[postgis-devel] Proposal: Adding buffer parameter to ST_TileEnvelope()

[Yuri Astrakhan]

What should the next steps be to get
https://github.com/postgis/postgis/pull/514 merged?  Are there any blockers
or required TODOs?  Thanks!

On Thu, Nov 14, 2019 at 2:29 PM Yuri Astrakhan <yuriastrakhan at gmail.com>
wrote:

> How should we grow tiles then with regards to the bounds parameter?  I see
> two approaches:
> * bbox longitude (x) is not clipped unless it grows wider than the bounds,
> in which case the result spans the whole bounding box. Latitude (y) is
> always clipped.
>     PROs: makes it possible to use with geometry columns without any extra
> modifications.
>     CONs: might cause confusion because the result could be outside of
> bounds, and because it might not match geometries across antimeredian.
> * bbox grows up to the bounds, and then gets clipped.
>     PROs: all generated bboxes are within the bounds, using it as filter
> always matches real data in the geometry columns.
>     CONs: have to manually extend it across antimeredian if needed.
>
> I'm inclined to go with the first approach, would that be ok?
>
> On Thu, Nov 14, 2019 at 7:58 AM Paul Ramsey <pramsey at cleverelephant.ca>
> wrote:
>
>>
>>
>> On Nov 13, 2019, at 11:35 PM, Yuri Astrakhan <yuriastrakhan at gmail.com>
>> wrote:
>>
>> Rough implementation PR - https://github.com/postgis/postgis/pull/514
>>
>> I am having some issues with unit tests (too much magic in auto-generated
>> code?), so a Postgis guru's help might be needed.
>>
>> One open concern: extending envelope beyond antimeredian. Is this
>> possible? Would a bbox from the tile that overflows to the other side of
>> antimeredian match any geometries? For example, given two points - one at
>> -179, and the other is at +179 (longitude), would they be found with the
>> bbox that goes from -200..-160 ?
>>
>>
>> In geometry they would not match, in geography they would.
>>
>> P
>>
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