- From: David Dailey <ddailey@zoominternet.net>
- Date: Thu, 12 Dec 2013 21:35:41 -0500
- To: "'Nikos Andronikos'" <nikos.andronikos@cisra.canon.com.au>, "'Dirk Schulze'" <dschulze@adobe.com>, <public-fx@w3.org>, "'www-svg'" <www-svg@w3.org>
- Message-ID: <002501cef7ac$04903bc0$0db0b340$@net>
Whatever ya'll decide here, there are a few use cases that have been with us since the beginning of time: Additive and subtractive color models: See the first two (from top left) illustrations at http://cs.sru.edu/~ddailey/canterbury/V9a.svg in ASV (so robust it was!) or In Opera (12.16 - is there a later version I should be using?) Things are good! But the drawing is disturbingly complex (though not nearly so awful as what other people do -- see for example http://en.wikipedia.org/wiki/File:SubtractiveColor.svg which breaks every conceivable concept of accessibility whether ya'll like those concepts or not) Then take a peek in IE 11 (which at least seems to understand what an author intended with regard to feComposite and feBlend) but seems to barf on the idea of replicated filters applied to one another? IE11 gets a passing grade (D) Of course it may be the spec that is flunking rather than the browsers, but my goodness! How hideous the discrepancies are! Now turn your attention to Chrome (I don't really know what Chrome likes to call itself now - I found myself in an upgrade path no doubt controlled by Samsung or Hitachi - I don't know who) Chrome 31.0.1650.63 m (which probably tells the NSA the exact machine in the universe I was using when I repeated the experiment) maybe it is Chromium maybe it is Bling, maybe it is the goofy banner thing that IE implemented that got standards folk so nutty in the 1990's)) , Oh my! I could not have figured out how to make this particular result happen if I wanted it to! Extra credit to anyone who can make this happen across browsers (on purpose!). Safari at least sees all the circles, but it just gives up altogether on the filters. Firefox is so terribly unhappy with the example that it refuses to try to render any more than two of the circles! All browsers respectfully disagree! It is exactly the sort of example I like since no two browsers do the same thing! Additional extra credit for the hall-of-fame-of-browser-breakers for things that make all eight browsers disagree (eight?). All I want to do is draw additive and subtractive models of color in as simple a way as possible! Dear standards-writers. please make sure that in your next version of SVG (I am patient and can wait for 3.0 if needed) there is a way to do this. Please let me know how to as well, so that if I write articles about how to do it, the spec won't change out from under me - not that that would ever happened of course! Perennial cheer and occasional irony. David From: Nikos Andronikos [mailto:nikos.andronikos@cisra.canon.com.au] Sent: Thursday, December 12, 2013 6:45 PM To: Dirk Schulze; public-fx@w3.org; www-svg Subject: Re: [filter-effects] Blending without compositing On 12/12/2013 5:21 PM, Dirk Schulze wrote: Are we trying to preserve backwards compatibility here? e.g. keep an option for the (incorrect) double composite and add an option for no composite? [DS] Yes, backwards compatibility is important. Do I understand your comment correctly that you also don't want to add compositing modes to feBlend? In this case I suggest a new attribute called composite = "true | false" (I would like to have a boolean attribute but that needs changes on SVG2.... lets see if we get that before LC.) This was discussed at this mornings telcon, but just for closure: Yes you do understand me correctly =) I don't think adding compositing operators to feBlend would be useful if the implementation is going to be different than the compositing and blending spec (because the double contribution of the backdrop needs to be retained for src-over). And on that note, I think it would be a good idea to add a note to Filter Effects explaining that the double contribution of the backdrop will occur if 'no-composite' is enabled. Nikos - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - The information contained in this email message and any attachments may be confidential and may also be the subject to legal professional privilege. If you are not the intended recipient, any use, interference with, disclosure or copying of this material is unauthorised and prohibited. If you have received this email in error, please immediately advise the sender by return email and delete the information from your system.
Received on Friday, 13 December 2013 02:36:38 UTC