R: Apply an opacity mask to a grid grob.

grid.mask {gridSVG} | R Documentation

## Apply an opacity mask to a grid grob.

### Description

Creates a `masked.grob` object which is a normal grid grob, with an opacity mask applied to it. Used in conjunction with `registerMask`, to produce an SVG document containing graphical elements with masked content.

### Usage

    grid.mask(path, mask = NULL, label = NULL, group = TRUE, redraw = FALSE,
              strict = FALSE, grep = FALSE, global = FALSE)
    maskGrob(x, mask = NULL, label = NULL, group = TRUE)

### Arguments

`x` | A grob to mask.
`path` | A grob path specifying a drawn grob.
`mask` | A `mask` object, provided by the `mask` function. Provides the definition of an opacity mask that will be applied to `x` or `path`.
`label` | A label that is associated with a definition of an opacity mask. This is the label used to create an opacity mask definition with `registerMask`.
`group` | A logical vector that indicates whether the opacity mask should be applied to the overall parent group for the relevant SVG element, or to individual SVG elements.
`redraw` | A logical value to indicate whether to redraw the grob.
`strict` | A boolean indicating whether the `path` must be matched exactly.
`grep` | Whether the `path` should be treated as a regular expression.
`global` | A boolean indicating whether the function should affect just the first match of the `path`, or whether all matches should be affected.

### Details

If `label` is specified, uses a mask that has been supplied to `registerMask`. If `mask` is specified it will be used as the opacity mask applied to each grob. If both are specified, it will attempt to define the opacity mask with the given label, as well as applying the mask to the appropriate grobs.

### Value

A `masked.grob` object (for `maskGrob`).

### Author(s)

Simon Potter

### See Also

`registerMask`, `mask`, `pushMask`.

[Package gridSVG version 1.6-0 Index]