List available built-in pattern names
Examples
list_patterns()
#> [1] "crosshatch" "crosshatch_dense" "crosshatch_sparse"
#> [4] "dots" "dots_dense" "dots_sparse"
#> [7] "hatch" "hatch_dense" "hatch_sparse"
#> [10] "horizontal" "horizontal_dense" "horizontal_sparse"
#> [13] "none" "vertical" "vertical_dense"
#> [16] "vertical_sparse" "weave" "weave_dense"
#> [19] "weave_sparse"