parallax_layers — GFX2D tile op

• 数据种类:sprites → rgba

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

用法

让一组 `rgba` 图层以不同速度滚动并合成。

> 以下的详细说明为原文 —— 摘要与标题已翻译。

`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.

参考(示例数据・文献)

• 示例数据目录(下载 URL / 许可证) —— 2-D 用 skimage.data(BSD/公有领域)加合成图,3-D 给出真实数据源(Stanford/PDS 等)的下载 URL。

• 算子来历与参考文献 —— 该算子族所依据的研究/方法出处。

• 算法的正典(作者・年份)与用途见上面的族使用指南。

可运行的示例(实际调用该算子并已验证的样例)

• gfx2d_scene — py -3.11 examples/gfx2d_scene.py

类型可衔接的下一个算子(可接受 rgba 作为输入)

premultiply · alpha_composite · sprite_blit · sprite_transform · sprite_sheet_slice · nine_slice

同类别(tile)

tilemap_render

*Provenance: gfx2d.py — GFX2D 算子登记表。本条目由 tools/opdocs.py md 自动生成(请勿手工编辑)。*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.