RE: PUA

From: Marco.Cimarosti@icl.com
Date: Wed Feb 23 2000 - 06:08:46 EST


James E. Agenbroad wrote:
>Using the PUA for glyphs sems contrary to the our basic premises,

Wait. What premises? Who is "we"?

>but can we prevent consenting users from doing so?

No. It would be against most countries' laws to break the door-locks of
private houses (or offices) to delete or change some programs from the
personal (or corporate) computers :-)

Using the PUA for encoding glyphs (e.g. Indic ligatures, Mongolian
contextual forms, mirrored bidi glyphs, etc.) is the most innocent use I can
think of it.

Imagine a display engine designed to use a simple bitmapped font:

        for each line L that is to be displayed
        { create TmpL
                copy L in TmpL
                for each character position I in TmpL
                { if IsInitial(TmpL, I)
                        { TmpL[I] = PuaGlyph(TmpL[I]) + 0
                        }
                        else if IsMedial(TmpL, I)
                        { TmpL[I] = PuaGlyph(TmpL[I]) + 1
                        }
                        else if IsFinal(TmpL, I)
                        { TmpL[I] = PuaGlyph(TmpL[I]) + 2
                        else if IsIsolated(TmpL, I)
                        { TmpL[I] = PuaGlyph(TmpL[I]) + 3
                        }
                }
                Display TmpL
                drop TmpL
        }

This is just one of the possible uses of PUA, and one that does not cause
PUA code points to be stored or transmitted. What's wrong with it?

Ciao. Marco



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