texture_manager.h

/********************************************************************
 * Copyright (C) 2015 Liangliang Nan <liangliang.nan@gmail.com>
 * https://3d.bk.tudelft.nl/liangliang/
 *
 * This file is part of Easy3D. If it is useful in your research/work,
 * I would be grateful if you show your appreciation by citing it:
 * ------------------------------------------------------------------
 *      Liangliang Nan.
 *      Easy3D: a lightweight, easy-to-use, and efficient C++ library
 *      for processing and rendering 3D data.
 *      Journal of Open Source Software, 6(64), 3255, 2021.
 * ------------------------------------------------------------------
 *
 * Easy3D is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License Version 3
 * as published by the Free Software Foundation.
 *
 * Easy3D 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
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 ********************************************************************/
 
#ifndef EASY3D_RENDERER_TEXTURE_MANAGER_H
#define EASY3D_RENDERER_TEXTURE_MANAGER_H
 
 
#include <string>
#include <unordered_map>
 
#include <easy3d/renderer/texture.h>
 
 
namespace easy3d {
 
    class Texture;

    class TextureManager {
    public:
        static Texture *request(const std::string &image_file,
                                Texture::WrapMode wrap = Texture::CLAMP_TO_EDGE,
                                Texture::FilterMode filter = Texture::LINEAR);

        static Texture *request(const std::string &image_file, int num_stripes,
                                Texture::WrapMode wrap = Texture::CLAMP_TO_EDGE,
                                Texture::FilterMode filter = Texture::LINEAR);

        static Texture *request(int num_stripes, int stride,
                                Texture::WrapMode wrap = Texture::CLAMP_TO_EDGE,
                                Texture::FilterMode filter = Texture::LINEAR);

        static void release(const Texture *texture);

        static void terminate();
 
    private:
        // maps of std::string can be super slow when calling find with a string literal or const char*
        // as find forces construction/copy/destruction of a std::sting copy of the const char*.
        static std::unordered_map<std::string, Texture *> textures_;
        static std::unordered_map<std::string, bool> attempt_load_texture_; // avoid multiple attempt
    };
 
 
} // namespace easy3d
 
 
#endif  // EASY3D_RENDERER_TEXTURE_MANAGER_H