playwith (version 0.9-32)

convertFromDevicePixels: Utilities for working with grobs and viewports in device coordinates.

Description

Utilities for working with grobs and viewports in device coordinates.

Usage

convertFromDevicePixels(x.px, y.px, unitTo = "native", valueOnly = FALSE)
convertToDevicePixels(x, y)

inViewport(x.px, y.px, viewport)
grobBBDevicePixels(grob, viewport)

showGrobsBB(draw = TRUE,
    gp.box = gpar(col = "yellow", lwd = 5, alpha = 0.2),
    gp.text = gpar(cex = 0.75, alpha = 0.5))

Arguments

x.px, y.px

locations in device coordinates (i.e. pixels, with origin at top-left corner of device). May be vectors.

unitTo

the unit to convert to.

valueOnly

to return values as numeric (native) rather than units.

x, y

locations in the current viewport (numeric native or units). May be vectors.

viewport

a viewport name or vpPath.

grob

a grob.

draw

whether to draw bounding boxes and grob names.

gp.box

graphical parameters for bounding boxes.

gp.text

graphical parameters for grob name text.

Value

• convertFromDevicePixels returns a list with x, y (units or numeric) locations in the current viewport. convertToDevicePixels returns a list with x, y (numeric) locations in pixels from the top-left corner of the device. inViewport returns a logical: whether the given pixel location is inside the given viewport. grobBBDevicePixels returns a list with x, y (numeric) locations in pixels giving the bounding box of the given grob. The grob must exist in the given viewport. showGrobsBB returns a data.frame giving information about all grobs in the current scene.

Details

Not yet...

See Also

grid.convert, grobX, grid.ls, grid.show.layout

Examples

print(xyplot(1:10 ~ 1:10 | c("a", "b")))

vpname <- trellis.vpname("panel", 1, 1)
downViewport(vpname)

convertToDevicePixels(x = 5:10, y = 5:10)
convertToDevicePixels(unit(0, "npc"), unit(0, "npc"))
convertFromDevicePixels(x = 100, y = 100)

inViewport(x = 100, y = 100, vpname)
inViewport(x = c(0, 100), y = c(0, 100), vpname)

myGrob <- grid.circle(r = 0.3, name = "myCircle")
grobBBDevicePixels(myGrob, vpname)

str(showGrobsBB(draw = TRUE))