[geos-devel] OverlayNG for Testing

[Paul Ramsey]

> On Jul 30, 2020, at 11:29 AM, Sandro Santilli <strk at kbt.io> wrote:
> 
> On Thu, Jul 30, 2020 at 09:51:05AM -0700, Martin Davis wrote:
>> On Thu, Jul 30, 2020 at 9:08 AM Sandro Santilli <strk at kbt.io> wrote:
>> 
>>> On Wed, Jul 29, 2020 at 02:08:59PM -0700, Martin Davis wrote:
>>> 
>>>> Another behavioural change is that now overlay operations do not return
>>>> mixed-dimension results.  Instead, a homogeneous geometry containing only
>>>> the highest dimension resultants is returned.
>>> 
>>> ST_MakeValid in PostGIS expects the old behavior, as the funders of it
>>> insisted in "not loosing any vertex" (so not throwing away anything).
>> 
>> How does ST_MakeValid use the overlay operations?
> 
> In many ways, but a quick look at the code seems to suggest it should
> not suffer from the behavioural change in that the "cut edges" seem to
> be extracted on the side (to be double-checked).

Just to be sure, I've pointed all the overlay ops in MakeValid at the old overlay code. Eventually MakeValid will be superceded by something that works off the overlay graph directly. Until then we'll just ensure it works as before.

P