[liblouis-liblouisxml] Re: Expanding the typeforrm parameter
- From: "John J. Boyer" <john.boyer@xxxxxxxxxxxxxxxxx>
- To: liblouis-liblouisxml@xxxxxxxxxxxxx
- Date: Tue, 15 Oct 2013 12:54:00 -0500
The reason for not using a larger data type is backward compatibility.
That is important. It is also important to preserve the spacing
parameter. The typeform and spacing parameters together give 16 bits, of
which 4 are already committed. That should be enough to handle colored
type, script, etc. the 12 uncommitted bits can be used for anything in
the particular document.
John
On Tue, Oct 15, 2013 at 05:16:38PM +0100, Michael Whapples wrote:
> This had also been going through my mind, why not just use a larger data
> type?
>
> I do not know enough about the internals to know what sort of impact
> this might have.
>
> Michael Whapples
> On 15/10/2013 16:31, Mesar Hameed wrote:
> >I haven't looked at the details of what might be required to do this,,
> >but since we are processing more than ascii in more recent versions of
> >liblouis, it might be worth considering changing the typeform from a
> >char array to a unsigned long int array.
> >That would give us a lot of additional bits, without the implicit
> >dependancy and complexity of always having to
> >decode both the intention by reading the mode and the typeform.
> >
> >thoughts?
> >thanks,
> >Mesar
> >
> >
> >
> >On Tue 15/10/13,15:04, Ken Perry wrote:
> >>My only concern here is how expandable will this be in the future if for
> >>example there turns out to be more than 12 needed?
> >>
> >>Ken
> >>
> >>-----Original Message-----
> >>From: liblouis-liblouisxml-bounce@xxxxxxxxxxxxx
> >>[mailto:liblouis-liblouisxml-bounce@xxxxxxxxxxxxx] On Behalf Of John J.
> >>Boyer
> >>Sent: Monday, October 14, 2013 7:09 AM
> >>To: liblouis-liblouisxml@xxxxxxxxxxxxx
> >>Subject: [liblouis-liblouisxml] Expanding the typeforrm parameter
> >>
> >>Let me know if you have comments on the folowing.
> >>
> >>At present the typeform parameter can handle only four kinds of
> >>emphasis, bold, italic, underline and computer Braille. Although this
> >>parameter is a character array the high-order bits are used for the
> >>ascii numeric code, -x30. This is because at the beginning loblouis
> >>functions were called from Visual Basic.
> >>
> >>However, four types of emphasis are not enough to handle the Braille
> >>indicators required by modern textbooks, where it may be necessary to
> >>indicate colored type, script, etc.
> >>
> >>Therefore, I am proposing to use all eight bits of the typeforrm
> >>parameter. To preserve backward compatibility an additional bit in the
> >>mode parameter will be defined, extTypoeform . Since the spacing
> >>parameter is used only by ViewPlus and they may stop using it, I
> >>propose to make it an extension of the typeform parameter. This will
> >>provide 12 additional ways to indicate things in the text. It will
> >>also be controlled by the extTypeform bit.
> >>
> >>The present system of defining opcodes for things like beginning of
> >>phrase, end of phrase, etc for each type of emphasis is unworkable for an
> >>extended typeform parameter because it would result in a huge number of
> >>opcodes.
> >>
> >>The present algorithm for handling Braille indicators cannot be expanded
> >>for the same reason. Therefore, the correct-context-multipass feature
> >>will be extended with a scripting language. The base of this language
> >>already exists.
> >>
> >>John
> >>
> >>--
> >>John J. Boyer; President, Chief Software Developer Abilitiessoft, Inc.
> >>http://www.abilitiessoft.com
> >>Madison, Wisconsin USA
> >>Developing software for people with disabilities
> >>
> >>For a description of the software, to download it and links to project
> >>pages go to http://www.abilitiessoft.com
> >>For a description of the software, to download it and links to
> >>project pages go to http://www.abilitiessoft.com
>
> For a description of the software, to download it and links to
> project pages go to http://www.abilitiessoft.com
--
John J. Boyer; President, Chief Software Developer
Abilitiessoft, Inc.
http://www.abilitiessoft.com
Madison, Wisconsin USA
Developing software for people with disabilities
For a description of the software, to download it and links to
project pages go to http://www.abilitiessoft.com
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