ODF specification regarding multistop/-color gradients

[Jos van den Oever]

Hello Heiko,

<svg:linearGradient/> is not a hack. It has been in the ODF specification since 
1.0.

Cheers,
Jos


On Saturday 10 September 2016 11:11:40 Heiko Tietze wrote:
> Hello all,
> 
> the LibreOffice conference gave me the chance to present some ideas
> regarding Draw and shapes in general. One of the most wanted features is
> the multistop gradient. Today we can define gradients between two colors,
> either linear, radial, or whatever. It would be nice to have a) non-linear
> multistop gradients, for example to illustrate a sundown with a small red
> and a larger yellow section, and b) a gradient over more than two colors,
> e.g. in order to add blue sky to the sundown.
> 
> Since Calligra offers multicolor gradients, Armin and me checked how it is
> saved (the rendering is build-in right now). And it turns out that they
> hack SVG into the ODF. For the (predefined) rainbow-like gradient the
> style.xml looks like this:
> 
> <svg:linearGradient draw:name="gradient1" svg:spreadMethod="pad"
> svg:x1="0.000000%" svg:x2="100.000000%" svg:y1="0.000000%"
> svg:y2="100.000000%"> <svg:stop svg:offset="0"
> svg:stop-color="#ff0000"/><svg:stop svg:offset="0.183575"
> svg:stop-color="#ffe100"/><svg:stop svg:offset="0.347826"
> svg:stop-color="#00ff00"/><svg:stop svg:offset="0.516908"
> svg:stop-color="#00ffff"/><svg:stop svg:offset="0.68599"
> svg:stop-color="#0000ff"/><svg:stop svg:offset="0.845411"
> svg:stop-color="#ff00fb"/><svg:stop svg:offset="1"
> svg:stop-color="#ff0004"/> </svg:linearGradient>
> 
> As an UX evangelist I don't care too much about the implementation and have
> rather the workflow and interactions in mind. Ideally the multi-gradient
> works with all features, and not as another type next to linear, radial
> etc. (There might be a problem that result in this sub-optimal solution).
> 
> And finally we have to take interoperability into account as well as the
> conformity to the ODF specs (no idea if and how it is defined).
> 
> So how do we make multistop/multicolor gradients possible?
> 
> Cheers,
> Heiko
> 
> PS: Suggestions on how to implement this feature in the UI are existing.