/*

Open Asset Import Library (assimp)

----------------------------------------------------------------------

Copyright (c) 2006-2025, assimp team

All rights reserved.

Redistribution and use of this software in source and binary forms,

with or without modification, are permitted provided that the

following conditions are met:

* Redistributions of source code must retain the above

  copyright notice, this list of conditions and the

  following disclaimer.

* Redistributions in binary form must reproduce the above

  copyright notice, this list of conditions and the

  following disclaimer in the documentation and/or other

  materials provided with the distribution.

* Neither the name of the assimp team, nor the names of its

  contributors may be used to endorse or promote products

  derived from this software without specific prior

  written permission of the assimp team.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

----------------------------------------------------------------------

*/

#if !defined(ASSIMP_BUILD_NO_EXPORT) && !defined(ASSIMP_BUILD_NO_STL_EXPORTER)

#include "STLExporter.h"

#include <assimp/version.h>

#include <assimp/IOSystem.hpp>

#include <assimp/scene.h>

#include <assimp/Exporter.hpp>

#include <memory>

#include <assimp/Exceptional.h>

#include <assimp/ByteSwapper.h>

using namespace Assimp;

namespace Assimp {

// ------------------------------------------------------------------------------------------------

// Worker function for exporting a scene to Stereolithograpy. Prototyped and registered in Exporter.cpp

void ExportSceneSTL(const char* pFile,IOSystem* pIOSystem, const aiScene* pScene, const ExportProperties* pProperties )

{

    bool exportPointClouds = pProperties->GetPropertyBool(AI_CONFIG_EXPORT_POINT_CLOUDS);

    // invoke the exporter

    STLExporter exporter(pFile, pScene, exportPointClouds );

    if (exporter.mOutput.fail()) {

        throw DeadlyExportError("output data creation failed. Most likely the file became too large: " + std::string(pFile));

    }

    // we're still here - export successfully completed. Write the file.

    std::unique_ptr<IOStream> outfile (pIOSystem->Open(pFile,"wt"));

    if (outfile == nullptr) {

        throw DeadlyExportError("could not open output .stl file: " + std::string(pFile));

    }

    outfile->Write( exporter.mOutput.str().c_str(), static_cast<size_t>(exporter.mOutput.tellp()),1);

}

void ExportSceneSTLBinary(const char* pFile,IOSystem* pIOSystem, const aiScene* pScene, const ExportProperties* pProperties )

{

    bool exportPointClouds = pProperties->GetPropertyBool(AI_CONFIG_EXPORT_POINT_CLOUDS);

    // invoke the exporter

    STLExporter exporter(pFile, pScene, exportPointClouds, true);

    if (exporter.mOutput.fail()) {

        throw DeadlyExportError("output data creation failed. Most likely the file became too large: " + std::string(pFile));

    }

    // we're still here - export successfully completed. Write the file.

    std::unique_ptr<IOStream> outfile (pIOSystem->Open(pFile,"wb"));

    if (outfile == nullptr) {

        throw DeadlyExportError("could not open output .stl file: " + std::string(pFile));

    }

    outfile->Write( exporter.mOutput.str().c_str(), static_cast<size_t>(exporter.mOutput.tellp()),1);

}

} // end of namespace Assimp

static constexpr char SolidToken[]    = "solid";

static constexpr char EndSolidToken[] = "endsolid";

// ------------------------------------------------------------------------------------------------

STLExporter::STLExporter(const char* _filename, const aiScene* pScene, bool exportPointClouds, bool binary) : filename(_filename) , endl("\n")

{

    // make sure that all formatting happens using the standard, C locale and not the user's current locale

    const std::locale& l = std::locale("C");

    mOutput.imbue(l);

    mOutput.precision(ASSIMP_AI_REAL_TEXT_PRECISION);

    if (binary) {

        char buf[80] = {0} ;

        buf[0] = 'A'; buf[1] = 's'; buf[2] = 's'; buf[3] = 'i'; buf[4] = 'm'; buf[5] = 'p';

        buf[6] = 'S'; buf[7] = 'c'; buf[8] = 'e'; buf[9] = 'n'; buf[10] = 'e';

        mOutput.write(buf, 80);

        unsigned int meshnum = 0;

        for(unsigned int i = 0; i < pScene->mNumMeshes; ++i) {

            for (unsigned int j = 0; j < pScene->mMeshes[i]->mNumFaces; ++j) {

                meshnum++;

            }

        }

        AI_SWAP4(meshnum);

        mOutput.write((char *)&meshnum, 4);

        if (exportPointClouds) {

            throw DeadlyExportError("This functionality is not yet implemented for binary output.");

        }

        for(unsigned int i = 0; i < pScene->mNumMeshes; ++i) {

            WriteMeshBinary(pScene->mMeshes[i]);

        }

    } else {

        // Exporting only point clouds

        if (exportPointClouds) {

            WritePointCloud("Assimp_Pointcloud", pScene );

            return;

        }

        // Export the assimp mesh

        const std::string name = "AssimpScene";

        mOutput << SolidToken << " " << name << endl;

        for(unsigned int i = 0; i < pScene->mNumMeshes; ++i) {

            WriteMesh(pScene->mMeshes[ i ]);

        }

        mOutput << EndSolidToken << " " << name << endl;

    }

}

// ------------------------------------------------------------------------------------------------

void STLExporter::WritePointCloud(const std::string &name, const aiScene* pScene) {

    mOutput << " " << SolidToken << " " << name << endl;

    aiVector3D nor;

    mOutput << " facet normal " << nor.x << " " << nor.y << " " << nor.z << endl;

    for (unsigned int i = 0; i < pScene->mNumMeshes; ++i) {

        aiMesh *mesh = pScene->mMeshes[i];

        if (nullptr == mesh) {

            continue;

        }

        for (unsigned int a = 0; a < mesh->mNumVertices; ++a) {

            const aiVector3D& v = mesh->mVertices[a];

            mOutput << "  vertex " << v.x << " " << v.y << " " << v.z << endl;

            mOutput << "  vertex " << v.x << " " << v.y << " " << v.z << endl;

            mOutput << "  vertex " << v.x << " " << v.y << " " << v.z << endl;

        }

    }

    mOutput << EndSolidToken << " " << name << endl;

}

// ------------------------------------------------------------------------------------------------

void STLExporter::WriteMesh(const aiMesh* m) {

    for (unsigned int i = 0; i < m->mNumFaces; ++i) {

        const aiFace& f = m->mFaces[i];

        if (f.mNumIndices < 3) {

            continue;

        }

        // we need per-face normals. We specified aiProcess_GenNormals as pre-requisite for this exporter,

        // but nonetheless we have to expect per-vertex normals.

        aiVector3D nor;

        if (m->mNormals) {

            for (unsigned int a = 0; a < f.mNumIndices; ++a) {

                nor += m->mNormals[f.mIndices[a]];

            }

            nor.NormalizeSafe();

        }

        mOutput << " facet normal " << nor.x << " " << nor.y << " " << nor.z << endl;

        mOutput << "  outer loop" << endl;

        for (unsigned int a = 0; a < f.mNumIndices; ++a) {

            const aiVector3D &v = m->mVertices[f.mIndices[a]];

            mOutput << "  vertex " << v.x << " " << v.y << " " << v.z << endl;

        }

        mOutput << "  endloop" << endl;

        mOutput << " endfacet" << endl << endl;

    }

}

void STLExporter::WriteMeshBinary(const aiMesh* m) {

    for (unsigned int i = 0; i < m->mNumFaces; ++i) {

        const aiFace& f = m->mFaces[i];

        if (f.mNumIndices < 3) {

            continue;

        }

        // we need per-face normals. We specified aiProcess_GenNormals as pre-requisite for this exporter,

        // but nonetheless we have to expect per-vertex normals.

        aiVector3D nor;

        if (m->mNormals) {

            for(unsigned int a = 0; a < f.mNumIndices; ++a) {

                nor += m->mNormals[f.mIndices[a]];

            }

            nor.Normalize();

        }

        // STL binary files use 4-byte floats. This may possibly cause loss of precision

        // for clients using 8-byte doubles

        float nx = (float) nor.x;

        float ny = (float) nor.y;

        float nz = (float) nor.z;

        AI_SWAP4(nx); AI_SWAP4(ny); AI_SWAP4(nz);

        mOutput.write((char *)&nx, 4); mOutput.write((char *)&ny, 4); mOutput.write((char *)&nz, 4);

        for(unsigned int a = 0; a < f.mNumIndices; ++a) {

            const aiVector3D& v  = m->mVertices[f.mIndices[a]];

            float vx = (float) v.x, vy = (float) v.y, vz = (float) v.z;

            AI_SWAP4(vx); AI_SWAP4(vy); AI_SWAP4(vz);

            mOutput.write((char *)&vx, 4); mOutput.write((char *)&vy, 4); mOutput.write((char *)&vz, 4);

        }

        char dummy[2] = {0};

        mOutput.write(dummy, 2);

    }

}

#endif