image-view.cpp

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/*
 * 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/image-view.hpp>
#include <engine/gl/opengl/gl-format-lut.hpp>
#include <stdexcept>
#include <glad/gl.h>
 
namespace gl {
 
image_view::image_view
(
    std::shared_ptr<gl::image> image,
    std::uint8_t dimensionality,
    gl::format format,
    std::uint32_t first_mip_level,
    std::uint32_t mip_level_count,
    std::uint32_t first_array_layer,
    std::uint32_t array_layer_count,
    std::uint8_t flags
)
{
    if (!image)
    {
        throw std::invalid_argument("Image view has null image.");
    }
    
    if (format == gl::format::undefined)
    {
        format = image->get_format();
    }
    
    const auto format_index = std::to_underlying(format);
    const auto gl_internal_format = gl_format_lut[format_index][0];
    
    if (!gl_internal_format)
    {
        throw std::invalid_argument("Image view has unsupported format.");
    }
    
    if (!mip_level_count)
    {
        throw std::invalid_argument("Image view has zero mip levels.");
    }
    
    if (first_mip_level + mip_level_count > image->get_mip_levels())
    {
        throw std::out_of_range("Image view mip range out of image mip range.");
    }
    
    if (!array_layer_count)
    {
        throw std::invalid_argument("Image view has zero array layers.");
    }
    
    if (first_array_layer + array_layer_count > image->get_array_layers())
    {
        throw std::out_of_range("Image view array layer range out of image array layer range.");
    }
    
    if (dimensionality != image->get_dimensionality())
    {
        throw std::invalid_argument("Image view dimensionality must match image dimensionality.");
    }
    
    if (flags & std::to_underlying(image_view_flag::cube))
    {
        if (!image->is_cube_compatible())
        {
            throw std::invalid_argument("Cube image views must be constructed from cube-compatible images.");
        }
        
        if (array_layer_count % 6 != 0)
        {
            throw std::invalid_argument("Cube image views array layer count must be a multiple of 6.");
        }
    }
    
    m_image = image;
    m_dimensionality = dimensionality;
    m_format = format;
    m_first_mip_level = first_mip_level;
    m_mip_level_count = mip_level_count;
    m_first_array_layer = first_array_layer;
    m_array_layer_count = array_layer_count;
    m_flags = flags;
    
    unsigned int gl_target = 0;
    switch (dimensionality)
    {
        case 1:
            gl_target = is_array() ? GL_TEXTURE_1D_ARRAY : GL_TEXTURE_1D;
            break;
        
        case 2:
            if (is_cube())
            {
                gl_target = is_array() ? GL_TEXTURE_CUBE_MAP_ARRAY : GL_TEXTURE_CUBE_MAP;
            }
            else
            {
                gl_target = is_array() ? GL_TEXTURE_2D_ARRAY : GL_TEXTURE_2D;
            }
            break;
        
        case 3:
            gl_target = GL_TEXTURE_3D;
            break;
        
        default:
            break;
    }
    
    glGenTextures(1, &m_gl_texture_name);
    glTextureView
    (
        m_gl_texture_name,
        gl_target,
        m_image->m_gl_texture_name,
        gl_internal_format,
        m_first_mip_level,
        m_mip_level_count,
        m_first_array_layer,
        m_array_layer_count
    );
}
 
image_view::~image_view()
{
    glDeleteTextures(1, &m_gl_texture_name);
}
 
image_view_1d::image_view_1d
(
    std::shared_ptr<gl::image> image,
    gl::format format,
    std::uint32_t first_mip_level,
    std::uint32_t mip_level_count,
    std::uint32_t first_array_layer
):
    image_view
    (
        image,
        1,
        format,
        first_mip_level,
        mip_level_count,
        first_array_layer,
        1,
        0
    )
{}
 
image_view_1d_array::image_view_1d_array
(
    std::shared_ptr<gl::image> image,
    gl::format format,
    std::uint32_t first_mip_level,
    std::uint32_t mip_level_count,
    std::uint32_t first_array_layer,
    std::uint32_t array_layer_count
):
    image_view
    (
        image,
        1,
        format,
        first_mip_level,
        mip_level_count,
        first_array_layer,
        array_layer_count,
        std::to_underlying(image_view_flag::array)
    )
{}
 
image_view_2d::image_view_2d
(
    std::shared_ptr<gl::image> image,
    gl::format format,
    std::uint32_t first_mip_level,
    std::uint32_t mip_level_count,
    std::uint32_t first_array_layer
):
    image_view
    (
        image,
        2,
        format,
        first_mip_level,
        mip_level_count,
        first_array_layer,
        1,
        0
    )
{}
 
image_view_2d_array::image_view_2d_array
(
    std::shared_ptr<gl::image> image,
    gl::format format,
    std::uint32_t first_mip_level,
    std::uint32_t mip_level_count,
    std::uint32_t first_array_layer,
    std::uint32_t array_layer_count
):
    image_view
    (
        image,
        2,
        format,
        first_mip_level,
        mip_level_count,
        first_array_layer,
        array_layer_count,
        std::to_underlying(image_view_flag::array)
    )
{}
 
image_view_3d::image_view_3d
(
    std::shared_ptr<gl::image> image,
    gl::format format,
    std::uint32_t first_mip_level,
    std::uint32_t mip_level_count
):
    image_view
    (
        image,
        3,
        format,
        first_mip_level,
        mip_level_count,
        0,
        1,
        0
    )
{}
 
image_view_cube::image_view_cube
(
    std::shared_ptr<gl::image> image,
    gl::format format,
    std::uint32_t first_mip_level,
    std::uint32_t mip_level_count,
    std::uint32_t first_array_layer
):
    image_view
    (
        image,
        2,
        format,
        first_mip_level,
        mip_level_count,
        first_array_layer,
        6,
        std::to_underlying(image_view_flag::cube)
    )
{}
 
image_view_cube_array::image_view_cube_array
(
    std::shared_ptr<gl::image> image,
    gl::format format,
    std::uint32_t first_mip_level,
    std::uint32_t mip_level_count,
    std::uint32_t first_array_layer,
    std::uint32_t array_layer_count
):
    image_view
    (
        image,
        2,
        format,
        first_mip_level,
        mip_level_count,
        first_array_layer,
        array_layer_count,
        std::to_underlying(image_view_flag::array) | std::to_underlying(image_view_flag::cube)
    )
{}
 
} // namespace gl