Mutli-format font support

  • The generic-text instrument would be able to take a font bitmap with more than one line.
  • Each line could be used for a different font, different size, or different color text.
  • Control codes (ASCII 1-31) in a string DataRef (char-array type DataRef) would be interpreted as style changes. A line in the text would be selected by running the control code through the instrument’s key frame table.

OPEN ISSUE: where would line size and line formatting information be stored?

  • These could be in the instrument.
  • They could also be in a text file co-named with the PNG. This is a bit atypical of the generic instrument system, but since the PNG is a shared resource, it makes development simpler to have the metrics be shared too.

Text-font-based Numeric

  • A new gen_numeric instrument would use the same font formatting rules as the gen_text, for shared fonts, but use numeric datarefs.
  • The key frame table would do numeric conversion.
  • Numeric formatting would be by property (similar to the LED and rolling instruments).
  • Color selection would be done via range bounds, similar to the pie instrument (e.g. different stripes could be selected based on five zones of dataref values).

OPEN ISSUE: should it simply be legal to allow the gen_text instrument use numeric datarefs? Pro: reduces number of instruments Con: key frame table acts differently, properties needed are very different too!

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  • Aircraft Development

Article type:

  • Request for comment (RFC)