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Re: [Transforms] svg-translate-001

From: Chris Lilley <chris@w3.org>
Date: Thu, 19 Apr 2012 16:03:08 +0200
Message-ID: <291467012.20120419160308@w3.org>
To: Rebecca Hauck <rhauck@adobe.com>
CC: Dirk Schulze <dschulze@adobe.com>, "public-css-testsuite@w3.org" <public-css-testsuite@w3.org>
On Wednesday, April 18, 2012, 11:27:02 PM, Rebecca wrote:

RH> Hi Chris,

RH> Yes, thanks for the feedback and I'm also in agreement.  However, I'm
RH> proposing the following change, where I eliminate the coordinates from the
RH> description altogether and add a second visual element that would a cause
RH> a diff if the test fails.  This is similar to your suggested improvement
RH> to the scale-XXX tests, where the pass/fail result is affected or defined
RH> by a fixed visual element on the page.

Great. My main concern was that careful testers would need to screenshot and count pixels, while slapdash ones might give false positives.

RH> Here's a sample code snippet:

RH> <p>The test passes if there is a green square and no red.</p>
RH> <svg>
RH>         <rect x="100" y="100" width="50" height="50" fill="red"/>
RH>         <rect width="100" height="100" fill="green"
RH> transform="translate(50 50)"/>
RH> </svg>


RH> I've attached pngs demonstrating PASS & FAIL for this test.  Would an
RH> approach like this be ok?

The general approach would satisfy my comment. 

For specific tests, though, its good to ensure that inaccuracies are visible. To take your code snippet above, the red rect is only 50x50 so if the implementation ends up with any transform from translate(25,25) to translate(75,75) the red rect is still covered.

(Unlikely with that specific transform syntax but could happen if other units are used or for more complex, combined transforms).

Allowing a 1px margin for anti-aliasing and thus specifying a 98x98 red rect would be more sensitive to errors in implementations.


RH> Thanks,
RH> -Rebecca



RH> On 4/18/12 8:46 AM, "Dirk Schulze" <dschulze@adobe.com> wrote:

>>I agree with your comments and we are already improving the tests, but
>>push when we are ready. So far translate and scale tests are affected by
>>the refactoring.

>>Greetings
>>Dirk

>>On Apr 18, 2012, at 8:40 AM, "Chris Lilley" <chris@w3.org> wrote:

>>> Hello public-css-testsuite,

>>> "The test passes if there is an orange square at 50,50"

>>>http://test.csswg.org/harness/test/CSS3-TRANSFORMS_DEV/svg-translate-001/

>>> Easier to see if there was a marker at 50,50 to which the top left
>>>corner of the square could align.

>>> Also "at 50,50" could be made more precise "whose top left corner is at
>>>50,50". 

>>> -- 
>>> Chris Lilley   Technical Director, Interaction Domain
>>> W3C Graphics Activity Lead, Fonts Activity Lead
>>> Co-Chair, W3C Hypertext CG
>>> Member, CSS, WebFonts, SVG Working Groups








-- 
 Chris Lilley   Technical Director, Interaction Domain                 
 W3C Graphics Activity Lead, Fonts Activity Lead
 Co-Chair, W3C Hypertext CG
 Member, CSS, WebFonts, SVG Working Groups
Received on Thursday, 19 April 2012 14:03:15 GMT

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