R: Create the definition of a non-rectangular clipping path.

Clipping Paths {gridSVG}

R Documentation

Create the definition of a non-rectangular clipping path.

Description

A feature of SVG is that elements can be clipped to by more than just a rectangular region. Most graphical elements can be drawn. The purpose of these functions is to define a more sophisticated clipping path that will be applied until the current viewport (or context, see popContext) is popped.

Usage

clipPath(grob)
registerClipPath(label, clippath)

Arguments

`grob`	A grid grob.
`label`	A character identifier that will be used to reference this definition.
`clippath`	A `clipPath` object produced by `clipPath` that defines a clipping path region.

Details

A clipping path will be drawn within the current viewport at the time of definition (if the grob has no vp specified).

Most grobs can be used for clipping but there are some limitations on what will actually be used for clipping. In general though, anything that is drawn as the clipping path will have the union of its drawn regions become the new region that the current viewport (or grob) will clip to.

The limitations are as follows:

Any viewport pushed by the clipping path grob will no longer clip to its contents. However, its clipping region will remain. This means that the clipping region for a pushed viewport will become the union of its contents and the viewport clipping region itself, instead of just the pushed viewport's clipping region.
When drawing a textGrob, only character labels will be used, no plotmath expressions will be used.
No pointGrobs are able to be used for clipping.
Any operations that apply to containers (e.g. gpars, garnishing, animation), will no longer work. Any operations that are not applied to groups are unaffected. This affects in particular viewports, gTrees, and the familiar gridSVG grob grouping that occurs.

Value

None

Author(s)

Simon Potter