/******************************************************************************
* Copyright (c) 2018, Danish Agency for Data Supply and Efficiency,
* sdfe@sdfe.dk
*
* All rights reserved.
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* modification, are permitted provided that the following
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*       notice, this list of conditions and the following disclaimer in
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*       with the distribution.
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*       used to endorse or promote products derived from this software
*       without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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****************************************************************************/

#include <cstddef> // NULL
#include "DelaunayFilter.hpp"
#include "private/delaunator.hpp"

namespace pdal
{

static PluginInfo const s_info
{
    "filters.delaunay",
    "Perform Delaunay triangulation of a pointcloud",
    "http://pdal.io/stages/filters.delaunay.html"
};

CREATE_STATIC_STAGE(DelaunayFilter, s_info)

std::string DelaunayFilter::getName() const
{
    return s_info.name;
}


DelaunayFilter::DelaunayFilter()
{}


DelaunayFilter::~DelaunayFilter()
{}


void DelaunayFilter::filter(PointView& pointView)
{
    // Returns NULL if the mesh already exists
    TriangularMesh *mesh = pointView.createMesh("delaunay2d");

    if (!mesh)
        throwError("Unable to create mesh 'delaunay2d'.");
    if (pointView.size() < 3)
    {
        log()->get(LogLevel::Warning) << getName() << ": triangulation "
            "requested for fewer than three points.\n";
        return;
    }

    std::vector<double> delaunayPoints;
    for (PointId i = 0; i < pointView.size(); i++)
    {
        delaunayPoints.push_back(
            pointView.getFieldAs<double>(Dimension::Id::X, i));
        delaunayPoints.push_back(
            pointView.getFieldAs<double>(Dimension::Id::Y, i));
    }

    // Actually perform the triangulation
    delaunator::Delaunator triangulation(delaunayPoints);

    for (std::size_t i = 0; i < triangulation.triangles.size(); i += 3)
        mesh->add(triangulation.triangles[i+2], triangulation.triangles[i+1],
            triangulation.triangles[i]);
}

} // namespace pdal
