library(alcyon)

lineStringMap <- st_read(
  system.file(
    "extdata", "testdata", "gallery",
    "gallery_lines.mif",
    package = "alcyon"
  ),
  geometry_column = 1L, quiet = TRUE
)

shapeMap <- as(lineStringMap, "ShapeMap")
#> Warning in asMethod(object): Non-numeric columns will not be transferred to the
#> ShapeMap: layer layertype block colour
isovistMap <- isovist(
  shapeMap,
  x = c(3.01),
  y = c(6.70),
  angle = 0.01,
  viewAngle = 3.14,
  FALSE
)

isovists <- shapeMapToPolygonSf(isovistMap)
plot(isovists$geometry)