Use the term "user coordinate system" instead of "local coordinate system"

[jarek-foksa]

Chapter 8 was recently edited to rely on the term "local coordinate system" instead of "user coordinate system".

Since all other chapters are relying on the term "user" rather than "local" in the context of coordinate systems and units, I would propose to revert this change for the sake of consistency. Also note the term "user" is baked into some DOM interfaces (userSpaceOnUse) which would be hard to change.

[svgeesus]

The term local coordinate system is also used elsewhere. For example in the definition of getBBox

The getBBox method is used to compute the bounding box of the current element. When the getBBox(options) method is called, the bounding box algorithm is invoked for the current element, with fill, stroke, markers and clipped members of the options dictionary argument used to control which parts of the element are included in the bounding box, using the element's local coordinate system as the coordinate system to return the bounding box in. A newly created DOMRect object that defines the computed bounding box is returned.

If the two terms are being used synonymously then I agree only one should be used, consistently; but it is not yet clear to me that they are being used to mean the exact same thing.

[jarek-foksa]

CSS Transforms spec (which is referenced by SVG 2) defines user coordinate system as an alias for local coordinate system:

• https://drafts.csswg.org/css-transforms/#user-coordinate-system
• https://drafts.csswg.org/css-transforms/#local-coordinate-system

[svgeesus]

Since these are defined to be synonyms, and since user is baked into attribute value and DOM interfaces, it seems we should replace all occurrences of local coordinate system with user coordinate system

Agenda+ to get a quick agreement check before making the edits.

[css-meeting-bot]

The SVG Working Group just discussed Use the term "user coordinate system" instead of "local coordinate system".

The full IRC log of that discussion

<AmeliaBR> Topic: Use the term "user coordinate system" instead of "local coordinate system"
<AmeliaBR> github: https://github.com//issues/519
<AmeliaBR> Amelia: Some confusing wording that affects many places.
<AmeliaBR> Chris: As the original poster notes, CSS Transforms defines these terms as synonymous. So it should come down to a find and replace.
<AmeliaBR> Amelia: Agree we should standardize on the phrase used in standard definitions.
<AmeliaBR> Tav: Are the terms clearly defined?
<AmeliaBR> Chris: yes, in CSS Transforms, which we reference.
<AmeliaBR> Tav: we also might want to include the definition, so that it can be understood without following links.
<AmeliaBR> Amelia: One area of possible confusion will be patterns & clipPath & so on, where you need to clearly distinguish userSpaceOnUse coordinates versus internal coordinates. Need to check that wording still makes sense after replacing.
<AmeliaBR> Chris: I'll try to handle this, though probably not before republishing this week.