Re: Coordinate conversion interface?

This function exists in SVG in the `getScreenCTM()` and
`getTransformToElement()` methods, but so far has not been adopted by the
Geometry Utils/CSSOM specs for generic CSS transforms.

https://www.w3.org/TR/SVG11/types.html#InterfaceSVGLocatable

In fact, the getTransformToElement() method was dropped from SVG 2 because
of implementators not wanting to add rules for calculating transformations
between elements that are in different SVG contexts (i.e, part of separate
inline <svg> regions in the same document).

Removal resolution is recorded here: https://lists.w3.org/
Archives/Public/www-svg/2015Aug/att-0009/SVGWG-F2F-
minutes-20150824.html#item02

I personally would strongly argue in favour of both these methods being
made available on all elements, as part of a CSSOM spec.  They are
incredibly useful when working with dynamically scripted transformed
elements.

Another usecase is creating a zoomable & rotatable SVG diagram with
fixed-size, non-rotating HTML labels.  Demo here, which no longer works in
browsers that have removed getTransformToElement() support:
https://codepen.io/AmeliaBR/details/kFDvH/

All that said, adding 3D support might not be trivial, as you'd need to
factor in "flattening" transforms in some way.

~ABR

On 20 June 2017 at 15:09, Henrik Andersson <henke@henke37.cjb.net> wrote:

> I've skimmed the CSS feature list, but I can't find this one.
>
> I am looking for a way to take a coordinate that is in the coordinate
> space of one element in the DOM and convert it into the equivalent
> coordinate, but in the coordinate system of another element in the same
> DOM.
>
> My usecase is as follows, a javascript would like to run a particle
> system and position particles relative to one object, but place them in
> another.
>
>