Modified version of lib3ds reader of .3ds format

#include "Lib3ds_viewport.h"

Lib3ds_viewport::Lib3ds_viewport()
{
}

bool Lib3ds_viewport::lib3ds_viewport_read(Lib3dsViewport *viewport)
{
    Lib3dsChunk c;
    uint16_t chunk;

    memset(&viewport->setting, 0, sizeof(Lib3dsViewport_setting));

    if(!lib3ds_chunk_read_start(&c, 0))
    {
        return false;
    }

    switch (c.chunk)
    {
        case CHK_VIEWPORT_LAYOUT: // Flag of viewpost layout
        {
            int cur = 0;
            viewport->setting.layout_style = lib3ds_io_read_word();
            viewport->setting.layout_active = lib3ds_io_read_intw();
            lib3ds_io_read_intw();
            viewport->setting.layout_swap = lib3ds_io_read_intw();
            lib3ds_io_read_intw();
            viewport->setting.layout_swap_prior = lib3ds_io_read_intw();
            viewport->setting.layout_swap_view = lib3ds_io_read_intw();
            lib3ds_chunk_read_tell(&c);
            while ((chunk = lib3ds_chunk_read_next(&c)) != 0)
            {
                switch (chunk)
                {
                    case CHK_VIEWPORT_SIZE: // Flag of viewport
                    {
                        viewport->setting.layout_position[0] = lib3ds_io_read_word();
                        viewport->setting.layout_position[1] = lib3ds_io_read_word();
                        viewport->setting.layout_size[0] = lib3ds_io_read_word();
                        viewport->setting.layout_size[1] = lib3ds_io_read_word();
                        break;
                    }

                    case CHK_VIEWPORT_DATA_3:  // Flag of reading of the views
                    {
                        if (cur < LIB3DS_LAYOUT_MAX_VIEWS)
                        {
                            lib3ds_io_read_intw();
                            viewport->layout_views[cur].setting.axis_lock = lib3ds_io_read_word();
                            viewport->layout_views[cur].setting.position[0] = lib3ds_io_read_intw();
                            viewport->layout_views[cur].setting.position[1] = lib3ds_io_read_intw();
                            viewport->layout_views[cur].setting.size[0] = lib3ds_io_read_intw();
                            viewport->layout_views[cur].setting.size[1] = lib3ds_io_read_intw();
                            viewport->layout_views[cur].setting.type = lib3ds_io_read_word();
                            viewport->layout_views[cur].setting.zoom = lib3ds_io_read_float();
                            lib3ds_io_read_vector(viewport->layout_views[cur].setting.center);
                            viewport->layout_views[cur].setting.horiz_angle = lib3ds_io_read_float();
                            viewport->layout_views[cur].setting.vert_angle = lib3ds_io_read_float();
                            lib3ds_io_read_string(viewport->layout_views[cur].camera, 11);
                            ++cur;
                        }
                        break;
                    }

                    case CHK_VIEWPORT_DATA:
                        /* 3DS R2 & R3 chunk unsupported */
                        break;

                    default:
                        lib3ds_chunk_unknown(chunk);
                }
            }
            break;
        }

        case CHK_DEFAULT_VIEW: // Flag reading of the default view
        {
            while ((chunk = lib3ds_chunk_read_next(&c)) != 0)
            {
                switch (chunk)
                {
                    case CHK_VIEW_TOP: // Flag of reading value of the top
                    {
                        viewport->setting.default_type = LIB3DS_VIEW_TOP;

                        lib3ds_io_read_vector(viewport->setting.default_position);

                        viewport->setting.default_width = lib3ds_io_read_float();

                        break;
                    }

                    case CHK_VIEW_BOTTOM: // Flag of reading value of the bottom
                    {
                        viewport->setting.default_type = LIB3DS_VIEW_BOTTOM;

                        lib3ds_io_read_vector(viewport->setting.default_position);

                        viewport->setting.default_width = lib3ds_io_read_float();

                        break;
                    }

                    case CHK_VIEW_LEFT: // Flag of reading value of the left
                    {
                        viewport->setting.default_type = LIB3DS_VIEW_LEFT;

                        lib3ds_io_read_vector(viewport->setting.default_position);

                        viewport->setting.default_width = lib3ds_io_read_float();

                        break;
                    }

                    case CHK_VIEW_RIGHT: // Flag of reading value of the right
                    {
                        viewport->setting.default_type = LIB3DS_VIEW_RIGHT;

                        lib3ds_io_read_vector(viewport->setting.default_position);

                        viewport->setting.default_width = lib3ds_io_read_float();

                        break;
                    }

                    case CHK_VIEW_FRONT: // Flag of reading value of the front
                    {
                        viewport->setting.default_type = LIB3DS_VIEW_FRONT;

                        lib3ds_io_read_vector(viewport->setting.default_position);

                        viewport->setting.default_width = lib3ds_io_read_float();

                        break;
                    }

                    case CHK_VIEW_BACK: // Flag of reading value of the back
                    {
                        viewport->setting.default_type = LIB3DS_VIEW_BACK;

                        lib3ds_io_read_vector(viewport->setting.default_position);

                        viewport->setting.default_width = lib3ds_io_read_float();

                        break;
                    }

                    case CHK_VIEW_USER: // Flag of reading of the user view
                    {
                        viewport->setting.default_type = LIB3DS_VIEW_USER;

                        lib3ds_io_read_vector(viewport->setting.default_position);

                        viewport->setting.default_width = lib3ds_io_read_float();

                        viewport->setting.default_horiz_angle = lib3ds_io_read_float();

                        viewport->setting.default_vert_angle = lib3ds_io_read_float();

                        viewport->setting.default_roll_angle = lib3ds_io_read_float();

                        break;
                    }

                    case CHK_VIEW_CAMERA: // Flag of reading of value of the view camera
                    {
                        viewport->setting.default_type = LIB3DS_VIEW_CAMERA;

                        lib3ds_io_read_string(viewport->default_camera, 11);

                        break;
                    }

                    default:
                        lib3ds_chunk_unknown(chunk);
                }
            }
            break;
        }
    }

    lib3ds_chunk_read_end(&c);

    return true;
}