[whatwg] Rename the 7-arg arcTo() to ellipseTo()?

Tab Atkins Jr. jackalmage at gmail.com
Mon Sep 24 12:11:28 PDT 2012


On Mon, Sep 24, 2012 at 11:51 AM, Ian Hickson <ian at hixie.ch> wrote:
> On Sun, 23 Sep 2012, Tab Atkins Jr. wrote:
>> On Sun, Sep 23, 2012 at 3:57 PM, Ian Hickson <ian at hixie.ch> wrote:
>> > On Fri, 21 Sep 2012, Tab Atkins Jr. wrote:
>> >> So, can we rename the 7-arg arcTo to ellipseTo?  That seems to
>> >> support your "always [require] all the arguments" recommendation. ^_^
>> >
>> > Just have one arcTo command, that takes all the arguments. Why split
>> > it into two, if you always require all the arguments?
>>
>> Oh, that's what you meant.
>>
>> That seems silly.  It's more convenient and simple for authors to have a
>> circular form, separate from the elliptical form.  It lets you omit the
>> second radius and the rotation, as they're irrelevant.
>
> Omitting two numbers, one of which is zero, is easily no more a win than
> the cost of having two different nearly-identical commands. Just consider
> C/c and S/s; is it really worth it?

Yes, it is.  ^_^  The authoring convenience of not having to repeat
things, or not having to read past useless things, is fairly
significant.


>> > So introduce a new one-letter command that fixes specifically the
>> > problems with A, don't drag in the entire canvas path API. :-)
>>
>> We're not, we're pulling in the two/four useful arc commands.
>
> I have to admit to being very confused about what you're trying to do.
>
> What's wrong with A/a? It seems to be equivalent to arcTo(). Is it arc()
> that you want to add? I'm very confused.

Oh, no, they're *completely* different.  arcTo() is *great*, because
it's convenient and solves a useful problem (rounding a corner)
without you having to do much math.  For A, you have to determine the
start/end points on the circle yourself, usually involving trig.  The
only similarity between the two commands is that they both draw an arc
as part of their operation.

~TJ



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