On Tue, Aug 31, 2010 at 3:39 PM, Chris Marrin <[email protected]> wrote: > > On Aug 31, 2010, at 3:25 PM, Maciej Stachowiak wrote: > >> >> On Aug 31, 2010, at 2:06 PM, Chris Marrin wrote: >> >>> >>> On Aug 31, 2010, at 11:48 AM, Kenneth Russell wrote: >>> >>>> On Tue, Aug 31, 2010 at 11:05 AM, David Hyatt <[email protected]> wrote: >>>>> On Aug 31, 2010, at 10:36 AM, Chris Marrin wrote: >>>>> >>>>>> Or should we get rid of Vector3, added the functionality it needs to >>>>>> FloatPoint3D and use that? Ken Russell already has plans to do add the >>>>>> functions to FloatPoint3D, so I would vote for that. >>>>> >>>>> I would vote for this. I don't think the geometry classes should move to >>>>> wtf. >>>> >>>> I'd like to unify the math, geometry, and linear algebra classes that >>>> are scattered around the WebKit tree -- for example, FloatPoint, >>>> FloatPoint3D, FloatRect, FloatSize, the classes under >>>> WebCore/platform/graphics/transforms/, these Complex and Vector3 >>>> types, ... -- under a directory like WebCore/math, remove duplicate >>>> functionality, and provide a cohesive set of interfaces that can be >>>> easily used by other modules like graphics and audio. >>> >>> It would be nice if we could do this unification and then later on we can >>> enhance it so the classes play nice together. For instance, >>> TransformationMatrix deals with many, but not all of the other geometric >>> classes. You can't cast between FloatPoint and FloatPoint3D, etc. Maybe we >>> could also use this opportunity to change TransformationMatrix to Matrix. >>> The current name is such a mouthful. And we might also want to think about >>> changing FloatPoint3D to FloatPoint3. That would make it more natural if >>> and when we want to add a FloatPoint4. We should also change >>> AffineTransform to AffineMatrix so it matches Matrix. >> >> Mathematically, you can have an affine transform, or a matrix that >> represents an affine transform. And there's such a thing as an affine space >> (in fact IntPoint and IntSize form an affine space). But there's no such >> thing as an affine matrix. > > Sure there is. It's a matrix that performs affine transformations. > Mathematically it's represented as a 3x3 matrix, but like others, we just > represent it as a linear transformation matrix (2x2) plus a 2D translation > value. I think the name AffineMatrix is descriptive because, unlike a general > 3x3 matrix, our truncated representation can only handle affine > transformations.
Chris, based on the precision of Maciej's reply, I suspect you do not want to get into a semantic argument here... :) http://www.google.com/search?q=affine+matrix -Ken _______________________________________________ webkit-dev mailing list [email protected] http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
