magnum-bindings/src/python/magnum/trade.cpp

/*
    This file is part of Magnum.

    Copyright © 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019,
                2020, 2021, 2022 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 <pybind11/pybind11.h>
#include <Corrade/Containers/Optional.h>
#include <Corrade/Containers/StridedArrayView.h>
#include <Corrade/Containers/StringStl.h> /** @todo drop once we have our string casters */
#include <Magnum/ImageView.h>
#include <Magnum/Trade/AbstractImporter.h>
#include <Magnum/Trade/AbstractImageConverter.h>
#include <Magnum/Trade/AbstractSceneConverter.h>
#include <Magnum/Trade/ImageData.h>
#include <Magnum/Trade/MeshData.h>

#include "Corrade/Containers/PythonBindings.h"
#include "Corrade/Containers/StridedArrayViewPythonBindings.h"
#include "Magnum/PythonBindings.h"

#include "corrade/pluginmanager.h"
#include "magnum/bootstrap.h"

namespace magnum {

namespace {

template<UnsignedInt dimensions, class T> PyObject* implicitlyConvertibleToImageView(PyObject* obj, PyTypeObject*) {
    py::detail::make_caster<Trade::ImageData<dimensions>> caster;
    if(!caster.load(obj, false)) {
        return nullptr;
    }

    Trade::ImageData<dimensions>& data = caster;
    if(data.isCompressed()) {
        PyErr_SetString(PyExc_RuntimeError, "image is compressed");
        throw py::error_already_set{};
    }

    auto r = pyCastButNotShitty(pyImageViewHolder(ImageView<dimensions, T>(data), py::reinterpret_borrow<py::object>(obj))).release().ptr();
    return r;
}

template<UnsignedInt dimensions> void imageData(py::class_<Trade::ImageData<dimensions>>& c) {
    /*
        Missing APIs:

        Dimensions
    */

    /* These two are quite hacky attempts to bring the ImageData -> ImageView
       conversion operator functionality here. Using py::implicitly_convertible
       alone doesn't work as it only calls conversion constructors exposed to
       Python, and we can't expose such a thing to Python because ImageView is
       defined in the `magnum` module while this is `magnum.trade`, and that
       would mean a cyclic dependency.

       Instead, I took the guts of py::implicitly_convertible and instead of
       calling into Python I'm calling the C++ conversion operator directly
       myself. That alone is not enough, as this implicit conversion is only
       chosen if the target type has a Python-exposed constructor that takes a
       type that's implicitly convertible from the source type. Ugh.

       If this ever breaks with a pybind update, I'm probably going to
       reimplement this in a pure duck-typed fashion. I hope not tho. */
    {
        auto tinfo = py::detail::get_type_info(typeid(ImageView<dimensions, char>));
        CORRADE_INTERNAL_ASSERT(tinfo);
        tinfo->implicit_conversions.push_back(implicitlyConvertibleToImageView<dimensions, char>);
    } {
        auto tinfo = py::detail::get_type_info(typeid(ImageView<dimensions, const char>));
        CORRADE_INTERNAL_ASSERT(tinfo);
        tinfo->implicit_conversions.push_back(implicitlyConvertibleToImageView<dimensions, const char>);
    }

    c
        /* There are no constructors at the moment --- expecting those types
           get only created by importers. (It would also need the Array type
           and movability figured out, postponing that to later.) */

        /* Properties */
        .def_property_readonly("is_compressed", &Trade::ImageData<dimensions>::isCompressed, "Whether the image is compressed")
        .def_property_readonly("storage", [](Trade::ImageData<dimensions>& self) {
            if(self.isCompressed()) {
                PyErr_SetString(PyExc_AttributeError, "image is compressed");
                throw py::error_already_set{};
            }

            return self.storage();
        }, "Storage of pixel data")
        .def_property_readonly("format", [](Trade::ImageData<dimensions>& self) {
            if(self.isCompressed()) {
                PyErr_SetString(PyExc_AttributeError, "image is compressed");
                throw py::error_already_set{};
            }

            return self.format();
        }, "Format of pixel data")
        .def_property_readonly("pixel_size", [](Trade::ImageData<dimensions>& self) {
            if(self.isCompressed()) {
                PyErr_SetString(PyExc_AttributeError, "image is compressed");
                throw py::error_already_set{};
            }

            return self.pixelSize();
        }, "Pixel size (in bytes)")
        .def_property_readonly("size", [](Trade::ImageData<dimensions>& self) {
            return PyDimensionTraits<dimensions, Int>::from(self.size());
        }, "Image size")
        .def_property_readonly("data", [](Trade::ImageData<dimensions>& self) {
            return Containers::pyArrayViewHolder(self.data(), py::cast(self));
        }, "Image data")
        .def_property_readonly("pixels", [](Trade::ImageData<dimensions>& self) {
            if(self.isCompressed()) {
                PyErr_SetString(PyExc_AttributeError, "image is compressed");
                throw py::error_already_set{};
            }

            return Containers::pyArrayViewHolder(Containers::PyStridedArrayView<dimensions + 1, const char>{self.pixels()}, py::cast(self));
        }, "View on pixel data");
}

/* For some reason having ...Args as the second (and not last) template
   argument does not work. So I'm listing all variants here ... which are
   exactly two, in fact. */
template<class R, R(Trade::AbstractImporter::*f)() const> R checkOpened(Trade::AbstractImporter& self) {
    if(!self.isOpened()) {
        PyErr_SetString(PyExc_AssertionError, "no file opened");
        throw py::error_already_set{};
    }
    return (self.*f)();
}
template<class R, class Arg1, R(Trade::AbstractImporter::*f)(Arg1)> R checkOpened(Trade::AbstractImporter& self, Arg1 arg1) {
    if(!self.isOpened()) {
        PyErr_SetString(PyExc_AssertionError, "no file opened");
        throw py::error_already_set{};
    }
    return (self.*f)(arg1);
}
/** @todo drop this in favor of our own string caster */
template<class R, R(Trade::AbstractImporter::*f)(Containers::StringView)> R checkOpenedString(Trade::AbstractImporter& self, const std::string& arg1) {
    if(!self.isOpened()) {
        PyErr_SetString(PyExc_AssertionError, "no file opened");
        throw py::error_already_set{};
    }
    return (self.*f)(arg1);
}

template<class R, R(Trade::AbstractImporter::*f)(UnsignedInt), UnsignedInt(Trade::AbstractImporter::*bounds)() const> R checkOpenedBounds(Trade::AbstractImporter& self, UnsignedInt id) {
    if(!self.isOpened()) {
        PyErr_SetString(PyExc_AssertionError, "no file opened");
        throw py::error_already_set{};
    }

    if(id >= (self.*bounds)()) {
        PyErr_SetNone(PyExc_IndexError);
        throw py::error_already_set{};
    }

    return (self.*f)(id);
}
/** @todo drop this in favor of our own string caster */
template<Containers::String(Trade::AbstractImporter::*f)(UnsignedInt), UnsignedInt(Trade::AbstractImporter::*bounds)() const> std::string checkOpenedBoundsReturnsString(Trade::AbstractImporter& self, UnsignedInt id) {
    if(!self.isOpened()) {
        PyErr_SetString(PyExc_AssertionError, "no file opened");
        throw py::error_already_set{};
    }

    if(id >= (self.*bounds)()) {
        PyErr_SetNone(PyExc_IndexError);
        throw py::error_already_set{};
    }

    return (self.*f)(id);
}

template<class R, Containers::Optional<R>(Trade::AbstractImporter::*f)(UnsignedInt), UnsignedInt(Trade::AbstractImporter::*bounds)() const> R checkOpenedBoundsResult(Trade::AbstractImporter& self, UnsignedInt id) {
    if(!self.isOpened()) {
        PyErr_SetString(PyExc_AssertionError, "no file opened");
        throw py::error_already_set{};
    }

    if(id >= (self.*bounds)()) {
        PyErr_SetNone(PyExc_IndexError);
        throw py::error_already_set{};
    }

    /** @todo log redirection -- but we'd need assertions to not be part of
        that so when it dies, the user can still see why */
    Containers::Optional<R> out = (self.*f)(id);
    if(!out) {
        PyErr_SetString(PyExc_RuntimeError, "import failed");
        throw py::error_already_set{};
    }

    return *std::move(out);
}

template<class R, Containers::Optional<R>(Trade::AbstractImporter::*f)(UnsignedInt, UnsignedInt), UnsignedInt(Trade::AbstractImporter::*bounds)() const, UnsignedInt(Trade::AbstractImporter::*levelBounds)(UnsignedInt)> R checkOpenedBoundsResult(Trade::AbstractImporter& self, UnsignedInt id, UnsignedInt level) {
    if(!self.isOpened()) {
        PyErr_SetString(PyExc_AssertionError, "no file opened");
        throw py::error_already_set{};
    }

    if(id >= (self.*bounds)()) {
        PyErr_SetNone(PyExc_IndexError);
        throw py::error_already_set{};
    }

    if(level >= (self.*levelBounds)(id)) {
        PyErr_SetNone(PyExc_IndexError);
        throw py::error_already_set{};
    }

    /** @todo log redirection -- but we'd need assertions to not be part of
        that so when it dies, the user can still see why */
    Containers::Optional<R> out = (self.*f)(id, level);
    if(!out) {
        PyErr_SetString(PyExc_RuntimeError, "import failed");
        throw py::error_already_set{};
    }

    return *std::move(out);
}
/** @todo drop std::string in favor of our own string caster */
template<class R, Containers::Optional<R>(Trade::AbstractImporter::*f)(UnsignedInt, UnsignedInt), Int(Trade::AbstractImporter::*indexForName)(Containers::StringView), UnsignedInt(Trade::AbstractImporter::*levelBounds)(UnsignedInt)> R checkOpenedBoundsResultString(Trade::AbstractImporter& self, const std::string& name, UnsignedInt level) {
    if(!self.isOpened()) {
        PyErr_SetString(PyExc_AssertionError, "no file opened");
        throw py::error_already_set{};
    }

    const Int id = (self.*indexForName)(name);
    if(id == -1) {
        PyErr_SetNone(PyExc_KeyError);
        throw py::error_already_set{};
    }

    if(level >= (self.*levelBounds)(id)) {
        PyErr_SetNone(PyExc_IndexError);
        throw py::error_already_set{};
    }

    /** @todo log redirection -- but we'd need assertions to not be part of
        that so when it dies, the user can still see why */
    Containers::Optional<R> out = (self.*f)(id, level);
    if(!out) {
        PyErr_SetString(PyExc_RuntimeError, "import failed");
        throw py::error_already_set{};
    }

    return *std::move(out);
}

/* Can't be named just checkResult() because the AbstractSceneConverter
   overload would confuse GCC 4.8 */
/** @todo drop std::string in favor of our own string caster */
template<class T, bool(Trade::AbstractImageConverter::*f)(const T&, Containers::StringView)> void checkImageConverterResult(Trade::AbstractImageConverter& self, const T& image, const std::string& filename) {
    /** @todo log redirection -- but we'd need assertions to not be part of
        that so when it dies, the user can still see why */
    bool out = (self.*f)(image, filename);
    if(!out) {
        PyErr_SetString(PyExc_RuntimeError, "conversion failed");
        throw py::error_already_set{};
    }
}

/* Can't be named just checkResult() because the AbstractImageConverter
   overload would confuse GCC 4.8 */
/** @todo drop std::string in favor of our own string caster */
template<class T, bool(Trade::AbstractSceneConverter::*f)(const T&, Containers::StringView)> void checkSceneConverterResult(Trade::AbstractSceneConverter& self, const T& mesh, const std::string& filename) {
    /** @todo log redirection -- but we'd need assertions to not be part of
        that so when it dies, the user can still see why */
    bool out = (self.*f)(mesh, filename);
    if(!out) {
        PyErr_SetString(PyExc_RuntimeError, "conversion failed");
        throw py::error_already_set{};
    }
}

}

void trade(py::module_& m) {
    m.doc() = "Data format exchange";

    /* AbstractImporter depends on this */
    py::module_::import("corrade.pluginmanager");

    py::class_<Trade::MeshData>{m, "MeshData", "Mesh data"}
        .def_property_readonly("primitive", &Trade::MeshData::primitive, "Primitive")
        .def_property_readonly("is_indexed", &Trade::MeshData::isIndexed, "Whether the mesh is indexed")
        .def_property_readonly("vertex_count", &Trade::MeshData::vertexCount)
        .def_property_readonly("index_count", &Trade::MeshData::indexCount)
        .def_property_readonly("attribute_count", static_cast<UnsignedInt(Trade::MeshData::*)() const>(&Trade::MeshData::attributeCount));

    py::class_<Trade::ImageData1D> imageData1D{m, "ImageData1D", "One-dimensional image data"};
    py::class_<Trade::ImageData2D> imageData2D{m, "ImageData2D", "Two-dimensional image data"};
    py::class_<Trade::ImageData3D> imageData3D{m, "ImageData3D", "Three-dimensional image data"};
    imageData(imageData1D);
    imageData(imageData2D);
    imageData(imageData3D);

    /* Importer. Skipping file callbacks and openState as those operate with
       void*. Leaving the name as AbstractImporter (instead of Importer) to
       avoid needless name differences and because in the future there *might*
       be pure Python importers (not now tho). */
    py::class_<Trade::AbstractImporter, PluginManager::PyPluginHolder<Trade::AbstractImporter>> abstractImporter{m, "AbstractImporter", "Interface for importer plugins"};
    corrade::plugin(abstractImporter);
    abstractImporter
        /** @todo features */
        .def_property_readonly("is_opened", &Trade::AbstractImporter::isOpened, "Whether any file is opened")
        .def("open_data", [](Trade::AbstractImporter& self, Containers::ArrayView<const char> data) {
            /** @todo log redirection -- but we'd need assertions to not be
                part of that so when it dies, the user can still see why */
            if(self.openData(data)) return;

            PyErr_SetString(PyExc_RuntimeError, "opening data failed");
            throw py::error_already_set{};
        }, "Open raw data", py::arg("data"))
        /** @todo drop std::string in favor of our own string caster */
        .def("open_file", [](Trade::AbstractImporter& self, const std::string& filename) {
            /** @todo log redirection -- but we'd need assertions to not be
                part of that so when it dies, the user can still see why */
            if(self.openFile(filename)) return;

            PyErr_Format(PyExc_RuntimeError, "opening %s failed", filename.data());
            throw py::error_already_set{};
        }, "Open a file", py::arg("filename"))
        .def("close", &Trade::AbstractImporter::close, "Close currently opened file")

        /** @todo all other data types */
        .def_property_readonly("mesh_count", checkOpened<UnsignedInt, &Trade::AbstractImporter::meshCount>, "Mesh count")
        .def("mesh_level_count", checkOpenedBounds<UnsignedInt, &Trade::AbstractImporter::meshLevelCount, &Trade::AbstractImporter::meshCount>, "Mesh level count", py::arg("id"))
        .def("mesh_for_name", checkOpenedString<Int, &Trade::AbstractImporter::meshForName>, "Mesh ID for given name")
        .def("mesh_name", checkOpenedBoundsReturnsString<&Trade::AbstractImporter::meshName, &Trade::AbstractImporter::meshCount>, "Mesh name", py::arg("id"))
        .def("mesh", checkOpenedBoundsResult<Trade::MeshData, &Trade::AbstractImporter::mesh, &Trade::AbstractImporter::meshCount, &Trade::AbstractImporter::meshLevelCount>, "Mesh", py::arg("id"), py::arg("level") = 0)
        .def("mesh", checkOpenedBoundsResultString<Trade::MeshData, &Trade::AbstractImporter::mesh, &Trade::AbstractImporter::meshForName, &Trade::AbstractImporter::meshLevelCount>, "Mesh", py::arg("name"), py::arg("level") = 0)
        /** @todo mesh_attribute_for_name / mesh_attribute_name */

        .def_property_readonly("image1d_count", checkOpened<UnsignedInt, &Trade::AbstractImporter::image1DCount>, "One-dimensional image count")
        .def_property_readonly("image2d_count", checkOpened<UnsignedInt, &Trade::AbstractImporter::image2DCount>, "Two-dimensional image count")
        .def_property_readonly("image3d_count", checkOpened<UnsignedInt, &Trade::AbstractImporter::image3DCount>, "Three-dimensional image count")
        .def("image1d_level_count", checkOpenedBounds<UnsignedInt, &Trade::AbstractImporter::image1DLevelCount, &Trade::AbstractImporter::image1DCount>, "One-dimensional image level count", py::arg("id"))
        .def("image2d_level_count", checkOpenedBounds<UnsignedInt, &Trade::AbstractImporter::image2DLevelCount, &Trade::AbstractImporter::image2DCount>, "Two-dimensional image level count", py::arg("id"))
        .def("image3d_level_count", checkOpenedBounds<UnsignedInt, &Trade::AbstractImporter::image3DLevelCount, &Trade::AbstractImporter::image3DCount>, "Three-dimensional image level count", py::arg("id"))
        .def("image1d_for_name", checkOpenedString<Int, &Trade::AbstractImporter::image1DForName>, "One-dimensional image ID for given name")
        .def("image2d_for_name", checkOpenedString<Int, &Trade::AbstractImporter::image2DForName>, "Two-dimensional image ID for given name")
        .def("image3d_for_name", checkOpenedString<Int, &Trade::AbstractImporter::image3DForName>, "Three-dimensional image ID for given name")
        .def("image1d_name", checkOpenedBoundsReturnsString<&Trade::AbstractImporter::image1DName, &Trade::AbstractImporter::image1DCount>, "One-dimensional image name", py::arg("id"))
        .def("image2d_name", checkOpenedBoundsReturnsString<&Trade::AbstractImporter::image2DName, &Trade::AbstractImporter::image2DCount>, "Two-dimensional image name", py::arg("id"))
        .def("image3d_name", checkOpenedBoundsReturnsString< &Trade::AbstractImporter::image3DName, &Trade::AbstractImporter::image3DCount>, "Three-dimensional image name", py::arg("id"))
        .def("image1d", checkOpenedBoundsResult<Trade::ImageData1D, &Trade::AbstractImporter::image1D, &Trade::AbstractImporter::image1DCount, &Trade::AbstractImporter::image1DLevelCount>, "One-dimensional image", py::arg("id"), py::arg("level") = 0)
        .def("image1d", checkOpenedBoundsResultString<Trade::ImageData1D, &Trade::AbstractImporter::image1D, &Trade::AbstractImporter::image1DForName, &Trade::AbstractImporter::image1DLevelCount>, "One-dimensional image", py::arg("name"), py::arg("level") = 0)
        .def("image2d", checkOpenedBoundsResult<Trade::ImageData2D, &Trade::AbstractImporter::image2D, &Trade::AbstractImporter::image2DCount, &Trade::AbstractImporter::image2DLevelCount>, "Two-dimensional image", py::arg("id"), py::arg("level") = 0)
        .def("image2d", checkOpenedBoundsResultString<Trade::ImageData2D, &Trade::AbstractImporter::image2D, &Trade::AbstractImporter::image2DForName, &Trade::AbstractImporter::image2DLevelCount>, "Two-dimensional image", py::arg("name"), py::arg("level") = 0)
        .def("image3d", checkOpenedBoundsResult<Trade::ImageData3D, &Trade::AbstractImporter::image3D, &Trade::AbstractImporter::image3DCount, &Trade::AbstractImporter::image3DLevelCount>, "Three-dimensional image", py::arg("id"), py::arg("level") = 0)
        .def("image3d", checkOpenedBoundsResultString<Trade::ImageData3D, &Trade::AbstractImporter::image3D, &Trade::AbstractImporter::image3DForName, &Trade::AbstractImporter::image3DLevelCount>, "Threee-dimensional image", py::arg("name"), py::arg("level") = 0);

    py::class_<PluginManager::Manager<Trade::AbstractImporter>, PluginManager::AbstractManager> importerManager{m, "ImporterManager", "Manager for importer plugins"};
    corrade::manager(importerManager);

    /* Image converter */
    py::class_<Trade::AbstractImageConverter, PluginManager::PyPluginHolder<Trade::AbstractImageConverter>> abstractImageConverter{m, "AbstractImageConverter", "Interface for image converter plugins"};
    abstractImageConverter
        /** @todo features */
        .def("convert_to_file", checkImageConverterResult<ImageView1D, &Trade::AbstractImageConverter::convertToFile>, "Convert a 1D image to a file", py::arg("image"), py::arg("filename"))
        .def("convert_to_file", checkImageConverterResult<ImageView2D, &Trade::AbstractImageConverter::convertToFile>, "Convert a 2D image to a file", py::arg("image"), py::arg("filename"))
        .def("convert_to_file", checkImageConverterResult<ImageView3D, &Trade::AbstractImageConverter::convertToFile>, "Convert a 3D image to a file", py::arg("image"), py::arg("filename"));
    corrade::plugin(abstractImageConverter);

    py::class_<PluginManager::Manager<Trade::AbstractImageConverter>, PluginManager::AbstractManager> imageConverterManager{m, "ImageConverterManager", "Manager for image converter plugins"};
    corrade::manager(imageConverterManager);

    /* Scene converter */
    py::class_<Trade::AbstractSceneConverter, PluginManager::PyPluginHolder<Trade::AbstractSceneConverter>> abstractSceneConverter{m, "AbstractSceneConverter", "Interface for scene converter plugins"};
    abstractSceneConverter
        /** @todo features */
        .def("convert_to_file", checkSceneConverterResult<Trade::MeshData, &Trade::AbstractSceneConverter::convertToFile>, "Convert a mesh to a file", py::arg("mesh"), py::arg("filename"));
    corrade::plugin(abstractSceneConverter);

    py::class_<PluginManager::Manager<Trade::AbstractSceneConverter>, PluginManager::AbstractManager> sceneConverterManager{m, "SceneConverterManager", "Manager for scene converter plugins"};
    corrade::manager(sceneConverterManager);
}

}

#ifndef MAGNUM_BUILD_STATIC
/* TODO: remove declaration when https://github.com/pybind/pybind11/pull/1863
   is released */
extern "C" PYBIND11_EXPORT PyObject* PyInit_trade();
PYBIND11_MODULE(trade, m) {
    magnum::trade(m);
}
#endif