Should SVG define the exact rendered result for a stroke?

[nikosandronikos]

Tav raised initial questions about how the pixels that are painted for a stroke are calculated:
http://tavmjong.free.fr/SVG/STROKING/

The following options are commonly used:

1. Line segment of length stroke-width centered on stroke and run along the stroke
   from start to end. Any point crossed is part of the stroke.
   Described as 'offset curve' (CAD) and 'parallel curve' (mathematical) methods
   in other communities.
2. Points are generated along the path at stroke-width/2 distance along the normal. A path is created on each side that passes through each these points.

Current Situation

Specs that state strongly which method to use:

• NV Path rendering

Specs that don't state which method to use:

• SVG
• PDF

Which option is used by implementations?
Cairo: 1
Ghostscript: 1
NV_Path: 1
Skia: 2
CoreGraphics: 2
Canon's PDF RIP: 1
Adobe PDF Print Engine: 1
Acrobat PRO: 1

[nikosandronikos]

A test: https://jsfiddle.net/dodgeyhack/46seq6nd/

[nikosandronikos]

Resolved that either option is allowed.
Specification updated in commit 27c3c20