void crawl_view_geometry::shift_player_to(const coord_def &c)
{
    // Preserve vgrdc offset after moving.
    const coord_def offset = crawl_view.vgrdc - you.pos();
    crawl_view.vgrdc = offset + c;
    last_player_pos = c;
    set_player_at(c);
    
    ASSERT(crawl_view.vgrdc == offset + c);
    ASSERT(last_player_pos == c);
}

void player::moveto(const coord_def &c)

void player::base_moveto(const coord_def &c)

    crawl_view.set_player_at(c);

void player::moveto(const coord_def &c)
{
    crawl_view.set_player_at(c);
    base_moveto(c);
}
void player::shiftto(const coord_def &c)
{
    crawl_view.shift_player_to(c);
    base_moveto(c);
}

    // Move the player during an abyss shift.
    void shiftto(const coord_def &c);

protected:
    void base_moveto(const coord_def &c);

    // Set new location, but preserve scrolling as if the player didn't move.
    void shift_player_to(const coord_def &c);

    you.moveto(abyss_center);

    you.shiftto(abyss_center);