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cultmath: regenerate CultMath.glsl for the snoise read constants

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Generated by CULTMATH_WRITE_GLSL=1 on Yggdrasil; glsl-parity.json is unchanged (the af and
span families keep their bytes). Builds.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
This commit is contained in:
Meta Vens 2026-10-16 06:35:34 +02:00
commit b37e07a52c
1 changed files with 9 additions and 3 deletions
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12
packages/cultmath/shaders/CultMath.glsl
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@ -748,6 +748,12 @@ vec4 cultmath_iv_frustum_ball(vec2 centreSlope, float z0, float z1, float footpr
// math.Affine.cs (SNOISE_HESSIAN).
const float CULTMATH_SNOISE_HESSIAN = 55.642143;
// The absolute rounding of one float32 read of cultmath_snoise_grad, value and gradient; the owner is
// math.Affine.cs (SNOISE_READ_VALUE, SNOISE_READ_GRADIENT), read here by cultmath_af_snoise and in
// CultMath.hlsl by cultmath_span_slack.
const float CULTMATH_SNOISE_READ_VALUE = 6.103515625e-5;
const float CULTMATH_SNOISE_READ_GRADIENT = 2.44140625e-4;
// An upper bound on the operator norm of the third-derivative tensor of cultmath_snoise(vec3), the
// next order after CULTMATH_SNOISE_HESSIAN; provenance in math.Span.cs (SNOISE_THIRD).
const float CULTMATH_SNOISE_THIRD = 535.8009;
@ -823,7 +829,7 @@ vec3 cultmath_af_snoise(vec3 centre, vec3 axis, float radius)
float lipschitz = CULTMATH_SNOISE_LIPSCHITZ * reach;
float a = dot(gradient, axis);
float remainder = length(gradient) * radius + 0.5 * CULTMATH_SNOISE_HESSIAN * reach * reach;
float allowance = 6.103515625e-5 + 2.44140625e-4 * reach
float allowance = CULTMATH_SNOISE_READ_VALUE + CULTMATH_SNOISE_READ_GRADIENT * reach
+ CULTMATH_SNOISE_LIPSCHITZ * 9.5367431640625e-7 * (abs(centre.x) + abs(centre.y) + abs(centre.z) + reach);
bool centred = abs(a) + remainder < lipschitz;
float slope = centred ? a : 0.0;
@ -912,8 +918,8 @@ float cultmath_span_rounding(float scale, vec3 mq, SpanStage stage, vec3 octaveS
vec3 cultmath_span_slack(float rounding)
{
return vec3(6.103515625e-5 + CULTMATH_SNOISE_LIPSCHITZ * rounding,
2.44140625e-4 + CULTMATH_SNOISE_HESSIAN * rounding,
return vec3(CULTMATH_SNOISE_READ_VALUE + CULTMATH_SNOISE_LIPSCHITZ * rounding,
CULTMATH_SNOISE_READ_GRADIENT + CULTMATH_SNOISE_HESSIAN * rounding,
9.765625e-4 + CULTMATH_SNOISE_THIRD * rounding);
}