/**** Sprite Aligner ****/

/** Window used for aligning sprites. */
struct SpriteAlignerWindow : Window {
    SpriteID current_sprite; ///< The currently shown sprite
    Scrollbar *vscroll;
    SmallMap<SpriteID, int> sprite_start_pos_map; ///< Mapping of offsets of all sprites viewed since opening the window

    SpriteAlignerWindow(WindowDesc *desc, WindowNumber wno) : Window(desc)
    {
        this->CreateNestedTree();
        this->vscroll = this->GetScrollbar(WID_SA_SCROLLBAR);
        this->FinishInitNested(wno);

        /* Oh yes, we assume there is at least one normal sprite! */
        while (GetSpriteType(this->current_sprite) != ST_NORMAL) SetCurrentSprite(this->current_sprite + 1);
    }

    void SetCurrentSprite(const SpriteID new_sprite)
    {
        this->current_sprite = new_sprite;

        if (this->sprite_start_pos_map.Contains(new_sprite)) return;
        /* Remember the original offset of the new sprite */
        this->sprite_start_pos_map.Insert(new_sprite, GetSprite(new_sprite, ST_NORMAL)->x_offs);
    }

    virtual void SetStringParameters(int widget) const
    {
        const Sprite *spr = GetSprite(this->current_sprite, ST_NORMAL);
        switch (widget) {
            case WID_SA_CAPTION:
                SetDParam(0, this->current_sprite);
                SetDParamStr(1, FioGetFilename(GetOriginFileSlot(this->current_sprite)));
                break;

            case WID_SA_OFFSETS: {
                SetDParam(0, spr->x_offs);
                SetDParam(1, spr->y_offs);
                break;
            }
            case WID_SA_OFFSETS_REL: {
                SetDParam(0, this->sprite_start_pos_map[this->current_sprite] - spr->x_offs);
                SetDParam(1, this->sprite_start_pos_map[this->current_sprite] - spr->y_offs);
                break;
            }

            default:
                break;
        }
    }




[SRC] Compiling newgrf_debug_gui.cpp
/home/tim/ttdp/openttd/trunk/src/newgrf_debug_gui.cpp: In member function ‘virtual void SpriteAlignerWindow::SetStringParameters(int) const’:
/home/tim/ttdp/openttd/trunk/src/newgrf_debug_gui.cpp:846:65: error: passing ‘const SmallMap<unsigned int, int>’ as ‘this’ argument of ‘U& SmallMap<T, U, S>::operator[](const T&) [with T = unsigned int; U = int; unsigned int S = 16u]’ discards qualifiers [-fpermissive]
     SetDParam(0, this->sprite_start_pos_map[this->current_sprite] - spr->x_offs);
                                                                 ^
/home/tim/ttdp/openttd/trunk/src/newgrf_debug_gui.cpp:847:65: error: passing ‘const SmallMap<unsigned int, int>’ as ‘this’ argument of ‘U& SmallMap<T, U, S>::operator[](const T&) [with T = unsigned int; U = int; unsigned int S = 16u]’ discards qualifiers [-fpermissive]
     SetDParam(1, this->sprite_start_pos_map[this->current_sprite] - spr->y_offs);