- From: Tab Atkins Jr. <jackalmage@gmail.com>
- Date: Mon, 2 Dec 2013 15:21:13 -0800
- To: Dirk Schulze <dschulze@adobe.com>
- Cc: Eric Seidel <eseidel@chromium.org>, www-svg <www-svg@w3.org>, Philip Rogers <pdr@chromium.org>, Stephen Chenney <schenney@chromium.org>, Erik Dahlstrom <ed@opera.com>
On Mon, Dec 2, 2013 at 3:04 PM, Dirk Schulze <dschulze@adobe.com> wrote: > On Dec 2, 2013, at 10:32 PM, Tab Atkins Jr. <jackalmage@gmail.com> wrote: >> Since the simplest behavior for undefined (just convert it to a >> number, resulting in NaN) is useless, the second behavior of turning >> null/undefined into zero is obviously the best behavior for arbitrary >> undefined arguments. We don't want a different behavior between >> DOMMatrix() and DOMMatrix(undefined), nor between DOMMatrix(undefined) >> and DOMMatrix(0). > > I strongly disagree on this. At least without arguments, authors nearly always want to have the identity transformation matrix. That is what is currently specified[1]. Well at least it was before we used a different preprocessor. I don't understand what you mean. I'm looking at the source, and it's simply not specified. What on earth could lead to switching preprocessors causing a loss of information in the source document? > Of course, we could introduce a function called identity() which makes the matrix the identity matrix. However, this would nearly always be called by authors and seems to be a useless requirement. People use matrices for more than just transforms, and having a zero matrix is useful for plenty of other things. (At least, as a starting point.) On the other hand, most of these other uses want arbitrary matrixes, while DOMMatrix is limited to 2x3 or 4x4. In this limited case, I agree that the identity matrix is probably the most useful. > I even could think about support 6 or 16 value for setting the transformation function. This is actually very common anyway. What do you mean by this? ~TJ
Received on Monday, 2 December 2013 23:22:00 UTC