feat(core): declare Worley and fractal noise variants for biome and cave shaping interface

core/include/vf/NoiseAdv.h

@@ -0,0 +1,79 @@
+#pragma once
+
+#include <array>
+#include <cstdint>
+
+namespace vf {
+
+// Distance metric used by worley2D to turn a feature-point offset into a
+// scalar cell distance.
+enum class DistanceMetric : uint8_t {
+    Euclidean = 0,
+    Manhattan = 1,
+    Chebyshev = 2,
+};
+
+// Closest (f1) and second-closest (f2) feature point distances for a worley
+// sample, plus the integer cell that produced the closest point.
+struct WorleyResult {
+    float f1 = 0.0f;
+    float f2 = 0.0f;
+    int cellX = 0;
+    int cellY = 0;
+};
+
+struct FbmParams {
+    int octaves = 5;
+    float lacunarity = 2.0f;
+    float gain = 0.5f;
+    float frequency = 1.0f;
+    float amplitude = 1.0f;
+};
+
+// Seeded advanced noise toolkit: gradient simplex noise (2D/3D), cellular
+// (worley) noise with selectable distance metric, ridged multifractal,
+// domain-warped fBm and lattice value noise. All outputs are clamped or
+// normalised to land in [-1, 1] (worley distances excepted, which are
+// unbounded by nature). Distinct symbol names from vf::PerlinNoise in
+// Noise.h so both can coexist in the same binary.
+class NoiseAdv {
+public:
+    explicit NoiseAdv(uint32_t seed = 1337u) { reseed(seed); }
+
+    void reseed(uint32_t seed);
+
+    float simplex2D(float x, float y) const;
+    float simplex3D(float x, float y, float z) const;
+
+    // Interpolated lattice noise (not gradient-based), useful where a
+    // blockier, less swirly texture than simplex is wanted.
+    float value2D(float x, float y) const;
+
+    WorleyResult worley2D(float x, float y, DistanceMetric metric = DistanceMetric::Euclidean) const;
+
+    // Single-octave ridge transform of simplex2D: 1 - |n|, range [0, 1].
+    float ridged2D(float x, float y) const;
+
+    // Ridged multifractal fBm: each octave is weighted by the previous
+    // octave's ridge signal, producing sharp connected crests. Range [0, 1].
+    float ridgedFbm2D(float x, float y, const FbmParams& params) const;
+
+    // Amplitude-normalised fractal Brownian motion. Range [-1, 1].
+    float fbm2D(float x, float y, const FbmParams& params) const;
+    float fbm3D(float x, float y, float z, const FbmParams& params) const;
+
+    // Samples fbm2D at (x, y) displaced by two independent simplex fields,
+    // producing the swirled, warped look used for organic terrain features.
+    float warpedFbm2D(float x, float y, const FbmParams& params, float warpStrength) const;
+
+private:
+    float gradDot2D(int hashIndex, float x, float y) const;
+    float gradDot3D(int hashIndex, float x, float y, float z) const;
+    uint32_t hashCell(int x, int y) const;
+    float latticeValue(int x, int y) const;
+
+    std::array<int, 512> perm{};
+    uint32_t seedValue = 1337u;
+};
+
+} // namespace vf