[postgis-tickets] [PostGIS] #4120: ST_AsMVTGeom: Clip using tile coordinates

[PostGIS]

#4120: ST_AsMVTGeom: Clip using tile coordinates
------------------------+---------------------------
 Reporter:  Algunenano  |      Owner:  Algunenano
     Type:  defect      |     Status:  assigned
 Priority:  medium      |  Milestone:  PostGIS 2.5.0
Component:  postgis     |    Version:  trunk
 Keywords:              |
------------------------+---------------------------
 ST_AsMVTGeom is clipping before doing the projection transformation but
 the buffer is given in tile coordinates, so some points that fall within
 the full extent are being incorrectly dropped.

 Example:
 {{{
 SELECT ST_AsText(ST_AsMVTGeom(
         ST_Point(11.49, 11.49),
         ST_MakeBox2D(ST_Point(0, 0), ST_Point(10, 10)),
         10, 1, true));
  st_astext
 -----------

 (1 row)
 }}}

 If we disable clipping we can see that the point falls within the bbox
 `(-1 -1, 11 11)` :
 {{{
 SELECT ST_AsText(ST_AsMVTGeom(
 ST_Point(11.49, 11.49),
 ST_MakeBox2D(ST_Point(0, 0), ST_Point(10, 10)),
 10, 1, false));
   st_astext
 --------------
  POINT(11 -1)
 (1 row)
 }}}

-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/4120>
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