- From: Tab Atkins Jr. <jackalmage@gmail.com>
- Date: Thu, 28 Apr 2011 18:33:16 -0700
- To: Boris Zbarsky <bzbarsky@mit.edu>
- Cc: "Dailey, David P." <david.dailey@sru.edu>, "public-html@w3.org" <public-html@w3.org>
On Thu, Apr 28, 2011 at 6:18 PM, Boris Zbarsky <bzbarsky@mit.edu> wrote: > On 4/28/11 7:53 PM, Dailey, David P. wrote: >> See for example: >> >> http://srufaculty.sru.edu/david.dailey/svg/recent/htmlsvgcanvas7b.htm >> >> It runs "properly" in no extant browser, that I'm aware of. > > In Gecko, this testcase fails because the <svg> has no intrinsic size > specified, so we have no idea how to actually go about drawing it into the > canvas. > > What the spec says about this case for drawImage is: > > If the sx, sy, sw, and sh arguments are omitted, they must default > to 0, 0, the image's intrinsic width in image pixels, and the image's > intrinsic height in image pixels, respectively. > > But this image has no intrinsic size, so this step can't really be > performed, and we throw instead. > > For the particular case of unspecified source rectangle, it seems like this > could be made to work for images with no intrinsic size in the spec. > > None of this has to do with the fact that the SVG contains a <script>. I believe there's a pending bug against the spec to specify that images should resolve their sizes using the algorithm specified in <http://dev.w3.org/csswg/css3-images/#default-sizing>, using the size of the canvas as the "specified size". (This has no effect on bitmap images, but handily fixes all the cases where an SVG doesn't have a definite size.) ~TJ
Received on Friday, 29 April 2011 01:34:03 UTC