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Units in Inkscape
by Tavmjong Bah 15 Sep '14

15 Sep '14

Units in Inkscape ================= Introduction ----------- The recent debate about units in Inkscape highlights the fact that we do not have a clearly defined approach on how to handle units in Inkscape. Units are not as straight-forward as one should think they are. This essay attempts to resolve this problem. Historical View --------------- Part of the problem with units in SVG and CSS in general is why they are there in the first place. In the early days it was assumed that one would want to display drawings on a screen at full scale. In other words, a "one inch square" would be display on a screen as a physical one inch square. This required that displays be queryable as to what there true DPI was. Display manufactures rarely provided the means to query the DPI of the display, and when they did, they often returned incorrect results. Thus, the use of "real" units never became popular and in reality is usually not what one wanted. Eventually, after long arguments, the CSS working group dictated that one inch would be fixed to 96 pixels regardless of screen resolution (ironically, with so called "Retina" displays, there is once again interest in scaling drawings based on DPI). A Philosophy ------------ Absolute units should not be used inside an SVG file with one exception: The 'root' width and height may have units, which with a proper 'viewBox' determines an appropriate scale for a drawing. (This sets the 'real' world value of the SVG 'user unit.) This reflect the opinion of the majority of the SVG working group. It should be noted that the relative units 'em', 'ex', and '%' can be useful in some cases. Inkscape & Units ---------------- Inkscape should not write out absolute units other than in the root SVG element. Inkscape must, however, be able to interpret units from non-Inkscape produced files according to the CSS defined value of 96 pixels (initial user-units) per inch. The use of units in the Inkscape GUI is for ease of authoring only. The actual values should be stored as 'user-units'. Changing the "Inkscape GUI unit" should not introduce any 'transforms' on elements (as seems to being done now) nor should changing the SVG root 'width'/'height units or the 'viewBox'. The GUI should reflect the chosen Inkscape GUI unit scaled to take into account the SVG root 'width'/'height' and 'viewBox'. For example: <svg width="100mm" height="100mm" viewBox="0 0 100 100"> describes a drawing 100mm x 100mm where one 'user-unit' is equivalent to one mm. If the Inkscape property inkscape:document-units="mm" then the GUI would show a width of '25.4' for a rectangle 25.4 'user-units' wide. If inkscape:document-units="in", the GUI would show '1.0'. To implement this, one either needs to find the proper scaling from examining the SVG root 'width'/'height' and 'viewBox' properties or create a new Inkscape property that fixes this scale (in which case changing the 'width'/'height' would change the 'viewBox' and vice versa). Tav

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Re: [Inkscape-devel] Units in Inkscape
by mathog 12 Sep '14

12 Sep '14

On 11-Sep-2014 10:23, Nathan Hurst wrote: > Ok, that's another vote for using double precision everywhere. That > gets us 14-15 digits, which should be enough for anybody. Adding more digits to the numerical representation does not in itself provide numerical stability, it just makes it easier to sweep the problem under the carpet of "looking at a smallish number of digits". Conversely, at least with respect to this units question, numerical stability, which for the purposes of this conversation means when a diff of two SVG's shows no changes, can be achieved if the lengths and coordinates inside the document are never changed, instead only one transform (or its equivalent) at the top level is. Then an end user could flip endlessly between different document units and never corrupt the numerical representations in the drawing. The only change that would show up, if no other changes were made, would be the values for that one transform. This assumes that the code did this: "we are currently using mm, user wants inches, REPLACE document unit transform with the pixels to inch transform" If instead it did: "we are currently using mm, user wants inches, MULTIPLY document transform by mm to inches conversion" then the single unit transform itself might not be numerically stable. (It could be if all of the units scaling factors have terminating binary representations with precision to spare, and the same is true for all combinations of their products.) Regards, David Mathog mathog@...1176... Manager, Sequence Analysis Facility, Biology Division, Caltech

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Inkscape devel very slow
by Javier García 11 Sep '14

11 Sep '14

Hi, I'm running inkscape devel on ubuntu 14.04 and it is going very slow even in smal documents.. what should I do? If you need some info about my computer/operative system I will be pleased to give you. Javi

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problem in po/cs.po while compiling rev 13546 on Windows XP.
by alvinpenner 09 Sep '14

09 Sep '14

while synching with the trunk I got some error messages related to .po files, but I neglected to write them down. after compiling I get the messages below, related to po/cs.po Cheers, Alvin .................................................................. ============ cmd ============ strip build\inkscape-console.exe ============================= ##### Target : i18n ##### compile gettext .po files to .mo --- i18n / msgfmt ============ cmd ============ msgfmt po/am.po -o build/locale/am/LC_MESSAGES/inkscape.mo ============================= ============ cmd ============ msgfmt po/ar.po -o build/locale/ar/LC_MESSAGES/inkscape.mo ============================= ============ cmd ============ msgfmt po/az.po -o build/locale/az/LC_MESSAGES/inkscape.mo ============================= ============ cmd ============ msgfmt po/be.po -o build/locale/be/LC_MESSAGES/inkscape.mo ============================= ============ cmd ============ msgfmt po/bg.po -o build/locale/bg/LC_MESSAGES/inkscape.mo ============================= ============ cmd ============ msgfmt po/bn.po -o build/locale/bn/LC_MESSAGES/inkscape.mo ============================= ============ cmd ============ msgfmt po/bn_BD.po -o build/locale/bn_BD/LC_MESSAGES/inkscape.mo ============================= ============ cmd ============ msgfmt po/br.po -o build/locale/br/LC_MESSAGES/inkscape.mo ============================= ============ cmd ============ msgfmt po/ca.po -o build/locale/ca/LC_MESSAGES/inkscape.mo ============================= ============ cmd ============ msgfmt po/ca@...3150... -o build/locale/ca@...1971.../LC_MESSAGES/inkscape.mo ============================= ============ cmd ============ msgfmt po/cs.po -o build/locale/cs/LC_MESSAGES/inkscape.mo ============================= Make error line 421: <msgfmt> problem: po/cs.po: warning: Charset missing in header. Message conversion to user's charset will not work. po/cs.po:12:2: syntax error po/cs.po:12: keyword "TREE" unknown po/cs.po:18: keyword "MERGE" unknown po/cs.po:145: missing `msgstr' section po/cs.po:146:2: syntax error po/cs.po:146: keyword "TREE" unknown po/cs.po:150: keyword "MERGE" unknown po/cs.po:197: missing `msgstr' section po/cs.po:198:2: syntax error po/cs.po:198: keyword "TREE" unknown po/cs.po:202: keyword "MERGE" unknown po/cs.po:243: missing `msgstr' section po/cs.po:244:2: syntax error po/cs.po:244: keyword "TREE" unknown po/cs.po:248: keyword "MERGE" unknown po/cs.po:403: missing `msgstr' section po/cs.po:404:2: syntax error po/cs.po:404: keyword "TREE" unknown po/cs.po:408: keyword "MERGE" unknown po/cs.po:1925: missing `msgstr' section msgfmt: too many errors, aborting -- View this message in context: http://inkscape.13.x6.nabble.com/problem-in-po-cs-po-while-compiling-rev-13… Sent from the Inkscape - Dev mailing list archive at Nabble.com.

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Re: [Inkscape-devel] Inkscape 0.48.5 Released
by Jon A. Cruz 09 Sep '14

09 Sep '14

On Jul 19, 2014 9:20 AM, Partha Bagchi <partha1b@...400...> wrote: > > I would think that any build (Mac/Windows/Linux) uses external libraries since Inkscape depends on gtk+ and friends. Only difference, on Linux it comes with the OS and so the user does not have to do the legwork while for the other 2 OSes, one has to build the dependencies. > Kinda, sorta on Mac. Some libraries do come with the system but may be optionally included with the distributed program. Others require a developer to explicitly include them. Also, the standard for applications on OSX is for each app to include its own copies of external libs, but infernally as part of the application bundle itself. For the end user on a Mac no extra legwork is needed as all external libs are internal in the "application binary". It's also common to end up with multiple app versions side-by-side by simply changing the name on one app package before copying the next into the Applications folder.

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Please check r13544 or later for problems at unit change
by mathog 08 Sep '14

08 Sep '14

One of the changes I introduced at revision 13544 was a modification of scaleChildItemsRec() so that it no longer recurses into groups to apply scaling changes associated with a change of units. This was breaking EMF import of clipped objects. That happened because during the recursion the coordinates of the clipped objects were changed directly, not by a transform. Since the clipping object (in defs) was not similarly scaled this broke the clip. See for instance: https://bugs.launchpad.net/inkscape/+bug/1348417 In the changed version the scaling change is applied as a transform at the group level, and all the coordinates within that group are not directly modified, so the clipping object and clipped objects are still at the same scale and they continue to work together. Since EMF import of clipped objects always works like (pseudocode): <g (clip reference)> clipped objects </g> applying the transform at the group level fixes the problem in that context. I suspect that scaleChildItemsRec() is still going to cause problems for any SVG object other than a group that looks something like (pseudocode): <(not a group) (a clip or mask ref) x=100 y=100 (other stuff) > when the document units are changed because it will change the 100's to something else, and not modify the referenced clipping object. I have not confirmed this though. In any case, would the people who worked on document units please see if my changes at revision 13544 break anything when the document units are changed? I did some preliminary testing and it looked OK, but I don't really know what test cases to use to explore all the edge cases. Thanks, David Mathog mathog@...1176... Manager, Sequence Analysis Facility, Biology Division, Caltech

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Re: [Inkscape-devel] Please check r13544 or later for problems at unit change
by mathog 08 Sep '14

08 Sep '14

On 07-Sep-2014 02:45, alvinpenner wrote: > two comments: the pre-existing bug has been reported at Bug 307656 and > Bug > 1366434. It appears to be related specifically to the rectangle tool > F4. > However there are two new regressions which are not related to F4. > > First one: rev 13544 has broken one of the fixes for Bug 1240455, > comment > 24: > https://bugs.launchpad.net/inkscape/+bug/1240455/comments/24 > > using Extensions->Render->Grids->Grid and using the default spacing of > 10 > px. > - case 1 : open Inkscape with default units of px, draw default Grid > - case 2 : open Inkscape, change units to mm, draw default Grid > > the expectation is that these two grids will look the same relative to > the > page size. Rev 13534 shows the expected behavior, rev 13546 does not. > > Second one: > - open Inkscape, draw two objects, a rectangle and a star, or ellipse > - select both of them > - change document units > - the expectation is that the shapes should not change size > - Rev 13534 shows the expected behavior, rev 13546 does not. I will revert that change in a little bit. Actually I'm going to add a parameter to the call, so that it can work one way (so that it works like it does now) for a call from EMF import, and as it did before when called from elsewhere (only one other place that I know of.) This is a short term hack until the actual problem is sorted. And I think the actual problem is in those parts of Inkscape which fail when the scale is applied to a top group. It is perfectly valid SVG to do: <g (scale to whatever conversion one wants)> (bunch of objects in completely arbitrary units. </g> All transform operations up the stack must be applied to an object. If some part of Inkscape only shows units properly when the top level scale is not present, then it is not correctly applying those transforms. How is it not that part of Inkscape that is broken? Regards, David Mathog mathog@...1176... Manager, Sequence Analysis Facility, Biology Division, Caltech

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Old Website will be Decommissioned
by Martin Owens 06 Sep '14

06 Sep '14

Dear Inkscape Devels, This is a warning that the old inkscape website currently at dev.inkscape.org will be decommissioned by November. Please make sure that any important information has been moved to the new django-cms website by then and let me know as soon as possible if you need help making this happen. Best Regards, Martin Owens

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VALS Semester of Code
by Tavmjong Bah 06 Sep '14

06 Sep '14

Hi, Do we want to participate in "VALS Semester of Code"? http://semesterofcode.com/?p=22 We should be able to come up with one or two good ideas. Deadline is Sept 12th. Tav

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Website Upgrade (1.2) Tonight
by Martin Owens 06 Sep '14

06 Sep '14

Dear Develoeprs, The inkscape website (inkscape.org) may be unavailable from 1am UTC (9pm EST) for a period lasting about half an hour. This upgrade will take us from django 1.5 to 1.6.5, django-cms from 1.4.2 to 3.0, haystack from 2.0 to 2.2, Whoosh 2.4 to 2.6 and finally inkscape-web from 1.1 to 1.2. The upgrade process involves a bunch of manual steps to the database and command line and I hope these will be completed shortly after upgrading the code. My thanks to Hachmann, jazzynico, Brynn and others in helping prepare this release. After the upgrade, content will be uploadable to inkscape.org and you may wish to populate your user account with some of your svg files to get the ball rolling. Also available will be the ability to upload Addon tarballs and inkscape release builds (exe files/tarballs etc) which can be used instead of sourceforge or your friendly file dumping service. Please see me directly if you need an increased quota to upload large release files. I'm going to start everyone off with 10MB quota to start gently. The idea for most users is to upload svg files which aren't that big. But we can increase this for different auth groups as needed. Any questions, reply here. Best Regards, Martin Owens

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