Luna/gui/libui/include/ui/Image.h

/**
 * @file Image.h
 * @author apio (cloudapio.eu)
 * @brief TGA image loading and rendering.
 *
 * @copyright Copyright (c) 2023, the Luna authors.
 *
 */

#pragma once
#include <luna/Buffer.h>
#include <luna/SharedPtr.h>
#include <os/Path.h>
#include <ui/Widget.h>

namespace ui
{
    /**
     * @brief An image in the TGA file format.
     */
    class Image : public Shareable
    {
      public:
        /**
         * @brief Load a new TGA image from a file.
         *
         * @param path The path to open.
         * @return Result<SharedPtr<Image>> An error, or a new Image object.
         */
        static Result<SharedPtr<Image>> load(const os::Path& path);

        /**
         * @brief Return the array of pixels contained in the image.
         *
         * @return u32* The array of pixels.
         */
        u32* pixels()
        {
            return (u32*)m_image_data.data();
        }

        /**
         * @brief Return the width of the image.
         *
         * @return u16 The width.
         */
        u16 width()
        {
            return m_tga_header.w;
        }

        /**
         * @brief Return the height of the image.
         *
         * @return u16 The height.
         */
        u16 height()
        {
            return m_tga_header.h;
        }

      private:
        struct [[gnu::packed]] TGAHeader
        {
            u8 idlen;
            u8 colormap;
            u8 encoding;
            u16 cmaporig, cmaplen;
            u8 cmapent;
            u16 x;
            u16 y;
            u16 w;
            u16 h;
            u8 bpp;
            u8 pixeltype;
        };

        TGAHeader m_tga_header;
        Buffer m_image_data;
    };

    class ImageWidget final : public Widget
    {
      public:
        static Result<OwnedPtr<ImageWidget>> load(const os::Path& path);

        Result<void> draw(Canvas& canvas) override;

      private:
        SharedPtr<Image> m_image;
    };
}