- From: Paul LeBeau via GitHub <sysbot+gh@w3.org>
- Date: Sat, 27 Jan 2018 12:36:39 +0000
- To: public-svg-issues@w3.org
> none of the browser engines (as far as I can tell) implements it this way
I suspect that this was mostly because the spec has a somewhat ambiguous reading:
> For raster images, hit-testing is either performed on a whole-image basis (i.e., the rectangular area for the image is one of the determinants for whether the image receives the event) or on a per-pixel basis (i.e., the alpha values for pixels under the pointer help determine whether the image receives the event):
I think the original author was probably referring to the fact that some values ("visiblePainted" and "painted") require pixel level hit testing, and some don't. The former options include the the text:
> if any pixel from the raster image which is under the pointer is not fully transparent
whereas the remaining options talk about:
> the rectangular area of the image
A loose reading of the introductory paragraph could be interpreted to mean that implementations had a choice whether to use pixels or not. I hope the spec doesn't get changed to remove the per-pixel options, and if it doesn't, then perhaps the intro should be modified to remove any ambiguity.
Browser bug reports for this issue here:
- https://bugzilla.mozilla.org/show_bug.cgi?id=311942
- https://bugs.chromium.org/p/chromium/issues/detail?id=806468
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Received on Saturday, 27 January 2018 12:37:16 UTC