dump_texture_to_file2.c

int dump_texture_to_file(SDL_Renderer *renderer, SDL_Texture *texture, const char *filename)
{
    SDL_Log("%s: ENTERING\n", __func__);

    Uint32 format = 0;
    int access = 0;
    int width = 0;
    int height = 0;
    int retval = 0;

    retval = SDL_QueryTexture(texture, &format, &access, &width, &height);
    if (retval < 0)
    {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                "%s: SDL_QueryTexture(): %s", __func__, SDL_GetError());
        return retval;
    }
        
    SDL_Log("%s: Texture info: Format: %s - Access: %d - Width: %d - Height: %d\n",
            __func__, SDL_GetPixelFormatName(format), access, width, height);

    Uint8 *pixels = malloc(width * height * SDL_BYTESPERPIXEL(format));
    if(!pixels)
    {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                "%s: malloc(pixels): %s", __func__, SDL_GetError());
        return retval;
    }

    SDL_RenderReadPixels(renderer, NULL, format, pixels, width * SDL_BYTESPERPIXEL(format));
    if (retval < 0)
    {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                "%s: SDL_RenderReadPixels(): %s", __func__, SDL_GetError());
        return retval;
    }

    SDL_Surface *surface = SDL_CreateRGBSurfaceWithFormatFrom(pixels, width, height, 32, width * SDL_BYTESPERPIXEL(format), format);
    if(!surface)
    {
       SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                "%s: SDL_CreateRGBSurfaceWithFormatFrom(): %s", __func__, SDL_GetError());
        return -1;        
    }

    SDL_Log("%s: Saving texture to file %s\n", __func__, filename);
    SDL_SaveBMP(surface, filename);
    if (retval < 0)
    {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                "%s: SDL_SaveBMP(): %s", __func__, SDL_GetError());
        return retval;
    }

    free(pixels);
    SDL_FreeSurface(surface);
    SDL_Log("%s: LEAVING\n", __func__);
    return 0;
}