Hi all,
Armin Le Grand schrieb:
> Hi Regina,
>
> good to start that. The definitions for draw:transform are correct AFAIS.
I have added case translate.
>
> Concerning the coordinate system mess:
>
> The two possible orientations of coordinate system are needed when you
> want to define 'clockwise' and 'counterclockwise'.
>
> Instead, speaking about 'positive orientation' and 'negative
> orientation' in the mathematical sense is independent from the
> orientation where mathematical 'positive orientation' means (in both
> cases) that the rotation starts on (1,0), goes through the first
> quadrant and ends at (0,1).
>
> I would use the independent description. Together with the information
> that AOO uses (in all 2D cases) the screen orientation the result is
> that 'positive orientation' goes 'clockwise'.
I have added that suggestion.
>
> This definitions are missing and adding them will be fine. They still do
> not describe the existing problem with angles (except the ones in
> draw:transform and 3D). They are numerically *mirrored*, independent
> from the definition of the orientation.
>
> Thus the current state:
>  Screen orientation is used in core, api and odf
>  mathematically correct 'positive orientation' goes 'clockwise'
>  draw:angle is 'wrong' because it is numerically mirrored, it goes
> 'counterclockwise', but resides in the same orientation
>
> Example: draw:angle(300) (in 0.1 degrees, another problem, independent
> from orientation) is not for lines, but *if* applied to a line from
> (0,0) to (1,0) on the XAxis the line would be rotated 30 degrees
> anticlockwise (!) in the current offic(es). The line will point from
> bottomleft to upright.
>
> To get what you want (and what would be mathematically correct with the
> given definitions), an angle of 300 (or 3300 what is 3600  300) has to
> be used.
>
> Example the other way around: A line from (0,0) to (1,1), thus from
> topleft to bottomright on screen *should* have a rotation value of 45
> degrees. The API value for rotation (do not know the exact name right
> now) will not give you 450, but 3150, which is 3600450. ARGH!
>
> Thus the error(s) with draw:angle are:
>  It's in 10th of degrees and not documented as that
>  It's numerically mirrored, *independent* from the orientation
I have added this problem too. My suggestion is, to deprecate draw:angle
and use svg:gradientTransform instead.
>
> On 09.08.2012 15:39, Regina Henschel wrote:
>> Hi all,
>>
>> I have written a mail to OASIS, that I think that a lot of angle
>> definitions are not clear enough. It seems that the committee is willing
>> to discuss the problem. I have therefore started with section "19.228
>> draw:transform" in spec ODF 1.2 part 1.
>>
>> You find my concerns and suggestions on
>> http://wiki.services.openoffice.org/wiki/User:Regina/MYDrafts4.
>>
>> I plan to show that to the OASIS committee. But first I like to know
>> your ideas. So please have a look.
I have added comments to the gradient types "radial", "square" and
"linear". My review is not finished yet. I hope I will find time to look
at the other types too. Although the page is under my user area, you can
add things and should correct errors you see.
I wonder why all these problems have not been addressed during the
development of ODF1.2.
Kind regards
Regina
