BLT-With-Graphics-Template/include/blt/gfx/renderer/resource_manager.h

/*
 *  <Short Description>
 *  Copyright (C) 2023  Brett Terpstra
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 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
 *  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 <https://www.gnu.org/licenses/>.
 */

#ifndef BLT_WITH_GRAPHICS_RESOURCE_MANAGER_H
#define BLT_WITH_GRAPHICS_RESOURCE_MANAGER_H

#include <blt/std/hashmap.h>
#include <blt/gfx/texture.h>
#include <mutex>
#include <vector>
#include <optional>
#include <string>
#include "blt/compatibility.h"

namespace blt::gfx
{
    
    struct loadable_texture
    {
        std::string path;
        std::string name;
        
        loadable_texture() = default;
        
        loadable_texture(std::string path, std::string name): path(std::move(path)), name(std::move(name))
        {}
    };
    
    class resource_manager
    {
        private:
            std::mutex load_lock;
            std::mutex save_lock;
            std::vector<loadable_texture> textures_to_load;
            std::vector<texture_file*> loaded_textures;
            blt::hashmap_t<std::string, texture_gl2D*> textures_2d;
            std::string resource_prefix;
        public:
            resource_manager() = default;
            
            void enqueue(std::string path, std::string name = "");
            
            void load_resources(std::size_t threads = 8);
            
            inline std::optional<texture_gl2D*> get(const std::string& name)
            {
                if (name.empty() || textures_2d.find(name) == textures_2d.end())
                    return {};
                return textures_2d[name];
            }
            
            /**
             * Directly sets the internal representation of the texture. Can be used to set custom, non file system loaded textures.
             * Note: this function takes ownership of the ptr.
             */
            inline void set(std::string_view name, texture_gl2D* texture)
            {
                textures_2d[name] = texture;
            }
            
            /**
             * Sets the directory used to prefix all asset loading with
             */
            inline void setPrefixDirectory(std::string path)
            {
                resource_prefix = std::move(path);
            }
            
            void cleanup();
    };
    
}

#endif //BLT_WITH_GRAPHICS_RESOURCE_MANAGER_H