The mirror compiles under using static CultMath.math, so it proves composition,
not intrinsic rules; HlslSemanticsTests alone pins those. design.md also states
where FMin/FMax/Saturate turn NaN or infinity into numbers and tells callers to
check isnan first.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
SequenceEqual on floats treats -0 as 0. The mirror test now compares
SingleToInt32Bits, with any NaN equal to any NaN. Its summary and
design.md now say the test proves CultMath.hlsl's text computes the same
float32 results as C# math on the CPU, not that a GPU agrees: driver sin
precision alone makes cultmath_hash and value noise differ on hardware.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Only cultmath_snoise was compared, at four inputs, so a flipped cultmath_step,
a changed hash constant, and a snoise2 tie change all passed. The mirror is
now discovered by reflection: every cultmath_* overload with a math
counterpart (26 functions) runs over 104 deterministic cases - each special
value in every argument (0, -0, +-1, ties, 1e-7, +-1e4, 1e7, NaN), special
pairs, seeded randoms, and vectors with x == y (snoise's x0.x == x0.y) - and
must match exactly. Both sides are float32 C# over the same intrinsics, so no
tolerance. A cultmath_* function with no counterpart must be named in
MirrorOnly. The four-input snoise theory is gone.
Mutations: flipped step args fail (349 mismatches); hash constants changed
by more than one float32 ulp fail (43758.55: 467, 127.2: 289, 74.8: 97).
43758.5453 -> .5454 is the same float32 and cannot fail. snoise2 x0.x > x0.y
-> >= is invisible: over 1,829,415 exact ties the result is bit-identical,
because the off-simplex corner's kernel is <= 0 on the shared edge.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
HlslSourceCompatibilityTests now reads shaders/CultMath.hlsl, applies only
the documented transformations (drop include guards, drop Texture2D/
SamplerState functions, file-scope static const -> const, f literal
suffixes, wrap in a class), and compiles it with Roslyn against CultMath.
Any compile error fails the test (probed with an undeclared call). The
compiled cultmath_snoise(float3/float2) also matches math.snoise.
dxc -T lib_6_3 -HV 2021 rejected the mirror: cultmath_snoise(float2) called
the undeclared cultmath_simplex_mod289/permute. Renamed to the declared
cultmath_snoise_* helpers. Vector const locals became plain locals (C# const
is primitives only), and cultmath_step uses value >= edge like HLSL step and
the C# mirror. dxc 1.9.0.5402 now compiles the file cleanly. The Unity
package's Shaders copy is synced.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
HLSL is now CultMath's semantic authority where it defines one.
- float2/3/4, int2, double2/3, bool2 and quaternion are plain structs with
public mutable fields instead of record structs. Indexers and swizzles
(float2.yx; float3 xy xz yx yz zy xyz xzy yzx zyx; float4 xy xyz xyw yzx)
have setters.
- ==, !=, <, >, <=, >= are component-wise and return bool2/3/4. Equals and
GetHashCode stay value-based so vectors remain dictionary keys.
quaternion is not an HLSL type and keeps a bool ==.
- Scalar/vector arithmetic and comparisons get explicit overloads on both
sides instead of leaning on implicit splat.
- New types: bool3, bool4, int3, int4, float2x2, float3x3 (row-major like
HLSL, _mRC fields, Rotate / RotateX/Y/Z / Euler with math.RotationOrder).
- New intrinsics: mul (matrix-vector both sides, matrix-matrix), any, all,
select (HLSL argument order), log, vector pow/sqrt/sin/cos/acos/atan2,
double min/max, int3/int4/bool3/bool4/float2x2/float3x3 constructor
functions.
- simplex_noise is renamed snoise and gains the Ashima 3D variant; the HLSL
mirror follows as cultmath_snoise(float2/float3).
- Random gains NextFloat3() and NextFloat3(float3 max) on the same draw order.
Tests pin snoise(float3), float3x3.Euler and float2x2.Rotate to
Unity.Mathematics reference values, and an HLSL-shaped source block compiles
under using static CultMath.math.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
