/*
 * Copyright (c) Contributors to the Open 3D Engine Project.
 * For complete copyright and license terms please see the LICENSE at the root of this distribution.
 *
 * SPDX-License-Identifier: Apache-2.0 OR MIT
 *
 */


#include "EditorDefs.h"

#include "Triangulate.h"

// this file is essentially a wrapper for a portion of the MIT-licenced
// ConvexDecomposition library by John W. Ratcliff mailto:jratcliffscarab@gmail.com.
// it contains no code from that library, it just provides it with the required types, then includes the
// portion we need.

static const float TRIANGULATION_EPSILON = 0.0000000001f;

#define MEMALLOC_MALLOC malloc
#define MEMALLOC_FREE free

namespace TriInternal
{
    class TVec;
    typedef double NxF64;
    typedef float NxF32;
    typedef unsigned char NxU8;
    typedef unsigned int NxU32;
    typedef int NxI32;
    typedef unsigned int TU32;

    typedef std::vector< TVec >  TVecVector;
    typedef std::vector< NxU32 >  TU32Vector;
    #include "Contrib/NvFloatMath.inl"
}

#undef MEMALLOC_MALLOC
#undef MEMALLOC_FREE

namespace Triangulator
{
    // given the contour of a triangle, triangulate it, and return the result
    // as a set of triangles
    // return false if you fail to triangulate it.
    bool Triangulate(const VectorOfVectors& contour, VectorOfVectors& result)
    {
        TriInternal::CTriangulator tri;
        for (auto pt : contour)
        {
            tri.addPoint(pt.x, pt.y, pt.z);
        }
        TriInternal::NxU32 tricount = 0;
        TriInternal::NxU32* indices = tri.triangulate(tricount, TRIANGULATION_EPSILON);
        if (!indices)
        {
            return false;
        }

        for (TriInternal::NxU32 currentIdx = 0; currentIdx < tricount * 3; ++currentIdx)
        {
            TriInternal::NxU32 indexValue = *indices++;
            result.push_back(contour[indexValue]);
        }

        return result.size() > 2;
    }
}