from_grid.hpp

// Copyright 2021 Arnaud Becheler    <abechele@umich.edu>
 
 
#pragma once
 
#include "detail/bound_policy.hpp"
#include "detail/concepts.hpp"
#include "detail/vicinity.hpp"
 
namespace quetzal::geography
{
 
template<
    two_dimensional SpatialGrid, 
    directional Directionality, 
    class VertexProperty, 
    class EdgeProperty, 
    class Vicinity,
    class Policy
>
auto from_grid(SpatialGrid const &grid, VertexProperty const &v, EdgeProperty const &e, Vicinity const &vicinity,
               Directionality dir, Policy const &bounding_policy)
{
    namespace geo = quetzal::geography;
    using connectedness = Vicinity::connectedness;
    using graph_type = geo::graph<VertexProperty, EdgeProperty, connectedness, Directionality>;
    using vertex_t = graph_type::vertex_descriptor;
 
    graph_type graph( grid.width() * grid.height() + bounding_policy.num_extra_vertices() ) ;
    vicinity.connect(graph, grid, bounding_policy);
 
    if constexpr ( ! std::is_same_v<VertexProperty, no_property>) {
        for( auto vertex : graph.vertices() ){
            graph[vertex] = v;
        }
    }
 
    if constexpr ( ! std::is_same_v<EdgeProperty, no_property>) {
        for(auto edge : graph.edges()){
            if constexpr (std::constructible_from<VertexProperty, vertex_t, vertex_t, SpatialGrid>){
                graph[edge] = EdgeProperty(edge.source(), edge.target(), grid);
            } else { 
                static_assert(std::is_default_constructible_v<EdgeProperty>);
                graph[edge] = e;
            }
        }
    }
 
    return graph;
}
 
} // namespace quetzal::geography