parallax_layers — GFX2D `tile` op

• 資料種類:sprites → rgba

• 呼叫:import gfx2d; gfx2d.parallax_layers(layers, camera_x, factors, camera_y=0.0, factors_y=None)(或 opsgfx2d.get("parallax_layers"))

讓一組 `rgba` 圖層以不同速度捲動並合成。

> 以下的詳細說明為原文 —— 摘要與標題已翻譯。

`layers[0]` is the farthest layer and is drawn first. Each layer is

shifted by `-round(camera_x * factors[i])` columns (and rows, if

`factors_y` is given) and wraps — a parallax backdrop is a loop, and

wrapping is what makes it one.

Shifts are rounded to whole pixels, so the scroll is a pure permutation: a

single layer shifted by exactly its own width comes back with its alpha

channel bit-identical and its colour identical wherever `alpha > 0`. (The

colour of *fully transparent* pixels is not preserved — compositing goes

through :func:premultiply, which zeroes it by definition. That is the

documented cost of the premultiplied round trip, not a bug in the scroll.)

Sub-pixel scrolling would resample every frame and accumulate blur, which is

why it is not offered here — put the fractional part in

:func:sprite_transform if you need it.

• 範例資料目錄(下載 URL / 授權) —— 2-D 用 skimage.data(BSD/公有領域)加合成圖,3-D 給出真實資料源(Stanford/PDS 等)的下載 URL。

• 運算子來歷與參考文獻 —— 該運算子族所依據的研究/方法出處。

• 演算法的正典(作者・年份)與用途見上面的族使用指南。

• gfx2d_scene — py -3.11 examples/gfx2d_scene.py

*Provenance: gfx2d.py — GFX2D 運算子登記表。本條目由 tools/opdocs.py md 自動產生(請勿手動編輯)。*

parallax_layers — GFX2D tile op