openstreetmap/iD

coastline: check for correct orientation

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#9,292 opened on Sep 12, 2022

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Description

For simple closed ways: Winding order should follow "right hand rule" (i.e. land is on the left side of the direction of the way)

For non-closed ways: The direction of the way should be the same as any adjacent coastline ways.1

From the wiki:

The direction the ways are drawn is very important! They must be drawn so that the land is on the left side and water on the right side of the way (when viewing in the direction of the way arrows). If you regard this as tracing around an area of land, e.g., an island, then the coastline way should be running counterclockwise.

Footnotes

  1. This can only be checked for if any adjacent coastline ways are loaded which might not always be the case. ↩

Contributor guide

Research direction
Implement logic to check winding order for closed ways (right hand rule: land on left, water on right) and for non closed ways, ensure direction matches adjacent coastline ways if available. Use the OpenStreetMap iD editor's way handling code.
Tech stack
javascript
Domain
frontend
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Git
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60