add_line_layer function

Add a line layer to a map

add_line_layer(
  map,
  id,
  source,
  source_layer = NULL,
  line_blur = NULL,
  line_cap = NULL,
  line_color = NULL,
  line_dasharray = NULL,
  line_emissive_strength = NULL,
  line_gap_width = NULL,
  line_gradient = NULL,
  line_join = NULL,
  line_miter_limit = NULL,
  line_occlusion_opacity = NULL,
  line_offset = NULL,
  line_opacity = NULL,
  line_pattern = NULL,
  line_round_limit = NULL,
  line_sort_key = NULL,
  line_translate = NULL,
  line_translate_anchor = "map",
  line_trim_color = NULL,
  line_trim_fade_range = NULL,
  line_trim_offset = NULL,
  line_width = NULL,
  line_z_offset = NULL,
  visibility = "visible",
  slot = NULL,
  min_zoom = NULL,
  max_zoom = NULL,
  popup = NULL,
  tooltip = NULL,
  hover_options = NULL,
  before_id = NULL,
  filter = NULL
)

Arguments

• map: A map object created by the mapboxgl or maplibre functions.
• id: A unique ID for the layer.
• source: The ID of the source, alternatively an sf object (which will be converted to a GeoJSON source) or a named list that specifies type and url for a remote source.
• source_layer: The source layer (for vector sources).
• line_blur: Amount to blur the line, in pixels.
• line_cap: The display of line endings. One of "butt", "round", "square".
• line_color: The color with which the line will be drawn.
• line_dasharray: Specifies the lengths of the alternating dashes and gaps that form the dash pattern.
• line_emissive_strength: Controls the intensity of light emitted on the source features.
• line_gap_width: Draws a line casing outside of a line's actual path. Value indicates the width of the inner gap.
• line_gradient: A gradient used to color a line feature at various distances along its length.
• line_join: The display of lines when joining.
• line_miter_limit: Used to automatically convert miter joins to bevel joins for sharp angles.
• line_occlusion_opacity: Opacity multiplier of the line part that is occluded by 3D objects.
• line_offset: The line's offset.
• line_opacity: The opacity at which the line will be drawn.
• line_pattern: Name of image in sprite to use for drawing image lines.
• line_round_limit: Used to automatically convert round joins to miter joins for shallow angles.
• line_sort_key: Sorts features in ascending order based on this value.
• line_translate: The geometry's offset. Values are c(x, y) where negatives indicate left and up, respectively.
• line_translate_anchor: Controls the frame of reference for line-translate.
• line_trim_color: The color to be used for rendering the trimmed line section.
• line_trim_fade_range: The fade range for the trim-start and trim-end points.
• line_trim_offset: The line part between c(trim_start, trim_end) will be painted using line_trim_color.
• line_width: Stroke thickness.
• line_z_offset: Vertical offset from ground, in meters.
• visibility: Whether this layer is displayed.
• slot: An optional slot for layer order.
• min_zoom: The minimum zoom level for the layer.
• max_zoom: The maximum zoom level for the layer.
• popup: A column name containing information to display in a popup on click. Columns containing HTML will be parsed.
• tooltip: A column name containing information to display in a tooltip on hover. Columns containing HTML will be parsed.
• hover_options: A named list of options for highlighting features in the layer on hover.
• before_id: The name of the layer that this layer appears "before", allowing you to insert layers below other layers in your basemap (e.g. labels)
• filter: An optional filter expression to subset features in the layer.

Returns

The modified map object with the new line layer added.

Examples

## Not run:

library(mapgl)
library(tigris)

loving_roads <- roads("TX", "Loving")

maplibre(style = maptiler_style("backdrop")) |>
    fit_bounds(loving_roads) |>
    add_line_layer(
        id = "tracks",
        source = loving_roads,
        line_color = "navy",
        line_opacity = 0.7
    )
## End(Not run)