CultMath

Clean-room C# math shaped for people who think in HLSL.

CultMath provides lowercase vector types and shader-style intrinsics so math-heavy renderer code can move between C# 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 and plain .NET.

Current Surface

• float2, float3, float4
• component-wise arithmetic
• scalar-to-vector splats
• swizzles for common lanes
• conversions to and from System.Numerics
• math intrinsics: radians, degrees, abs, floor, ceil, frac, min, max, clamp, saturate, lerp, step, smoothstep, dot, cross, length, distance, normalize, and reflect

Example

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);

Build

dotnet build CultMath.slnx
dotnet test CultMath.slnx

Doctrine

The goal is mechanical sympathy between CPU-side authoring and GPU-side shader math. If an intrinsic exists here, it should behave like the shader concept unless .NET numeric rules make that impossible. Weird deviations get tests and documentation, not folklore.