Re: ISSUE-2318 (textdeco-bbox): How should text-decorations be rendered wrt boundingbox units (gradients, filters)? [SVG Full 1.1]

On Wednesday, April 7, 2010, 12:27:25 PM, SVG wrote:

SWGIT> ISSUE-2318 (textdeco-bbox): How should text-decorations be
SWGIT> rendered wrt boundingbox units (gradients, filters)? [SVG Full 1.1]


SWGIT> Raised by: Erik Dahlström
SWGIT> On product: SVG Full 1.1

SWGIT> The spec doesn't define whether text-decoration[2] are to be
SWGIT> included in the boundingbox of the 'text'/'tspan' element[1] or
SWGIT> if it's separate. This can affect gradients, filters etc.

The following language from [1] leads me to conclude that text decorations contribute to the bounding box of the text element, and that this (block-level) bounding box is also used even for (inline) child elements:

It is possible to apply a gradient, pattern, clipping path, mask or filter to text. When one of these facilities is applied to text and keyword objectBoundingBox  is used (see Object bounding box units) to specify a graphical effect relative to the "object bounding box", then the object bounding box units are computed relative to the entire 'text'  element in all cases, even when different effects are applied to different 'tspan' elements within the same 'text' element.

SWGIT> Should the decoration use its own boundingbox, should it use
SWGIT> the text element boundingbox or should it use the text
SWGIT> boundingbox unioned with the decoration boundingbox?

I agree this should be made more explicit in 1.1SE, but I think the intent is already there is 1.1.

SWGIT> [1]
SWGIT> [2]

 Chris Lilley          
 Technical Director, Interaction Domain
 W3C Graphics Activity Lead
 Co-Chair, W3C Hypertext CG

Received on Wednesday, 7 April 2010 13:22:46 UTC