PdfiumCore + SDL2 in C#

Pdfium_SDL2.cs

/** packages to install
  <ItemGroup>
    <PackageReference Include="PDFiumCore" Version="120.0.6056" />
    <PackageReference Include="ppy.SDL2-CS" Version="1.0.82" />
  </ItemGroup>
 */


using PDFiumCore;
using static SDL2.SDL;
using static PDFiumCore.fpdfview;


namespace SDLMu;


internal class Program
{
    static unsafe void Main(string[] args)
    {
        FPDF_InitLibrary();

        if (SDL_Init(SDL_INIT_VIDEO) < 0)
            return;

        IntPtr window = SDL_CreateWindow("PDF Viewer", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1024, 768, 0);

        IntPtr renderer = SDL_CreateRenderer(window, -1,SDL_RendererFlags.SDL_RENDERER_ACCELERATED);


        
        var document = FPDF_LoadDocument("document.pdf", "");

        var page = FPDF_LoadPage(document, 0);

        using var pageSize = new FS_SIZEF_();
        FPDF_GetPageSizeByIndexF(document, 0, pageSize);
        var bitmap = FPDFBitmapCreateEx((int)pageSize.Width, (int)pageSize.Height,
            (int)FPDFBitmapFormat.BGRA, IntPtr.Zero, 0);

        if (bitmap == null) throw new Exception("failed to create a bitmap object");

        uint color = uint.MaxValue;
        FPDFBitmapFillRect(bitmap, 0, 0, (int)pageSize.Width, (int)pageSize.Height, color);

        FPDF_RenderPageBitmap(bitmap, page, 0, 0, (int)pageSize.Width, (int)pageSize.Height, 0,
            (int)RenderFlags.RenderAnnotations);

        var scan0 = FPDFBitmapGetBuffer(bitmap);
        var stride = FPDFBitmapGetStride(bitmap);




        var texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_ARGB8888, (int)SDL_TextureAccess.SDL_TEXTUREACCESS_STREAMING, (int)pageSize.Width, (int)pageSize.Height);
        
        
        var rect = new SDL_Rect();
        rect.h = (int)pageSize.Height; rect.w = (int)pageSize.Width; 
        rect.y = 0; rect.x = 0;
        SDL_UpdateTexture(texture, ref rect, scan0, stride);

        



        FPDFBitmapDestroy(bitmap);
        FPDF_ClosePage(page);


        

        bool quit = false;
        while (!quit)
        {
            SDL_Event e;
            while (SDL_PollEvent(out e) != 0)
            {
                if (e.type == SDL_EventType.SDL_QUIT)
                {
                    quit = true;
                }
            }

            
            

            SDL_RenderClear(renderer);


            SDL_RenderCopy(renderer, texture, ref rect, ref rect);

            SDL_RenderPresent(renderer);
        }



        FPDF_CloseDocument(document);
        FPDF_DestroyLibrary();

        SDL_DestroyTexture(texture);
        SDL_DestroyRenderer(renderer);
        SDL_DestroyWindow(window);
        SDL_Quit();
    }
}