ISO 21757-1:2020 section 12.27.1 [Runtime] General needs clarification

[datalogics-pgallot]

section 12.27.1 [Runtime] General contains the following description:

"An object that represents the run-time instance of the player. Each Runtime object can have its own unique script engine and set of annotations. The variable runtime is a global reference to this object."

I think this passage could use some clarity on what constitutes a set of annotations that would be associated with a runtime. Is it all 3D annotations of a document? all 3D and RichMedia annotations of a document? or is it all 3D annotations that share a 3D reference dictionary? Can you have more than one runtime per document? Can you have an AcroForm that interacts with more than one [3D Player] Runtime in the same document?

This came up in the context of a PDF GoTo3DView actions, which requires a Producer to specify a "target annotation for which to set the view." However this required parameter is curiously missing from Runtime.getView (sections 12.27.3.8 and 12.27.3.9) and RunTime.setView (sections 12.27.3.18 and 12.27.3.19).

Also note that Table 121 in section 12.27.2 seems to have a notion of an "active 3D annotation", for the canvasCount property, which is does not seem to be exposed, while viewCount's description is more ambiguous: "The number of named views for annotation."

Lastly, as a side issue, "player" seems to only be used in this one sentence in the spec and does not seem to be otherwise defined.

[petervwyatt]

I think this goes to the varying terminology, phrasing and expressions used in ISO 32000-2:2020 clause 13, and how (and what) various runtimes, environments and/or players are, can do, how they interact (if they are different things), etc. These are clearly around processor requirements, and we don't want to assume all processors necessarily have the same capabilities or that there is simply a "mega runtime" (e.g. a processor may not have a JS environment but may be able to do some forms of multimedia).