bittermelon (version 2.2.1)

bm_pixel_picker: Bitmap pixel picker

Description

bm_pixel_picker() lets you use an interactive graphics device to click on a bitmap's pixels and learn the column/row coordinates for the clicked pixel and its integer/color value. To end the program click a non-left mouse button within the graphics device.

Usage

bm_pixel_picker(x, ...)
# S3 method for bm_bitmap
bm_pixel_picker(
  x,
  ...,
  col = getOption("bittermelon.col", col_bitmap),
  silent = FALSE
)
# S3 method for bm_pixmap
bm_pixel_picker(x, ..., silent = FALSE)
# S3 method for raster
bm_pixel_picker(x, ..., silent = FALSE)

Value

A list with named components "row", "col", and "value" for the last clicked pixel returned invisibly.

Arguments

x

Either a bm_bitmap(), bm_pixmap(), or raster object

...

Currently ignored.

col

Character vector of R color specifications. First color is used for values equal to 0, second color for values equal to 1, etc.

silent

Don't generate messages about clicked pixels.

See Also

This function wraps grid::grid.locator().

Examples

if (interactive() && dev.interactive(orNone = TRUE)) {
  corn <- farming_crops_16x16()$corn$portrait
  bm_pixel_picker(corn)
}