- From: Simon Fraser via GitHub <sysbot+gh@w3.org>
- Date: Thu, 12 Jan 2017 17:10:39 +0000
- To: public-css-archive@w3.org
smfr has just created a new issue for https://github.com/w3c/csswg-drafts: == transform-origin: 0% not equivalent to 0px is confusing == https://www.w3.org/mid/525F2287.8050002@mcc.id.au I think the behaviour of transform-origin, where lengths mean different things depending on whether the element is an SVG element or not, isn't great. It leads to questions like: - Why shouldn't 'transform-origin: 0px 0px' and 'transform-origin: 0% 0%' mean the same thing? Surely 0% of anything is 0, and so that should be equivalent to 0px. - How do we treat 'transform-origin: calc(0% + 0px) calc(0% + 0px)'? What about having something in the property value that explicitly opts in to having values be relative to the SVG viewport rather than the bounding box? For example: transform-origin: viewport 50% 50%; /* middle of the viewport */ transform-origin: 50% 50%; /* middle of the bbox */ transform-origin: viewport 4px 4px; /* relative to viewport origin */ transform-origin: 4px 4px; /* relative to the bbox origin */ And then the UA style sheet could set transform-origin: viewport 0 0; on SVG elements. Alternatively, since setting the transform origin to be anything viewport relative except for the origin isn't that useful -- and could be handled by translations in the 'transform' property -- we could just add a single new value which means the viewport origin for SVG elements, and the bbox origin for other elements: transform-origin: auto; This would then be the initial value, no need for a UA style sheet rule. Percentages and lengths would always be relative to the bbox. Even if we don't do either of these, and leave the "percentages are interpreted differently" behaviour, we should define what happens with calc()s that contain percentages. Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/895 using your GitHub account
Received on Thursday, 12 January 2017 17:10:45 UTC