cube-map.cpp

Go to the documentation of this file.

/*
 * Copyright (C) 2023  Christopher J. Howard
 *
 * This file is part of Antkeeper source code.
 *
 * Antkeeper source code 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.
 *
 * Antkeeper source code 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 Antkeeper source code.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#include <engine/gl/cube-map.hpp>
 
namespace gl {
 
cube_map_layout infer_cube_map_layout(std::uint32_t width, std::uint32_t height) noexcept
{
    if (width == height / 6)
    {
        return cube_map_layout::column;
    }
    else if (width == height * 6)
    {
        return cube_map_layout::row;
    }
    else if (width == (height / 4) * 3)
    {
        return cube_map_layout::vertical_cross;
    }
    else if (width == (height * 4) / 3)
    {
        return cube_map_layout::horizontal_cross;
    }
    else if (width == height * 2)
    {
        return cube_map_layout::equirectangular;
    }
    else if (width == height)
    {
        return cube_map_layout::spherical;
    }
    
    return cube_map_layout::unknown;
}
 
std::uint32_t infer_cube_map_face_width(std::uint32_t width, std::uint32_t height, cube_map_layout layout) noexcept
{
    switch (layout)
    {
        case cube_map_layout::column:
        case cube_map_layout::spherical:
            return width;
        
        case cube_map_layout::row:
            return height;
        
        case cube_map_layout::vertical_cross:
            return height / 4;
        
        case cube_map_layout::horizontal_cross:
        case cube_map_layout::equirectangular:
            return width / 4;
        
        default:
            return 0;
    }
}
 
} // namespace gl