Re: Canvas Test Submission approval/feedback request

On Oct 5, 2010, at 10:57 AM, Kris Krueger wrote:

> It combines simple SVG support with canvas's drawImage. 
> Surely you don't expect the SVG WG to start to write canvas tests.
> 
> The SVG image is very simple - not exotic specifically so that it's not testing the actual SVG implementation.

SVG 1.1 seems to include a very open-ended conformance requirement on HTML, XHTML and CSS implementations if they also happen to implement SVG 1.1. It may be hard for SVG WG to comprehensively test, since the other technologies in question are changing over time and can continue to gain new ways to reference an image. But I don't think that makes it the HTML WG's responsibility to test the requirement.

Depending on requirements of other specs in our test suites is largely at our discretion. In some cases, it may be impossible to test an HTML conformance requirement without depending on requirements of other specs; or it may simply make our life easier to assume certain things for harness purposes. From a practical point of view, it's probably better not to depend on requirements of other specs when they are not implemented widely enough, and are not essential to testing HTML itself.

Incidentally, I'm not sure of the state of other browsers supporting SVG in images (canvas or otherwise). I believe Safari and Chrome support SVG in all image contexts, and the test appears to pass. Opera and Firefox seem to fail.

Regards,
Maciej


> 
> 
> -----Original Message-----
> From: James Graham [mailto:jgraham@opera.com] 
> Sent: Tuesday, October 05, 2010 7:47 AM
> To: Kris Krueger
> Cc: Philip Taylor; Anne van Kesteren; 'public-html-testsuite@w3.org' (public-html-testsuite@w3.org)
> Subject: Re: Canvas Test Submission approval/feedback request
> 
> On 10/05/2010 04:17 PM, Kris Krueger wrote:
>> It's quite reasonable to expect that an img tag supports svg.
>> 
>> http://www.w3.org/TR/2003/REC-SVG11-20030114/conform.html#ConformingSV
>> GViewers
>> 
>> If the user agent includes an HTML or XHTML viewing capability or can 
>> apply CSS/XSL styling properties to XML documents, then a Conforming 
>> SVG Viewer must support resources of MIME type "image/svg+xml" 
>> wherever raster image external resources can be used, such as in the 
>> HTML or XHTML 'img' element and in CSS/XSL properties that can refer 
>> to raster image resources (e.g., 'background-image').
> 
> Strictly speaking, that seems to be a conformance criterion of SVG 1.1, not of HTML. Therefore the SVG testsuite would be the right place to test it. As far as I can tell HTML 5 does not require SVG support and the references to SVG are to SVG 1.2 Tiny. Unless I am overlooking something, SVG 1.2 Tiny omits the conformance criterion that you mention.
> 
> As a practical matter it may sometimes be necessary to go beyond the letter of the spec where it does not require support for specific formats e.g. it is hard to test video without assuming some set of possible codecs. It is unclear that this is such a case.
>

Received on Wednesday, 6 October 2010 12:23:45 UTC