ImplicitSurfaceNetwork/primitive_process/interface/subface/simple/cone_face.hpp

#pragma once

#include <base/subface.hpp>
#include <primitive_descriptor.h>

namespace internal
{
// local: cone face x^2+y^2-z^2=0(z<=0)
struct cone_face_t final : subface {
};
} // namespace internal

namespace detail
{
template <>
struct hasher<internal::cone_face_t> {
    // Q' = M^{-T}QM^{-1}
    // Q = {
    // 1, 0, 0, 0
    // 0, 1, 0, 0
    // 0, 0, -1, 0
    // 0, 0, 0, 0
    // }
    size_t operator()(const internal::cone_face_t& subface) const
    {
        // build M^{-T}Q directly
        Eigen::Matrix4d mat     = internal::empty_affine_matrix;
        const auto&     M_inv_T = subface.world_to_local.matrix();
        mat.leftCols<2>()       = M_inv_T.topRows<2>().transpose();
        mat.col(2)              = -M_inv_T.row(2).transpose();
        auto res                = mat * subface.world_to_local;
        return hash_funcs(res.matrix());
    }
};

template <>
struct eq_compare<internal::cone_face_t> {
    bool operator()(const internal::cone_face_t& lhs, const internal::cone_face_t& rhs) const
    {
        return eq_funcs(lhs.local_to_world, rhs.local_to_world);
    }
};
} // namespace detail