Re: Text allignement

Emmanuel BEUQUE (ebeuque@pratique.fr)
Tue, 3 Feb 1998 11:52:32 +0100

À (At) 13:32 +0900 3/02/98, Yoshiharu DEWA >On Mon, 2 Feb 1998 21:30:06
+0100 (MET),
> Andreas Kraft <kraft@fokus.gmd.de> said:
>> a colleague asked me about the orientation of text in the Text class.
>> It is obvious that the "LineOrientation" and "StartCorner" attributes
>> are to be used in combination.
>>
>> Is the following table of assumed text rendering directions correct:
>>
>>
>> LineOrientation| |
>> -------------+ | Horizontal | Vertical
>> StartCorner \| |
>> ---------------+----------------------------+----------------------------
>> upper-left | left,top -> right,bottom | left,top -> bottom,right
>> lower-left | left,bottom -> right, top | left,bottom -> top, right
>> upper-right | right, top -> left, bottom | right,top -> bottom, left
>> lower-right | right, bottom -> left, top | right, bottom -> top, left
>>
>>
>> If yes, is this somewhere stated or do I just remember it from one of
>> the meetings?
>> Do we need a clarification here?
>
>I remember this discussed in first Tokyo meeting concerning MHEG-5,
>but there is no inscription in the standard. IMHO, it is quite natual,
>isn't it?

I'm not so sure it is clear in any case. As Andreas has shown, there may be
8 cases. 4 cases clearly provides the ability to rotate the text of every
90 degrees. For instance, with our roman languages (english, german,
french), we could have 4 possibilities.

StartCorner Line orientation
Normal text upper-left horizontal
90 deg clockwise upper-right vertical
180 degrees lower-right horizontal
90 deg counterclockwise lower-left vertical

But the 4 other cases may be specified by the author. In this case, how
shall an engine render the text. Should it apply a mirror effect to render
it correctly, e.g. the following :

StartCorner Line orientation
90 deg clockwise then H-mirror upper-left vertical
Normal text, horizontal mirror upper-right horizontal
90 deg clockwise then V-mirror lower-right vertical
Normal text, vertical mirror lower-left horizontal

I think that it definitely need a clarification. The note in 36.1.2 Line
Orientation is not sufficient IMHO.

Best regards,
Emmanuel

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