materials.h

/*****************************************************************************
 * VCLib                                                                     *
 * Visual Computing Library                                                  *
 *                                                                           *
 * Copyright(C) 2021-2025                                                    *
 * Visual Computing Lab                                                      *
 * ISTI - Italian National Research Council                                  *
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 * All rights reserved.                                                      *
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 * This program is free software; you can redistribute it and/or modify      *
 * it under the terms of the Mozilla Public License Version 2.0 as published *
 * by the Mozilla Foundation; either version 2 of the License, or            *
 * (at your option) any later version.                                       *
 *                                                                           *
 * This program is distributed in the hope that it will be useful,           *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of            *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the              *
 * Mozilla Public License Version 2.0                                        *
 * (https://www.mozilla.org/en-US/MPL/2.0/) for more details.                *
 ****************************************************************************/
 
#ifndef VCL_MESH_COMPONENTS_MATERIALS_H
#define VCL_MESH_COMPONENTS_MATERIALS_H
 
#include "base/component.h"
 
#include <vclib/space/core.h>
 
namespace vcl::comp {
 
namespace detail {
 
struct MData
{
    // The base path of the mesh, used to resolve relative texture paths.
    std::string meshPath;
    // A vector containing all the materials defined for the mesh.
    std::vector<Material> materials;
    // A map where keys are texture paths and values are the loaded Image data.
    std::map<std::string, Image> textureImages;
};
 
} // namespace detail
 
class Materials :
        public Component<
            Materials,
            CompId::MATERIALS,
            detail::MData,
            void,
            false,
            false>
{
    using Base = Component<
        Materials,
        CompId::MATERIALS,
        detail::MData,
        void,
        false,
        false>;
 
    inline static const Image EMPTY_IMAGE;
 
public:
    using MaterialType = Material;
 
    // iterators
 
    using MaterialIterator = std::vector<Material>::iterator;
    using ConstMaterialIterator = std::vector<Material>::const_iterator;
    using TextureImageIterator = std::map<std::string, Image>::iterator;
    using ConstTextureImageIterator =
        std::map<std::string, Image>::const_iterator;
 
    Materials() = default;
 
    /* Member functions */
 
    uint materialsNumber() const { return mats().size(); }
 
    uint textureImagesNumber() const { return txtImgs().size(); }
 
    const std::string& meshBasePath() const { return Base::data().meshPath; }
 
    std::string& meshBasePath() { return Base::data().meshPath; }
 
    const Material& material(uint i) const { return mats()[i]; }
 
    Material& material(uint i) { return mats()[i]; }
 
    const Image& textureImage(const std::string& texturePath) const
    {
        auto it = txtImgs().find(texturePath);
        if (it == txtImgs().end()) {
            return EMPTY_IMAGE;
        }
        return it->second;
    }
 
    void clearMaterials()
    {
        mats().clear();
        txtImgs().clear();
    }
 
    void pushMaterial(const Material& mat) { mats().push_back(mat); }
 
    void pushTextureImage(const std::string& texturePath, const Image& img)
    {
        txtImgs()[texturePath] = img;
    }
 
    void pushTextureImage(const std::string& texturePath, Image&& img)
    {
        txtImgs()[texturePath] = std::move(img);
    }
 
    MaterialIterator materialBegin() { return mats().begin(); }
 
    MaterialIterator materialEnd() { return mats().end(); }
 
    ConstMaterialIterator materialBegin() const { return mats().begin(); }
 
    ConstMaterialIterator materialEnd() const { return mats().end(); }
 
    TextureImageIterator textureImageBegin() { return txtImgs().begin(); }
 
    TextureImageIterator textureImageEnd() { return txtImgs().end(); }
 
    ConstTextureImageIterator textureImageBegin() const
    {
        return txtImgs().begin();
    }
 
    ConstTextureImageIterator textureImageEnd() const
    {
        return txtImgs().end();
    }
 
    View<MaterialIterator> materials()
    {
        return View(materialBegin(), materialEnd());
    }
 
    View<ConstMaterialIterator> materials() const
    {
        return View(materialBegin(), materialEnd());
    }
 
    View<TextureImageIterator> textureImages()
    {
        return View(textureImageBegin(), textureImageEnd());
    }
 
    View<ConstTextureImageIterator> textureImages() const
    {
        return View(textureImageBegin(), textureImageEnd());
    }
 
protected:
    // Component interface functions
    template<typename Element>
    void importFrom(const Element& e, bool = true);
 
    void serialize(std::ostream& os) const
    {
        vcl::serialize(os, meshBasePath());
        vcl::serialize(os, mats());
        vcl::serialize(os, txtImgs());
    }
 
    void deserialize(std::istream& is)
    {
        vcl::deserialize(is, meshBasePath());
        vcl::deserialize(is, mats());
        vcl::deserialize(is, txtImgs());
    }
 
private:
    // members that allow to access the data
    std::vector<Material>& mats() { return Base::data().materials; }
 
    const std::vector<Material>& mats() const { return Base::data().materials; }
 
    std::map<std::string, Image>& txtImgs()
    {
        return Base::data().textureImages;
    }
 
    const std::map<std::string, Image>& txtImgs() const
    {
        return Base::data().textureImages;
    }
};
 
/* concept */
 
template<typename T>
concept HasMaterials = std::derived_from<std::remove_cvref_t<T>, Materials>;
 
/* imoportFrom function */
 
template<typename Element>
void Materials::importFrom(const Element& e, bool)
{
    if constexpr (HasMaterials<Element>) {
        mats().clear();
        txtImgs().clear();
        for (const auto& mat : e.materials()) {
            mats().push_back(mat);
        }
        for (const auto& [path, img] : e.textureImages()) {
            txtImgs()[path] = img;
        }
        meshBasePath() = e.meshBasePath();
    }
}
 
} // namespace vcl::comp
 
#endif // VCL_MESH_COMPONENTS_MATERIALS_H