- From: Dirk Schulze <dschulze@adobe.com>
- Date: Thu, 19 Jul 2012 16:54:03 -0700
- To: "L. David Baron" <dbaron@dbaron.org>
- CC: "www-style@w3.org" <www-style@w3.org>

Hi David, On Jul 19, 2012, at 2:38 PM, L. David Baron wrote: > http://dev.w3.org/csswg/css3-transforms/Overview.html#animation > says something that's not compatible with earlier drafts of the > transforms spec. In particular, I'm concerned about the "is a > derivative of a primitive" in: > # If from- and to-transform have the same number of transform > # functions, each transform function is a derivative of a > # primitive and each function pair is a derivative of the same > # primitive. > and the later text: > # Transform functions not listed above are neither primitives nor > # derivatives and can neither be interpolated with transform > # functions of primitives listed above nor with itself. UAs have > # to follow the last rule on Interpolation of Transforms then. > > Earlier drafts said that any matched list of transform functions is > interpolated function-by-function rather than via matrix > interpolation. The new draft adds this concept of primitives to say > that some pairs of syntactically-different but semantically-similar > functions (e.g., translate() and translateX()) can be considered > equivalent for the purpose of this matching. I think this is fine. > > But it also says that some transform functions: in particular, > perspective(), rotate3d(), matrix(), and matrix3d(). I could > understand the desire to interpolate these (or maybe all of these > except perspective()) as matrices, but it seems inappropriate for > the presence of one of these in a transform list to force other > items in that transform list into the matrix decomposition path, > particularly if it's the other items that are changing in the > animation. Do I understand your point correctly, that you just want the affected transformation functions to get interpolated as matrices? Lets take the following two transform function lists: translate(200px,100px) rotate3d(1,0,0,45deg) scale(1) translate(0,0) rotate3d(0,0,1,45deg) scale(2) Do you suggest that just rotate3d gets interpolated as matrix and translation as well as scale still get animated numerically? Greetings, Dirk

Received on Thursday, 19 July 2012 23:54:33 UTC