[Ipe-discuss] Gradient

Otfried Cheong otfried at ipe.airpost.net
Wed Nov 23 20:48:41 CET 2016


If you do not want to edit stylesheets directly, currently the only way
to create gradients is using the Ipelet posted on this list a while ago
(http://lists.science.uu.nl/pipermail/ipe-discuss/2015-July/001646.html).

The actual ipelet is here:

http://lists.science.uu.nl/pipermail/ipe-discuss/attachments/20150707/b31d5a50/attachment.obj

Save it as "gradients.lua" into your ipelet directory.

Cheers,
 Otfried

On Wed, Nov 23, 2016, at 19:36, Roberto D wrote:
> Thank you for your kind answer. Just another question. In order to write
> the commands you say, you would suggest to draw a rectangle and the "Edit
> as xml" in order to apply the gradient definition?
> Sorry, but I usually use IPE interactively and not using line commands,
> so
> I am a little bit confused.
> Best regards
> Roberto
> 
> 2016-11-22 22:21 GMT+01:00 Otfried Cheong <otfried at ipe.airpost.net>:
> 
> > In the current Ipe version, the gradient coordinates apply to the object
> > coordinates without the matrix.   For instance, if you draw this
> > rectangle:
> > <path layer="alpha" fill="1" gradient="linear">
> > 128 640 m
> > 128 576 l
> > 256 576 l
> > 256 640 l
> > h
> > </path>
> >
> > then you can apply a gradient to it by using the same coordinates:
> > <gradient name="linear" type="axial" coords="128 0 256 0" extend="yes">
> >  <stop offset="0" color="1 0.4 0"/>
> >  <stop offset="0.05" color="1 0.4 0"/>
> >  <stop offset="0.95" color="1 1 0.4"/>
> >  <stop offset="1" color="1 1 0.4"/>
> > </gradient>
> >
> >  When you move the rectangle from the Ipe user interface, this will
> >  change only the matrix of the object, and so it still has the correct
> >  gradient:
> >
> > <path layer="alpha" matrix="1 0 0 1 288 96" fill="1" gradient="linear">
> > 128 640 m
> > 128 576 l
> > 256 576 l
> > 256 640 l
> > h
> > </path>
> >
> > However, if you edit the object or perform some other operation that
> > will change the coordinates of the rectangle, it will stop to work
> > correctly.
> >
> > In the next version, I plan to simplify the use of gradients by making
> > it possible to write gradient coordinates that ALWAYS apply to the
> > object.   My current idea is that 0,0 would be the bottom left corner,
> > 100, 100 the top right corner of the objects bounding box.
> >
> > Cheers,
> >  Otfried
> >
> >
> > On Tue, Nov 22, 2016, at 22:11, Roberto D wrote:
> > > Hi everybody,
> > > I am not an expert about IPE.
> > > Please look at the linear gradient example here
> > > http://ipe.otfried.org/manual/manual_32.html, that is the following
> > lines
> > > <gradient name="linear" type="axial" extend="yes" coords="75 0 325 0">
> > > <stop offset="0.05" color="1 0.4 0"/>
> > > <stop offset="0.95" color="1 1 0.4"/>
> > > </gradient>
> > >
> > > My question is the following. Is it possible to modify the lines above so
> > > that the coordinates become the local coordinates of the rectangle (that
> > > is
> > > attached to the object, wherever I draw it in the plane)?
> > > I cannot figure out how to use the matrix option.
> > > Thank you
> > > Roberto
> > > _______________________________________________
> > > Ipe-discuss mailing list
> > > Ipe-discuss at lists.science.uu.nl
> > > http://lists.science.uu.nl/mailman/listinfo/ipe-discuss
> > _______________________________________________
> > Ipe-discuss mailing list
> > Ipe-discuss at lists.science.uu.nl
> > http://lists.science.uu.nl/mailman/listinfo/ipe-discuss
> >


More information about the Ipe-discuss mailing list