[gdal-dev] adding points to geometries

[Paul Harwood]

Create a new geometry,
iterate through each segment of the old geometry
if the segment does not intersect the equator, add that segment to the new
geometry,
else, use  the intersection point to create two segments in the new
geometry.

On Sun, 26 Jan 2025 at 12:49, Javier Jimenez Shaw <j1 at jimenezshaw.com>
wrote:

> Thanks Paul
>
> I don't know if I was clear. Every segment that crosses the equator should
> become two segments, with the common point at lat=0.
> (I do not need the points themselves, I just want to add points to the
> lines and polygons, making "explicit" where they cross the equator).
>
> On Sun, 26 Jan 2025 at 13:37, Paul Harwood <runette at gmail.com> wrote:
>
>> I would have thought : create a linesegment that is the equator and
>> perform an intersection between that linesegment and the target geometry to
>> identify the point in question and then create a new geometry with the new
>> point, or something like that.
>>
>> I am not sure what it would mean to add a point to polygon crosses the
>> equator - I would guess that would mean adding a vertex at the equator, in
>> which case I think the intersection would return a line (I have never done
>> it) and the vertices in question would be the points of the returned
>> linesegment.
>>
>> On Sun, 26 Jan 2025 at 10:26, Javier Jimenez Shaw via gdal-dev <
>> gdal-dev at lists.osgeo.org> wrote:
>>
>>> Hi
>>>
>>> I have a vector layer (like
>>> /usr/share/qgis/resources/data/world_map.gpkg) and I need to add a point at
>>> latitude 0 for every segment (in line or polygon) that crosses the equator.
>>>
>>> How can I do it?
>>>
>>> Thanks,
>>> Javier.
>>> _______________________________________________
>>> gdal-dev mailing list
>>> gdal-dev at lists.osgeo.org
>>> https://lists.osgeo.org/mailman/listinfo/gdal-dev
>>>
>>
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