ShaderLoader.h

/*
 * Copyright 2021 Adobe. All rights reserved.
 * This file is licensed to you under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License. You may obtain a copy
 * of the License at http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under
 * the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
 * OF ANY KIND, either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
#pragma once
 
#include <lagrange/ui/Entity.h>
#include <lagrange/ui/api.h>
#include <lagrange/ui/types/Shader.h>
 
namespace lagrange {
namespace ui {
 
struct LA_UI_API ShaderLoader
{
    enum class PathType { REAL, VIRTUAL };
 
    using result_type = std::shared_ptr<Shader>;
 
    result_type operator()(
        const std::string& generic_path,
        PathType pathtype,
        const ShaderDefines& defines = {}) const;
};
using ShaderCache = entt::resource_cache<Shader, ShaderLoader>;
using ShaderResource = entt::resource<Shader>;
 
// using ShaderDef = std::tuple<std::string, std::string, ShaderLoader::PathType, ShaderDefines>;
struct ShaderDefinition
{
    std::string path;
    ShaderLoader::PathType path_type = ShaderLoader::PathType::REAL;
    std::string display_name;
    ShaderDefines defines;
};
using RegisteredShaders = std::unordered_map<entt::id_type, ShaderDefinition>;
 
 
//Register shader with given id that can be used to load/reload and access the shader
LA_UI_API entt::id_type
register_shader_as(Registry& r, entt::id_type id, const ShaderDefinition& def);
 
//Register shader, returns and ID that can be used to load/reload and access the shader
LA_UI_API entt::id_type register_shader(Registry& r, const ShaderDefinition& def);
LA_UI_API entt::id_type
register_shader(Registry& r, const std::string& path, const std::string& display_name);
 
LA_UI_API entt::id_type
register_shader_variant(Registry& r, entt::id_type id, const ShaderDefines& shader_defines);
 
LA_UI_API ShaderResource get_shader(Registry& r, entt::id_type id);
 
 
LA_UI_API RegisteredShaders& get_registered_shaders(Registry& r);
LA_UI_API ShaderCache& get_shader_cache(Registry& r);
 
LA_UI_API bool add_file_to_shader_virtual_fs(
    const std::string& virtual_path,
    const std::string& contents,
    bool overwrite = false);
 
} // namespace ui
} // namespace lagrange