Save a globe as a PNG image

Draws a globe made by hex_globe with the same WebGPU shader and pipelines the widget uses, and saves the view it opens with, without its controls, as a PNG file. The image is drawn on the graphics card and read back from it, so it is the same on a machine without a display. Pixels off the globe are transparent.

Usage

hex_globe_png(
  widget,
  file,
  width = 800,
  height = 800,
  scale = 1,
  timeout = 30,
  renderer = c("wgpu", "chrome")
)

Arguments

widget

A globe from hex_globe.

file

Path of the PNG file to write.

width, height

Size of the view in CSS pixels.

scale

Image pixels per CSS pixel; 2 draws the view at twice the resolution.

timeout

Seconds to wait for the globe to be drawn in Chrome.

renderer

"wgpu" or "chrome", as above.

Value

file, invisibly.

Details

renderer = "wgpu" draws through 'wgpu', the 'Rust' implementation of WebGPU, in the 'hexglobe' package, with no browser. renderer = "chrome" draws in headless Chrome, which needs the 'chromote' and 'htmlwidgets' packages and a Chromium browser, such as Chrome or Edge, that chromote::find_chrome() finds; the browser is started with its GPU, which WebGPU draws on.

See also

plot for a static plot that needs no graphics card

Examples

if (FALSE) { # \dontrun{
grid <- hex_grid(resolution = 3, aperture = 3)
globe <- hex_globe(grid, surface = "solid", center = "pacific")
hex_globe_png(globe, tempfile(fileext = ".png"), scale = 2)
} # }