polygon_bit_flags.h

/*****************************************************************************
 * VCLib                                                                     *
 * Visual Computing Library                                                  *
 *                                                                           *
 * Copyright(C) 2021-2025                                                    *
 * Visual Computing Lab                                                      *
 * ISTI - Italian National Research Council                                  *
 *                                                                           *
 * All rights reserved.                                                      *
 *                                                                           *
 * This program is free software; you can redistribute it and/or modify      *
 * it under the terms of the Mozilla Public License Version 2.0 as published *
 * by the Mozilla Foundation; either version 2 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              *
 * Mozilla Public License Version 2.0                                        *
 * (https://www.mozilla.org/en-US/MPL/2.0/) for more details.                *
 ****************************************************************************/
 
#ifndef VCL_MESH_COMPONENTS_POLYGON_BIT_FLAGS_H
#define VCL_MESH_COMPONENTS_POLYGON_BIT_FLAGS_H
 
#include "bases/container_component.h"
 
#include <vclib/concepts/mesh/components/bit_flags.h>
#include <vclib/space/core/bit_set.h>
 
namespace vcl::comp {
 
template<int N, typename ParentElemType = void, bool OPT = false>
class PolygonBitFlags :
        public ContainerComponent<
            PolygonBitFlags<N, ParentElemType, OPT>,
            CompId::BIT_FLAGS,
            BitSet<char>,
            N,
            BitSet<char>,
            ParentElemType,
            !std::is_same_v<ParentElemType, void>,
            OPT,
            true>
{
    using FT = char; // FlagsType, the integral type used for the flags
 
    using Base = ContainerComponent<
        PolygonBitFlags<N, ParentElemType, OPT>,
        CompId::BIT_FLAGS,
        BitSet<FT>,
        N,
        BitSet<FT>,
        ParentElemType,
        !std::is_same_v<ParentElemType, void>,
        OPT,
        true>;
 
    static const uint FIRST_USER_BIT      = 6;
    static const uint FIRST_EDGE_USER_BIT = 3;
 
    // indices of the bits
    enum {
        DELETED  = 0, // bit 0
        SELECTED = 1, // bit 1
        VISITED  = 2, // bit 2
        // Faux edges, for portability with TriangleBits
        FAUX0 = 3 // bits [3, 5]
    };
 
    // indices of the bits used for each edge of the polygon
    enum { EDGEBORD = 0, EDGESEL = 1, EDGEVIS = 2 };
 
public:
    inline static const uint USER_BITS_NUMBER = sizeof(FT) * 8 - FIRST_USER_BIT;
 
    static const uint EDGE_USER_BITS_NUMBER =
        sizeof(FT) * 8 - FIRST_EDGE_USER_BIT;
 
    /* Constructors */
 
    PolygonBitFlags()
    {
        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> visited() { return flags()[VISITED]; }
 
    bool visited() const { return flags()[VISITED]; }
 
    bool onBorder() const
    {
        for (uint i = 0; i < 12; ++i)
            if (edgeOnBorder(i))
                return true;
        return false;
    }
 
    BitProxy<FT> edgeOnBorder(uint i)
    {
        assert(i < edgeFlags().size());
        return edgeFlags()[i][EDGEBORD];
    }
 
    bool edgeOnBorder(uint i) const
    {
        assert(i < edgeFlags().size());
        return edgeFlags()[i][EDGEBORD];
    }
 
    BitProxy<FT> edgeSelected(uint i)
    {
        assert(i < edgeFlags().size());
        return edgeFlags()[i][EDGESEL];
    }
 
    bool edgeSelected(uint i) const
    {
        assert(i < edgeFlags().size());
        return edgeFlags()[i][EDGESEL];
    }
 
    BitProxy<FT> edgeVisited(uint i)
    {
        assert(i < edgeFlags().size());
        return edgeFlags()[i][EDGEVIS];
    }
 
    bool edgeVisited(uint i) const
    {
        assert(i < edgeFlags().size());
        return edgeFlags()[i][EDGEVIS];
    }
 
    BitProxy<FT> edgeFaux(uint i)
    {
        assert(i < 3);
        return flags()[FAUX0 + i];
    }
 
    bool edgeFaux(uint i) const
    {
        assert(i < 3);
        return flags()[FAUX0 + i];
    }
 
    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];
    }
 
    bool edgeUserBit(uint i, uint bit) const
    {
        assert(bit < EDGE_USER_BITS_NUMBER);
        return edgeFlags()[i][bit + FIRST_EDGE_USER_BIT];
    }
 
    BitProxy<FT> edgeUserBit(uint i, uint bit)
    {
        assert(bit < EDGE_USER_BITS_NUMBER);
        return edgeFlags()[i][bit + FIRST_EDGE_USER_BIT];
    }
 
    void resetBitFlags()
    {
        bool isD = deleted();
        flags().reset();
        for (uint i = 0; i < edgeFlags().size(); ++i)
            edgeFlags()[i].reset();
        deletedBit() = isD;
    }
 
    void importFlagsFromVCGFormat(int f)
    {
        if (f & 0x00000010)
            visited() = true;
        if (f & 0x00000020)
            selected() = true;
        if (f & 0x00000040)
            edgeOnBorder(0) = true;
        if (f & 0x00000080)
            edgeOnBorder(1) = true;
        if (f & 0x00000100)
            edgeOnBorder(2) = true;
        if (f & 0x00008000)
            edgeSelected(0) = true;
        if (f & 0x00010000)
            edgeSelected(1) = true;
        if (f & 0x00020000)
            edgeSelected(2) = true;
        if (f & 0x00040000)
            edgeFaux(0) = true;
        if (f & 0x00080000)
            edgeFaux(1) = true;
        if (f & 0x00100000)
            edgeFaux(2) = true;
    }
 
    int exportFlagsToVCGFormat() const
    {
        int f = 0;
        if (visited())
            f &= 0x00000010;
        if (selected())
            f &= 0x00000020;
        if (edgeOnBorder(0))
            f &= 0x00000040;
        if (edgeOnBorder(1))
            f &= 0x00000080;
        if (edgeOnBorder(2))
            f &= 0x00000100;
        if (edgeSelected(0))
            f &= 0x00008000;
        if (edgeSelected(1))
            f &= 0x00010000;
        if (edgeSelected(2))
            f &= 0x00020000;
        if (edgeFaux(0))
            f &= 0x00040000;
        if (edgeFaux(1))
            f &= 0x00080000;
        if (edgeFaux(2))
            f &= 0x00100000;
        return f;
    }
 
    // dummy member to discriminate between triangle and non-triangle bit flags
    void __polygonBitFlags() const {}
 
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>) {
                flags()     = e.flags();
                edgeFlags() = e.edgeFlags();
            }
            else {
                // BitFlags
                deletedBit()  = e.deleted();
                selected()    = e.selected();
                visited()     = e.visited();
                const uint UM = std::min(USER_BITS_NUMBER, e.USER_BITS_NUMBER);
                for (uint i = 0; i < UM; ++i)
                    userBit(i) = e.userBit(i);
                if constexpr (HasTriangleBitFlags<Element>) {
                    // TriangleBitFlags
                    for (uint i = 0; i < 3; ++i) {
                        edgeOnBorder(i) = e.edgeOnBorder(i);
                        edgeSelected(i) = e.edgeSelected(i);
                        edgeVisited(i)  = e.edgeVisited(i);
                        edgeFaux(i)     = e.edgeFaux(i);
                    }
                }
            }
        }
    }
 
    void serialize(std::ostream& os) const
    {
        flags().serialize(os);
        edgeFlags().serialize(os);
    }
 
    void deserialize(std::istream& is)
    {
        flags().deserialize(is);
        edgeFlags().deserialize(is);
    }
 
    // ContainerComponent interface functions
    void resize(uint n) requires (N < 0) { edgeFlags().resize(n); }
 
    void pushBack(BitSet<FT> f = BitSet<FT>()) requires (N < 0)
    {
        edgeFlags().pushBack(f);
    }
 
    void insert(uint i, BitSet<FT> f = BitSet<FT>()) requires (N < 0)
    {
        edgeFlags().insert(i, f);
    }
 
    void erase(uint i) requires (N < 0) { edgeFlags().erase(i); }
 
    void clear() requires (N < 0) { edgeFlags().clear(); }
 
private:
    // members that allow to access the flags, trough data (horizontal) or
    // trough parent (vertical)
 
    BitSet<FT>& flags() { return Base::additionalData(); }
 
    const BitSet<FT>& flags() const { return Base::additionalData(); }
 
    Vector<BitSet<FT>, -1>& edgeFlags() { return Base::container(); }
 
    const Vector<BitSet<FT>, -1>& edgeFlags() const
    {
        return Base::container();
    }
};
 
} // namespace vcl::comp
 
#endif // VCL_MESH_COMPONENTS_POLYGON_BIT_FLAGS_H