Change project structure;

Added new c# binding;

native/header/Algorithm/MicrofacetGGX.h

@@ -0,0 +1,17 @@
+#ifndef MICROFACET_GGX_H
+#define MICROFACET_GGX_H
+
+#include "Common.h"
+#include "Algorithm/BSDF.h" // create_orthonormal_basis
+#include "cglm/struct/vec3.h"
+
+// Trowbridge-Reitz GGX helpers (isotropic)
+float ggx_distribution(float n_dot_h, float roughness);
+float ggx_g1(float n_dot_v, float roughness);
+float ggx_g_smith(float n_dot_v, float n_dot_l, float roughness);
+
+// GGX VNDF sampling (Heitz 2018) for isotropic GGX.
+// Returns a half-vector (H) sampled from the distribution of visible normals.
+vec3s ggx_sample_vndf(vec3s n, vec3s v, float roughness, float u1, float u2);
+
+#endif // MICROFACET_GGX_H