Declare screen geometry for GazeWeave

Usage

gaze_screen(width, height, unit = c("px", "deg", "normalized"), center = NULL)

Arguments

width, height: Positive screen dimensions.
unit: Coordinate unit. One of `"px"`, `"deg"`, or `"normalized"`.
center: Optional two-element screen centre, in data coordinates. Defaults to half the screen dimensions, so the screen spans `[0, width] x [0, height]`; with a centre such as `c(0, 0)` (for example degrees of visual angle measured from fixation) it spans `center +/- dimensions / 2`.

Value

A `gaze_screen` specification.

Examples

gaze_screen(1024, 768)                                # pixels, origin at a corner
#> $width
#> [1] 1024
#> 
#> $height
#> [1] 768
#> 
#> $unit
#> [1] "px"
#> 
#> $center
#> [1] 512 384
#> 
#> $xlim
#> [1]    0 1024
#> 
#> $ylim
#> [1]   0 768
#> 
#> attr(,"class")
#> [1] "gaze_screen" "list"       
gaze_screen(30, 20, unit = "deg", center = c(0, 0))   # degrees from centre
#> $width
#> [1] 30
#> 
#> $height
#> [1] 20
#> 
#> $unit
#> [1] "deg"
#> 
#> $center
#> [1] 0 0
#> 
#> $xlim
#> [1] -15  15
#> 
#> $ylim
#> [1] -10  10
#> 
#> attr(,"class")
#> [1] "gaze_screen" "list"