- From: Brian Birtles <bbirtles@mozilla.com>
- Date: Fri, 13 Jan 2012 17:11:41 +1100
- To: public-svg-wg@w3.org
Hi all, In our discussion about allowing linear interpolation on discrete values (e.g. enumerations) I raised the concern that I thought SMIL somewhere suggested using discrete animation even when linear interpolation is possible if the animation values used enumerated values.[1] It turned out the prose in question actually refers to addition: If a given attribute or property can take values of keywords (which are not additive) or numeric values (which are additive), then additive animations are possible if the subsequent animation uses a numeric value even if the base animation uses a keyword value; however, if the subsequent animation uses a keyword value, additive animation is not possible.[2] As a result it doesn't impact the proposal. Gecko and Presto don't appear to heed the above section with regards to addition either. I couldn't get sensible results out of WebKit for the following test (it possibly doesn't support single-valued values animation). <?xml version="1.0"?> <svg xmlns="http://www.w3.org/2000/svg" width="100" height="100"> <script> function reportColours() { var colours = ""; colours += "a:" + getColourForId("a"); colours += "\n"; colours += "b:" + getColourForId("b"); alert(colours); } function getColourForId(id) { var elem = document.getElementById(id); return window.getComputedStyle(elem).getPropertyValue("color"); } </script> <g color="rgb(50,50,50)" id="a"> <animate attributeName="color" values="rgb(105,105,105)" additive="sum"/> </g> <g color="rgb(50,50,50)" id="b"> <animate attributeName="color" values="dimgrey" additive="sum" onbegin="reportColours()"/> </g> </svg> Both Gecko and Presto report a:rgb(155, 155, 155) b:rgb(155, 155, 155) Best regards, Brian Birtles (ACTION-3210) [1] http://www.w3.org/2012/01/12-svg-irc#T00-50-31 [2] http://www.w3.org/TR/SVG11/animate.html#AnimationAttributesAndProperties
Received on Friday, 13 January 2012 06:12:54 UTC