On 03 Mar 2011, at 13:08, Vincent Hennebert wrote:
>> Unless ... the viewport is where the actual rotation takes place.
>> IIC, the region-viewport's before-edge is still parallel to the
>> page-reference-area's before edge. The before-edge of the
>> region-reference-area, however, is the one that is rotated another 90
> See the following sentence in Section 6.4.15, “fo:region-before”:
> “The reference-orientation and writing-mode of the
> region-viewport-area are determined by the formatting object that
> generates the area (see 6.4.5 fo:page-sequence). The
> reference-orientation of the region-reference-area is set to "0" and
> is, therefore, the same as the orientation established by the
> region-viewport-area. The writing-mode of the region-reference-area
> is set to the same value as that of the region-viewport-area.”
> So the region-reference-area has the same orientation as the
Let's assume that this refers to the default/normal situation. After all, we
are quoting the _general_ fo:region-before definition (= where no deviating
reference-orientation has been specified on the region). I would not believe
anyone claiming that this definition was written with the intention of covering
all possible combinations of reference-orientation/writing-mode.
The general definition just states the normal behavior: if no deviating
reference-orientation has been specified, the region-reference-area will have
the same orientation as the viewport.
The definition of reference-orientation (7.21.3) states that a value of '90'
means that "the reference-orientation of this *reference-area* is rotated 90
degrees counter-clockwise from the reference-orientation of the *containing
So, specifying reference-orientation="90" on the region rotates its
reference-area by 90 degrees from the page-reference-area. Nothing is said
about the viewport here, mind you.
It is in the viewport that a new coordinate system is established, not 'around'
it, so to speak. The before-edge still remains in parallel with the
page-reference-area's before-edge, when looking at it from the parent.
Inside the viewport, before/after/start/end get different meanings, for the
placement/dimensions of the child (reference-area).