bit_flags.h

/*****************************************************************************
 * VCLib                                                                     *
 * Visual Computing Library                                                  *
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 * Copyright(C) 2021-2025                                                    *
 * Visual Computing Lab                                                      *
 * ISTI - Italian National Research Council                                  *
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 * it under the terms of the Mozilla Public License Version 2.0 as published *
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of            *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the              *
 * Mozilla Public License Version 2.0                                        *
 * (https://www.mozilla.org/en-US/MPL/2.0/) for more details.                *
 ****************************************************************************/
 
#ifndef VCL_MESH_COMPONENTS_BIT_FLAGS_H
#define VCL_MESH_COMPONENTS_BIT_FLAGS_H
 
#include "bases/component.h"
 
#include <vclib/concepts/mesh/components/bit_flags.h>
#include <vclib/space/core/bit_set.h>
 
namespace vcl::comp {
 
template<typename ParentElemType = void, bool OPT = false>
class BitFlags :
        public Component<
            BitFlags<ParentElemType, OPT>,
            CompId::BIT_FLAGS,
            BitSet<char>,
            ParentElemType,
            !std::is_same_v<ParentElemType, void>,
            OPT>
{
    using Base = Component<
        BitFlags<ParentElemType, OPT>,
        CompId::BIT_FLAGS,
        BitSet<char>,
        ParentElemType,
        !std::is_same_v<ParentElemType, void>,
        OPT>;
 
    using FT = char; // FlagsType, the integral type used for the flags
 
    // indices of the bits
    enum {
        DELETED  = 0, // bit 0
        SELECTED = 1, // bit 1
        BORDER   = 2, // bit 2
        VISITED  = 3  // bit 3
    };
 
    static const uint FIRST_USER_BIT = 4;
 
public:
    inline static const uint USER_BITS_NUMBER = sizeof(FT) * 8 - FIRST_USER_BIT;
 
    /* Constructors */
 
    BitFlags()
    {
        if constexpr (!Base::IS_VERTICAL) {
            init();
        }
    }
 
    void init() { flags().reset(); }
 
    /* Member functions */
 
    bool deleted() const { return flags()[DELETED]; }
 
    BitProxy<FT> selected() { return flags()[SELECTED]; }
 
    bool selected() const { return flags()[SELECTED]; }
 
    BitProxy<FT> onBorder() { return flags()[BORDER]; }
 
    bool onBorder() const { return flags()[BORDER]; }
 
    BitProxy<FT> visited() { return flags()[VISITED]; }
 
    bool visited() const { return flags()[VISITED]; }
 
    bool userBit(uint bit) const
    {
        assert(bit < USER_BITS_NUMBER);
        return flags()[bit + FIRST_USER_BIT];
    }
 
    BitProxy<FT> userBit(uint bit)
    {
        assert(bit < USER_BITS_NUMBER);
        return flags()[bit + FIRST_USER_BIT];
    }
 
    void resetBitFlags()
    {
        bool isD = deleted();
        flags().reset();
        deletedBit() = isD;
    }
 
    void importFlagsFromVCGFormat(int f)
    {
        resetBitFlags();
        if (f & 0x0010)
            visited() = true;
        if (f & 0x0020)
            selected() = true;
        if (f & 0x0100)
            onBorder() = true;
    }
 
    int exportFlagsToVCGFormat() const
    {
        int f = 0;
        if (visited())
            f &= 0x0010;
        if (selected())
            f &= 0x0020;
        if (onBorder())
            f &= 0x0100;
        return f;
    }
 
protected:
    BitProxy<FT> deletedBit() { return flags()[DELETED]; }
 
    // Component interface functions
    template<typename Element>
    void importFrom(const Element& e, bool = true)
    {
        if constexpr (HasBitFlags<Element>) {
            resetBitFlags();
            if constexpr (
                HasPolygonBitFlags<Element> || HasTriangleBitFlags<Element>) {
                deletedBit()  = e.deleted();
                selected()    = e.selected();
                visited()     = e.visited();
                onBorder()    = e.onBorder();
                const uint UM = std::min(USER_BITS_NUMBER, e.USER_BITS_NUMBER);
                for (uint i = 0; i < UM; ++i)
                    userBit(i) = e.userBit(i);
            }
            else {
                flags() = e.flags();
            }
        }
    }
 
    void serialize(std::ostream& os) const { flags().serialize(os); }
 
    void deserialize(std::istream& is) { flags().deserialize(is); }
 
private:
    // members that allow to access the flags, trough data (horizontal) or
    // trough parent (vertical)
    BitSet<FT>& flags() { return Base::data(); }
 
    BitSet<FT> flags() const { return Base::data(); }
};
 
} // namespace vcl::comp
 
#endif // VCL_MESH_COMPONENTS_BIT_FLAGS_H