[cairo] Path length
behdad.esfahbod at gmail.com
Tue Mar 24 12:16:55 PDT 2015
On 15-03-24 01:45 PM, Bryce Harrington wrote:
> On Tue, Mar 24, 2015 at 05:09:50PM +0000, Stuart Axon wrote:
>> Is the best way to get the length of a cairo path to call cairo_copy_path_flat and sum the lengths of the LINE_TOs contained inside ?
That's what I've personally done in the past. However:
>> I've been looking at arc lengths and it seems it can get complex,
There are very decent and simple approximations that I think are good enough
for most purposes. Read here for example:
Would be interesting to measure or calculate the error of that approximation
for small values of n.
>> any chance of cairo providing cairo_path_length in future, or should I be looking at something like 2geom for this sort of thing ?
> I haven't seen anyone making plans to implement that, so 2geom might be
> your best choice right now. That said, I imagine patches to add that to
> cairo would be entertained if the use case for it is strong enough.
Would be nice, but we'd need a nice API for it too.
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