- From: Paul LeBeau <paul.lebeau@gmail.com>
- Date: Thu, 13 Feb 2014 22:22:48 +1300
- To: Cameron McCormack <cam@mcc.id.au>
- Cc: www-svg <www-svg@w3.org>
- Message-ID: <CACfsppCux=9iawpRStuFFiA28isPAiOQ2bUH8PziG7oidt8mYQ@mail.gmail.com>
Hi Cameron > In the section of each command it describes what effect the current bearing has. Ah. Thanks. Didn't see that. In the definition of 'h' you say: > When a relative *h* command is used, the end point of the line is (cpx + x cos cb, cpy + x sin cb). Given that the cpx,cpy moves, I assume that means that you can use "b 90 h 10 10 10 z" to draw a square? >Although multiple parameters may be specified, this usually will not be useful, as they could be combined into a single angle value. I'm not sure about the clarity of this statement. For example, does the following draw a pentagon or not? "b 36 36 h 47 47 47 47 z" And is the following equivalent to your pentagon example or not? "M 150,10 b -36 72 h 47 47 47 47 z" Paul On 13 February 2014 18:07, Cameron McCormack <cam@mcc.id.au> wrote: > Hi Paul, > > > Paul LeBeau wrote: > >> I was just looking at the latest draft and noticed the inclusion of the >> new B/b bearing path command. This is the first time I've seen this new >> feature, so apologies if this has been discussed before. >> > > This is the first WD it's appeared in. > > > I think this section may need a little expansion, as it raised some >> questions for me about implementation. >> >> 1. The first line says it "influences the orientation of subsequent >> relative path commands". Does that mean that it, in effect, rotates the >> axes for subsequent (relative) path commands? The only example provided >> used 'h' commands. What effect does it have on other commands? >> > > In the section of each command it describes what effect the current > bearing has. For example see below the table in > https://svgwg.org/svg2-draft/paths.html#PathDataLinetoCommands for what a > relative lineto command means in terms of the current point and current > bearing. > > > 2. What happens if there is an absolute command next, or after that? >> Does it reset the bearing? Does subsequent mean all subsequent >> relative commands of just the consecutive ones after the bearing command? >> > > No, the only commands that influence the current bearing are "B" and "b". > If you have a sequence of segments "M, B, l, L, l" then the current > bearing will be the same value for all three lineto commands, and it will > affect both of the relative linetos. > > > 3. If an absolute command doesn't reset the bearing, is there anything >> that does? >> > > Just "B" and "b". > > > 4. Does the bearing have any effect on the orientation of markers? >> > > That wasn't my intention but it's a good question. I think vertex markers > shouldn't be rendered on each B/b command. So for something like "M > 100,100 B 45 h 100 b 90 h 100 b 90 h 100" you would still only get three > vertex markers, and they would be at the same orientation as if you'd > written the path string using only absolute path commands and without the > bearing commands. >
Received on Thursday, 13 February 2014 09:23:36 UTC