- From: Robert O'Callahan <robert@ocallahan.org>
- Date: Mon, 23 Sep 2013 08:56:50 +1200
- To: Dirk Schulze <dschulze@adobe.com>
- Cc: www-style list <www-style@w3.org>
- Message-ID: <CAOp6jLbyPJmhyyYaEE7MnUN0gRM4CieT8F5CajZn01Qv8KRWdw@mail.gmail.com>
On Sun, Sep 22, 2013 at 1:42 PM, Dirk Schulze <dschulze@adobe.com> wrote: > Some people objected in using double precision, since double precision > operations can take more computation cycles, especially on mobile devices. > The counter proposal is to use single precision floating points and > truncate on passing double precision values. Truncation to single precision > and expanding to double precision (for instance to return a DOMPoint) takes > more time as well. So even that has disadvantages. Note that arithmetic > operations in JS are done with double precision, internal operations could > still benefit of single precision operations. > > On the other side, many implementations with at least one exception > (Gecko) operate on double precision already. The web exposed, prefixed > interfaces WebKitCSSMatrix [2] and MSCSSMatrix [3] for instance are > operating on double precision values. This already causes accumulating > errors that can be seen between Gecko's and WebKit's implementation of CSS > Transforms when applying multiple transformations. > > DOMQuad and DOMPoint will be involved in arithmetic operations as well and > it would be great to find a consensus on the precision question which may > solve problems on CSS Transforms as well. > I'm OK with going with doubles everywhere. Rob -- Jtehsauts tshaei dS,o n" Wohfy Mdaon yhoaus eanuttehrotraiitny eovni le atrhtohu gthot sf oirng iyvoeu rs ihnesa.r"t sS?o Whhei csha iids teoa stiheer :p atroa lsyazye,d 'mYaonu,r "sGients uapr,e tfaokreg iyvoeunr, 'm aotr atnod sgaoy ,h o'mGee.t" uTph eann dt hwea lmka'n? gBoutt uIp waanndt wyeonut thoo mken.o w * *
Received on Sunday, 22 September 2013 20:57:21 UTC