Inkscape

On 3/24/10, Zhenfeng Zhao wrote:
> Hello,
>
> I am interested in working on the "transformation-anchors" project in GSOC
> this year.

Go bless you for that! Some hardcore XFig users get really hot about
this feature missing in Inkscape.

And... You traded GIMP for Inkscape this GSoC? :)

> SVN: I used it at work before.

We rely on bazaar-ng these days, but it bears some resemblance to SVN,
so it shouldn't be a problem.

Alexandre

On Wed, Mar 24, 2010 at 4:04 AM, Zhenfeng Zhao
<zhenfeng.zhao.8@...> wrote:
> Hello,
>
> I am interested in working on the "transformation-anchors" project in GSOC
> this year. I am a graduate student in Computer Science in Canada.

Great, thanks! Please take into account my comment at the page of the spec:

http://wiki.inkscape.org/wiki/index.php/SpecTransformAnchors

As far as I can see the interface mock-ups ignore this comment, so
they need to be redone. The essence of it is that we must not
introduce two different entities: center of rotation and anchor; we
should have a single thing, the one now marked by the cross, and
everything should move it and refer to it. This object already exists
in the code, basically what you need is just add more UI facilities to
move it. It is also (already) automatically saved into SVG per object,
if moved. So we don't need that star button for separate "rotation
center", but instead we need a way to set its coordinates numerically.

Please feel free to discuss or ask any questions you might have. The
saving of the rotation center was coded by John Cliff, maybe he will
agree to be your mentor for this?

-- 
bulia byak
Inkscape. Draw Freely.
http://www.inkscape.org

Hi Bulia,

Thank you very much for the quick reply, and comments.

On Wed, Mar 24, 2010 at 12:55 PM, bulia byak <buliabyak@...> wrote:

> On Wed, Mar 24, 2010 at 4:04 AM, Zhenfeng Zhao
> <zhenfeng.zhao.8@...> wrote:
> > Hello,
> >
> > I am interested in working on the "transformation-anchors" project in
> GSOC
> > this year. I am a graduate student in Computer Science in Canada.
>
> Great, thanks! Please take into account my comment at the page of the spec:
>
> http://wiki.inkscape.org/wiki/index.php/SpecTransformAnchors
>
> As far as I can see the interface mock-ups ignore this comment, so
> they need to be redone. The essence of it is that we must not
> introduce two different entities: center of rotation and anchor; we
> should have a single thing, the one now marked by the cross, and
> everything should move it and refer to it. This object already exists
> in the code, basically what you need is just add more UI facilities to
> move it. It is also (already) automatically saved into SVG per object,
> if moved.


OK. I have tried it and found out what it does. The center of rotation,
marked as cross, can be dragged and moved to a different location. It is
saved for the object, so that when closing and reopening this SVG file, we
can see the cross (center of rotation) stays where it is left. In the SVG
file, it shows:

       inkscape:transform-center-x="7.6874748"
       inkscape:transform-center-y="-3.2402241" /

I can see it is a field or attribute of the path object.


> So we don't need that star button for separate "rotation
> center", but instead we need a way to set its coordinates numerically.
>
>
Do you mean that we need some UI facilities to allow moving this center
easily with better control? This way, it would be easier for users to know
where it can be moved to, and what that will do.

Do we need to use that 9-button-matrix shown in the Wiki?

I understand the needs to input center coordinates. This way, all
transformations will perform based on it.

I also tried to move the center, and did some tests for different
transformations.
- For rotate and skew, different centers will give different results. (It is
the most obvious for rotation.)
- For scale, moving the center gives the same results, with the same
transform values.

Are we keep this way?

Regards,

Zhenfeng.



Please feel free to discuss or ask any questions you might have. The
> saving of the rotation center was coded by John Cliff, maybe he will
> agree to be your mentor for this?
>
> --
> bulia byak
> Inkscape. Draw Freely.
> http://www.inkscape.org
>

On Thu, Mar 25, 2010 at 3:44 AM, Zhenfeng Zhao
<zhenfeng.zhao.8@...> wrote:
> Do you mean that we need some UI facilities to allow moving this center
> easily with better control? This way, it would be easier for users to know
> where it can be moved to, and what that will do.

Right now it can be dragged freely, but some people need more
precision, which is why we need X/Y fields for it I think they should
be at a separate tab of the Transform dialog.

> Do we need to use that 9-button-matrix shown in the Wiki?

Definitely, it's a handy widget, and familiar to users from other programs.

> I also tried to move the center, and did some tests for different
> transformations.
> - For rotate and skew, different centers will give different results. (It is
> the most obvious for rotation.)
> - For scale, moving the center gives the same results, with the same
> transform values.
>
> Are we keep this way?

Not quite. Speaking about transform with handles, we're fine: we have
simple drag  which should remain as is, and Shift+drag which scales
around the rotation center which is also fine. But scaling by numbers
is messy: selector toolbar does it relative to top right corner, and
Transform scales around geometric center. Both should use rotation
center too, and X/Y in selector toolbar should also display the coords
of that center, not the top left corner as now.

-- 
bulia byak
Inkscape. Draw Freely.
http://www.inkscape.org

On Thu, Mar 25, 2010 at 11:22 AM, bulia byak <buliabyak@...> wrote:

Not quite. Speaking about transform with handles, we're fine: we have
> simple drag  which should remain as is, and Shift+drag which scales
> around the rotation center which is also fine. But scaling by numbers
> is messy: selector toolbar does it relative to top right corner, and
> Transform scales around geometric center. Both should use rotation
> center too, and X/Y in selector toolbar should also display the coords
> of that center, not the top left corner as now.
>
> --
> bulia byak
> Inkscape. Draw Freely.
> http://www.inkscape.org
>

OK, I thought that was a bug/issue, having scaling works slightly
differently from other transformations, or not using the rotation center. I
agree that they should be consistent and use the rotation center. If I
understand correctly, the goals are to (i) allow precisely inputting XY
coordinates, and have 9-button widget to assist it, and (ii) have a few
fixes so that all transformations will be around the rotation center, which
is more consistent.

It sounds like some interesting work to do. I will need some time to be
familiar with these parts. I just saw what selector toolbar is. It is the
mouse icon, and its tool bar shows the XY coordinates for the shape. It
seems to be the bottom left corner though. Or, it is just my version is not
really updated.

At work before, I recommended some GUI adjustments and designs according to
Inkscape's style. That software has too many pop-up dialog boxes. With the
tools on the left, and its tool bar in the top, it is much better than
having to open and close any input dialogs. :-)

I wonder what kind of UI is needed for rotation center XY coordinates.
Thanks.

Regards,

Zhenfeng.

On Thu, Mar 25, 2010 at 8:19 PM, Zhenfeng Zhao
<zhenfeng.zhao.8@...> wrote:
> OK, I thought that was a bug/issue, having scaling works slightly
> differently from other transformations, or not using the rotation center. I
> agree that they should be consistent and use the rotation center. If I
> understand correctly, the goals are to (i) allow precisely inputting XY
> coordinates, and have 9-button widget to assist it, and (ii) have a few
> fixes so that all transformations will be around the rotation center, which
> is more consistent.

Exactly.

> It sounds like some interesting work to do. I will need some time to be
> familiar with these parts. I just saw what selector toolbar is. It is the
> mouse icon

called "tool"

>, and its tool bar shows the XY coordinates for the shape. It
> seems to be the bottom left corner though. Or, it is just my version is not
> really updated.

weird, it is normally above the canvas

> At work before, I recommended some GUI adjustments and designs according to
> Inkscape's style. That software has too many pop-up dialog boxes. With the
> tools on the left, and its tool bar in the top, it is much better than
> having to open and close any input dialogs. :-)

Yes, certainly, being able to do more in the main interface without
opening any dialogs is best.

> I wonder what kind of UI is needed for rotation center XY coordinates.

Just a couple spinbuttons for X and Y plus a unit selector, defaulting
to the document units.

-- 
bulia byak
Inkscape. Draw Freely.
http://www.inkscape.org

Hi, I'm the author of the specification.

@Z. Zhao
> I am interested in working on the "transformation-anchors" project in GSOC this year.

Good to hear! Welcome. If something on the spec is not clear just ask
on this mailing list. I'm not a coder but I might be able to help you.
I have the original SVG files of the GUI mock-up in case you want to
play with them.

For your consideration: there are two other projects related to this one:
* 1) adjust origin of coordinates of document
* 2) allow math operations (like sum, substraction, multiplication,
division) inside the spin boxes for Height, Width, X, Y; and now I
would add center of transformations.
Doing everything in just one run might be too much but try to keep them in mind.


@b. byak
>> I wonder what kind of UI is needed for rotation center XY coordinates.
>
>Just a couple spinbuttons for X and Y plus a unit selector, defaulting
>to the document units.
The unit selector is already there with X, Y, Height and Width. Why
not reuse it and just have one unit selector for everything? (I'm
guessing you meant this).

>As far as I can see the interface mock-ups ignore this comment, so
>they need to be redone.

The mockups do ignore it. But I left you a comment saying that I
agreed with you. I didn't want to update them because I prefer if the
development of the idea is shown. New mockups should be done and
appended instead of updating the old ones. It would be confusing if
readers read old comments which point to new mockups.


@both:
>> the goals are to (i) allow precisely inputting XY
>> coordinates, and have 9-button widget to assist it, and (ii) have a few
>> fixes so that all transformations will be around the rotation center, which
>> is more consistent.
>
>Exactly.
Yes, exactly. The 9-button widget is there to move the X/Y
coordinates. The spinbuttons should be update to reflect the selection
of one of nine anchors.


Regards.

On 3/26/10, Pajarico wrote:

> * 2) allow math operations (like sum, substraction, multiplication,
> division) inside the spin boxes for Height, Width, X, Y; and now I
> would add center of transformations.

Just steal code from GIMP 2.7.0+ :)

Alexandre

On Fri, 2010-03-26 at 23:09 +0300, Alexandre Prokoudine wrote:
> On 3/26/10, Pajarico wrote:
> 
> > * 2) allow math operations (like sum, substraction, multiplication,
> > division) inside the spin boxes for Height, Width, X, Y; and now I
> > would add center of transformations.
> 
> Just steal code from GIMP 2.7.0+ :)

And C++ify it ;)

Cheers,
Josh