ViewDesignEngine/include/vde/boolean/boolean_mesh.h

#pragma once
#include "vde/boolean/boolean_2d.h"
#include "vde/core/polygon.h"
#include "vde/mesh/halfedge_mesh.h"

namespace vde::boolean {
using core::Point2D;
using core::Polygon2D;
using mesh::HalfedgeMesh;

/// ── Core 3D mesh boolean operations ──────────────────────

/// Union: A ∪ B — keep faces of each mesh whose centroids lie outside the other
HalfedgeMesh mesh_union(const HalfedgeMesh& a, const HalfedgeMesh& b);

/// Intersection: A ∩ B — keep faces whose centroids lie inside the other
HalfedgeMesh mesh_intersection(const HalfedgeMesh& a, const HalfedgeMesh& b);

/// Difference: A − B — keep A-faces outside B
HalfedgeMesh mesh_difference(const HalfedgeMesh& a, const HalfedgeMesh& b);

/// Symmetric difference: (A − B) ∪ (B − A)
HalfedgeMesh mesh_sym_diff(const HalfedgeMesh& a, const HalfedgeMesh& b);

/// ── Helpers ──────────────────────────────────────────────

/// Crop mesh `a` by mesh `b`'s boundary: keep faces of `a` whose
/// centroids lie OUTSIDE the volume of `b`.
/// If `invert_b` is true, test against the flipped-volume (inside↔outside) of `b`.
HalfedgeMesh clip_mesh(const HalfedgeMesh& a, const HalfedgeMesh& b,
                       bool invert_b = false);

/// Invert all face orientations in the mesh
HalfedgeMesh invert_mesh(const HalfedgeMesh& m);

/// Merge two meshes into one (concatenate vertices and faces)
HalfedgeMesh merge_meshes(const HalfedgeMesh& a, const HalfedgeMesh& b);

/// Convenience dispatcher — route by BooleanOp enum
HalfedgeMesh mesh_boolean(const HalfedgeMesh& a, const HalfedgeMesh& b, BooleanOp op);

/// ── Point classification ─────────────────────────────────

/// Test whether point `p` is inside `mesh` using ray-casting
bool is_point_inside_mesh(const core::Point3D& p, const HalfedgeMesh& mesh);

}  // namespace vde::boolean