filter_drop_shadow: Filter: add a drop shadow to an element
In omsvg: Build and Transform 'SVG' Objects

Description Usage Arguments Value Examples

With the filter_drop_shadow() drop shadow appears beneath the input image or shape and its offset is controlled by dx and dy. The blurring of the drop shadow is set by the stdev value.

1	filter_drop_shadow(dx = 0.2, dy = 0.2, stdev = 1, color = "black", opacity = 1)

`dx, dy`	The offset of the drop shadow compared to the position of the input image or shape.
`stdev`	The number of standard deviations for the blur effect.
`color`	The color of the drop shadow.
`opacity`	The opacity of the drop shadow. We can use a real number from `0` to `1` or a value in percentage units.

An svg object.

if (interactive()) {

# Apply a drop shadow filter on a
# text element (orange in color,
# and semi-opaque)
SVG(width = 250, height = 100) %>%
  svg_filter(
    id = "shadow",
    filters = list(
      filter_drop_shadow(
        dx = 1, dy = 2,
        color = "orange",
        opacity = 0.5
      )
    )
  ) %>%
  svg_text(
    x = 10, y = 40,
    text = "Shadowed",
    attrs = svg_attrs_pres(
      font_size = "2em",
      fill = "#555555",
      font_weight = "bolder",
      filter = "shadow"
    )
  )
}