magnum/src/Magnum/MeshTools/sceneconverter.cpp

/*
    This file is part of Magnum.

    Copyright © 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019,
                2020 Vladimír Vondruš <mosra@centrum.cz>

    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
    to deal in the Software without restriction, including without limitation
    the rights to use, copy, modify, merge, publish, distribute, sublicense,
    and/or sell copies of the Software, and to permit persons to whom the
    Software is furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included
    in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    DEALINGS IN THE SOFTWARE.
*/

#include <algorithm>
#include <chrono>
#include <set>
#include <sstream>
#include <Corrade/Containers/Optional.h>
#include <Corrade/Utility/Arguments.h>
#include <Corrade/Utility/DebugStl.h>
#include <Corrade/Utility/Directory.h>
#include <Corrade/Utility/FormatStl.h>
#include <Corrade/Utility/String.h>

#include "Magnum/PixelFormat.h"
#include "Magnum/Math/Color.h"
#include "Magnum/Math/FunctionsBatch.h"
#include "Magnum/MeshTools/RemoveDuplicates.h"
#include "Magnum/Trade/AbstractImporter.h"
#include "Magnum/Trade/MaterialData.h"
#include "Magnum/Trade/MeshData.h"
#include "Magnum/Trade/MeshObjectData3D.h"
#include "Magnum/Trade/TextureData.h"
#include "Magnum/Trade/AbstractSceneConverter.h"
#include "Magnum/Trade/Implementation/converterUtilities.h"

namespace Magnum {

/** @page magnum-sceneconverter Scene conversion utility
@brief Converts scenes of different formats
@m_since{2020,06}

@m_footernavigation
@m_keywords{magnum-sceneconverter sceneconverter}

This utility is built if both `WITH_TRADE` and `WITH_SCENECONVERTER` is enabled
when building Magnum. To use this utility with CMake, you need to request the
`sceneconverter` component of the `Magnum` package and use the
`Magnum::sceneconverter` target for example in a custom command:

@code{.cmake}
find_package(Magnum REQUIRED imageconverter)

add_custom_command(OUTPUT ... COMMAND Magnum::sceneconverter ...)
@endcode

See @ref building, @ref cmake and the @ref Trade namespace for more
information.

@section magnum-sceneconverter-usage Usage

@code{.sh}
magnum-sceneconverter [-h|--help] [--importer IMPORTER]
    [--converter CONVERTER]... [--plugin-dir DIR] [--remove-duplicates]
    [--remove-duplicates-fuzzy EPSILON]
    [-i|--importer-options key=val,key2=val2,…]
    [-c|--converter-options key=val,key2=val2,…]... [--mesh MESH]
    [--level LEVEL] [--info] [--bounds] [-v|--verbose] [--profile]
    [--] input output
@endcode

Arguments:

-   `input` --- input file
-   `output` --- output file
-   `-h`, `--help` --- display this help message and exit
-   `--importer IMPORTER` --- scene importer plugin (default:
    @ref Trade::AnySceneImporter "AnySceneImporter")
-   `--converter CONVERTER` --- scene converter plugin(s)
-   `--plugin-dir DIR` --- override base plugin dir
-   `--only-attributes "i j …"` --- include only attributes of given IDs in the
    output
-   `--remove-duplicates` --- remove duplicate vertices using
    @ref MeshTools::removeDuplicates(const Trade::MeshData&) after import
-   `--remove-duplicates-fuzzy EPSILON` --- remove duplicate vertices using
    @ref MeshTools::removeDuplicatesFuzzy(const Trade::MeshData&, Float, Double)
    after import
-   `-i`, `--importer-options key=val,key2=val2,…` --- configuration options to
    pass to the importer
-   `-c`, `--converter-options key=val,key2=val2,…` --- configuration options
    to pass to the converter(s)
-   `--mesh MESH` --- mesh to import (default: `0`)
-   `--level LEVEL` --- mesh level to import (default: `0`)
-   `--info` --- print info about the input file and exit
-   `--bounds` --- show bounds of known attributes in `--info` output
-   `-v`, `--verbose` --- verbose output from importer and converter plugins
-   `--profile` --- measure import and conversion time

If `--info` is given, the utility will print information about all meshes
and images present in the file.

The `-i` / `--importer-options` and `-c` / `--converter-options` arguments
accept a comma-separated list of key/value pairs to set in the importer /
converter plugin configuration. If the `=` character is omitted, it's
equivalent to saying `key=true`; configuration subgroups are delimited with
`/`.

It's possible to specify the `--converter` option (and correspondingly also
`-c` / `--converter-options`) multiple times in order to chain more converters
together. All converters in the chain have to support the
@ref Trade::SceneConverterFeature::ConvertMesh feature,
the last converter either @ref Trade::SceneConverterFeature::ConvertMesh or
@ref Trade::SceneConverterFeature::ConvertMeshToFile. If the last converter
doesn't support conversion to a file,
@ref Trade::AnySceneConverter "AnySceneConverter" is used to save its output;
if no `--converter` is specified, @ref Trade::AnySceneConverter "AnySceneConverter"
is used.

@section magnum-sceneconverter-example Example usage

Printing info about all meshes in a glTF file:

@code{.sh}
magnum-sceneconverter --info scene.gltf
@endcode

Converting an OBJ file to a PLY, using @ref Trade::StanfordSceneConverter "StanfordSceneConverter"
picked by @ref Trade::AnySceneConverter "AnySceneConverter":

@code{.sh}
magnum-sceneconverter chair.obj chair.ply
@endcode

Processing an OBJ file with @ref Trade::MeshOptimizerSceneConverter "MeshOptimizerSceneConverter",
setting @ref Trade-MeshOptimizerSceneConverter-configuration "plugin-specific configuration options"
to reduce the index count to half, saving as a PLY, with verbose output showing
the processing stats:

@m_class{m-console-wrap}

@code{.sh}
magnum-sceneconverter chair.obj --converter MeshOptimizerSceneConverter -c simplify=true,simplifyTargetIndexCountThreshold=0.5 chair.ply -v
@endcode

@see @ref magnum-imageconverter
*/

}

using namespace Magnum;

namespace {

struct Duration {
    explicit Duration(std::chrono::high_resolution_clock::duration& output): _output(output), _t{std::chrono::high_resolution_clock::now()} {}

    ~Duration() {
        _output += std::chrono::high_resolution_clock::now() - _t;
    }

    private:
        std::chrono::high_resolution_clock::duration& _output;
        std::chrono::high_resolution_clock::time_point _t;
};

/** @todo const Array& doesn't work, minmax() would fail to match */
template<class T> std::string calculateBounds(Containers::Array<T>&& attribute) {
    /** @todo clean up when Debug::toString() exists */
    std::ostringstream out;
    Debug{&out, Debug::Flag::NoNewlineAtTheEnd} << Math::minmax(attribute);
    return out.str();
}

/* Named attribute index from a global index */
/** @todo some helper for this directly on the MeshData class? */
UnsignedInt namedAttributeId(const Trade::MeshData& mesh, UnsignedInt id) {
    const Trade::MeshAttribute name = mesh.attributeName(id);
    for(UnsignedInt i = 0; i != mesh.attributeCount(name); ++i)
        if(mesh.attributeId(name, i) == id) return i;
    CORRADE_INTERNAL_ASSERT_UNREACHABLE();
}

}

int main(int argc, char** argv) {
    Utility::Arguments args;
    args.addArgument("input").setHelp("input", "input file")
        .addArgument("output").setHelp("output", "output file")
        .addOption("importer", "AnySceneImporter").setHelp("importer", "scene importer plugin")
        .addArrayOption("converter").setHelp("converter", "scene converter plugin(s)")
        .addOption("plugin-dir").setHelp("plugin-dir", "override base plugin dir", "DIR")
        .addOption("only-attributes").setHelp("only-attributes", "include only attributes of given IDs in the output", "\"i j …\"")
        .addBooleanOption("remove-duplicates").setHelp("remove-duplicates", "remove duplicate vertices in the mesh after import")
        .addOption("remove-duplicates-fuzzy").setHelp("remove-duplicates-fuzzy", "remove duplicate vertices with fuzzy comparison in the mesh after import", "EPSILON")
        .addOption('i', "importer-options").setHelp("importer-options", "configuration options to pass to the importer", "key=val,key2=val2,…")
        .addArrayOption('c', "converter-options").setHelp("converter-options", "configuration options to pass to the converter(s)", "key=val,key2=val2,…")
        .addOption("mesh", "0").setHelp("mesh", "mesh to import")
        .addOption("level", "0").setHelp("level", "mesh level to import")
        .addBooleanOption("info").setHelp("info", "print info about the input file and exit")
        .addBooleanOption("bounds").setHelp("bounds", "show bounds of known attributes in --info output")
        .addBooleanOption('v', "verbose").setHelp("verbose", "verbose output from importer and converter plugins")
        .addBooleanOption("profile").setHelp("profile", "measure import and conversion time")
        .setParseErrorCallback([](const Utility::Arguments& args, Utility::Arguments::ParseError error, const std::string& key) {
            /* If --info is passed, we don't need the output argument */
            if(error == Utility::Arguments::ParseError::MissingArgument &&
                key == "output" && args.isSet("info")) return true;

            /* Handle all other errors as usual */
            return false;
        })
        .setGlobalHelp(R"(Converts scenes of different formats.

If --info is given, the utility will print information about all meshes and
images present in the file.

The -i / --importer-options and -c / --converter-options arguments accept a
comma-separated list of key/value pairs to set in the importer / converter
plugin configuration. If the = character is omitted, it's equivalent to saying
key=true; configuration subgroups are delimited with /.

It's possible to specify the --converter option (and correspondingly also
-c / --converter-options) multiple times in order to chain more converters
together. All converters in the chain have to support the ConvertMesh feature,
the last converter either ConvertMesh or ConvertMeshToFile. If the last
converter doesn't support conversion to a file, AnySceneConverter is used to
save its output; if no --converter is specified, AnySceneConverter is used.)")
        .parse(argc, argv);

    PluginManager::Manager<Trade::AbstractImporter> importerManager{
        args.value("plugin-dir").empty() ? std::string{} :
        Utility::Directory::join(args.value("plugin-dir"), Trade::AbstractImporter::pluginSearchPaths()[0])};

    Containers::Pointer<Trade::AbstractImporter> importer = importerManager.loadAndInstantiate(args.value("importer"));
    if(!importer) {
        Debug{} << "Available importer plugins:" << Utility::String::join(importerManager.aliasList(), ", ");
        return 1;
    }

    /* Set options, if passed */
    if(args.isSet("verbose")) importer->setFlags(Trade::ImporterFlag::Verbose);
    Trade::Implementation::setOptions(*importer, args.value("importer-options"));

    std::chrono::high_resolution_clock::duration importTime;

    /* Open the file */
    {
        Duration d{importTime};
        if(!importer->openFile(args.value("input"))) {
            Error() << "Cannot open file" << args.value("input");
            return 3;
        }
    }

    /* Print file info, if requested */
    if(args.isSet("info")) {
        if(!importer->meshCount() && !importer->image1DCount() && !importer->image2DCount() && !importer->image2DCount()) {
            Debug{} << "No meshes or images found.";
            return 0;
        }

        struct MaterialInfo {
            UnsignedInt material;
            UnsignedInt references;
            Trade::MaterialData data{{}, {}};
            std::string name;
        };

        struct TextureInfo {
            UnsignedInt texture;
            UnsignedInt references;
            Trade::TextureData data{{}, {}, {}, {}, {}, {}};
            std::string name;
        };

        struct MeshAttributeInfo {
            std::size_t offset;
            UnsignedInt stride, arraySize;
            Trade::MeshAttribute name;
            std::string customName;
            VertexFormat format;
            std::string bounds;
        };

        struct MeshInfo {
            UnsignedInt mesh, level;
            UnsignedInt references;
            MeshPrimitive primitive;
            UnsignedInt indexCount, vertexCount;
            MeshIndexType indexType;
            Containers::Array<MeshAttributeInfo> attributes;
            std::size_t indexDataSize, vertexDataSize;
            std::string name;
        };

        /* Parse everything first to avoid errors interleaved with output */

        /* Scene properties. Currently just counting how much is each mesh /
           material shared. Texture reference count is calculated when parsing
           materials. */
        Containers::Array<UnsignedInt> materialReferenceCount{importer->materialCount()};
        Containers::Array<UnsignedInt> meshReferenceCount{importer->meshCount()};
        for(UnsignedInt i = 0; i != importer->object3DCount(); ++i) {
            Containers::Pointer<Trade::ObjectData3D> object = importer->object3D(i);
            if(object && object->instanceType() == Trade::ObjectInstanceType3D::Mesh) {
                auto& meshObject = static_cast<Trade::MeshObjectData3D&>(*object);
                if(std::size_t(meshObject.instance()) < meshReferenceCount.size())
                    ++meshReferenceCount[meshObject.instance()];
                if(std::size_t(meshObject.material()) < materialReferenceCount.size())
                    ++materialReferenceCount[meshObject.material()];
            }
        }

        /* Material properties */
        bool error = false;
        Containers::Array<MaterialInfo> materialInfos;
        Containers::Array<UnsignedInt> textureReferenceCount{importer->textureCount()};
        for(UnsignedInt i = 0; i != importer->materialCount(); ++i) {
            Containers::Optional<Trade::MaterialData> material;
            {
                Duration d{importTime};
                if(!(material = importer->material(i))) {
                    error = true;
                    continue;
                }
            }

            /* Calculate texture reference count for all properties that
               look like a texture */
            for(UnsignedInt j = 0; j != material->layerCount(); ++j) {
                for(UnsignedInt k = 0; k != material->attributeCount(j); ++k) {
                    if(material->attributeType(j, k) != Trade::MaterialAttributeType::UnsignedInt || !Utility::String::endsWith(material->attributeName(j, k), "Texture"))
                        continue;

                    const UnsignedInt texture = material->attribute<UnsignedInt>(j, k);
                    if(texture < textureReferenceCount.size())
                        ++textureReferenceCount[texture];
                }
            }

            MaterialInfo info{};
            info.material = i;
            info.name = importer->materialName(i);
            info.references = materialReferenceCount[i];
            info.data = *std::move(material);

            arrayAppend(materialInfos, std::move(info));
        }

        /* Mesh properties */
        Containers::Array<MeshInfo> meshInfos;
        for(UnsignedInt i = 0; i != importer->meshCount(); ++i) {
            for(UnsignedInt j = 0; j != importer->meshLevelCount(i); ++j) {
                Containers::Optional<Trade::MeshData> mesh;
                {
                    Duration d{importTime};
                    if(!(mesh = importer->mesh(i, j))) {
                        error = true;
                        continue;
                    }
                }

                MeshInfo info{};
                info.mesh = i;
                info.level = j;
                info.primitive = mesh->primitive();
                info.vertexCount = mesh->vertexCount();
                info.vertexDataSize = mesh->vertexData().size();
                if(!j) {
                    info.name = importer->meshName(i);
                    info.references = meshReferenceCount[i];
                }
                if(mesh->isIndexed()) {
                    info.indexCount = mesh->indexCount();
                    info.indexType = mesh->indexType();
                    info.indexDataSize = mesh->indexData().size();
                }
                for(UnsignedInt k = 0; k != mesh->attributeCount(); ++k) {
                    const Trade::MeshAttribute name = mesh->attributeName(k);

                    /* Calculate bounds, if requested and this is not an
                       implementation-specific format */
                    std::string bounds;
                    if(args.isSet("bounds") && !isVertexFormatImplementationSpecific(mesh->attributeFormat(k))) switch(name) {
                        case Trade::MeshAttribute::Position:
                            bounds = calculateBounds(mesh->positions3DAsArray(namedAttributeId(*mesh, k)));
                            break;
                        case Trade::MeshAttribute::Tangent:
                            bounds = calculateBounds(mesh->tangentsAsArray(namedAttributeId(*mesh, k)));
                            break;
                        case Trade::MeshAttribute::Bitangent:
                            bounds = calculateBounds(mesh->bitangentsAsArray(namedAttributeId(*mesh, k)));
                            break;
                        case Trade::MeshAttribute::Normal:
                            bounds = calculateBounds(mesh->normalsAsArray(namedAttributeId(*mesh, k)));
                            break;
                        case Trade::MeshAttribute::TextureCoordinates:
                            bounds = calculateBounds(mesh->textureCoordinates2DAsArray(namedAttributeId(*mesh, k)));
                            break;
                        case Trade::MeshAttribute::Color:
                            bounds = calculateBounds(mesh->colorsAsArray(namedAttributeId(*mesh, k)));
                            break;
                        case Trade::MeshAttribute::ObjectId:
                            Debug{} << mesh->objectIdsAsArray(namedAttributeId(*mesh, k));
                            bounds = calculateBounds(mesh->objectIdsAsArray(namedAttributeId(*mesh, k)));
                            break;

                        /* And also all other custom attribs. Not saying
                           default: here so we get notified when we forget to
                           handle newly added attribute names */
                        case Trade::MeshAttribute::Custom:
                            break;
                    }

                    arrayAppend(info.attributes, Containers::InPlaceInit,
                        mesh->attributeOffset(k),
                        mesh->attributeStride(k),
                        mesh->attributeArraySize(k),
                        name, Trade::isMeshAttributeCustom(name) ?
                            importer->meshAttributeName(name) : "",
                        mesh->attributeFormat(k),
                        bounds);
                }

                std::sort(info.attributes.begin(), info.attributes.end(),
                    [](const MeshAttributeInfo& a, const MeshAttributeInfo& b) {
                        return a.offset < b.offset;
                    });

                arrayAppend(meshInfos, std::move(info));
            }
        }

        /* Texture properties */
        Containers::Array<TextureInfo> textureInfos;
        for(UnsignedInt i = 0; i != importer->textureCount(); ++i) {
            Containers::Optional<Trade::TextureData> texture;
            {
                Duration d{importTime};
                if(!(texture = importer->texture(i))) {
                    error = true;
                    continue;
                }
            }

            TextureInfo info{};
            info.texture = i;
            info.name = importer->textureName(i);
            info.references = textureReferenceCount[i];
            info.data = *std::move(texture);

            arrayAppend(textureInfos, std::move(info));
        }

        /* In case the images have all just a single level and no names, write
           them in a compact way without listing levels. */
        bool compactImages = false;
        Containers::Array<Trade::Implementation::ImageInfo> imageInfos =
            Trade::Implementation::imageInfo(*importer, error, compactImages);

        for(const MaterialInfo& info: materialInfos) {
            Debug d;
            d << "Material" << info.material;
            /* Print reference count only if there actually is a scene,
               otherwise this information is useless */
            if(importer->object3DCount())
                d << Utility::formatString("(referenced by {} objects)", info.references);
            d << Debug::nospace << ":";
            if(!info.name.empty()) d << info.name;

            d << Debug::newline << "  Type:" << info.data.types();

            for(UnsignedInt i = 0; i != info.data.layerCount(); ++i) {
                /* Print extra layers with extra indent */
                const char* indent;
                if(info.data.layerCount() != 1 && i != 0) {
                    d << Debug::newline << "  Layer" << i << Debug::nospace << ":";
                    if(!info.data.layerName(i).isEmpty())
                        d << info.data.layerName(i);
                    indent = "   ";
                } else indent = " ";

                for(UnsignedInt j = 0; j != info.data.attributeCount(i); ++j) {
                    /* Ignore layer name (which is always first) unless it's in
                       the base material, in which case we print it as it
                       wouldn't otherwise be shown anywhere */
                    if(i && !j && info.data.attributeName(i, j) == "$LayerName")
                        continue;

                    d << Debug::newline << indent
                        << info.data.attributeName(i, j) << "@"
                        << info.data.attributeType(i, j) << Debug::nospace
                        << ":";
                    switch(info.data.attributeType(i, j)) {
                        case Trade::MaterialAttributeType::Bool:
                            d << info.data.attribute<bool>(i, j);
                            break;
                        #define _c(type) case Trade::MaterialAttributeType::type: \
                            d << info.data.attribute<type>(i, j);           \
                            break;
                        _c(Float)
                        _c(Deg)
                        _c(Rad)
                        _c(UnsignedInt)
                        _c(Int)
                        _c(UnsignedLong)
                        _c(Long)
                        _c(Vector2)
                        _c(Vector2ui)
                        _c(Vector2i)
                        _c(Vector3)
                        _c(Vector3ui)
                        _c(Vector3i)
                        _c(Vector4)
                        _c(Vector4ui)
                        _c(Vector4i)
                        _c(Matrix2x2)
                        _c(Matrix2x3)
                        _c(Matrix2x4)
                        _c(Matrix3x2)
                        _c(Matrix3x3)
                        _c(Matrix3x4)
                        _c(Matrix4x2)
                        _c(Matrix4x3)
                        #undef _c
                        case Trade::MaterialAttributeType::Pointer:
                            d << info.data.attribute<const void*>(i, j);
                            break;
                        case Trade::MaterialAttributeType::MutablePointer:
                            d << info.data.attribute<void*>(i, j);
                            break;
                        case Trade::MaterialAttributeType::String:
                            d << info.data.attribute<Containers::StringView>(i, j);
                            break;
                        case Trade::MaterialAttributeType::TextureSwizzle:
                            d << info.data.attribute<Trade::MaterialTextureSwizzle>(i, j);
                            break;
                    }
                }
            }
        }

        for(const MeshInfo& info: meshInfos) {
            Debug d;
            if(info.level == 0) {
                d << "Mesh" << info.mesh;
                /* Print reference count only if there actually is a scene,
                   otherwise this information is useless */
                if(importer->object3DCount())
                    d << Utility::formatString("(referenced by {} objects)", info.references);
                d << Debug::nospace << ":";
                if(!info.name.empty()) d << info.name;
                d << Debug::newline;
            }
            d << "  Level" << info.level << Debug::nospace << ":"
                << info.primitive << Debug::nospace << "," << info.vertexCount
                << "vertices (" << Debug::nospace
                << Utility::formatString("{:.1f}", info.vertexDataSize/1024.0f)
                << "kB)";
            if(info.indexType != MeshIndexType{}) {
                d << Debug::newline << "   " << info.indexCount << "indices @"
                    << info.indexType << "(" << Debug::nospace
                    << Utility::formatString("{:.1f}", info.indexDataSize/1024.0f)
                    << "kB)";
            }

            for(const MeshAttributeInfo& attribute: info.attributes) {
                d << Debug::newline << "    Offset" << attribute.offset
                    << Debug::nospace << ":" << attribute.name;
                if(Trade::isMeshAttributeCustom(attribute.name)) {
                    d << "(" << Debug::nospace << attribute.customName
                        << Debug::nospace << ")";
                }
                d << "@" << attribute.format << Debug::nospace << ", stride"
                    << attribute.stride;
                if(!attribute.bounds.empty())
                    d << Debug::newline << "      bounds:" << attribute.bounds;
            }
        }

        for(const TextureInfo& info: textureInfos) {
            Debug d;
            d << "Texture" << info.texture;
            /* Print reference count only if there actually are some
                materials, otherwise this information is useless */
            if(importer->materialCount())
                d << Utility::formatString("(referenced by {} materials)", info.references);
            d << Debug::nospace << ":";
            if(!info.name.empty()) d << info.name;
            d << Debug::newline;
            d << "  Type:" << info.data.type();
            d << "\n  Minification:" << info.data.minificationFilter() << info.data.mipmapFilter();
            d << "\n  Magnification:" << info.data.magnificationFilter();
            d << "\n  Wrapping:" << info.data.wrapping();
            d << "\n  Image:" << info.data.image();
        }

        for(const Trade::Implementation::ImageInfo& info: imageInfos) {
            Debug d;
            if(info.level == 0) {
                d << "Image" << info.image << Debug::nospace << ":";
                if(!info.name.empty()) d << info.name;
                if(compactImages) d << Debug::newline;
            }
            if(compactImages) d << "  Level" << info.level << Debug::nospace << ":";
            if(info.compressed) d << info.compressedFormat;
            else d << info.format;
            if(info.size.z()) d << info.size;
            else if(info.size.y()) d << info.size.xy();
            else d << Math::Vector<1, Int>(info.size.x());
        }

        if(args.isSet("profile")) {
            Debug{} << "Import took" << UnsignedInt(std::chrono::duration_cast<std::chrono::milliseconds>(importTime).count())/1.0e3f << "seconds";
        }

        return error ? 1 : 0;
    }

    Containers::Optional<Trade::MeshData> mesh;
    {
        Duration d{importTime};
        if(!importer->meshCount() || !(mesh = importer->mesh(args.value<UnsignedInt>("mesh"), args.value<UnsignedInt>("level")))) {
            Error{} << "Cannot import the mesh";
            return 4;
        }
    }

    std::chrono::high_resolution_clock::duration conversionTime;

    /* Filter attributes, if requested */
    if(!args.value("only-attributes").empty()) {
        std::set<UnsignedInt> only;
        for(const std::string& i: Utility::String::split(args.value("only-attributes"), ' '))
            only.insert(std::stoi(i));

        Containers::Array<Trade::MeshAttributeData> attributes;
        for(UnsignedInt i = 0; i != mesh->attributeCount(); ++i) {
            if(only.find(i) != only.end())
                arrayAppend(attributes, mesh->attributeData(i));
        }

        const Trade::MeshIndexData indices{mesh->indices()};
        const UnsignedInt vertexCount = mesh->vertexCount();
        mesh = Trade::MeshData{mesh->primitive(),
            mesh->releaseIndexData(), indices,
            mesh->releaseVertexData(), std::move(attributes),
            vertexCount};
    }

    /* Remove duplicates, if requested */
    if(args.isSet("remove-duplicates")) {
        const UnsignedInt beforeVertexCount = mesh->vertexCount();
        {
            Duration d{conversionTime};
            mesh = MeshTools::removeDuplicates(*std::move(mesh));
        }
        if(args.isSet("verbose"))
            Debug{} << "Duplicate removal:" << beforeVertexCount << "->" << mesh->vertexCount() << "vertices";
    }

    /* Remove duplicates with fuzzy comparison, if requested */
    /** @todo accept two values for float and double fuzzy comparison */
    if(!args.value("remove-duplicates-fuzzy").empty()) {
        const UnsignedInt beforeVertexCount = mesh->vertexCount();
        {
            Duration d{conversionTime};
            mesh = MeshTools::removeDuplicatesFuzzy(*std::move(mesh), args.value<Float>("remove-duplicates-fuzzy"));
        }
        if(args.isSet("verbose"))
            Debug{} << "Fuzzy duplicate removal:" << beforeVertexCount << "->" << mesh->vertexCount() << "vertices";
    }

    /* Load converter plugin */
    PluginManager::Manager<Trade::AbstractSceneConverter> converterManager{
        args.value("plugin-dir").empty() ? std::string{} :
        Utility::Directory::join(args.value("plugin-dir"), Trade::AbstractSceneConverter::pluginSearchPaths()[0])};

    /* Assume there's always one passed --converter option less, and the last
       is implicitly AnySceneConverter. All converters except the last one are
       expected to support ConvertMesh and the mesh is "piped" from one to the
       other. If the last converter supports ConvertMeshToFile instead of
       ConvertMesh, it's used instead of the last implicit AnySceneConverter. */
    for(std::size_t i = 0, converterCount = args.arrayValueCount("converter"); i <= converterCount; ++i) {
        const std::string converterName = i == converterCount ?
            "AnySceneConverter" : args.arrayValue("converter", i);
        Containers::Pointer<Trade::AbstractSceneConverter> converter = converterManager.loadAndInstantiate(converterName);
        if(!converter) {
            Debug{} << "Available converter plugins:" << Utility::String::join(converterManager.aliasList(), ", ");
            return 2;
        }

        /* Set options, if passed */
        if(args.isSet("verbose")) converter->setFlags(Trade::SceneConverterFlag::Verbose);
        if(i < args.arrayValueCount("converter-options"))
            Trade::Implementation::setOptions(*converter, args.arrayValue("converter-options", i));

        /* This is the last --converter (or the implicit AnySceneConverter at
           the end), output to a file and exit the loop */
        if(i + 1 >= converterCount && (converter->features() & Trade::SceneConverterFeature::ConvertMeshToFile)) {
            if(converterCount > 1 && args.isSet("verbose"))
                Debug{} << "Saving output with" << converterName << Debug::nospace << "...";

            Duration d{conversionTime};
            if(!converter->convertToFile(args.value("output"), *mesh)) {
                Error{} << "Cannot save file" << args.value("output");
                return 5;
            }

            break;

        /* This is not the last converter, expect that it's capable of
           ConvertMesh */
        } else {
            CORRADE_INTERNAL_ASSERT(i < converterCount);
            if(converterCount > 1 && args.isSet("verbose"))
                Debug{} << "Processing (" << Debug::nospace << (i+1) << Debug::nospace << "/" << Debug::nospace << converterCount << Debug::nospace << ") with" << converterName << Debug::nospace << "...";

            if(!(converter->features() & Trade::SceneConverterFeature::ConvertMesh)) {
                Error{} << converterName << "doesn't support mesh conversion, only" << converter->features();
                return 6;
            }

            Duration d{conversionTime};
            if(!(mesh = converter->convert(*mesh))) {
                Error{} << converterName << "cannot convert the mesh";
                return 7;
            }
        }
    }

    if(args.isSet("profile")) {
        Debug{} << "Import took" << UnsignedInt(std::chrono::duration_cast<std::chrono::milliseconds>(importTime).count())/1.0e3f << "seconds, conversion"
            << UnsignedInt(std::chrono::duration_cast<std::chrono::milliseconds>(conversionTime).count())/1.0e3f << "seconds";
    }
}