134 lines
5.6 KiB
Markdown
134 lines
5.6 KiB
Markdown
# CultMath (archived)
|
|
|
|
CultMath now lives in [`GameCult/CultLib`](https://github.com/GameCult/CultLib)
|
|
under `packages/cultmath`. This repository preserves pre-monorepo history and
|
|
release provenance; it is not the source or release authority.
|
|
|
|
Clean-room math shaped for people who think in HLSL.
|
|
|
|
CultMath provides lowercase vector types, shader-style intrinsics, and native
|
|
hot-path kernels so math-heavy renderer code can move between C#, Rust, and HLSL
|
|
without turning every line into a translation exercise. It is not a
|
|
Unity.Mathematics clone. It is a small, Aquarium-born library built from public
|
|
shader semantics.
|
|
|
|
## Current Surface
|
|
|
|
- `float2`, `float3`, `float4`
|
|
- component-wise arithmetic
|
|
- scalar-to-vector splats
|
|
- swizzles for common lanes
|
|
- conversions to and from `System.Numerics`
|
|
- `BatchMath` SoA kernels over `Span<float>` / `ReadOnlySpan<float>` using
|
|
`System.Numerics.Vector<float>` when available, including radial falloff
|
|
acceleration and semi-implicit Euler integration
|
|
- `math` intrinsics: `radians`, `degrees`, `abs`, `floor`, `ceil`, `frac`,
|
|
`min`, `max`, `clamp`, `saturate`, `lerp`, `step`, `smoothstep`, `dot`,
|
|
`cross`, `length`, `distance`, `normalize`, `reflect`, `csum`, exponential
|
|
`decay`/`damp`, intercept/segment helpers, Catmull-Rom, Bezier curves, and
|
|
deterministic value-noise primitives
|
|
- `shaders/CultMath.hlsl`, a canonical HLSL mirror include for shader-side
|
|
parity. HLSL already owns `float2`, `float3`, and `float4`; the include
|
|
exposes `cultmath_*` functions for shared semantics, including CultMath's
|
|
safe `normalize` contract.
|
|
- `Voronoi.SampleTones`, a C# batch surface that calls the Rust
|
|
`cultmath-core` native kernel when `cultmath_core` is available and falls back
|
|
to the managed parity path otherwise.
|
|
|
|
## Native Core
|
|
|
|
The canonical hot-path body lives in `native/cultmath-core`. It exports a C ABI
|
|
for batch kernels such as `cultmath_apollonian_voronoi_tones`.
|
|
|
|
Runtime wrappers own syntax and integration. Rust owns optimized primitive
|
|
kernel behavior and parity fixtures.
|
|
|
|
## Example
|
|
|
|
```csharp
|
|
using CultMath;
|
|
|
|
float3 normal = math.normalize(new float3(0.25f, 1.0f, -0.1f));
|
|
float rim = math.saturate(1.0f - math.dot(normal, new float3(0.0f, 0.0f, -1.0f)));
|
|
float glow = math.smoothstep(0.2f, 1.0f, rim);
|
|
float grain = math.value_noise_bicubic(math.float2(12.0f, 3.5f));
|
|
```
|
|
|
|
```hlsl
|
|
#include "CultMath.hlsl"
|
|
|
|
float3 normal = cultmath_normalize(float3(0.25, 1.0, -0.1));
|
|
float rim = cultmath_saturate(1.0 - dot(normal, float3(0.0, 0.0, -1.0)));
|
|
float glow = cultmath_smoothstep(0.2, 1.0, rim);
|
|
float grain = cultmath_value_noise_bicubic(float2(12.0, 3.5));
|
|
```
|
|
|
|
## Provenance
|
|
|
|
The small spline, damping, and pursuit helpers were promoted from Aetheria's
|
|
local `AetheriaMath` surface. The value-noise family follows public shader
|
|
literature from Inigo Quilez's noise and mini-spline articles, expressed in
|
|
CultMath names with tests instead of copied project-local helper drift.
|
|
|
|
## Build
|
|
|
|
```powershell
|
|
dotnet build CultMath.slnx
|
|
dotnet test CultMath.slnx
|
|
cargo test --manifest-path native/cultmath-core/Cargo.toml
|
|
cargo build --release --manifest-path native/cultmath-core/Cargo.toml
|
|
.\scripts\build-unity-package.ps1
|
|
```
|
|
|
|
## Unity package
|
|
|
|
CultMath's Unity 2021.3 surface is the tracked precompiled package at
|
|
`unity/org.gamecult.cultmath`. Unity consumes `CultMath.dll` and the numeric
|
|
`CultMath.hlsl`; it does not compile the repository's current-language C# source
|
|
tree and does not require a consumer `csc.rsp` workaround.
|
|
|
|
```json
|
|
"org.gamecult.cultmath": "https://github.com/GameCult/CultLib.git?path=/packages/cultmath/unity/org.gamecult.cultmath#cultmath-unity-v0.1.2"
|
|
```
|
|
|
|
The repository root is not a Unity package. Build the tracked package with
|
|
`scripts/build-unity-package.ps1`; the script fresh-builds the netstandard2.1
|
|
assembly and rejects stale binaries, missing metadata, unexpected assemblies,
|
|
or leaked C# source.
|
|
|
|
## Shader Tooling
|
|
|
|
CultMath keeps portable DXC outside git under `.tools/`:
|
|
|
|
```powershell
|
|
.\tools\get-dxc.ps1
|
|
.\tools\get-spirv-cross.ps1
|
|
.\tools\compile-hlsl-spirv.ps1 `
|
|
-ShaderPath E:\Projects\Odin\crates\muninn-move-tracker\shaders\MoveSphereCandidate.comp.hlsl `
|
|
-OutputPath E:\Projects\Odin\crates\muninn-move-tracker\artifacts\shader\MoveSphereCandidate.comp.spv `
|
|
-IncludePath E:\Projects\CultLib\packages\cultmath\shaders
|
|
.\tools\compile-spirv-metal.ps1 `
|
|
-SpirvPath E:\Projects\Odin\crates\muninn-move-tracker\artifacts\shader\MoveSphereCandidate.comp.spv `
|
|
-OutputPath E:\Projects\Odin\crates\muninn-move-tracker\artifacts\shader\MoveSphereCandidate.comp.metal
|
|
```
|
|
|
|
DXC emits Vulkan SPIR-V with `-spirv`. `-TargetEnv vulkan1.2` is exposed by the
|
|
script, but the current Windows DXC release compiled this shader successfully
|
|
with DXC's default Vulkan target while rejecting the dotted target-env value.
|
|
The SPIR-V script applies default Vulkan register shifts for cbuffers, textures,
|
|
UAVs, and samplers so cross-compiled Metal buffers do not alias by resource
|
|
class. SPIRV-Cross emits Metal Shading Language from SPIR-V on Windows; building
|
|
an iPad-ready `.metallib` still belongs to Apple's Metal compiler on an Apple
|
|
toolchain.
|
|
|
|
## Doctrine
|
|
|
|
The goal is mechanical sympathy between CPU-side authoring, native kernels, and
|
|
GPU-side shader math. If an intrinsic exists here, it should behave like the
|
|
shader concept unless a runtime's numeric rules make that impossible. Weird
|
|
deviations get tests and documentation, not folklore.
|
|
|
|
CultMath is still not a shader generator. Projects should include
|
|
`shaders/CultMath.hlsl` directly or add that directory to their shader include
|
|
path. If a shared operation needs CPU/GPU parity, put the primitive here and
|
|
test it here before copying local math helpers into a renderer or daemon.
|