Commit graph CultLib/packages/cultmath/README.md
Author SHA1 Message Date
Meta Vens
0acc3728ed CultMath: Phacelle port moves into MPL-2.0 files; prune cut pinned by boundary points
MPL-2.0 is file-level and the Phacelle port sat inside MIT files. phacelle and
CultPhasor now live in math.Phacelle.cs and CultPhasor.cs, and cultmath_phacelle
in CultMath.Phacelle.hlsl (included by CultMath.hlsl, both tracked copies), each
with the MPL header and Johansen / Luke Mitchell attribution. math stays one
partial class, so math.phacelle is called exactly as before. The GameCult.Math
package declares MIT AND MPL-2.0 and packs THIRD-PARTY-NOTICES.md and the new
include; the Unity LICENSE.md points at CultLib; build-unity-package.ps1
requires the new include.

The random sweeps never met a cell whose box bound sits just under the 2.25 cut
while its weight is still nonzero, so cuts of 2.245, 2.24 and 2.2 survived.
Six hard-coded points (found by an offline search) sit next to such cells; the
C# pruned-vs-unpruned test and the HLSL mirror test both use them, with a
witness check that re-derives the property from the hash.

Docs: the prune keeps about 45 of 64 cells (14 is the nonzero-weight count),
the support radius is 1.49998 (d^2 = 2.24995), normalization's range and
saturation, W = 0 only for adversarial hashes, and the support-edge gradient
seam size.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
2026-09-30 00:34:27 +02:00
Meta Vens
6e8362b7dc List erf/erfinv in the README's math vocabulary
They shipped without ever being added to the public surface list.
Scalar-only is noted explicitly: every other scalar in math.cs has
float2/3/4 overloads, erf/erfinv do not, and that stays a separate
scope decision since the only consumer (Aetheria fire control) is
scalar.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-22 21:30:07 +02:00
Meta Vens
111b918ec0 Make CultMath normalize follow dxc and release 0.2.2
dxc 1.9.0.5402 lowers float2/3/4 normalize(x) to x * Rsqrt(Dot(x, x)),
and DXIL.rst defines Rsqrt as 1 / sqrt(src). A zero vector normalizes
to NaN and a NaN component poisons every component. CultMath divided
by max(length, 1e-20), which returned 0 for a zero vector and a huge
finite component beside a NaN one.

- math.normalize(float2/3/4) is now value * (1 / sqrt(dot(value, value))).
- The HLSL mirror drops cultmath_normalize and its epsilon constant: it
  now equals the normalize intrinsic, and nothing consumed it.
- HlslSemanticsTests pins zero and NaN normalize, the rsqrt bit pattern,
  and zero length/distance. design.md states the rule and notes that
  DXIL.rst's Rsqrt special-value table is a copy of Round's.
- GameCult.Geometry's iso-surface gave degenerate triangles (an inside
  vertex on the isovalue) a zero normal through the old epsilon. It now
  guards them explicitly, with a test.
- quaternion normalize keeps its identity fallback: quaternion is not
  an HLSL type.
- Bump to 0.2.2 and rebuild the tracked Unity DLL and pdb.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-14 18:04:04 +02:00
Meta Vens
7a1bd1ebb1 Document the full HLSL target and its source transformations
design.md states the generated swizzle and mixed-constructor surface, writable
matrix rows, HLSL intrinsic types and NaN behavior, the deferred matrix items
(float4x4, transpose, determinant, _11 names), the exact HLSL-to-C#
transformations the compatibility test applies, and the dxc check.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
2026-09-14 13:57:03 +02:00
Meta Vens
63d6094c94 Clarify CultMath and CultGeometry ownership 2026-08-26 17:47:06 +02:00
Meta Vens
ea88cfcd05 Move CultMath into the CultLib monorepo 2026-08-26 17:35:51 +02:00