Re: comments on Matrix

2013/3/22 Rik Cabanier <cabanier@gmail.com>

>
>
> On Fri, Mar 22, 2013 at 4:48 AM, Benoit Jacob <jacob.benoit.1@gmail.com>wrote:
>
>> The following points don't seem to have been discussed yet:
>>
>> 2013/3/19 Benoit Jacob <jacob.benoit.1@gmail.com>
>>
>>> 3. Many concepts are not defined (and their mathematical names aren't
>>> that specific).
>>> Examples "the skew angle in degrees",
>>
>>
> This matches the CSS transforms spec:
> http://dev.w3.org/csswg/css3-transforms/#two-d-transform-functions
> Maybe we should make that more clear
>

OK, the skews are actually precisely defined there:
http://dev.w3.org/csswg/css3-transforms/#SkewDefined

Should just transplant that (and other relevant definitions from there)
into the matrix spec.


>
>
>> the "perspective" vector, the order of coefficients in a quaternion (is
>>> the unit quaternion 1,0,0,0 or 0,0,0,1 in your convention?)
>>>
>>
> Those have been removed.
> They might come back in the pseudo code if we want to add matrix
> interpolation.
>

OK.


>
>
>>
>>> 4. Some method names are verbs, yet they do not perform an action on
>>> their object. Example: translate(). I would call that translated(), I
>>> suppose.
>>
>>
> 'translate' can't change because it needs to be compatible with SVG.
>

:-(


> As Tab suggest, I'd like to hear what JS people think about this.
>
> What I *think* is open for now:
> - clear up skewing, etc by referring to CSS transforms
> - look into past tense for method names
> - look into adding a matrix interpolation call
> - look into matrix decomposition call
> - look into an 'IsInvertible' call that determines if the matrix is
> reasonably invertible
>
> We can tackle these as separate discussions.
>
>
Benoit