- Inkscape Devel - Inkscape Mailman

Lighting Effects in Inkscape
by Jean-René Reinhard 28 Jul '07

28 Jul '07

Hi, It's been a long time since I started using Inkscape. During the last two weeks, I got frustrated that lighting effects weren't implemented in Inkscape. I took advantage of Niko Kiirala great filter framework to write a first simple implementation of these lighting effects. Almost everything is implemented now. (kernelUnitsLength support is still missing but I plan to get it done soon). I write this email to the list to signal a discreprancy I noticed while implementing feSpecularLighting. In fact the svg feSpecularLighting specification, and test examples, do not follow Phong lighting model. In the SVG specs, the specular lighting is computed by taking ks * N.H^speExp In every Phong lighting model I found by googling it is computed as ks * R.E^speExp where ks is the specular constant speExp is the specular exponent N is the surface normal vector L is the light vector, unit vector from the surface point to the light E is the eye vector, unit vector from the surface to the viewer R is the reflected light vector, unit vector from the surface point indicating the reflection direction. H is the normalized vector colinear to L+E/2 writing things down we have N.H = cos (alpha) for some alpha and R.E = cos(2*alpha). The formula using R.E seems much more natural since the viewer sees reflection if R is "close" to E, ie R.E is close to 1. For the time being the N.H is implemented in Inkscape (standard compliance above all). However, can anybody explain the formula using N.H? Does anybody know why svg specularLighting uses N.H instead of R.E? Cheers, Jean-Rene

2 1

Bug : [ 1653629 ] 0.45 from source in ubuntu
by Jean-René Reinhard 26 Jul '07

26 Jul '07

Hi, after building the latest inkscape svn version, the exec I obtained kept crashing. After some tests I solved the problem. Inkscape wasn't able to find the key binding file. I just looked into the bugtracker. This bug was already reported and the bug report was closed. ([ 1653629 ] 0.45 from source in ubuntu). http://sourceforge.net/tracker/index.php?func=detail&aid=1653629&group_id=9… Shouldn't inkscape die in a nicer way than a segfault, with an explicit warning, if the key file cannot be found? Jean-René

2 2

GTK+ the cause of Wacom issues in Windows XP SP2?
by FooManChu 26 Jul '07

26 Jul '07

I'm new to mailing lists so figure me if they follow a specific format. Basically, I've ran across posts in the GIMP newsgroup (comp.graphics.apps.gimp): http://groups.google.com/group/comp.graphics.apps.gimp/browse_thread/thread… http://groups.google.com/group/comp.graphics.apps.gimp/browse_thread/thread… I remember myself specifically asking in that group if Wacom tablets had known usability in The GIMP: http://groups.google.com/group/comp.graphics.apps.gimp/browse_thread/thread… Then I posted this, somewhat desperate for any responses: http://groups.google.com/group/comp.graphics.apps.gimp/browse_thread/thread… ...and also recently on InkscapeForum.com I posted a thread: http://www.inkscapeforum.com/viewtopic.php?f=22&t=135&start=0&st=0&sk=t&sd=a ...they all related to GTK+ possibly being the culprit, at least that is what conclusion I came to. Anyway, I seem to have problems mostly when using the Pencil tool, Bezier, and Calligraphy tool. Mostly, as in 95% of the time, it is the Pencil tool. I can draw and draw and sometimes, the tool just stops responding (the cursor hangs) until I lift the Stylus and then put it back to the Tablet. Even then, sometimes I have to do it *several* times before it will respond. Then there are some times when I have no problem. Or one jerky movement, lift the Stylus and everything works fine again. I simply cannot reproduce it consistently. Anyway, the kind, and somewhat more experienced than myself administrator of InkscapeForum.com suggested I send you guys/gals an e-mail. My setup is Windows XP SP2, with a Graphire4 4x5. Do I need to provide more information? Any ideas on what the culprit may be? Is it GTK+? Is it something else? Thanks for your patience and assistance in this manner. FooManChu

2 1

displacementmap renderer bug
by Felipe Sanches 26 Jul '07

26 Jul '07

SVG spec (http://www.w3.org/TR/SVG11/filters.html#feDisplacementMap) states that pixel values must be alpha-demultiplied before processing this filter operation. The following code does it, but when we DON'T do it, output is more similar to output from Batik. if (map->mode == NR_PIXBLOCK_MODE_R8G8B8A8P){ alpha = (unsigned int) map_data[4*((x-x0) + width*(y-y0)) + 3]; if (alpha==0){ coordx = x-x0; coordy = y-y0; } else { coordx = x-x0 + scale * ( ((double)NR_DEMUL_111( (unsigned int)map_data[4*((x-x0) + width*(y-y0)) + Xchannel], alpha))/255 - 0.5 ); coordy = y-y0 + scale * ( ((double)NR_DEMUL_111( (unsigned int)map_data[4*((x-x0) + width*(y-y0)) + Ychannel], alpha))/255 - 0.5 ); } } Batik output: http://bighead.poli.usp.br/~juca/code/inkscape/batik-fed02.png Inkscape output without demultiplication: http://bighead.poli.usp.br/~juca/code/inkscape/displacement-map-test.png There is also this other bug that can be seen in the above screenshot: the lower and the right portions are not rendered, I dont know why. JucaBlues

2 4

Inkscape 0.46 release?
by Bryce Harrington 26 Jul '07

26 Jul '07

Hi all, It's been a while since our 0.45.1 release, and a ton of good new features have been added in. However, in recent months many of us have busy with new jobs, school, conferences, etc. However with summer here I'd like to hear if there is interest in seeing 0.46 released? Ubuntu's next feature freeze is August 16th, one month from now. I would love to see Inkscape 0.46 ready for inclusion there, and would be able to pitch in help if others are also interested in getting an Inkscape release out in that timeframe. What do you think? Bryce

13 21

3 more attention-to-detail observations
by joel＠...1709... 26 Jul '07

26 Jul '07

Hi Everyone, 3 questions about the inkscape UI. The first relates to Windows users only: why is it that the menu item icons are shrunk slightly? I get the impression that GTK has taken the Windows system item height (which is good), then squished the menu bitmaps into that height (which is bad). The the MS Office applications got around this problem by simply increasing the height of each item so as to accomodate the icon. Is it possible to do this with GTK?, because right now the icons look more like a mush than attractive decoration. (BTW: Roll on the Tango icons) Second observation: It seems to me that "Vacuum Defs" is a bit of an unfortunate title for this menu item, in that from reading it, even an experianced user such as myself struggles to comprehend what it might actually do. Is this the best title? I've never seen another menu item ever with the word "Vacuum" in it; it's not a well understood UI term. And most users aren't going to know what a "def" is either. Third observation: in XP/Vista in the development builds (but not in 0.45.1), there's some wierd toolbar behaviour at the moment, as you'll see in this screenshot: http://www.airwebreathe.org.uk/toolbar.png. In both XP and Vista, when the mouse hovers over the chevron at the end of the toolbar you get a wierd double bevel effect. Can this be sorted out? Also in the Vista screenshot you may notice that the toolbar gradient doesn't line up with the toolbar frame properly. Any comments?

2 1

Committing LivePathEffects to trunk
by Johan Engelen 25 Jul '07

25 Jul '07

Hello all, I want to get LivePathEffects (LPE) into trunk soon. The benefit of having my own branch (i.e. few people build it, so highly unstable code is no prob ;-) ; thanks for testing guys!!!) is starting to become a drawback (i.e. I'd like people to use it and report bugs/problems/RFE's) There is a problem though: Dependencies. LPE needs lib2geom (this is a *good* thing!), which needs Boost. 1. I don't think Boost is going to be a big problem. Well... it is big, but 2geom does not use that many headers; i have to check but only a small part of boost is necessary i think. 2. lib2geom does not have an official release and LPE uses the latest SVN version. Development is very active, often providing new features InkscapeLPE wants. This basically means that to build LPE, one first must svn up 2geom and make install it. A. What are your thoughts on the dependency issues? B. Now I think of it, I think the file-format extension introduced by LPE must be agreed upon as well. It is SVG compatible and not very intrusive but still... Kind regards, Johan

8 12

Re: [Inkscape-devel] filters UI
by Nicholas Bishop 25 Jul '07

25 Jul '07

Regarding selection and the filter dialog, how about the following setup: the dialog will still display all filters, but the user can set which filter is currently applied to the selected object(s) by double clicking a filter in the left-hand list. The active filter will get a dot or a small icon to show it is being used on the selection. Single-clicking a filter will select it for editing of its primitives/attributes, but won't apply it to the selection. How's this sound? If it's OK, it shouldn't take too long to do. I'll post again soon with my thoughts on the discussion of showing better simplified controls than the current Blend Mode combo. -Nicholas On 7/23/07, bulia byak <buliabyak@...400...> wrote: > Hi Nicholas, > > You never responded to this discussion. Do you agree that the Filters > dialog must track selection and instant-apply to the selected objects? > > On another subject, please make your dialog remember size and position > across sessions, as other dialogs do. Now it always starts in minimum > size which is annoying. > > Also I highly encourage you to keep an up-to-date summary of what already > works (and what is likely to remain more or less the same at the end > of the project) at > http://wiki.inkscape.org/wiki/index.php/ReleaseNotes046#Filters_UI. > It's important to do it as you code. Don't wait until everything is > completed - you will forget some valuable details by then. Just as > soon as you finish some feature, no matter how small, add it to the > list there, with complete description of the functionality as well as, > ideally, examples and usage tips. > > ---------- Forwarded message ---------- > From: bulia byak <buliabyak@...400...> > Date: Jul 21, 2007 4:09 PM > Subject: Re: [Inkscape-devel] filters UI > To: MenTaLguY <mental@...3...> > Cc: Florian Köberle <FloriansKarten@...128...>, Nicholas Bishop > <nicholasbishop@...400...>, inkscape-devel(a)lists.sourceforge.net, Niko > Kiirala <niko@...1267...> > > > On 7/21/07, MenTaLguY <mental@...3...> wrote: > > I do think simply calling that option "Filter" is a little weird. How > > about labeling the blend mode drop-down as a whole "Filter", and > > changing the "Filter" option to "Custom..."? That may be a better > > description of what it does, and then it would make sense to put other > > filter presets there too. > > I'm all for adding more preset blending and composite modes to that > list, yes. But why do we need "custom" at all? As it is now, it's out > of place there. When I'm in fill&stroke, I don't think in terms of > choosing among "filter2578" and "filter2593". That is an entirely > different task for the different specialized dialog - the Filters > dialog. This list in fill&stroke contains various ways of compositing > an object over its background, period. A "Custom" there would only > make sense if its function would be to allow you to edit a customized > expression for compositing (e.g. for the "arithmetic" option in > feComposite), but NOT for assigning the overall filter stack for an > object as now. That assignment must be done automatically by the > Filter dialog (which is where you edit those stacks). > > > I would also like to see some feComposite presets in that list. > > Sure, one thing I would really enjoy is inverting the background - is > this possible with feComposite? > > > > This list, like the Blur slider below it, must > > > search the selected object's filter stack for feBlend or feComposite, > > > display the current mode of that filter and let me change it (or add a > > > new filter to the top of the stack, but only if no such filter already > > > exists in the selected object's stack). > > > > That would interact very badly with many interesting filters, as they > > may be built out of multiple feBlend/feGaussianBlur elements; simply > > picking the first or last feBlend element (or even all of them, > > depending on how the filter is designed) won't give desirable results. > > OK, that was just one of my ideas, I don't insist on making it that > way too much. It may indeed be confusing sometimes, although also > useful IMHO. What do others think? > > -- > bulia byak > Inkscape. Draw Freely. > http://www.inkscape.org >

4 3

hacking latex-pstricks.cpp to export text as text
by Richard Henwood 25 Jul '07

25 Jul '07

Hi folks, I'm would like to provide a choice for psTricks export to export text as text (not paths). My problems are that I can't get the position of the text within: PrintLatex::text(Inkscape::Extension::Print *mod, char const *text,NR::Point p, SPStyle const *const style) 'p' looks like it should contain this information (ie. p[NR::X]) but it contains the value 0. Further up, 'latex-pstricks-out.cpp' is making a call to: sp_item_invoke_print (mod->base, &context); where Inkscape::Extension::Print = *mod; mod->base = SP_ITEM (sp_document_root (doc)); ...so; any thoughts appreciated! r,

2 1

filter effects - who is working on what?
by Felipe Sanches 25 Jul '07

25 Jul '07

I have recently jumped in and I still feel a bit uncomfortable with the idea of possible redundant work. Can we start a new page at the wiki to map our current efforts on the filter effects development? It would list for each filter, who has already done what an which problems have emerged. I feel that this way we can have a better idea of which areas need more work and which filters are already fully compliant with the specs. Juca

3 3