swizzle.h

Go to the documentation of this file.

// =====================================================================================================================
//  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_H
#define FENNEC_MATH_SWIZZLE_H
 
 
#include <fennec/lang/metasequences.h>
 
#include <fennec/math/swizzle_storage.h>
 
namespace fennec
{
 
template<typename VectorT, typename DataT, typename ScalarT, size_t...IndicesV>
struct swizzle : public detail::swizzle_storage<DataT, ScalarT, IndicesV...>
{
public:
 
    using scalar_t = ScalarT;
 
    inline static constexpr size_t dimension      = sizeof...(IndicesV); 
    inline static constexpr size_t num_components = sizeof...(IndicesV); 
    inline static constexpr size_t size           = sizeof...(IndicesV); 
    inline static constexpr size_t N              = sizeof...(IndicesV); 
 
    constexpr VectorT decay() const {
        VectorT res;
        return decay_impl(res, make_index_metasequence<size>{});
    }
 
    constexpr explicit operator VectorT() const {
        return decay();
    }
 
    swizzle() = default;
 
private:
    template<size_t...VecIndicesV>
    constexpr VectorT& decay_impl(VectorT& vec, index_metasequence<VecIndicesV...>) {
        return ((vec[VecIndicesV] = this->data[IndicesV]), ..., vec);
    }
};
 
}
 
#endif // FENNEC_MATH_SWIZZLE_H