Geometry Boost List: [ggl] Snapping

Subject: [ggl] Snapping
From: Stephen Leary (sleary)
Date: 2009-11-27 03:23:30

Thanks Barend,

I will do some simple snap tests at the weekend.

Stephen

On Sun, Nov 22, 2009 at 10:29 PM, Stephen Leary <sleary_at_[hidden]> wrote:

> This is a very crude first attempt at a diagram (I will do another soon)
> but the left hand scenario the line at an angle snaps to the other side with
> the result being on the right.
>
> In GIS we usually have rules for what snaps to what. Most common new
> features snap to existing ones.
>
> If we get this snapping in place it would allow us to do ISO 19107 topology
> further down the line.
>
> Cheers,
> Stephen
>
> On Sun, Nov 22, 2009 at 6:48 PM, Barend Gehrels <Barend.Gehrels_at_[hidden]>wrote:
>
>>  Hi Stephen,
>>
>>
>>
>>  You mean something like: ggl::snap(geometry_from, geometry_to,
>>> snapped_geometry);
>>>
>>
>> Something like that yeah. Most of the actual work involved is in finding
>> points on a line that are at the snapping tolerance distance from "snap to"
>> feature.
>>
>>
>> Ah, of course, specifying a tolerance is essential :-)
>>
>>
>>
>>
>> I'll have a look at the extension model then and see how this can fit. For
>> me a snap feature is just as important as a "buffer" feature.
>>
>>
>> OK, you'll need the account then, I'll send it to you privately.
>>
>>
>>
>> poly/poly breaks down to multiple line/line snaps. line line is a
>> complicated beast because all parts of the line that are within a snap
>> tolerance of the "snap to" line get snapped. I'll produce some diagrams of
>> this and post them.
>>
>> I see. Points/lines might be snapped potentially to multiple lines or
>> holes. I'll wait your diagrams.
>>
>> Regards, Barend
>>
>>
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>>
>>
>
>
> --
> Stephen Leary
>

-- 
Stephen Leary
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