I'm trying to put an x/y offset to the point-geometry-layer to get map-tip-informations from all overlapping points like in the Point Displacement Renderer.
For getting map-tip-informations it seems to be important that the point is visible at the stored coordinate and is not modified by an offset in the renderer. So I have to recalculate the stored coordinates and modify it with a varying offset which depends for example on the actual scale. With this recalulated, displaced coordinates I'm trying to create a new layer. This displaced points should be recognized by map-tips.
I created a virtual fields (X_modified, y_modified) and virtual_geometry with the field name "geometry" (by "geom_from_wkt('Point(X_modified || Y_modified)') - but there is no geometry-field-type available. The virtual layer didn't recognize the virtual geometry or other virtual fields...
-> Is it possible to create a virtual layer based upon virtual (geometry) fields of another layer ?
The calculation of the modified coordinates in the postgresql-data-provider seems not to be possible, because i do not know how to transfer the actual scale-variables (or other ones) from qgis to postgresql and its view-definitons. Or - do you know a way to do this ? [QGIS 2.18]