swizzle_storage.h

// =====================================================================================================================
//  fennec, a free and open source game engine
//  Copyright © 2025  Medusa Slockbower
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <https://www.gnu.org/licenses/>.
// =====================================================================================================================
 
 
#ifndef FENNEC_MATH_SWIZZLE_STORAGE_H
#define FENNEC_MATH_SWIZZLE_STORAGE_H
 
namespace fennec::detail
{
 
//
// \brief Backing storage struct for \ref fennec::swizzle "swizzle"
// \tparam DataT Data Type
// \tparam ScalarT Element Types
// \tparam IndicesV Swizzle Order
template<typename DataT, typename ScalarT, size_t...IndicesV>
struct swizzle_storage
{
    //
    // \brief an array containing the indices of this swizzle
    inline static constexpr size_t indices[] = { IndicesV... };
 
    //
    // \brief an array containing the scalar values of this swizzle
    DataT data;
 
    //
    // \brief element access, returns a copy of the value at index \p i
    // \param i the index
    // \returns a copy of the scalar value at index \p i
    constexpr ScalarT operator[](size_t i) const noexcept {
        return data[indices[i]];
    }
};
 
}
 
 
#endif // FENNEC_MATH_SWIZZLE_STORAGE_H