トリミング描画: drawImage (image, sx, sy, sWidth, sHeight, dx, dy, dWidth, dHeight) 画像の一部を切り抜いて描画します。 スプライトシート（複数のアイコンが1枚にまとまった画像）の使用時などに必須となる、最も柔軟な形式です。

This class creates a drawable_wrapper object which does a debugging trace print of its operations as it draws (then forwards the actual drawing operation to its wrapped drawable). Find the min and max ...

Subclass of drawable_wrapper that conditionally does or skips drawing operations based on a settable boolean flag. All state changes such as color and clipping changes are always performs. This allows ...