) for why the old bit-pattern hash failed a uniformity check.
- "Precision domain" gets a new paragraph: the lower-bound prune's bit
identity to the unpruned 5x5x5 search holds for |p| < 2^25, not
unconditionally. Above that, cell + offset itself starts to round in
float32, so the pruned and unpruned loops can visit different actual
neighbours at the same nominal offset (Soul, cut 2a-i: 180 of 1,100,000
points differ at |p| ~= 3.4e7). This is a float32 domain limit on the
equivalence proof, not a bug in the prune; the committed test's [-50, 50]^3
sweep is comfortably inside it.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Soul (cut 2a-i, pass 2) found two defects in cellular's own math.cs source
and its HLSL mirror:
- cellular hashed pcg3d/pcg4d over the FLOAT32 BIT PATTERN of each
integer-valued cell coordinate (pcg3d(neighbor), pcg4d(float4(cellId, 0)))
instead of the integer coordinate itself. Two adjacent cells' bit patterns
share more structure (same exponent, mantissa one increment apart) than
the integers do going into pcg3d's own mixing, and that structure survived
into the jitter: measured chi-square 203.8 for jitter.x over 1,000,000
cells against 15 degrees of freedom (critical value 37.7). Both call sites
now hash int3(neighbor)/int4(int3(cellId), 0) directly, in C# and in the
HLSL mirror (both shaders/CultMath.hlsl and the Unity copy, byte-identical
as before). This changes cellular's noise output — nothing has shipped, so
that is acceptable, but it is a real behavioural change, not a comment fix.
- The F6 exactness proof's "near-side neighbour" bound was wrong as written:
picking the near-side neighbour on a FIXED axis is not always within
sqrt(3) of the query (counterexample: u = (0.5, 0, 0) with the x-neighbour
jittered to (-1, 1-2^-24, 1-2^-24) gives ~2.06, past the radius-2
exclusion). The comment is rewritten to the correct argument: choose the
axis whose u_i sits closest to a cell boundary (m = min(u_i, 1-u_i) <=
1/2 on that axis), and the near-side neighbour on THAT axis has squared
distance at most (1+m)^2 + 2*(1-m)^2 = 3 - 2m + 3m^2 <= 3 on [0, 1/2],
strictly below 3 since the jitter never reaches the boundary. Margin
2 - sqrt(3) ~= 0.268 (Soul's adversarial check: worst in-box F2 is exactly
sqrt(3), only in the unattainable corner limit).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Stryker (mtp, --since 29e50ad3) found 261 survivors / 24 timeouts across the
whole repo; triaging the ones in this fix batch's own new code (cellular's
loop, its prune, cellular_unit) surfaced one real gap disguised as
collateral timeout noise from a batched infinite-loop mutant: dz < 2 (and
the dy/dx equivalents), silently dropping the +2 layer on one axis alone,
passed every existing random-sampled test. That is not the sweeps being
weak: the exactness proof's own margin (F1, F2 always < sqrt(3), radius-2
cells' lower bound is exactly 2) makes a genuine win from any single
|offset component| = 2 cell astronomically rare over uniformly random
points (measured zero hits in 3,000,000 samples).
SearchReachesEveryAxisAlignedRadiusTwoSlice constructs a real example for
each of the six axis-aligned radius-2 offsets directly: for a candidate
integer cell, build the query point that is the closest point of that
cell's own unit cube to the target neighbour's actual jittered feature.
That construction finds a hit for every offset within a couple thousand
candidate cells, deterministically. This kills dz < 2 / dy < 2 / dx < 2 (all
manually confirmed).
Also manually confirmed via Stryker's own reported mutants: the dz--/dy--/
dx-- (increment-to-decrement) mutants are genuine infinite loops, correctly
caught as timeouts. The f2 >= 0.0f mutant (disabling the F2 = 0 guard) is
killed by the existing NoNaNAtIntegerPointsNear2To24 test. The remaining
survivors/timeouts in the new code (the lower-bound prune's >>= vs >
comparison, its arithmetic terms, and cellular_unit's >> vs >>> shift on an
already-unsigned operand) are equivalent mutants: since the per-axis lower
bound is always 0 or 1 by construction, and pruning is a proven-safe
optimization that never changes cellular's output, no mutation confined to
"when does the prune trigger" can be observed by any value-based test.
Verified by hand: disabling pruning entirely reproduces the unpruned
reference bit for bit, as it must.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Asura Cut 2 (GameCult/Asura docs/cut-map.md). CultGeometrySurfaceNets.Extract
emits a welded quad mesh with each quad named by the grid edge it crosses,
(cell, axis), in strictly ascending order; orientation comes from the inside
flag and a per-axis handedness table, one authority. Face-weighted normals
are area-weighted via quad diagonals. Non-finite inputs are rejected.
Stryker is scoped to GameCult.Geometry.
Closed after three Soul passes; byte-identical behaviour across the
closing refactor on 31 fixtures. The 7 GeometryDocumentTests failures
predate this merge (e420410, registry check D11) and are tracked
separately.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
- smin_grad is Quilez's quadratic-polynomial smin, not cubic.
- cellular's search radius is 5x5x5 (F6), not 3x3x3; adds the exactness
proof and the pruning claim.
- id source is now pcg4d over the winning cell, not the pcg3d hash that
produced its jitter (F4).
- F2 = 0 is documented as reachable (past |p| of about 2^23), not
unreachable; removes the false "unreachable" claim and adds a "Precision
domain" note stating the float32 feature-spacing/tie behaviour honestly
(F3, minor finding).
- The struct-mirror comparison note now says it also matches field name and
type in declaration order, not just position (F2).
No entry added to THIRD-PARTY-NOTICES for the Quilez/Worley formulas: per
Self's standing ruling, a published formula is not ported code.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Cut 2a-i fix batch 1, findings F1, F3, F4, F5, F6, F7 (Soul falsification of
the first landing):
- cellular now searches a provably exact 5x5x5 neighbourhood (radius 2), not
3x3x3: 3x3x3 missed the true F2 for 9 of 400,000 sampled points. The
comment in math.cs proves 5x5x5 always contains the true F1 and F2 (both
are always < sqrt(3), every excluded cell is always > 2). A cheap
position-only lower-bound prune skips the pcg3d/jitter/distance work for
cells that provably cannot beat the running F2, without changing any
output bit (F6).
- F2 = 0 now gets the same degenerate-gradient guard F1 = 0 already had,
fixing a NaN that was reachable past |p| of about 2^23 (F3).
- id now comes from pcg4d over the winning cell alone, never from the pcg3d
hash that produced that cell's jitter, so id and jitter are no longer
deterministic functions of each other (F4).
- cellular_unit maps the top 24 bits instead of a plain divide-by-2^32, so
the mapping is always inside [0, 1); the old formula rounded
0xFFFFFF80..0xFFFFFFFF up to exactly 1.0f (F7).
- Central-difference tolerances tightened from 0.02 to 3e-4 (measured float
noise at the committed eps is about 6e-5), and cellular's own gradient
test now differentiates cellular's RETURNED .w values instead of a
duplicate FindF1F2 search, so a mutant that corrupts only the returned
gradient can't hide behind an independently-computed value (F1, F5).
- The struct-mirror comparison in HlslSourceCompatibilityTests now checks
field name and declared type in declaration order, not just position, so
a reordered-and-relabelled mirror struct (H2) or a renamed/retyped one
(H3) both fail the walk instead of surviving on values alone (F2).
- FindF1F2 widened to a true independent 7x7x7 brute-force oracle; new tests
pin production's exact agreement with it, the pruned search's bit-for-bit
equivalence to an unpruned 5x5x5 reference, no NaN at 2^24, and id's
correlation with jitter under 0.05.
- Comment/doc fix: smin_grad is Quilez's quadratic-polynomial smin, not
cubic.
Both shaders/CultMath.hlsl and unity/.../Shaders/CultMath.hlsl stay
byte-identical.
Manually verified mutants M9 (grad1 x 1.01), M16 (grad2 x 1.01), and M18 (id
from hash.y) all die against these tests; H2/H3 struct mutants die via the
new comparator tests. Local dotnet test: 191/191 passing. FXC cs_5_0 compile
of a scratch kernel using both cultmath_smin_grad and cultmath_cellular
succeeds.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
samples and cellSize were validated but isoValue and origin were not:
iso = NaN or +inf silently returned an empty mesh, and origin = NaN gave
NaN positions. Extend Extract's existing top-of-method validation authority
to reject non-finite isoValue and non-finite origin components with
ArgumentException, matching the existing style, with tests for each
component.
Overflow at extreme magnitudes (cellSize ~3e38, or finite samples whose
interpolation overflows to inf) is a separate, float-domain limit rather
than a validated-input error; documented in the XML doc and provenance
notes, deliberately not range-checked.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
TryGetOtherEndpoint's bool return was dead control flow: when a mutant
flipped its `return false` guard to `return true`, `other` stayed a clone
of `coord` (only one component would have been incremented on the true
path that never runs for that guard), so the caller compared a sample
against itself and behaved identically either way. That produced the
equivalent survivors at Extract's :92 continue and the guard's :198
return.
Bound the edge loop with the same condition (coord[axis] < cellCounts[axis])
directly, computing `other` inline once the bound holds. One path instead
of two that happened to agree; the helper is gone, and so is the `continue`
that used to depend on it. Behaviour is unchanged: verified with a
before/after run of the existing suite plus a temporary harness comparing
Extract's Positions/Quads/QuadEdges against ca220a5's code on sphere,
non-cubic, open-plane (each axis), checkerboard, and minimal 2x2x2
fixtures - all byte-for-byte identical.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Mutating obj is CultGeometryGridEdge other && Equals(other) to && true
passed the suite: nothing exercised object.Equals directly with a mismatched
X/Y/Z/Axis, null, or an unrelated type. Add a behavioural test that checks
each component independently, rejects null and other types, and agrees with
the typed Equals and GetHashCode.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
The provenance doc still described the deleted geometric winding rule
(diagonal cross product must have a positive dot product with the
inside->outside direction) as the spec. That rule was replaced by the
inside-flag times per-axis handedness table (OrientationSign: +1, -1, +1;
axis 1's perpendicular pair (X, Z) is left-handed) when the geometric
fallback was deleted. State that as the actual rule, with the
outward-cross-product property following only on non-degenerate quads.
Also record that non-finite isoValue/origin are rejected.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
The `==`->`!=` and `< 0`->`> 0` mutants on Extract's orientation check are
both Killed. The one survivor, `OrientationSign[axis] <= 0`, is an
equivalent mutant, not a coverage gap: OrientationSign only ever holds ±1,
so `< 0` and `<= 0` agree on every value it can produce. No vstest
coverage-based false survivor has actually been confirmed for
GameCult.Geometry; remove the withdrawn claim and keep the correct notes
about full-SHA --since, safe.directory, and config-change scope fan-out.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Stryker's diff-scoped run against this cut reported CultGeometrySurfaceNets
.Extract's `if (inside == (OrientationSign[axis] < 0))` - the sole authority
for quad winding after F4's fix deleted the geometric cross-product fallback
- as a Survived Equality mutation (== -> !=). Hand-mutating it and running
dotnet test directly failed 4 of 38 SurfaceNetsTests (the three per-axis
corner-order tests and the outward-winding test), confirming it is a real
vstest coverage-based test-selection miss, not a genuine gap. Recorded this
as a second confirmed case alongside the mtp/static-readonly-initializer
caveat, per this cut's verification requirement to hand-confirm any survivor
that looks like it must be covered.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Stryker (scoped to this cut's diff) survived two mutants on the grad2 ternary
in math.cellular: forcing the true branch unconditionally, and loosening
f2 > 0.0f to f2 >= 0.0f. Both are real findings about the code, not the
tests: F2 = 0 needs two distinct integer cells' pcg3d-jittered feature points
to land on the exact float32 value in every component, which the jitter's
~24-bit float precision makes unreachable for any p this function is
actually called with. The spec only asks for the degenerate guard at F1 = 0;
F2's copy of it was added for symmetry and had no reachable case to defend.
Deleted the guard (grad2 is now a bare (p - c2) / f2) in math.cs and both
HLSL mirrors, and corrected design.md's invariant-8 section, which had
overstated this as symmetric with F1's guard.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
The three TryGetOtherEndpoint survivors were triaged as a vstest coverage
false-survivor, mirroring the confirmed mtp/static-readonly caveat above.
That triage was wrong: the actual mutant is `return false` -> `return true`
inside each per-axis guard, which is equivalent (it makes the method report
an edge going nowhere, so the caller compares a sample against itself and
skips it exactly as it would with a correct `false`). Rewrote the paragraph
to say so, and removed the unsupported claim that this project has a
confirmed vstest false-survivor case. Also recorded, per this cut's
verification requirements, that `--since` needs a full commit SHA and that
`safe.directory` must be set in a container.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
- Fixed An_extremely_small_edge_delta_falls_back_to_the_edge_midpoint (renamed
A_tiny_but_normal_edge_delta_...): it pinned the wrong value (1/6) for the
fallback that F3's production commit deleted; now asserts the exact
interpolated value, hand-derived in double precision independently of
Interpolate. Added a genuinely subnormal-delta sibling test.
- Added two more vertex-placement fixtures (crossing counts 4 and 6) to kill
the sum/count -> sum/3 mutant, each with a hand-derived expected mean.
Counts of 1 and 2 from the finding are not used: a single cell's 12 edges
form the cube graph Q3 (3-regular, 8 vertices), whose edge-cut size for any
corner sign pattern is never 1 or 2 for any nonzero cut (minimum nonzero
cut is 3, already covered by the existing symmetric/unequal fixtures) -
see the fork note in this cut's report.
- Added three corner-order pinning tests (one per axis), each asserting the
exact welded vertex at each of Quads[0..3] for a chosen edge against a
hand-computed position, including the axis-1 v1/v3 swap that F4's fixed
OrientationSign now performs. These kill the axis-0-mirrored, c0/c2-swapped
and equivalent per-axis corner-order mutants.
- Added four degenerate-quad orientation tests (sample exactly at iso,
large-origin/tiny-cellSize sphere, octahedron at iso, tiny-tolerance
sphere) asserting every shared undirected edge is traversed in opposite
directions (net zero), via a new AssertEdgeDirectionsBalance helper that
also covers the 4-use case. Restricted the existing
Every_quad_winds_outward_from_inside_to_outside test's geometric check to
non-degenerate (non-zero cross product) quads, per spec.
- Added Grid_edge_inequality_is_the_negation_of_equality (F6: != is compiler-
mandated alongside ==, and needed its own direct test) and
A_non_finite_sample_is_rejected (F7: NaN and +-Infinity samples).
All 38 SurfaceNetsTests pass; the 7 pre-existing GeometryDocumentTests
failures from CultLib commit e420410 are untouched.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
F1: Extract's locals (position, v0..v3) were assigned through pattern-match
and short-circuited out-var chains whose definite-assignment analysis breaks
under a single mutated operator, so Stryker's Safe Mode dropped all 98
mutants in Extract as compile errors. Restructured to plain null checks and
a for-loop over a uint[4] so every local is unconditionally assigned; no
mutation of a boolean operator can make it fail to compile.
F3: deleted the `<= 1e-20f` fallback in Interpolate. A straddling edge always
has delta > 0 (.NET preserves subnormals), so the guard only ever replaced a
correct interpolated value with a wrong 0.5 midpoint.
F4: deleted the per-quad geometric cross-product winding test. Orientation
now comes only from the topological inside/outside flag plus a fixed
per-axis handedness sign (OrientationSign; axis 1's (X, Z) perpendicular
pairing is the one left-handed case, X x Z == -Y). This is now determined
purely by which endpoint of the crossing edge is inside and the axis, never
by quad geometry, so degenerate (zero-area) quads orient consistently with
their neighbours instead of falling back to an unstable dot-product sign.
F7: Extract now rejects any non-finite sample (NaN or +-Infinity) with
ArgumentException, in the same style as the existing shape/cellSize checks.
F8: collapsed three duplicated (edge, axis) mappings - TryGetOtherEndpoint's
per-axis switch, the three Axis*EdgeStarts tables plus the axis==0?1:0
ternaries in AccumulateAxisEdges, and TryGetQuadCells' three axis-specific
corner blocks - into one PerpAxes/PerimeterLoop table pair, used by all
three. Replaced the three duplicated `<= isoValue` inside tests with one
IsInside predicate. Deleted the per-axis trailing `InRange(x, cellsX)` /
`InRange(y, cellsY)` / `InRange(z, cellsZ)` checks (provably always true,
since TryGetOtherEndpoint already guarantees the edge's own-axis coordinate
indexes a valid cell) and the explicit TryGetValue+throw invariant guard
(the four cells around a crossing edge are proven to always have a vertex;
a direct dictionary index now fails loudly via KeyNotFoundException if that
invariant is ever actually violated, with no reachable branch to maintain).
F6: deleted CultGeometryGridEdge's <, >, <=, >= operators (CultGeometryQuadMesh.cs).
Nothing in production or tests used them; ordering goes through CompareTo.
!= is kept only because C# requires it whenever == is defined (CS0216).
Builds clean; does not touch CultGeometryIsoSurface.cs, CultGeometryDocuments.cs,
or ISOSURFACE-PROVENANCE.md.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
dotnet test found two failures where a fixed-decimal-place Assert.Equal
snapped two numbers that already agreed to within about 2e-5 to different
rounded digits, because their true difference straddled a rounding boundary
(0.824987829 vs 0.825006127 -> 0.82 vs 0.83). Both were central-difference
checks (smin_grad's own invariant-8 property test, and cellular's gradient-
matches-central-differences test), not a correctness bug in the primitives.
AssertWithinTolerance replaces the precision-based assertion for both central-
difference comparisons with an explicit absolute-difference check, which
states the actual claim (agreement within the finite-difference step's own
truncation error) without the rounding-boundary artifact. Also dropped an
unused local function (F2At) the build flagged.
Found by the third ygg-verify.sh test run on 77c3580.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
