Code page handling needs faster lookup table for converting Unicode *back* to the code page

[joncampbell123]

Is your feature request related to a problem? Please describe.

Current code is fast when converting a code page to Unicode.

However converting back to Unicode is currently done by a slow for() loop that searches the table.

What you want

The code page generation code needs to make a reverse lookup table to speed this up.

If the new UI toolkit is to allow Unicode so that language files could be used in the future, it should accept UTF-8 strings and needs this table to prevent bitmap text drawing performance issues (FreeType Unicode glyph lookup doesn't need this, when we get around to TrueType font support).

For example, Unicode to CP437 for the initial stock VGA font object in the GUI toolkit.

Describe alternatives you've considered

No response

Additional information

No response

Have you checked that no similar feature request(s) exist?

• I have searched and didn't find any similar feature request.

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[Torinde]

I think such conversion function exists in Staging.