CARD_GLASS,                 // make walls transparent

    CARD_MAP, CARD_DOWSING, CARD_SPADE, CARD_TROWEL, CARD_MINEFIELD

    CARD_GLASS, CARD_MAP, CARD_DOWSING, CARD_SPADE, CARD_TROWEL, CARD_MINEFIELD

    case CARD_GLASS: return "Vitrification";

}
static void glass_card(int power, deck_rarity_type rarity)
{
    const int power_level = get_power_level(power, rarity);
    int radius2;
    if ( power_level == 2 )
        radius2 = 1000000;
    else
    {
        radius2 = random2(power/40) + 2;
        radius2 *= radius2;
    }
    for ( int x = X_BOUND_1; x <= X_BOUND_2; ++x )
    {
        for ( int y = Y_BOUND_1; y <= Y_BOUND_2; ++y )
        {
            if ( distance(x,y,you.x_pos,you.y_pos) < radius2 )
            {
                if ( grd[x][y] == DNGN_ROCK_WALL )
                    grd[x][y] = DNGN_CLEAR_ROCK_WALL;
                else if ( grd[x][y] == DNGN_STONE_WALL )
                    grd[x][y] = DNGN_CLEAR_STONE_WALL;
                else if ( grd[x][y] == DNGN_PERMAROCK_WALL )
                    grd[x][y] = DNGN_CLEAR_PERMAROCK_WALL;
            }
        }
    }
            

    case CARD_GLASS:            glass_card(power, rarity); break;