Unsupported SGF properties

[herzbube]

This issue is here to track SGF properties for which there is currently no clear way forward how to support them:

• All timing properties: BL, OB, OW, WL
  • Obviously these can be supported as soon as the app supports time-based gameplay.
  • In the meantime maybe they could at least be treated as node annotations?
• Miscellaneous properties: FG, PM, VW.
• Move properties
  • KO: Execute a given move (B or W) even if it's illegal.
  • MN: Sets the move number to the given value.
• Markup properties
  • DD: Dim (grey out) the given points.
• Root properties: AP, ST
• Go-specific properties without a type: TB, TW
  • These specify the black/white territory or area (depends on rule set used).
  • It's not clear what these properties exactly mean, i.e. how their values are supposed to be interpreted. Educated guess: Scoring information.

[herzbube]

Created some property-specific issues:

• What is the meaning of the SGF root property ST and should the app support it? #424
• Decide whether to support SGF move property MN (move number) #425

[herzbube]

Timing properties: From the property description it seems as if timing properties must always accompany a move.

[herzbube]

KO property

Decision: Do not support.

Rationale: Setting up illegal positions is not supported by the app, and loading a game with an illegal position is not possible, even though the SGF standard states that

SGF viewers themselves should execute ALL moves.

One may therefore consider the app to not be an SGF viewer.

[herzbube]

AP property

The app could show this when an SGF file is displayed in the archive, but once the SGF file is loaded there is no purpose to preserve this property.

The app should use its own value for this property when it writes an SGF file. IIRC the value that is currently used comes from SGFC.