Modify fill transparency — fill

This works much like alpha() in that it modifies the transparency of fill colours. It differs in that fill_alpha() also attempts to set the transparency of <GridPattern> objects.

Usage

fill_alpha(fill, alpha)

Arguments

fill: A fill colour given as a character or integer vector, or as a (list of) <GridPattern> object(s).
alpha: A transparency value between 0 (transparent) and 1 (opaque), parallel to fill.

Value

A character vector of colours, or list of <GridPattern> objects.

Examples

# Typical colour input
fill_alpha("red", 0.5)
#> [1] "#FF000080"

if (utils::packageVersion("grid") > "4.2") {
  # Pattern input
  fill_alpha(list(grid::linearGradient()), 0.5)
}
#> [[1]]
#> $x1
#> [1] 0npc
#> 
#> $y1
#> [1] 0npc
#> 
#> $x2
#> [1] 1npc
#> 
#> $y2
#> [1] 1npc
#> 
#> $stops
#> [1] 0 1
#> 
#> $colours
#> [1] "#00000080" "#FFFFFF80"
#> 
#> $extend
#> [1] "pad"
#> 
#> $group
#> [1] TRUE
#> 
#> attr(,"class")
#> [1] "GridLinearGradient" "GridPattern"       
#>