20:12:16 RRSAgent has joined #svg 20:12:16 logging to http://www.w3.org/2011/12/22-svg-irc 20:12:18 RRSAgent, make logs public 20:12:18 Zakim has joined #svg 20:12:20 Zakim, this will be GA_SVGWG 20:12:20 ok, trackbot, I see GA_SVGWG(SVG1)3:00PM already started 20:12:21 Meeting: SVG Working Group Teleconference 20:12:21 Date: 22 December 2011 20:12:26 yes, don't tell me I woke up early for nothing :) 20:13:50 +??P2 20:13:54 Zakim, ??P2 is me 20:13:54 +heycam; got it 20:14:00 +[IPcaller] 20:14:01 Zakim, who is on the call? 20:14:01 + +33.9.53.77.aabb 20:14:03 On the phone I see +61.2.980.5.aaaa, heycam, +33.9.53.77.aabb, [IPcaller] 20:14:15 Zakim, [IP is me 20:14:15 +ed; got it 20:14:49 Chair: Cameron 20:15:17 Agenda: http://lists.w3.org/Archives/Public/public-svg-wg/2011OctDec/0109.html 20:15:23 zakim, +61 is me 20:15:23 +cyril; got it 20:15:46 scribeNick: ed 20:16:10 Topic: mesh gradients 20:16:18 http://tavmjong.free.fr/SVG/MESH/Mesh_Boundaries.html 20:16:40 TB: i've been looking at cyril's comments on the problems with mesh gradients 20:17:06 ... as can be seen in the examples in the link above, there are discontinuity in the gradient 20:17:35 ... scroll down, and you can see the same problem for linear gradients too 20:18:25 ... look at where the red line breaks 20:18:38 mach banding effect I think 20:18:59 TB: probably the brain is geared towards finding discontinuities 20:19:18 CM: where there's a bend in the line, it looks brigther 20:19:30 http://en.wikipedia.org/wiki/Mach_banding 20:19:47 CC: not sure it's this exactly, but it's related 20:20:10 TB: with mesh gradients you have the control points along the sides, that not only control the shape but also the spread 20:20:50 ... next figure shows the same discontinuities as for the linear gradients but with mesh gradients 20:21:43 ... i've moved the control points in the figure with the purple curve, giving a smoother look 20:22:26 ... if you change the controlpoints you change two things at once, both shape and color 20:22:52 ... the mesh in this case is still a rectangle 20:23:08 CC: would be nice to show the controlpoints in the example, for understanding it better 20:23:15 TB: will add that 20:23:58 ... now in "Understanding Coons Patches" 20:24:35 ... shows controlpoints, and what you get 20:25:11 ... if you move controlpoints further you get discontinuities 20:25:23 ... you can never have a derivative of 0 at the edge of a patch 20:25:42 CC: what if you put the controlpoint in horizontal? 20:25:47 TB: can't do that 20:25:53 ... they're in colorspace 20:26:11 ... 1/3 of the way up and 1/3 of the way down 20:26:37 ... it's not a controlpoint for the mesh, it's for the color 20:26:59 CM: are you illustrating the rate of the change? 20:27:10 TB: something like that yes 20:28:05 CM: so the color moves quicker at the start of the curve 20:28:21 TB: i've plotted what happens when you move the controlpoints 20:28:36 CC: are you using the same controlpoints for the upper and lower parts of the curve 20:28:40 TB: yes 20:29:10 -heycam 20:29:23 CC: you use linear interpolation since you have two colors, you'd have bilinear if you had one color in each corner 20:29:49 TB: just illustrating that it's possible to reduce the effect 20:29:57 +??P2 20:30:03 Zakim, ??P2 is me 20:30:03 +heycam; got it 20:30:28 ... once you move the controlpoint outside the mesh it overlaps itself 20:30:38 ... if you introduce a tensor 20:30:53 ... you could change the the way the colors inside the mesh are distributed 20:31:03 ... doesn't affect the edges 20:31:55 ... i've looked at the cairo code and it exploits this to compute the gradient, divides the patch from top to bottom using the tensor points so that you have a series of bezier curves taht are no wider than a pixel 20:32:03 ... and then it draws each bezier curve in turn 20:33:00 CC: illustrator doesn't use coons patches 20:33:14 ... probably tensor product patches with tensor derivatives 20:33:22 ... with bicubic interpolation 20:33:39 TB: what they show in illustration... 20:33:51 ... is shown as one patch but is actually many patches 20:34:05 ... the boundaries don't correspond to the object, but to the edges to the mesh 20:34:53 ... some examples have rough shapes that can't be described by a simple bezier 20:35:29 CM: clipping is another trick 20:35:56 TB: when we discussed it previously there was a request to use the mesh as a clip or by itself 20:36:11 CC: but then tehre would be a problem with the stroke 20:36:24 ... not sure if we decided to do it as a paintserver or not 20:36:41 TB: anyway, that's the state atm 20:37:07 CM: does messing with the controlpoints help for eliminating the disconts? 20:37:14 TB: a bit 20:37:40 ... by adding extra patches it's possible to smooth it out 20:38:18 CC: i've experimented with corel draw, looks like they do something very similar to illustrator 20:39:07 CM: could the subdivision of patches be useful to define in the document? 20:39:43 ... could we describe this simply, and would we want to enable that by an attribute for example? 20:40:01 CC: i think they're approximating, not sure there's a single way to do this 20:40:09 ... depends on quality etc 20:40:23 TB: leaning towards letting the author handle it 20:41:45 ... if you have a regular gradient you owuld not use meshes, or they would subdivide 20:42:21 ... i'm going to read the paper cyril linked to again 20:42:31 CC: let's discuss this at the F2F 20:43:11 ... coons patches are fine and you can do good things with them, but there are limitations, and authoring tools solve them atm, but we may want to introduce something like that in the future 20:43:39 TB: we might want to smooth out linear gradients too 20:44:01 ... using catmull-rom curves 20:45:22 -heycam 20:46:12 +??P2 20:46:15 Zakim, ??P2 is me 20:46:15 +heycam; got it 20:46:21 zakim, +33 is me 20:46:21 +Tav; got it 20:47:05 topic: SVG2 requirements 20:47:07 http://www.w3.org/Graphics/SVG/WG/wiki/SVG2_Requirements_Input#Free_audio.2Fvideo_codec_requirements 20:47:19 http://mpeg.chiariglione.org/meetings/geneva11-1/geneva_press.htm 20:47:35 CC: this is from MPEG 20:48:00 ... one track for MPEG1, since patents are phasing out 20:48:22 ... other option is AVC standard but with a baseline where patent holders agree to make it free 20:48:28 ... that's not yet decided 20:48:42 ... there are big interests, political and economical 20:49:10 CM: what's your sense of these two possible ways forward? 20:49:26 CC: first option is clear in terms of patent conflicts 20:49:39 ... if there were other patents they would have been claimed before 20:49:49 ... thing is it won't be good quality 20:50:10 ... building on mpeg1 is unclear, due to patents 20:50:35 ... other option H264 / AVC one, it would be compatible with most exisitng codecs 20:50:46 ... but it's a big question for the stakeholders 20:51:05 TB: what does google support in their browser? 20:51:15 CC: on pc it's different from on android 20:51:30 ...think they're talking about dropping 264 on pc, and android 20:51:41 TB: what's the fallback? 20:51:44 CC: webm 20:51:52 ... but the licensing isn't clear either 20:52:26 ... mpeg issued a call for patents covering webm, and got responses (3 digits) 20:52:43 CM: the responses will be published yes? 20:52:53 CC: i think so, next year maybe 20:54:18 CM: in terms of requirements i don't think we should be reuqiring codecs at this point 20:54:25 http://www.webm-ccl.org/ 20:54:29 ... it's something that should be done for the whole web platform 20:55:39 CC: apple and microsoft are missing from the webm licensing members list 20:58:20 RRSAgent, pointer 20:58:20 See http://www.w3.org/2011/12/22-svg-irc#T20-58-20 20:59:30 SVG WG supports the goal, including for the whole web platform, but it does not seem feasible at the moment 20:59:57 RESOLUTION: SVG WG supports the goal, including for the whole web platform, but it does not seem feasible at the moment 21:00:11 http://www.w3.org/Graphics/SVG/WG/wiki/SVG2_Requirements_Input#Tooltip_element 21:00:19 CM: next tooltip elements 21:00:34 ... this has come up before 21:00:49 ... i've never really been satisfied with the tooltips in tiny so far 21:01:08 ... not clear to me what's a good solution 21:01:39 -heycam 21:02:13 ... he wants a way to generate tooltips 21:02:19 +[IPcaller] 21:02:21 Zakim, [ is me 21:02:22 +heycam; got it 21:02:38 TB: doesn't browsers differ today with what's displayed as a tooltip, or xlink:title 21:03:03 <ed> CM: yes I think you're right TB 21:03:32 <ed> ... html is a bit different because it has a title attribute 21:04:05 <ed> ... i think our title element has a broader meaning than @title in html 21:04:41 <ed> ... people are used to what it does in html 21:04:58 <ed> ... i think we should look into the issue for svg2 21:05:37 <ed> ... agree with DOH that using metadata with role isn't the right way to do this 21:05:44 <ed> CC: maybe a should req? 21:06:52 <Tav> http://tavmjong.free.fr/SVG/PROGRESSBAR/SteamEngineProgressBar_StandAlone.svg 21:06:56 <heycam> SVG 1.1 also says "Alternate presentations are possible, both visual and aural, which display the ‘desc’ and ‘title’ elements but do not display ‘path’ elements or other graphics elements. This is readily achieved by using a different (perhaps user) style sheet." 21:07:26 <Zakim> -Tav 21:08:13 <Zakim> +Tav 21:09:15 <Zakim> -Tav 21:09:45 <Zakim> +Tav 21:10:21 <ed> CM: the document has both <title> and <desc> duplicating the content 21:10:52 <ed> ED: don't think any of the browser display <desc> as a tooltip 21:11:49 <ed> CM: think we can improve on the requirements for tooltips, to align with html implementation 21:12:05 <ed> ... so that they're shown under the same circumstances 21:12:31 <ed> ... we can investigate more when we look into the issue 21:13:04 <ed> RESOLUTION: SVG2 will have stronger requirements for when to display tooltips 21:13:18 <heycam> http://www.w3.org/Graphics/SVG/WG/wiki/SVG2_Requirements_Input#Hit-testing_on_image_alpha 21:13:44 <ed> CM: this was discussed in an FXTF meeting IIRC 21:13:58 <ed> ... perhaps more generic, with images and fill 21:15:42 <ed> ED: probably the proposal from zynga, with masks for mouse events 21:16:03 <ed> CC: we could discuss this with alex at the F2F 21:17:00 <ed> ACTION: ED to summarize the discussions about hittesting with alpha from the FX list 21:17:00 <trackbot> Created ACTION-3190 - Summarize the discussions about hittesting with alpha from the FX list [on Erik Dahlström - due 2011-12-29]. 21:17:25 <heycam> http://www.w3.org/Graphics/SVG/WG/wiki/SVG2_Requirements_Input#Anchor_events_.28anchorActivated.2C_anchorTargeted.29 21:17:58 <ed> CM: doug is requesting an event for when the link changes 21:18:12 <ed> ... html already has the hashchanged events 21:18:24 <ed> CC: this should be part of the harmonization with html, right? 21:18:41 <ed> CM: not sure if we said before if we decided on document level events and such 21:19:34 <ed> ... think we should consider all the documentwide events 21:20:27 <ed> ... in html, and make them apply to svg 21:20:42 <ed> ... where it makes sense 21:22:14 <cyril> "SVG 2 will have HTML document wide events (including hashchange) apply to SVG documents when they make sense" 21:23:17 <ed> RESOLUTION: SVG 2 will consider adding HTML document wide events (including hashchange) in SVG documents where they make sense 21:23:35 <heycam> http://www.w3.org/Graphics/SVG/WG/wiki/SVG2_Requirements_Input#Consider_adding_drag_and_drop_functionality 21:24:15 <ed> CM: DND in html5 is dragsources and dragtargets, and getting things from other applications 21:24:24 <ed> ...not with moving elements around 21:24:54 <ed> ... we should try to get the html5 dnd functionality 21:25:22 <ed> ... not sure about the dnd for moving things in the document 21:25:59 <ed> ... probably better to focus on improving the DOM apis for getting the mouse cursor in the variious cooridnate systems, to ease moving things around that way 21:27:29 <ed> ED: aligning with html5 on this sounds good to me 21:27:37 <heycam> http://www.whatwg.org/specs/web-apps/current-work/multipage/dnd.html#dnd 21:28:22 <ed> ... and improving the DOM apis too 21:29:39 <ed> ACTION: CM to investigate how html5 drag&drop could be used in svg 21:29:39 <trackbot> Sorry, amibiguous username (more than one match) - CM 21:29:39 <trackbot> Try using a different identifier, such as family name or username (eg. charles, cmccorma) 21:29:49 <ed> ACTION: heycam to investigate how html5 drag&drop could be used in svg 21:29:50 <trackbot> Created ACTION-3191 - Investigate how html5 drag&drop could be used in svg [on Cameron McCormack - due 2011-12-29]. 21:30:26 <ed> ACTION: heycam to investigate what document wide events would make sense to apply to svg documents too 21:30:27 <trackbot> Created ACTION-3192 - Investigate what document wide events would make sense to apply to svg documents too [on Cameron McCormack - due 2011-12-29]. 21:31:24 <ed> RESOLUTION: SVG2 may require drag&drop functionality, and we'll investigate html5's functionality for that 21:32:36 <Zakim> -ed 21:32:38 <Zakim> -heycam 21:32:42 <Zakim> -cyril 21:32:45 <Zakim> -Tav 21:32:46 <Zakim> GA_SVGWG(SVG1)3:00PM has ended 21:32:48 <Zakim> Attendees were +61.2.980.5.aaaa, heycam, [IPcaller], +33.9.53.77.aabb, ed, cyril, Tav 21:32:58 <ed> Zakim, end telcon 21:32:58 <Zakim> I don't understand 'end telcon', ed 21:33:06 <ed> trackbot, end telcon 21:33:06 <trackbot> Zakim, list attendees 21:33:06 <Zakim> sorry, trackbot, I don't know what conference this is 21:33:07 <trackbot> RRSAgent, please draft minutes 21:33:07 <RRSAgent> I have made the request to generate http://www.w3.org/2011/12/22-svg-minutes.html trackbot 21:33:08 <trackbot> RRSAgent, bye 21:33:08 <RRSAgent> I see 4 open action items saved in http://www.w3.org/2011/12/22-svg-actions.rdf : 21:33:08 <RRSAgent> ACTION: ED to summarize the discussions about hittesting with alpha from the FX list [1] 21:33:08 <RRSAgent> recorded in http://www.w3.org/2011/12/22-svg-irc#T21-17-00 21:33:08 <RRSAgent> ACTION: CM to investigate how html5 drag&drop could be used in svg [2] 21:33:08 <RRSAgent> recorded in http://www.w3.org/2011/12/22-svg-irc#T21-29-39 21:33:08 <RRSAgent> ACTION: heycam to investigate how html5 drag&drop could be used in svg [3] 21:33:08 <RRSAgent> recorded in http://www.w3.org/2011/12/22-svg-irc#T21-29-49 21:33:08 <RRSAgent> ACTION: heycam to investigate what document wide events would make sense to apply to svg documents too [4] 21:33:08 <RRSAgent> recorded in http://www.w3.org/2011/12/22-svg-irc#T21-30-26