How to create mutually clipping polygons

Question

Is it possible to create buffers (in my case, but polygons in general also) that would create a boundary at their point of contact ? (so that they don't overlap on each other).

Like this (from left to right)

I am trying to solve this question where I need to join points representing addresses to their nearby parcel without including points related to adjacent parcels or parcels on the other side of the street.

It seems to me that there are two main options: either using voronoi/thiessen diagram but based on polygons, not points, or creating many buffers (making sure they overlap with the address points outside on the street), and then making these new polygons crop each other at the medium of their intersection line (which would be the median line of the street for street facing vertices, and the property boundary line for the vertice between two adjacent parcels/plots of land).

Spatially join attributes from point to polygon side in QGIS3 with numerous contiguous polygons and numerous adjacent points

Answer 1

This is an approach to this problem using that strategy of the 'inner central horizontal edge'. In resume:

1. Create buffers of the polygons.
2. Intersection of buffers to get overlaping zones.
3. Extract intersection coords to create the new medium edge.
4. Clip buffers with lines and assign the parcel ID.

Here are the layers to try out.

Here is the code:

library(sf)
library(mapview)

# read data
pol <- st_read('./data/Parcels.gpkg')
mapview(pol)

# make the buffer
polbuf <- st_buffer(pol, 10, 0)
mapview(pol)+mapview(st_buffer(pol, 10, 0), alpha.regions=0.1)

# get intersection points
p_intersect <- gIntersection(as(as_Spatial(polbuf)[1,], "SpatialLines"), as_Spatial(polbuf))
mapview(p_intersect)

# extract intersection coordinates
# adapted from: https://stackoverflow.com/questions/55106950/r-sf-intersect-lines-with-the-borders-of-multipolygons-extract-coordinates-of
line_1 <- st_as_sf(as(as_Spatial(polbuf), "SpatialLines"))
poly_1 <- st_as_sf(as(as_Spatial(polbuf), "SpatialLines"))
pnts   <- st_intersection(line_1, st_cast(poly_1, "MULTILINESTRING", group_or_split = FALSE))

# catch points and get unique (as they will be duplicated...)
ps <- unique(pnts[st_geometry_type(pnts)=='MULTIPOINT',])
mapview(ps)+mapview(pol)+mapview(st_buffer(pol, 10, 0), alpha.regions=0.1)

# Create clipping lines with this points
# catched here: https://gis.stackexchange.com/questions/270725/r-sf-package-points-to-multiple-lines-with-st-cast
ls <- st_cast(ps, "LINESTRING")
mapview(ls)+mapview(ps)+mapview(pol)+mapview(st_buffer(pol, 10, 0), alpha.regions=0.1)

# split buffers with lines and consolidate
# cathed here: https://stackoverflow.com/questions/5726297/cut-polygons-using-contour-line-beneath-the-polygon-layers
library(rgeos)
lpi <- gIntersection(as_Spatial(polbuf), as_Spatial(ls))
blpi <- gBuffer(lpi, width = 0.000001)
dpi <- gDifference(as_Spatial(polbuf), blpi)
mapview(dpi)

# Asign parcel to each polygon
polbuf2 <- st_join(st_cast(st_as_sf(dpi), 'POLYGON'), pol)
mapview(pol)+mapview(polbuf2, alpha.regions = 0.2)