city-maps.R

library(tidyverse)
library(osmdata)
library(sf)


# Define functions --------------------------------------------------------

query_streets <- function(place) {
  query <- getbb(place) |>
    opq()

  highways <- query |>
    add_osm_feature("highway", c("motorway", "trunk", "primary", "secondary", "tertiary")) |>
    osmdata_sf() |>
    pluck("osm_lines")

  streets <- query |>
    add_osm_feature("highway", c("unclassified", "residential", "living_street")) |>
    osmdata_sf() |>
    pluck("osm_lines")

  coords <- tidygeocoder::geo(place, return_addresses = FALSE, min_time = 0) |>
    mutate(
      across(everything(), round, 2),
      lat = if_else(lat > 0, paste0(abs(lat), "°N"), paste0(abs(lat), "°S")),
      long = if_else(long > 0, paste0(abs(long), "°E"), paste0(abs(long), "°W"))
    ) |>
    t() |>
    paste0(collapse = " · ")

  list(place = place, highways = highways, streets = streets, coords = coords)
}

create_map <- function(street_list, title = TRUE, caption = TRUE, scale = 1,
                       width = 8.3, height = 11.7) {
  colours <- list(
    bg = "#0b0e14",
    fg = "#95e6cb",
    fg2 = colorspace::darken("#95e6cb", .2)
  )

  bbox <- map2_dbl(
    st_bbox(street_list$highways),
    st_bbox(street_list$streets),
    max
  )

  xrange <- quantile(
    c(bbox[["xmin"]], bbox[["xmax"]]),
    probs = seq(0, 1, .05)
  )[c(2, 20)]

  yrange <- c(bbox[["ymin"]], bbox[["ymax"]])

  p <- ggplot() +
    geom_sf(data = street_list$streets, size = .3 * scale, colour = colours$fg2) +
    geom_sf(data = street_list$highways, size = .45 * scale, colour = colours$fg) +
    coord_sf(xlim = xrange, ylim = c(NA, yrange[[2]])) +
    theme_void() +
    theme(
      plot.background = element_rect(fill = colours$bg, colour = NA),
      plot.margin = margin(60, 60, 70, 60)
    )

  if (title) {
    p <- p +
      annotate("text",
        x = mean(xrange),
        y = yrange[[1]] - (yrange[[2]] - yrange[[1]]) / 7,
        label = paste(
          paste0(rep("―", 2), collapse = ""),
          " ", toupper(street_list$place), " ",
          paste0(rep("―", 2), collapse = "")
        ),
        family = "Metropolis", fontface = "bold", size = 10 * scale, colour = colours$fg
      )
  }

  if (caption) {
    p <- p +
      annotate("text",
        x = mean(xrange),
        y = yrange[[1]] - (yrange[[2]] - yrange[[1]]) / 4.5,
        label = street_list$coords,
        family = "Inter", size = 9 * scale, colour = colours$fg2
      )
  }

  cairo_pdf(
    paste0("city-maps/", str_replace_all(tolower(street_list$place), " |,", "-"), ".pdf"),
    width = width,
    height = height,
    bg = colours$bg,
    antialias = "subpixel"
  )
  print(p)
  dev.off()
}


# Use defined functions to create maps ------------------------------------

streets <- query_streets("Bielefeld")

# saveRDS(streets, here::here("city-maps/bi_streets.RDS"))
# streets <- readRDS(here::here("city-maps/bi_streets.RDS"))

create_map(streets)