Function mesh_boolean 

pub fn mesh_boolean(
    mesh_a: &SimpleMesh,
    mesh_b: &SimpleMesh,
    op: MeshBooleanOp,
) -> SimpleMesh

Perform a mesh boolean operation.

This is a simplified approach that classifies triangles by their centroid and selects/rejects based on the operation. For production use, a full re-triangulation along intersection curves is needed.