Hi Regina,
good to hear from you, wanted to contact you already anyways, but we
were just moving, so I was pretty busy :-)
On 3/14/23 14:09, Regina Henschel wrote:
Hi Armin,
you put the ColorSteps into a sorted vector with unique offsets of the
ColorSteps.
I see a problem with "unique". Both OOXML and SVG allow several color
stops to have the same offset. Users need it in OOXML and SVG
gradients to create stepped gradients like those from ODF draw:gradient.
Thus forcing uniqueness in our core will give problems in import
filter and in implementing the <svg:radialGradient> and
<svg:linearGradient> from ODF.
Very good hints, thanks for that.
Indeed I thought about having two (or more) identical ColorStops to
allow a 'rapid' color change at the same offset. I abandoned that by
thinking that a very small step could be used that will never get
visible, so e.g.
0.5
0.5000001
But allowing multiple identical may express that indeed better.
The problem is and why I chose uniqueness is also/mainly the UI - how to
represent equal ColorSteps in a UI trying to visualize the ColorSteps...?
So:
- It should then be OK to have a maximum of *two* ColorStops with
identical offset?
- When correcting that, and there are more than two, delete all but 1st
and last? So the in-between ones?
- Also dependent of used colors: if all the same color, identicals can
be deleted, so go to uniqueness.
And Questions for ODF format:
I see e.g. in SVG something like
<linearGradient id="Gradient2" x1="0" x2="0" y1="0" y2="1">
<stop offset="0%" stop-color="red" />
<stop offset="50%" stop-color="black" stop-opacity="0" />
<stop offset="100%" stop-color="blue" />
</linearGradient>
so I would just add elements like
<stop offset="0%" stop-color="red" />
to our ODF, is that OK from your POV? I remember we once discussed that
already, so should be no problem to do that I guess?
I would take out from this the StartColor (AKA offset == 0.0) and the
EndColor (AKA offset == 1.0), so in the normal case there would be no
change at all.
If there are ColorSteps with offset != 0.0 or 1.0 I would create that
extra-entries for these.
Currently we have something like
<draw:gradient draw:name="Gradient_20_2"
draw:display-name="Gradient 2" draw:style="radial" draw:cx="50%"
draw:cy="50%"
draw:start-color="#bf0041"
draw:end-color="#127622"
draw:start-intensity="100%" draw:end-intensity="100%"
draw:border="0%"/>
which would then be something like
<draw:gradient draw:name="Gradient_20_2"
draw:display-name="Gradient 2" draw:style="radial" draw:cx="50%"
draw:cy="50%"
draw:start-color="#bf0041"
<stop offset="0%" stop-color="red" />
draw:end-color="#127622"
draw:start-intensity="100%" draw:end-intensity="100%"
draw:border="0%"/>
For import of 'older' stuff all will be good.
For import of new stuff in older Offices we would fallback to
Start/EndColor and ignore the In-Between steps - any ways the best we
can do AFAIS.
Greetings & thanks in advance,
Armin
Kind regards,
Regina
--
--
ALG (PGP: EE1C 4B3F E751 D8BC C485 DEC1 3C59 F953 D81C F4A2)
