brep-vertex.cpp

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/*
 * Copyright (C) 2023  Christopher J. Howard
 *
 * This file is part of Antkeeper source code.
 *
 * Antkeeper source code 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.
 *
 * Antkeeper source code 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 Antkeeper source code.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#include <engine/geom/brep/brep-vertex.hpp>
#include <engine/geom/brep/brep-mesh.hpp>
 
namespace geom {
 
void brep_vertex_edge_list::push_back(brep_edge* edge)
{
    // Determine index of vertex in new edge vertex array
    const std::size_t i = (edge->m_vertices[1] == m_vertex);
    
    if (empty())
    {
        // List empty, initialize
        m_head = edge;
        edge->m_vertex_next[i] = edge;
        edge->m_vertex_previous[i] = edge;
    }
    else
    {
        // Determine index of vertex in head edge vertex array
        const std::size_t j = (m_head->m_vertices[1] == m_vertex);
        
        // Append edge
        edge->m_vertex_next[i] = m_head;
        edge->m_vertex_previous[i] = m_head->m_vertex_previous[j];
        edge->m_vertex_previous[i]->m_vertex_next[edge->m_vertex_previous[i]->m_vertices[1] == m_vertex] = edge;
        m_head->m_vertex_previous[j] = edge;
    }
    
    ++m_size;
}
 
void brep_vertex_edge_list::remove(brep_edge* edge)
{
    // Determine index of vertex in edge vertex array
    const std::size_t i = (edge->m_vertices[1] == m_vertex);
    
    // Get pointers to the next and previous edges
    brep_edge* next = edge->m_vertex_next[i];
    brep_edge* previous = edge->m_vertex_previous[i];
    
    // Directly link next and previous edges
    next->m_vertex_previous[next->m_vertices[1] == m_vertex] = previous;
    previous->m_vertex_next[previous->m_vertices[1] == m_vertex] = next;
    
    // If edge was the list head, update head
    if (m_head == edge)
    {
        m_head = next;
    }
    
    --m_size;
}
 
brep_vertex* brep_vertex_container::emplace_back()
{
    brep_vertex* vertex = brep_element_container<brep_vertex>::emplace_back();
    vertex->m_index = size() - 1;
    vertex->m_edges.m_vertex = vertex;
    return vertex;
};
 
void brep_vertex_container::erase(brep_vertex* vertex)
{
    // Erase all edges bounded by this vertex
    while (!vertex->edges().empty())
    {
        m_mesh->edges().erase(vertex->edges().back());
    }
    
    // Erase vertex
    brep_element_container<brep_vertex>::erase(vertex);
}
 
void brep_vertex_container::clear() noexcept
{
    while (!empty())
    {
        erase(back());
    }
}
 
} // namespace geom